Indian Patents
Title of Invention

IMAGE FORMING APPARATUS
Abstract An image forming apparatus enables the output of a high-quality image even when an expendable supply, such as ink, recording head, or recording sheet other than a specific expendable supply, such as one designated by a manufacturer, is used. The image forming apparatus includes a carriage for moving a recording head having plural recording nozzles in a horizontal scan direction. The recording head discharges ink onto a recording medium. A detection unit detects whether one or more expendable supplies required for image formation is a specific expendable supply. Upon detection of a non-specific expendable supply, a notifying unit notifies an operator and suggests that the image forming method be changed.
Full Text DESCRIPTION
IMAGE FORMING APPARATUS
TECHNICAL FIELD
The present invention relates to image forming
apparatuses, and particularly to an image forming apparatus
capable of providing stable image quality when an expendable
supply, such as ink, an inkjet head, or a recording medium,
that is not a specific expendable supply is used.
BACKGROUND ART
In an inkjet recording apparatus, which is an
example of image forming apparatuses including printers,
facsimile machines, and copy machines, a liquid discharge head
is used as a recording head. The liquid discharge head
discharges ink as a recording liquid onto a sheet to form
(i.e., record, print, or transcribe) an image. The "sheet"
herein is not limited to a sheet of paper but it includes any
medium onto which a droplet of ink or other liquid can attach.
Thus, the sheet may also be referred to as a "recorded
medium," a "recording medium," a "recording paper," or a
"recording sheet."
In such an image forming apparatus, a user may
use ink other than a specific ink, such as a manufacturer's

designated ink, a "recommended" ink, or a "genuine" ink.
While this can be a cause for troubles such as image defect or
failure, some users prefer non-genuine products for cost-
reducing purposes, aware of the potential troubles that the
non-specific item may cause. Some other users may purchase
and use non-genuine products without knowing it. Technologies
for preventing the use of products other than a specific
product are proposed in Japanese Laid-Open Patent Applications
No. 2000-326518 and 2004-188635; Japanese Patent No. 3095008;
and Japanese Laid-Open Patent Application No. 2001-075455.
Japanese Laid-Open Patent Application No. 2006-
276709 discloses an image forming apparatus in which use of a
non-genuine product can be appropriately reflected in leasing
charge. Japanese Laid-Open Patent Applications No. 2005-
288845 and 2005-193522 disclose image forming apparatuses in
which, instead of restricting a printing operation, a
maintenance operation is performed to prevent failure or other
troubles upon detection of use of a non-genuine product.
Although measures have been taken from the
maintenance aspect as mentioned above in response to the use
of non-specific products, no consideration is given with
regard to the quality of an output image. As a practical
matter, differences in ink material may lead to problems such
as a failure to discharge an intended amount of ink, or a drop
in landing position accuracy. Furthermore, because the amount

of ink that a sheet can absorb varies depending on the type of
ink, the probability of image quality deterioration such as
beading increases when an excessive amount of ink attaches to
the sheet.
In some inkjet printers, a recording head and an
ink tank are integrated. In this case, a user may also use a
recording head other than a specific head, such as one
recommended by the manufacturer. If that happens, an intended
amount of ink may not be discharged, or landing position
accuracy may decrease.
Another example of the potential use of a non-
specific product is the recording media (such as a sheet of
paper). Many users are unaware of the characteristics of a
recording medium they print on. Many users also tend to
select non-specific recording media, which may be called a
"glossy sheet," a "photographic sheet," or a "high-quality
paper," simply because they are less expensive. In such a
case too, because different sheets have different ink
absorption amounts, excessive ink attachment may occur,
resulting in beading or other image quality degradation.
Because such various recording media also have different
thicknesses, it may become impossible to cause an ink droplet
to become attached to a target landing position.

Thus, the image quality may greatly drop below
the optimum quality when even any one of the factors of ink,
recording head, and recording medium is changed.
It is therefore a general object of the present
invention to overcome the aforementioned problems. A more
specific object is to provide an image forming apparatus
capable of producing a high-quality image even when an
expendable supply such as ink, a recording head, or a
recording medium that is not a specific product is used.
DISCLOSURE OF THE INVENTION
In one embodiment, the invention provides an
image forming apparatus configured to move a recording head
including plural nozzles in a horizontal scan direction in
order to record a recording medium by discharging ink via the
nozzles onto the recording medium. The image forming
apparatus includes a detection unit configured to detect
whether one or more expendable supplies required for image
formation are specific expendable supplies; and a notifying
unit configured to notify an operator upon detection by the
detection unit of a non-specific expendable supply, and
configured to suggest to a user that an image forming method
that is currently set be changed.
In another embodiment, the invention provides an
image forming apparatus configured to move a recording head

including plural nozzles in a horizontal scan direction in
order to record a recording medium by discharging ink via the
nozzles onto the recording medium. The image forming
apparatus includes a detection unit configured to detect
whether one or more expendable supplies required for image
formation are specific expendable supplies; a notifying unit
configured to notify an operator upon detection of a non-
specific expendable supply; and an image forming method
changing unit configured to automatically change an image
forming method that is currently set.
In a preferred embodiment, the image forming
method changing unit is configured to allow the operator to
make a setting regarding whether the changing of the image
forming method is to be made automatically or not.
In another preferred embodiment, the detection
unit is configured to detect a non-specific expendable supply
automatically using an automatic detection unit or manually
based on an operator input.
In another preferred embodiment, the automatic
detection unit is configured to examine an ink cartridge
having a storage unit configured to store information about an
ink use period. The automatic detection unit detects that the
ink is not a specific expendable supply when the use period of
the ink is longer than a specific period.

In another embodiment, the automatic detection
unit is configured to examine an ink cartridge having a
storage unit configured to store information about an
accumulated amount of the ink used. The automatic detection
unit detects that the ink is not a specific expendable supply
when the accumulated amount of the ink used is greater than a
specific amount.
In yet another embodiment, the automatic
detection unit is configured to examine the recording head and
identify a unique ID stored in a storage unit provided in the
recording head. The automatic detection unit detects that the
recording head is not a specific expendable supply when the
unique ID does not correspond to a specific ID at the start of
recording.
In yet another embodiment, the automatic
detection unit is configured to examine a transport path in
which a sensor for detecting a thickness of the recording
medium is provided. The automatic detection unit detects that
the recording medium is not a specific expendable supply when
the thickness detected by the sensor at the start of recording
is not within a specific range of values.
In yet another embodiment, the automatic
detection unit is configured to examine a transport path in
which a sensor for detecting a basis weight of the recording
medium is provided. The automatic detection unit detects that

the recording medium is not a specific expendable supply when
the basis weight detected by the sensor at the start of
recording is not within a specific range of values.
In yet another embodiment, the changing of the
image forming method involves reducing the speed of movement
of the carriage.
In another preferred embodiment, the changing of
the image forming method involves increasing the number of
scan passes made by the recording head for image formation.
In another preferred embodiment, the changing of
the image forming method involves reducing the number of
droplet sizes for gradation expression.
In another preferred embodiment, the changing of
the image forming method involves changing a bidirectional
printing to a one-directional printing.
In another preferred embodiment, the changing of
the image forming method involves reducing the number of lines
in halftone processing.
In another preferred embodiment, the changing of
the image forming method involves reducing the amount of ink
that attaches to the recording medium per unit area.
In another preferred embodiment, the changing of
the image forming method involves eliminating a use of a color
ink when generating colors of black and gray.

In another preferred embodiment, the changing of
the image forming method involves reducing an amount of a
color ink used for generating colors of black and gray.
The changing of the image forming method may
involve extending a standby time between successive vertical
scan operations.
The changing of the image forming method may
involve extending a standby time for each of plural pages that
are recorded successively.
The changing of the image forming method may be
carried out near a border of the recording medium when a
borderless printing is performed on the recording medium.
The changing of the image forming method may
involve extending a standby time that is provided in an
interval between a switching of recording surfaces when
printing both top and bottom surfaces of the recording medium
successively.
In accordance with the present invention, a high-
quality image can be provided even when an ink, a recording
head, or a recording medium that is not a specific ink,
recording head, or recording medium is used.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects, features and advantages
of the invention will be apparent to those skilled in the art

from the following detailed description of the invention, when
read in conjunction with the accompanying drawings in which:
FIG. 1 shows a side view of a mechanism portion
of an image forming apparatus that outputs image data
generated by an image processing method according to an
embodiment of the present invention;
FIG. 2 shows a plan view of a main portion of the
mechanism portion shown in FIG. 1;
FIG. 3 shows a cross section taken along the
longer direction of a fluid chamber of a recording head in the
image forming apparatus;
FIG. 4 shows a cross section taken along the
shorter direction of the fluid chamber of the recording head;
FIG. 5 shows a block diagram of a control unit of
the image forming apparatus;
FIG. 6 shows a block diagram of an image forming
system according to an embodiment of the present invention;
FIG. 7 shows a block diagram of an image
processing apparatus in the image forming system;
FIG. 8 shows a functional block diagram of a
printer driver, which is a program according to an embodiment
of the present invention;
FIG. 9 shows a functional block diagram of
another example of the printer driver;

FIG. 10 shows an overall structure of an image
forming apparatus according to an embodiment of the present
invention;
FIG. 11 shows a block diagram of a control unit
of the image forming apparatus;
FIG. 12A illustrates a sequence of dots according
to original digital data;
FIG. 12B illustrates a sequence of dots that are
actually printed using a system that is other than a specific
system;
FIG. 13A illustrates a sequence of dots according
to original digital data;
FIG. 13B illustrates a sequence of dots that are
actually printed by lowering the speed of movement of the
carriage below normal;
FIG. 14A illustrates a sequence of dots according
to original digital data;
FIG. 14B illustrates a sequence of dots that are
actually printed after a first pass;
FIG. 14C illustrates a sequence of dots that are
actually printed after a second pass;
FIG. 15A illustrates a sequence of dots according
to original digital data;
FIG. 15B illustrates a sequence of dots that are
actually printed using a system other than a specific system;

FIG. 16A illustrates a sequence of dots according
to original digital data;
FIG. 16B illustrates a sequence of dots that are
actually printed by eliminating the use of small droplets;
FIG. 17A illustrates a sequence of dots according
to original digital data;
FIG. 17B illustrates a sequence of dots that are
actually printed when printing the digital data in one
direction;
FIG. 17C illustrates a sequence of dots that are
actually printed when printing the digital data in two
directions;
FIG. 18A illustrates a line screen according to
original digital data in the case of a high line number;
FIG. 18B illustrates a line screen that is
actually printed from the digital data of FIG. 18A;
FIG. 18C illustrates a line screen according to
original digital data in the case of a low line number;
FIG. 18D illustrates a line screen that is
actually printed from the digital data of FIG. ISC-
FIG. 19A illustrates halftone dots according to
original digital data in the case of a high line number;
FIG. 19B illustrates halftone dots that are
actually printed from the digital data of FIG. 19A;

FIG. 19C illustrates halftone dots according to
original digital data in the case of a low line number;
FIG. 19D illustrates halftone dots that are
actually printed from the digital data of FIG. 19C;
FIG. 20 shows a cross section of an inkjet head
nozzle plate according to an embodiment of the present
invention;
FIG. 21A shows a cross section of an example of
an inkjet head nozzle plate;
FIG. 21B shows a cross section of another example
of an inkjet head nozzle plate;
FIG. 21C shows a cross section of yet another
example of an inkjet head nozzle plate;
FIG. 22A shows an example of the profile of an
opening edge portion of an ink-repellent film where r FIG. 22B shows another example of the profile of
the opening edge portion of the ink-repellent film where Ø >
90";
FIG. 22C illustrates two possibilities of the
formation of a meniscus at the opening edge;
FIG. 23 illustrates an example of how silicone
resin is applied to form an ink-repellent film;
FIG. 24A illustrates the coated width according
to an embodiment of the present invention;

FIG. 24B illustrates the coated width according
to the related art;
FIG. 25 illustrates another example of how
silicone resin is applied using a dispenser;
FIG. 26 illustrates the formation of an ink-
repellent layer of silicone resin according to another
embodiment of the present embodiment;
FIG. 27 shows an inkjet head according to an
embodiment of the present invention;
FIG. 28 schematically shows an excimer laser
processing apparatus used for forming a nozzle opening;
FIG. 29A shows a resin film as a base material
for forming a nozzle in a process of manufacturing an inkjet
head;
FIG. 2 9B shows a step of forming an SiO2 thin-
film layer on the resin film;
FIG. 29C shows a step of coating the SiO2 thin-
film layer with a fluorine water-repellent;
FIG. 29D shows a step of forming a fluorine
water-repellent layer;
FIG. 29E shows a step of affixing adhesive tape
to the fluorine water-repellent layer;
FIG. 29F shows a step of forming a nozzle
opening;

FIG. 30 schematically shows an apparatus for
manufacturing an inkjet head according to an embodiment of the
present invention; and
FIG. 31 shows an example of how an image forming
method is changed depending on whether an expendable supply is
a specific product.
BEST MODE FOR CARRYING OUT THE INVENTION
In the following, an inkjet recording apparatus,
which is an image forming apparatus, according to an
embodiment of the invention is described with reference to the
drawings.
FIGs. 1 and 2 show the image forming apparatus,
which outputs image data generated by an image processing
method according to an embodiment of the present invention.
FIG. 1 shows a side view of a mechanism portion of the image
forming apparatus. FIG. 2 shows a plan view of the mechanism
portion.
The image forming apparatus according to the
present embodiment includes a carriage 3 supported by a guide
rod 1 and a guide rail 2 in such a manner as to be slidable in
a horizontal scan direction. The guide rod 1 and the guide
rail 2 are guide members laterally mounted on the left- and
right-side plates (not shown). The carriage 3 is moved in the
directions indicated by arrows in FIG. 2 (horizontal scan

direction) by a horizontal scan motor 4, via a timing belt 5
extended between a drive pulley 6A and a driven pulley 6B.
The carriage 3 may carry four recording heads 7y,
7c, 7m, and 7k (which may be referred to collectively as a
"recording head 7" when no distinctions are made between the
individual colors). These recording heads are liquid
discharge heads for discharging ink droplets of yellow (Y),
cyan (C), magenta (M), and black (K). The individual ink
discharge openings of the four recording heads 7y, 7c, 7m, and
7k may be arranged in a direction perpendicular to the
horizontal scan direction, with the direction of ink discharge
facing downward.
Each of the liquid discharge heads, of which the
recording head 7 is composed, has a pressure generator for
generating the pressure for discharging a droplet. Examples
of the pressure generator include a piezoelectric actuator; a
thermal actuator that utilizes a phase change caused by liquid
film boiling produced by an electric-thermal conversion
element, such as a heating resistor; a shape-memory alloy
actuator utilizing a metal phase change due to temperature
change; or an electrostatic actuator utilizing electrostatic
force. The individual head units provided for the individual
colors are merely an example. In another embodiment, the
recording head 7 may consist of one or more liquid discharge

head units having a line of nozzles for discharging droplets
of multiple colors.
The carriage 3 also carries sub-tanks 8 for
supplying ink of individual colors to the recording head 7.
To each of the sub-tanks 8, ink is supplied via an ink supply
tube 9 from a main tank (ink cartridge), which is not shown.
While in the present embodiment ink is supplied from the
external main tanks, this is merely an example. In another
embodiment, the ink cartridges may be mounted at the position
of the sub-tanks 8.
The image forming apparatus further includes a
sheet feeding unit for supplying a sheet 12 placed on a sheet
tray 11, such as a sheet-feeding cassette 10. The sheet
feeding unit includes a half-moon shaped roller (sheet-feeding
roller) 13 for picking up and sending the sheet 12 from the
sheet tray 11, one sheet at a time. The sheet feeding unit
also includes a separating pad 14 disposed opposite the sheet-
feeding roller 13. The separating pad 14, which is made of
material with a large friction coefficient, is biased toward
the sheet-feeding roller 13.
In order to transport the sheet 12 fed by the
sheet feeding unit under the recording head 7, there are
provided a transfer belt 21 for transporting the sheet 12
using electrostatic adsorption; a counter roller 22 for
transporting the sheet 12, as it is fed from the sheet feeding

unit via a guide 15, between the counter roller 22 and a
transfer belt 21; a transport guide 23 for changing the
direction of the sheet 12 by substantially 90°, so that the
sheet 12 can follow along the transfer belt 21; and a holddown
roller 25 that is biased toward the transfer belt 21 by a
holddown member 24. There is also provided a charge roller 26
for charging the surface of the transfer belt 21.
The transfer belt 21 is an endless belt extended
between a transfer roller 27 and a tension roller 28. As the
transfer roLler 27 is rotated by a vertical scan motor 31 via
a timing belt 32 and a timing roller 33, the transfer belt 21
turns in a belt transport direction (vertical scan direction)
indicated by an arrow in FIG. 2. Facing the back side of the
transfer belt 21, a guide member 29 is disposed at a location
corresponding to an image formation region of the recording
head 7. The charge roller 26 is in contact with the surface
layer of the transfer belt 21 so that it can rotate in
accordance with the turning of the transfer belt 21.
As shown in FIG. 2, a disc 34 having slits is
attached to the shaft of the transfer roller 27. A sensor 35
is provided to detect the slits of the disc 34. The disc 34
and the sensor 35 form a rotary encoder 36.
The image forming apparatus further includes a
paper ejection unit for ejecting the sheet 12 that has been
recorded by the recording head 7. The paper ejection unit

comprises a separating nail 51 for separating the sheet 12
from the transfer belt 21; paper ejection rollers 52 and 53;
and an ejected paper tray 54 for stocking the ejected sheet
12.
In a back portion, a both-side sheet-feeding unit
61 is detachably attached. The both-side sheet-feeding unit
61 is configured to take the sheet 12 as it is returned by the
rotation of the transfer belt 21 in the opposite direction,
invert the sheet 12, and then feed it again between the
counter roller 22 and the transfer belt 21.
As shown in FIG. 2, in a non-printing region on
one side of the carriage 3 along the horizontal scan
direction, a maintain/recover mechanism 56 for maintaining or
recovering the condition of the nozzles of the recording head
7 is disposed.
This maintain/recover mechanism 56 includes caps
57 for capping the nozzle surface of each of the recording
heads 7, a wiper blade 58 which is a blade member for wiping
the nozzle surface, and a blank discharge receiver 59 for
receiving droplets when performing a blank discharge involving
the discharge of droplets that do not contribute to recording
for the purpose of ejecting recording fluid having increased
viscosity.
In the thus constructed image forming apparatus,
the sheet 12 is fed from the sheet feeding unit one by one.

The sheet 12 is guided by the guide 15 substantially
vertically upwardly and then transferred sandwiched between
the transfer belt 21 and the counter roller 22. The tip of
the sheet 12 is guided by the transport guide 23, and the
sheet 12 is held down onto the transfer belt 21 by the
holddown roller 25, whereby the direction of transport is
changed by substantially 90°.
A control unit (not shown) causes an AC bias
supply unit to apply an alternating voltage which alternates
between positive and negative levels to the charge roller 26.
As a result, the transfer belt 21 is charged with an
alternating charge voltage pattern in which positive and
negative levels appear alternately at predetermined individual
durations in the rotating direction, i.e., the vertical scan
direction. When the sheet 12 is fed onto the thus charged
transfer belt 21, the sheet 12 is adsorbed onto the transfer
belt 21 by electrostatic force, so that the sheet 12 can be
transported in the vertical scan direction as the transfer
belt 21 rotates.
The recording head 7 is driven in accordance with
an image signal while the carriage 3 is moved in the forward
or the backward direction, whereby ink droplets are discharged
onto the stationary sheet 12, thus recording one line of data.
The sheet 12 is then moved a predetermined distance, followed
by the recording of the next line. Upon reception of a record

end signal or a signal indicating that the bottom end of the
sheet 12 has reached the recording region, the recording
operation is stopped, and the sheet 12 is ejected to the
ejected paper tray 54.
In the case of a both-side printing, the transfer
belt 21 is rotated in the opposite direction upon completion
of the recording on the upper surface (which is initially
printed). Thereby, the recorded sheet 12 is sent into the
both-side sheet-feeding unit 61, in which the sheet 12 is
inverted (so that the back surface is made the printed
surface). Thereafter, the sheet 12 is again fed between the
counter roller 22 and the transfer belt 21, carried on the
transfer belt 21 while timing control is performed. The sheet
is recorded on the back surface in the same way as described
above, and finally ejected onto the ejected paper tray 54.
During a print (record) standby period, the
carriage 3 is moved toward the maintain/recover mechanism 55,
where the nozzle surfaces of the recording head 7 are capped
with the caps 57 so that the nozzles can maintain their wet
condition to thereby prevent discharge failure due to the
drying of ink. Further, with the recording head 7 capped with
the caps 57, a recovery operation may be performed in which
the recording fluid is sucked out of the nozzles in order to
discharge the recording fluid having increased viscosity or
bubbles. This is followed by wiping with the wiper blade 58,

whereby the ink that has become attached to the nozzle
surfaces of the recording head 7 due to the recovery operation
is cleared or removed. Before or during recording, a blank
discharge operation may be performed in which ink that does
not contribute to recording is discharged. In this way, a
stable discharge performance of the recording head 7 is
maintained.
Hereafter, an example of the liquid discharge
head, i.e., the recording head 7, is described with reference
to FIGs. 3 and 4. FIG. 3 shows a cross section of the head
taken along the longer direction of a fluid chamber. FIG. 4
shows a cross section taken in the shorter direction of the
fluid chamber (along which the nozzles are arranged).
The liquid discharge head includes a channel
plate 101, which may be formed by anisotropic etching of a
single-crystal silicon substrate. A vibrating plate 102,
which may be formed by nickel electroforming, is joined to a
bottom surface of the channel plate 101. A nozzle plate 103
is joined to an upper surface of the channel plate 101. In
these laminated layers, there are formed a nozzle
communication passage 105 with which a nozzle 104 for
discharging an ink droplet is in fluid communication; a fluid
chamber 106 which is a pressure generating chamber; and an ink
supply opening 109 with which a common fluid chamber 108 is in
fluid communication in order to supply ink to the fluid

chamber 106 via a fluid resistance portion (supply passage)
107.
The liquid discharge head also includes two lines
of laminated piezoelectric elements 121 (In FIG. 4, only one
line of the laminated piezoelectric element 121 is shown).
The laminated piezoelectric element 121 is an
electromechanical transducer element as a pressure generator
(actuator unit) configured to deform the vibrating plate 102
in order to apply pressure to the ink in the fluid chamber
106. The piezoelectric element 121 is fixed to a base
substrate 122. Between the piezoelectric elements 121, a
support portion 123 is provided. The support portion 123 is
formed simultaneously with the piezoelectric elements 121 by
dividing the piezoelectric element material. Because no drive
voltage is applied to the support portion 123, it merely
functions as a support.
To the piezoelectric element 121, a flexible
printed circuit board (FPC) cable 126 equipped with a drive
circuit (drive IC), not shown, is connected.
A peripheral portion of the vibrating plate 102
is joined to a frame member 130. In the frame member 130,
there are formed a bored portion 131 for housing the actuator
unit including the piezoelectric element 121 and the base
substrate 122; a depressed portion for the common fluid
chamber 108; and an ink supply opening 132 for supplying

external color ink to the common fluid chamber 108. The frame
member 130 may be formed by injection molding of a
thermosetting resin, such as epoxy resin or polyphenylene
sulfide.
The depressions or openings in the channel plate
101, such as the nozzle communication passage 105 and the
fluid chamber 106, may be formed by anisotropic etching of a
single-crystal silicon substrate having the crystal face
orientation (110), using an alkaline etching solution, such as
an aqueous solution of potassium hydroxide (KOH). However,
the substrate is not limited to a single-crystal silicon
substrate but may be a stainless substrate or a photosensitive
resin.
The vibrating plate 102 may be made of a nickel
metal plate by electroforming process. In another embodiment,
the vibrating plate 102 may be made of other types of metal
plate, or of a metal-resin composite material. To the
vibrating plate 102, the piezoelectric elements 121 and the
support portion 123 are bonded with adhesive. The frame
member 130 is also bonded to the vibrating plate 102 with
adhesive.
The nozzle plate 103 has the nozzle 104 formed
therein for each fluid chamber 106, with a diameter of 10 to
30 urn. The nozzle plate 103 is bonded to the channel plate
101 with adhesive. The nozzle plate 103 is made of a metal

nozzle forming member on the outer-most surface of which a
water-repellent layer is formed via any required layers.
The piezoelectric element 121 is a piezoelectric
transducer (PZT) consisting of a piezoelectric material 151
and internal electrodes 152 that are alternately laminated.
The internal electrodes 152 are drawn out of the piezoelectric
element 121 via alternately different end faces thereof, and
are connected to an individual electrode 153 or a common
electrode 154. In the present embodiment, the piezoelectric
element 121 employs displacement in the d33 direction as the
piezoelectric direction in order to apply pressure to the ink
in the fluid chamber 10 6. Alternatively, displacement in the
d31 direction may be employed as the piezoelectric direction
of the piezoelectric element 121 in order to apply pressure to
the ink in the fluid chamber 106. In another embodiment, one
line of the piezoelectric element 121 may be provided on a
single substrate 122.
In the thus constructed liquid discharge head,
when the voltage applied to the piezoelectric element 121 is
lowered below a reference potential, the piezoelectric element
121 contracts, whereby the vibrating plate 102 moves downward.
As a result, the volume of the fluid chamber 106 expands,
causing ink to flow into the fluid chamber 106. Thereafter,
the voltage applied to the piezoelectric element 121 is
increased in order to cause the piezoelectric element 121 to

extend in the laminated direction, thereby deforming the
vibrating plate 102 in the direction of the nozzle 104. As a
result, the volume of the fluid chamber 10 6 decreases, whereby
the recording fluid in the fluid chamber 106 is pressurized
and discharged (ejected) out of the nozzle 104 in the form of
a droplet.
By bringing the voltage applied to the
piezoelectric element 121 back to the reference potential, the
vibrating plate 102 returns to its initial position, whereby
the fluid chamber 106 expands and a negative pressure is
generated. The negative pressure causes the fluid chamber 106
to be filled with the recording fluid from the common fluid
chamber 108. After the vibration of the meniscus surface at
the nozzle 104 dampens to a stable state, an operation for the
discharge of the next droplet is initiated.
The above (pull-push discharge process) is merely
an example of the method of driving the head. A pull
discharge or a push discharge process may be employed
depending on the way a drive waveform is given.
Hereafter, the control unit of the image forming
apparatus is described with reference to a block diagram shown
in FIG. 5.
The control unit 200 includes a central
processing unit (CPU) 201 for controlling the apparatus as a
whole; a read-only memory (ROM) for storing a program executed

by the CPU 201 and other fixed data; a random access memory
(RAM) 203 which may temporarily store image data; a rewritable
nonvolatile memory 204 for retaining data when power to the
apparatus is turned off; and an application-specific
integrated circuit (ASIC) 205 for performing various signal
processes on image data, image processing for data
rearrangement, and an input/output signal processing for
controlling the apparatus as a whole.
The control unit 200 also includes an interface
(I/F) 206 for exchanging data and signals with a host; a data
transfer unit for driving and controlling the recording head
7; a print control unit 207 including a drive waveform
generating unit for generating a drive waveform; a head
driver (driver IC) 208 for driving the recording head 7
mounted on the carriage 3; a motor drive unit 210 for driving
the horizontal scan motor 4 and the vertical scan motor 31; an
AC bias supply unit 212 for supplying an AC bias to the charge
roller 34; and an input/output (I/O) unit 213 for the input of
detection signals from various sensors such as encoder sensors
43 and 35 and a temperature sensor for detecting ambient
temperature. Further, an operating panel 214 for the input
and display of necessary information is connected to the
control unit 200.
The control unit 200 receives image data from a
host via the I/F 206. The host may be an information

processing apparatus such as a personal computer, an image
reading apparatus such as an image scanner, or an imaging
device such as a digital camera, connected via a cable or a
network.
The CPU 201 of the control unit 200 reads and
analyzes print data in a reception buffer included in the I/F
206, performs necessary image processing in the ASIC 205 in
order to rearrange the data, for example, and then transfers
the image data from the head drive control unit 207 to the
head driver 208. The generation of dot pattern data for the
output of an image is performed by a printer driver on the
host end, as will be described later.
The print control unit 207 transfers the
aforementioned image data to the head driver 208 in the form
of serial data. The print control unit 207 also outputs to
the head driver 208 a transfer clock and a latch signal, which
are necessary for transfer of image data and for finalizing
transfer, and a drop control signal (mask signal). The print
control unit 207 also includes a drive waveform generating
unit including a D/A converter for D/A converting drive signal
pattern data stored in the ROM, a voltage amplifier, and a
current amplifier. The print control unit 207 further
includes a drive waveform selection unit for selecting a drive
waveform to be fed to the head driver. Using these units, the
print control unit 207 generates a drive waveform consisting

of one or more drive pulses (drive signals) and outputs the
drive waveform to the head driver 208.
The head driver 208, based on the serially fed
image data corresponding to one line to be recorded with the
recording head 7, drives the recording head 7 by selectively
applying a drive signal corresponding to the drive waveform
fed from the print control unit 207 to the drive elements
(such as the aforementioned piezoelectric elements) for
generating the energy for causing the discharge of droplets
out of the recording head 7. By selecting an appropriate
drive pulse of which the drive waveform is composed, dots
having various sizes, such as large, medium, or small dots,
can be discharged.
A speed detection value and a position detection
value are obtained by sampling a detection pulse from the
encoder sensor 43, which is a linear encoder. A target speed
value and a target position value are obtained from a pre-
stored speed/position profile. Based on these values, the CPU
201 calculates a drive output value (control value) and then
drives the horizontal scan motor 4 via the motor drive unit
210 based on the control value. Similarly, a speed detection
value and a position detection value are obtained by sampling
a detection pulse from the encoder sensor 35, which is a
rotary encoder. A target speed value and a target position
value are obtained from a pre-stored speed/position profile.

Based on these values, the CPU 201 calculates a drive output
value (control value), and then drives the vertical scan motor
31 via the motor drive unit 210 and a motor driver based on
the control value.
Hereafter, an image forming system according to
an embodiment of the present invention is described with
reference to FIG. 6. The system includes one or more image
processing apparatuses 400 and an inkjet printer 500 (inkjet
recording apparatus) corresponding to the aforementioned image
forming apparatus.
The image processing apparatus 400, which may be
a personal computer (PC), and the inkjet printer 500 are
connected via a predetermined interface or a network.
The image processing apparatus 4 00 includes a CPU
401 and various memory units, such as a ROM 402 and a RAM 403,
which are connected by a bus line, as shown in FIG. 7.
Various units are connected to the bus line via predetermined
interfaces, such as a storage unit 406 which may consist of a
magnetic storage unit such as a hard disk; an input device 404
such as a mouse or a keyboard; a monitor 405 such as a liquid
crystal display (LCD) or a cathode-ray tube (CRT) display; and
a storage medium reading device (not shown) for reading a
storage medium such as an optical disc. A predetermined
interface (external I/F) unit 407 for communication with an

external network such as the Internet or an external device
via USB connection is also connected to the bus line.
The storage unit 406 of the image processing
apparatus 4 00 stores an image processing program. The image
processing program may be read from a storage medium using the
storage medium reading device, or downloaded from a network
such as the Internet, and then installed on the storage unit
406. By thus installing the image processing program, the
image processing apparatus 400 is enabled to perform image
processing as described below. The image processing program
may be adapted to operate on a predetermined operating system
(OS). The image processing program may also constitute a part
of particular application software.
With reference to a functional block diagram
shown in FIG. 8, an image processing method using the program
on the part of the image processing apparatus 400 according to
an embodiment of the present invention is described.
This is an example in which most of imaging
processes are carried out by a host computer such as a
personal computer (PC) functioning as an image processing
apparatus, as is suitable in the case of a relatively low-cost
Inkjet recording apparatus.
A printer driver 411 includes the program stored
in the image processing apparatus 400 (PC). The printer
driver 411 includes a color management module (CMM) processing

unit 412 for converting image data 410, which may be fed from
application software, from a color space for monitor display
into a color space for a recording apparatus, such as an image
forming apparatus (i.e., from the RGB color system to the CMY
color system); a black generation/under color removal (BG/UCR)
processing unit 413 for black generation and under color
removal from the CMY values; a γ correction processing unit
414 for correction of recording apparatus characteristics or
input/output correction to suit a user's preferences; a
halftone processing unit 415 for performing a halftone process
on image data; a dot arrangement processing unit 416 (which
may be incorporated into the halftone processing unit) for
converting the result of halftone processing into a pattern
arrangement corresponding to the order of ejection of dots
from the recording apparatus; and a rasterizing unit 417 for
spreading the dot pattern data, i.e., the print image data
obtained by the halftone processing and the dot arrangement
processing, in accordance with the print nozzle positions. An
output 418 of the rasterizing unit 417 is delivered to the
inkjet printer 500.
Hereafter, an example of performing part of the
image processing according to the present embodiment on the
part of the inkjet printer 500 is described with reference to
a functional block diagram shown in FIG. 9.

This example enables high-speed processing, and
may be suitably used in high-speed machines.
A printer driver 421 on the part of the image
processing apparatus 400 (PC) includes a CMM processing unit
422 for converting image data 410, which may be fed from
application software, from a color space for monitor display
into a color space for a recording apparatus (i.e., from the
RGB color system to the CMY color system); a BG/UCR processing
unit 423 for black generation and under color removal from the
CMY values; and a y correction processing unit 424 for
correction of recording apparatus characteristics or
input/output correction to suit a user's preferences. Image
data generated by the y correction processing unit 424 is
delivered to the inkjet printer 500.
A printer controller 511 (control unit 200) on
the part of the inkjet printer 500 includes a halftone
processing unit 415 for performing a halftone processing on
image data; a dot arrangement processing unit 416 (which may
be incorporated into the halftone processing unit) for
converting the result of halftone processing into a pattern
arrangement corresponding to the order of ejection of dots
from the recording apparatus; and a rasterizing unit 517 for
spreading the print image data, i.e., the dot pattern data
obtained by the halftone processing and the dot arrangement
processing, in accordance with the individual nozzle

positions. The output of the rasterizing unit 517 is
delivered to the print control unit 207.
The image processing method according to the
present embodiment of the invention may be implemented by
either the configuration of FIG. 8 or FIG. 9. In the
following, reference is made to the configuration of FIG. 8,
in which the Inkjet recording apparatus does not have the
function to generate a dot pattern that is actually recorded
in response to a print instruction to draw an image or a
character. Thus, a print instruction, which may be sent from
application software executed by the image processing
apparatus 400 as a host, is subjected to image processing by
the printer driver 411, which is provided in the image
processing apparatus 400 (host computer) in the form of
software. The resultant multiple-value dot pattern data
(print image data) that the inkjet printer 500 can output is
then rasterized and transferred to the inkjet printer 500,
which produces a printed output.
Specifically, in the image processing apparatus
400, an image-drawing or character-recording instruction from
an application or the operating system (describing, e.g., the
position, thickness, and shape of a line to be recorded, or
the font and position of a character to be recorded) is
temporarily saved in a rendering data memory. Such an
instruction may be described in a particular print language.

The instruction saved in the rendering data
memory is interpreted by the rasterizer. If it is a line-
recording instruction, it is converted into a recording dot
pattern corresponding to a designated position or thickness.
If the instruction is a character-recording instruction, it is
converted into a recording dot pattern corresponding to a
designated position or size based on corresponding character
profile information which is recalled from font outline data
stored in the image processing apparatus (host computer) 400.
In the case of image data, the data is converted into a
recording dot pattern as is.
Thereafter, the recording dot pattern (image data
410) is image-processed and then stored in the raster data
memory. Specifically, the image processing apparatus 400
rasterizes the data into recording dot pattern data with
reference to orthogonal grids as reference recording
positions. The image processing includes a color management
module (CMM) processing for color adjustment; γ correction
processing; halftone processing using a dither method or an
error diffusion method; an underlayer eliminating processing;
and a total ink amount regulating processing, some of which
have been mentioned above. The recording dot pattern stored
in the raster data memory is transferred to the inkjet
recording apparatus 500 via an interface.

In the following, an image forming apparatus
(multifunction peripheral) combining the function of an inkjet
recording apparatus and a copier function is described with
reference to FIG. 10. FIG. 10 shows an overall structure of
the image forming apparatus.
The image forming apparatus has an apparatus body-
(casing) 1001 in which an image forming unit 1002 for forming
an image and a vertical scan transfer unit 1003 (which may be
collectively referred to as a printer engine unit) are
disposed. At the bottom of the apparatus body 1001, there is
provided a sheet feeding unit 1004, from which a recording
medium (sheet) 1005 is taken one by one. The sheet 1005 is
then transported by a vertical scan transfer unit 1003 to a
position opposite an image forming unit 1002, where the image
forming unit 1002 discharges ink droplets onto the sheet 1005
to form (record) a required image. The sheet 1005 is then
ejected onto an ejected paper tray 1007 formed at the top of
the apparatus body 1001 via an ejected paper transfer unit
1006.
The image forming apparatus also includes an
image reading unit (scanner unit) 1011 disposed above the
ejected paper tray 1007 for reading an image. The image
reading unit 1011, which is an input system for image data
(print data) used by the image forming unit 1002, includes a
scanning optical system 1015 including an illuminating light

source 1013 and a mirror 1014, and another scanning optical
system 1018 including mirrors 1016 and 1017. The scanning
optical systems 1015 and 1018 are configured to move in order
to acquire an image of a manuscript placed on a contact glass
1012. The scanned manuscript image is then acquired as an
image signal by an image reading element 1020 disposed behind
a lens 1019. The acquired image signal is digitized and
subjected to image processing, and the image-processed print
data can be then printed. Over the contact glass 1012, a
cover plate 1010 for holding a manuscript is attached.
The image forming apparatus may be configured to
receive data, such as print image data, from an external data
input system, in order to input data for an image formed by
the forming unit 1002. Examples of the external data input
system include an information processing apparatus, such as a
personal computer functioning as an image processing
apparatus; an image reading device such as an image scanner;
and an imaging device such as a digital camera. Such data
including print image data delivered from a host may be
received via a print cable or a network, processed, and then
printed.
The image forming unit 1002 is of the shuttle
type. Specifically, the image forming unit 1002,
substantially similar to the aforementioned inkjet recording
apparatus (image forming apparatus), includes a carriage 1023

adapted to be guided by a guide rod 1021 to move in the
horizontal scan direction (perpendicular to the sheet
transport direction). On the carriage 1023, there is disposed
a recording head 1024 consisting of one or more liquid
discharge heads, each of which has a line of nozzles for
discharging droplets of multiple different colors. The
recording head 1024 is configured to discharge droplets of ink
while the carriage 1023 is moved by a carriage scan mechanism
in the horizontal scan direction and while the sheet 1005 is
transferred in the sheet transfer direction (vertical scan
direction) by the vertical scan transfer unit 1003.
Alternatively, the image forming unit 1002 may be of the line
type equipped with a line head.
To the line of nozzles on the recording head 1024
for discharging droplets of black (Bk) ink, cyan(C) ink,
magenta (M) ink, and yellow (Y) ink, ink of each color is
supplied from a sub-tank 1025 mounted on the carriage 1023.
The sub-tank 1025 is replenished with ink from an ink
cartridge 1026 for each color, which is a main tank detachably
attached in the apparatus body 1001, via tubing (not shown).
The vertical scan transfer unit 1003 includes an
endless transfer belt 1031 extended between a transfer roller
1032, which is a drive roller, and a driven roller 1033, for
changing the direction of transfer of the sheet 1005 as it is
fed from below by substantially 90° toward the image forming

unit 1002; a charge roller 1034 to which an AC bias is applied
for charging the surface of the transfer belt 1031; a guide
member 1035 for guiding the transfer belt 1031 in an area
opposite the image forming unit 1002; a holddown roller
(pressure roller) 1036 for holding down the sheet 1005 onto
the transfer belt 1031 at a position opposite the transfer
roller 1032; and a transfer roller 1037 for sending the sheet
1005 on which an image has been formed by the image forming
unit 1002 onto an ejected paper transfer unit 1006.
The transfer belt 1031 of the vertical scan
transfer unit 1003 rotates in the vertical scan direction as
the transfer roller 1032 is rotated by a vertical scan motor
1131 via a timing belt 1132 and a timing roller 1133.
The sheet feeding unit 1004 includes a sheet-
feeding cassette 1041 that can be inserted and removed from
the apparatus body 1001, for storing a number of sheets 1005;
a sheet-feeding roller 1042 and a friction pad 1043 for
feeding the sheets 1005 from the sheet-feeding cassette 1041
one sheet at a time; and a sheet-feeding transfer roller 1044
which is a resist roller for transporting the sheet 1005 to
the vertical scan transfer unit 1003. The sheet-feeding
roller 1042 is rotated by a sheet-feeding motor 1141, which
may be a hybrid (HB) stepping motor, via a sheet-feeding
clutch (not shown). The sheet-feeding transfer roller 1044 is
also rotated by the sheet-feeding motor 1141.

The ejected paper transfer unit 1006 includes
ejected paper transfer roller pairs 1061 and 1062 for
transporting the sheet 1005 on which an image has been formed;
and ejected paper transfer roller pairs 1063 and 1064 for
sending the sheet 1005 out to the ejected paper tray 1007.
In the following, a control unit 1200 of the
image forming apparatus is described with reference to a block
diagram shown in FIG. 11.
The control unit 1200 includes a main control
unit 1210 for controlling the apparatus as a whole. The main
control unit 1210 includes a CPU 1201; a ROM 1202 for storing
a program executed by the CPU 1201 and other fixed data; a RAM
1203 for temporary storage of image data or the like; a
nonvolatile memory (NVRAM) 1204 for retaining data while power
to the apparatus is turned off; and an ASIC 1205 for
performing image processing on an input image, such as
halftone processing.
The control unit 1200 also includes an external
I/F 1211 disposed between a host, such as an information
processing apparatus functioning as an image processing
apparatus, and the main control unit 1210, in order to process
the transmission and reception of data and signals; a print
control unit 1212 that includes a head driver for driving and
controlling the recording head 1024; a horizontal scan drive
unit (motor driver) 1213 for driving the horizontal scan motor

1027 by which the carriage 1023 is moved; a vertical scan
drive unit 1214 for driving the vertical scan motor 1131; a
sheet-feeding drive unit 1215 for driving the sheet-feeding
motor 1141; a paper ejection drive unit 1216 for driving the
paper ejection motor 1103 by which each roller in the paper
ejection unit 1006 is driven; a both-side drive unit 1217 for
driving a both-side refeeding motor 1104 by which each roller
of a both-side unit (not shown) is driven; a recovery system
drive unit 1218 for driving a maintain/recover motor 1105 by
which the maintain/recover mechanism is driven; and an AC bias
supply unit 1219 for supplying AC bias to the charge roller
1034.
The control unit 1200 further includes a
solenoids drive unit (driver) 1222 for driving various types
of solenoids (SOL) 1106; a clutch drive unit 1224 for driving
electromagnetic clutches 1107 as they relate to feeding of
sheets; and a scanner control unit 1225 for controlling the
image reading unit 1011.
To the main control unit 1210, a detection signal
from a temperature sensor 1108 for detecting the temperature
of the transfer belt 1031 is inputted. Though not shown,
detection signals from various other sensors may also be
inputted to the main control unit 1210. The main control unit
1210 is also connected with an operating/display unit 1109 in
order to receive necessary key inputs and output display

information. The operation/display unit 1109 may include
various keys such as a numerical keypad and a print start key
and various indicators, which may be provided on the apparatus
body 1001.
The main control unit 1210 is also fed with an
output signal (pulse) from a linear encoder 1101, which
detects the speed and the amount of movement of the carriage
1023, and an output signal (pulse) from a rotary encoder 1102
for detecting the speed and the amount of movement of the
transfer belt 1031. Based on these output signals and their
correlation, the main control unit 1210 drives and controls
the horizontal scan motor 1027 and the vertical scan motor
1131 via the horizontal scan drive unit 1213 and the vertical
scan drive unit 1214, respectively, thereby moving the
carriage 1023 and causing the transfer belt 1031 to move to
transport the sheet 1005.
An image formation operation in the thus
constructed image forming apparatus is briefly described. As
the AC bias supply unit 1219 applies a rectangular-wave high
voltage alternating between positive and negative poles to the
charge roller 1034, which is in contact with an insulated
layer (surface layer) of the transfer belt 1031, the surface
layer of the transfer belt 1031 is charged with alternating
bands of positive and negative charges in the transport
direction of the transfer belt 1031. Thus, the surface of the

transfer belt 1031 is charged with predetermined charge
widths, thereby producing a non-uniform electric field.
Then, the sheet 1005 is fed from the sheet
feeding unit 1004 onto the transfer belt 1031 between the
transfer roller 1032 and the holddown roller 1036. There,
because the non-uniform electric field is present due to the
formation of the positive- and negative-pole charges, the
sheet 1005 is instantaneously polarized in accordance with the
direction of the electric field. As a result, the sheet 1005
is adsorbed on the transfer belt 1031 by the electrostatic
force, and transported as the transfer belt 1031 moves.
As the sheet 1005 is intermittently transported
on the transfer belt 1031, droplets of recording fluid is
discharged onto the sheet 1005 by the recording head 1024 in
accordance with print data, whereby an image is formed
(printed). Thereafter, the tip of the image-formed sheet 1005
is separated from the transfer belt 1031 by the separating
nail, and the sheet 1005 is ejected onto the ejected paper
tray 1007 by the ejected paper transfer unit 1006.
In accordance with an embodiment of the present
invention, it is also possible to print a print medium such
that no margin is provided in at least one of the edges. In
this case, ink is inevitably discharged outside the print
medium when printing an edge portion. This is due to the fact
that even if ink is ejected in such a manner as to print just

up to the edge of the print medium, the ink in reality often
fails to land on an ideal landing position because of errors,
such as feed error in the print medium transfer system or a
drive error in the carriage, resulting in the creation of a
margin. Consequently, it is necessary to print an area larger
than is ideal, taking into consideration the print position
errors, thereby resulting in the discharge of ink outside the
print medium. The ink that misses the print medium does not
contribute to recording and is therefore a waste of ink. In
order to reduce such a waste ink as much as possible, a method
is known whereby the transfer accuracy of the print medium is
enhanced so that, by reducing the expected area in which the
waste ink lands, the waste ink is reduced. For example,
transfer accuracy may be improved by reducing the rate of feed
of the print medium when printing its edge portion.
When an expendable supply such as ink, a
recording medium, or a recording head that is not a specific
product, such as a recommended product, is used, problems such
as beading and other various image quality degradations tend
to occur because of inability to discharge an ink droplet
normally or the difference in ink absorbing properties among
different recording media, for example. Thus, users are
encouraged to use specific expendable supplies, such as ones
recommended by the manufacturer.

Therefore, in an embodiment of the invention,
upon detection of ink, a recording medium, or a recording head
that is not a specific item, the user is notified that the
currently selected expendable supply is not a specific item,
and informed that switching to a specific expendable supply
will result in better image quality. As long as the user
switches to a suggested specific expendable supply, the user
can be provided with a high quality image.
Even when a specific expendable supply is not
used, a stable quality image may be provided to a user by
changing the image forming method, such as by selecting a more
stable ink-droplet discharge method, or by adjusting the
amount of droplet that becomes attached to the recording
medium.
In order to enable such a change of the method,
the recording apparatus may be equipped with a dedicated mode
for the case where a specific expendable supply is not used.
Alternatively, it is also possible to accommodate such a
change by modifying part of a standard image forming method
(as will be described in detail later with reference to FIG.
33). By thus allowing a user to select an appropriate output
method, an output image that is more in line with the user's
preferences can be provided.

Whether the expendable supply is a specific
expendable supply or not may be detected either automatically
by the system or based on a user's manual input.
In a method of automatically detecting ink that
is not a specific product, the use period of an ink cartridge
may be acquired from an IC chip attached to the cartridge.
If the use period is excessively long, it is
possible that the user has refilled the ink cartridge by
himself. Alternatively, information about the accumulated
amount of ink that has been used may be acquired from an IC
chip attached to the cartridge. If the accumulated amount of
ink used is greater than the original amount of ink in the ink
cartridge, it is possible that the user has refilled the ink
cartridge with ink by himself. In these cases, the use of a
non-specific product can be detected.
In a method of automatically detecting a
recording head that is not a specific product, a unique ID of
the recording head may be acquired from an IC chip attached to
the recording head.
In this case, a unique ID may be stored in the IC
chip by a manufacturer upon shipping of the recording head. A
recording apparatus acquires the unique ID at the start of
recording, and determines whether the acquired ID corresponds
to the manufacturer's designated ID. If not, the recording
head can be detected as a non-specific product.

In a method of automatically detecting a
recording medium that is not a specific products, the
thickness or the basis weight of the recording medium may be
acquired.
For example, a sensor may be provided in a
transfer passage in a recording apparatus, in order to measure
the thickness or the basis weight of a recording medium at the
start of recording. If the obtained values are outside a
specific range, which may be designated by the recording
apparatus manufacturer, the recording medium can be detected
as a non-specific product. For example, the thickness may be
set in the range of from 90 to 110 μm, and the basis weight
may be set in the range of between 50 to 250 g/m2, although
the present invention is not limited by such ranges.
By thus providing an automatic detection
mechanism, it becomes possible to automatically provide a
stable quality image to a user.
In the case of a user's manual input, a switch or
the like may be mounted on the exterior of the recording
apparatus so that whether ink, a recording medium, and/or a
recording head are specific products can be selected. In this
way, a user can indicate whether any of the above items is a
specific item. Alternatively, a check box or radio buttons
may be provided in a print setting screen in a window of a PC
or on a display unit of the recording apparatus, in order for

the user to enter information indicating whether a certain
element is a specific product or not. In this way, a user can
confirm whether a certain item is a specific expendable
supply.
By thus providing a manual-input detecting
mechanism, it becomes possible to provide a stable-quality
image to the user without providing the aforementioned
automatic detecting mechanism.
In the following, the change of the image forming
method in a case where a specific expendable supply is not
used is described.
Based on similarity in various means to obtain a
high-quality image, the following four aspects are described
in order.
• Improvement of landing position error (to prevent
nonuniformity)
• Adjustment of attached ink amount (to prevent beading,
cockeling, or transfer)
• Improvement of hue error (to achieve a certain specific hue)
• Ensuring ink drying time (to prevent beading, cockeling, or
transfer)

Of those four items, the initial three items
relate to the change of the image forming method; the other
one relates to a change in another operation.
Improvement of landing position error
In an actual image forming apparatus, a landing
position error may be caused by various factors, resulting in
image quality degradation. One of such factors is the
discrepancy between the period of fluctuation of the meniscus
and the print clock (i.e., the discharge timing).
Specifically, if the meniscus is not stabilized within the
duration between the discharge of an ink droplet and the
discharge of the next ink droplet, a landing position error
may occur due to abnormal discharge (see FIG. 12B).
In accordance with an embodiment of the present
invention, the time for the meniscus to stabilize is ensured
by reducing the speed of movement of the carriage. For
example, by decreasing the speed of movement of the carriage
below normal, a longer time can be provided between one
discharge and the next, so that the meniscus can be stabilized
in time. Thus, the landing position error can be reduced, and
a high-quality image can be obtained (see FIG. 13B).
The meniscus can also be stabilized by increasing
the number of passes above normal. Specifically, as shown in
FIG. 14B and 14C, by forming an image over plural passes, the

intervals of time at which droplets are discharged
successively in one scan can be extended, so that the meniscus
can be stabilized. While the number of passes in the example
of FIG. 14B and 14C is two, this is merely an example and the
number may be greater than two.
Nonuniformity can also be reduced by not using
droplets with a large landing position error. For example, a
large droplet (i.e., a droplet corresponding to a large dot
size) and a small droplet (i.e., a droplet corresponding to a
small dot size) have different energies required for discharge
and also different weights.
In the case of a small droplet, because it can be
discharged with a very small energy, it is possible that a
discharge cannot be performed in the absence of meniscus
stability. Also, because its weight is small, the small
droplet may become scattered and tend to land at an unintended
position (see FIG. 15B). Thus, by forming an image in which
gradation process is optimized with large or intermediate
droplets, which have higher landing position accuracy, while
avoiding small droplets, a high-quality image can be obtained
(see FIG. 16B). When it is expected that the large and small
droplets have low discharge stability, an image may be formed
with intermediate droplets alone, thus suppressing the
discharge of more than one kind of droplet.

Nonuniformity can also be reduced by switching
from a bidirectional printing to a one-directional printing.
For example, when the thickness of a recording medium differs
from a recommended value, or when the manner in which energy
is applied to a droplet differs from a recommended manner, a
landing position error may occur in the horizontal scan
direction (see FIG. 17B). In this case, if a bidirectional
printing is carried out, the printed position may differ
between the forward direction and the backward direction,
resulting in an image quality degradation such as
nonuniformity (see FIG. 17C). Such a nonuniformity in the
image may be reduced and a high-quality image may be obtained
by recording only in the forward direction. Simultaneously,
this may eliminate the color difference between a dot printed
in the forward direction and a dot printed in the backward
direction in the case of bidirectional printing. Further, the
one-directional printing makes it easier to reduce beading
because of the time required for the carriage to return to the
print start position. The effect of a landing position error
can also be made less visible by reducing the number of lines
in halftones.
FIG. 18B and FIG. 19B show actual printed images
in the case of a high line number. While the original digital
data should appear as a basic tone shown in FIG. 18A or FIG.
19A, the basic tone appear weakened in FIG. 18B and FIG. 19B,

due to the influence of a landing position error. By reducing
the number of lines, the basic tone can be made to appear more
clearly, as shown in FIG. 18D and FIG. 19D. In this way, the
influence of a landing position error can be made less
visible. When a borderless print is performed, discharge of
ink onto areas outside the recording medium is undesirable.
In this case, because it is difficult to support the sheet,
image quality degradation is likely to occur. Thus, the
landing position accuracy needs to be increased near the
edges, and some measure needs to be taken to improve image
quality. For this reason, a process is preferably carried out
to achieve higher image quality when performing borderless
print.
Adjustment of attached ink amount
When an ink or a sheet other than a specific
product, such as a manufacturer's recommended product, is
used, because the amount of ink that can be absorbed differs
from one type of sheet to another, an excessive amount of ink
may become attached, resulting in image quality degradation
such as beading, cockeling, or transfer. Thus, the attached
ink amount in this case needs to be limited. This can be
realized by reducing the amount of ink that becomes attached
per unit area below normal when recording.

Improvement of hue error
When an ink or a sheet other than a specific
product is used, the probability is high that the ink has a
hue that differs from the hue of the specific product. In
this case, when the color of black or gray is produced by
combining black ink and color ink, it may become impossible to
maintain a specific gray balance. In order to maintain a
specific gray balance, either black ink alone or composite
black in which very small amounts of color ink are used may be
used (i.e., the types of ink used are limited). Recently,
image forming apparatuses are available in which light color
inks, such as light magenta or light cyan, are adopted. In
the case of these apparatuses, a recommended gray balance may
be better maintained by using inks with smaller chroma values
in combination while avoiding the use of inks with relatively
large chroma values, such as cyan, magenta, or yellow,
whenever possible.
Ensuring ink drying time
When an ink or a sheet other than a specific
product is used, because the amount of ink absorbed differs
from one type of sheet to another, an excess amount of ink may
become attached, resulting in the ink requiring a long time to
dry. In such a case, if high-speed printing is performed,
large amounts of ink may remain undried on the sheet surface,

possibly resulting in image quality degradation such as
beading or cockeling. Such an image quality degradation can
be reduced by making the period between the end of one scan in
the horizontal scan direction and the start of the next scan
longer than normal. For example, the standby time at the home
position or the print start position before the next scan is
initiated may be extended.
The need for an extended period of time before
the ink dries may also lead to the ink remaining undried even
in the ejected paper tray after the sheet is ejected. In this
case, if continuous printing is performed, there is the danger
that, as a second printed sheet is laid over a first printed
sheet in the ejected paper tray, the printed surface of the
first sheet may be scratched, or the back surface of the
second sheet may be soiled. Such an image quality degradation
in the first and/or the second sheets can be prevented by
making the time between the end of printing the recording
medium and its ejection longer than normal.
In the case of a both-side printing, typically
the recording medium is printed on its first surface and then
transferred back to have its second surface printed. In this
case, if an ink or a sheet other than a recommended product
is used, because the amount of ink absorbed differs from one
type of sheet to another, an excessive amount of ink may
become attached, possibly resulting in the ink on the first

surface attaching to the sheet transfer mechanism. If that
happens, image quality suffers not only on the first surface
but also the second surface. Such an image quality
degradation on the first surface and the second surface can be
prevented by making the time between the end of printing of
the first surface and the start of printing of the second
surface longer than normal.
The aforementioned processes for changing the
image forming method may be performed using the aforementioned
program executed by the image forming apparatus described with
reference to FIGs. 1 through 10. The program is therefore an
embodiment of the present invention. The program, which may
be stored as part of the printer driver in the ROM 202 shown
in the block diagram of FIG. 5, may be started up by an
operator operation and expanded on the RAM 203, followed by
execution by the CPU 201. The printer driver including the
program may be downloaded to the image forming apparatus from
a storage unit on a network. Alternatively, the program may
be installed on the image forming apparatus via a computer-
readable recording medium such as a compact disc.
Examples of the aforementioned computer-readable
recording medium include semiconductor media (such as a ROM or
a nonvolatile memory card); optical media (such as a digital
versatile disc (DVD) , a rnagnetooptical disc (MO) , a MiniDisc
(MD), and a Compact Disc Recordable (CD-R)); and magnetic

media (such as magnetic tape or a flexible disc). Based on an
instruction from the program that is loaded, part or all of
the actual processes may be carried out by the operating
system in order to realize the functions of the present
embodiment. When the program is stored in a storage unit such
as a hard disk drive in a server computer, and downloaded via
a user's computer connected to a network for distribution, or
when the program is distributed from a server computer, the
storage unit of the server computer is included in the
computer-readable recording medium according to the present
embodiment of the invention. By thus writing the necessary
functions in a program, recording it in a computer-readable
recording medium, and then distributing it, improvements in
terms of cost reduction, portability, and versatility can be
achieved.
Hereafter, an example of a specific recording
medium used in the present embodiment of the invention is
described.
Media
A recording medium according to the present
embodiment comprises a support member and a coating layer on
at least one side of the support. The recording medium may
also include other layers as needed.

Preferably, the recording medium has an ink
transfer amount of 4 to 15 ml/m2 and more preferably 6 to 14
ml/m2 as measured with a dynamic scanning absorptometer at the
contact time of 100 ms. The transfer amount of pure water to
the recording medium is preferably 4 to 26 ml/m and more
preferably 8 to 25 ml/m2.
If the transfer amount of ink or pure water at
the contact time of 100 ms is too small, beading may become
more likely to occur. If the transfer amount is too much, the
recorded ink dot size may become smaller than desired.
The transfer amount of ink to the recording
medium of the present embodiment as measured with the dynamic
scanning absorptometer at the contact time 400 ms is 7 to 20
ml/m2 and preferably 8 to 19 ml/m2. Preferably, the transfer
amount of pure water to the recording medium is 5 to 29 ml/m2
and more preferably 10 to 28 ml/m2.
If the transfer amount at the contact time 4 00 ms
is too small, drying property is insufficient and a spur mark
may become more likely to occur. If the transfer amount is
too much, bleeding tends to occur, and the glossiness at an
image portion after drying may become more likely to decrease.
The dynamic scanning absorptometer (DSA) (as
described by Shigenori Kuga in Japan TAPPI Journal, Vol. 48,
pp. 88-92, May 1994) is an apparatus capable of accurately
measuring the amount of liquid absorbed within an extremely

short period of time. The dynamic scanning absorptometer is
capable of performing automatic measurement using a method
whereby the rate of liquid absorption is directly read from
the movement of the meniscus in a capillary, a disc-shaped
sample is scanned with a liquid absorption head in a helical
manner, and the scan speed is automatically changed in
accordance with a preset pattern to measure as many points as
necessary on a single sample. A head for supplying liquid to
a paper sample is connected to a capillary via a Teflon
(registered trademark) tube, and the position of the meniscus
in the capillary is automatically read by an optical sensor.
Specifically, a dynamic scanning absorptometer (K350 Series,
Type D, manufactured by Kyowa Co., Ltd.) was used to measure
the transfer amount of pure water and ink. The transfer
amount at contact times 100 ms and 400 ms can be determined by
interpolation of measured values of transfer amounts at
contact times around each of these contact times. The
measurement was performed at 23 "C and 50% RH.
Support member
The support member is not particularly limited
and may be appropriately selected depending on the purpose.
Examples are a sheet of paper mainly made of wood fibers and a
sheet of nonwoven fabric mainly made of wood and synthetic
fibers.

The aforementioned sheet of paper is not
particularly limited and may be appropriately selected
depending on the purpose. For example, it may be made of wood
pulp or recycled pulp. Examples of wood pulp are leaf
bleached kraft pulp (LBKP), needle bleached kraft pulp (NBKP),
NBSP, LBSP, GP, and TMP.
As materials of recycled pulp, recycled papers
indicated in the list of standard qualities of recycled papers
from the Paper Recycling Promotion Center may be used.
Examples include high-quality white; white with lines; cream
white; cards; special white; medium white; high-quality with
ink; white with color ink; Kent; white art; medium-quality
chip with color ink; low-quality chip with color ink;
newspaper; and magazine. More specific examples are
information-related paper such as non-coating computer paper,
and printer paper such as thermal paper and impact paper; OA
recycled paper such as PPC; coated paper such as art paper,
ultra lightweight coated paper, and mat paper; and uncoated
paper such as high-quality paper, high-quality paper with
color ink, notebooks, letter paper, packaging paper, fancy
paper, medium-quality paper, newspaper, coarse paper, high-
quality with ink, pure-white roll paper, chemical pulp paper,
and high-yield pulp containing paper. These types of paper may
be used individually or in combination.

Normally, recycled pulp is made by a combination
of the following four steps:
(1) A defibrating step of breaking down used paper into fibers
and separating ink from the fibers using mechanical force and
chemicals in a pulper.
(2) A dust removing step of removing foreign matter (such as
plastic) and dust in the used paper with a screen or a
cleaner.
(3) A deinking step of expelling the ink separated by a
surfactant from the fibers out of the system by a flotation
method or a cleaning method.
(4) A bleaching step of increasing the whiteness of the fibers
by oxidization or reduction.
When mixing recycled pulp, the percentage of
recycled pulp to the entire pulp is preferably 40% or lower so
that produced paper does not curl after recording.
As an internal filler for the support, a
conventional white pigment may be used. Examples include
inorganic pigments such as precipitated calcium carbonate,
heavy calcium carbonate, kaolin, clay, talc, calcium sulfate,
barium sulfate, titanium dioxide, zinc oxide, zinc sulfide,
zinc carbonate, satin white, aluminum silicate, diatomaceous
earth, calcium silicate, magnesium silicate, synthetic silica,
aluminum hydroxide, alumina, lithophone, zeolite, magnesium
carbonate, and magnesium hydrate; and organic pigments such as

styrene plastic pigment, acrylic plastic pigment,
polyethylene, microcapsule, urea resin, and melamine resin.
The above substances may be used individually or in
combination.
As an internal sizing agent used when producing
the support, a neutral rosin size agent used for neutral
papermaking, alkenyl succinic anhydride (ASA), alkyl ketene
dimer (AKD), or a petroleum resin size agent may be used.
Especially, a neutral rosin size agent and alkenyl succinic
anhydride are preferable. Alkyl ketene dimer has a high
sizing effect and therefore does not require a large added
amount. However, because alkyl ketene dimer reduces the
friction coefficient of the surface of recording paper
(medium) and thus makes the paper made slippery, alkyl ketene
dimer may not be suitable from the viewpoint of transport
during inkjet recording.
Coating layer
The coating layer contains a pigment and a
binder, and may also contain a surfactant and other components
as needed.
As the. pigment, an inorganic pigment or a mixture
of an inorganic pigment and an organic pigment may be used.
Examples of the inorganic pigment include kaolin,
talc, heavy calcium carbonate, precipitated calcium carbonate,

calcium sulfite, amorphous silica, alumina, titanium white,
magnesium carbonate, titanium dioxide, aluminum hydroxide,
calcium hydrate, magnesium hydrate, zinc hydroxide, and
chlorite. Among those, kaolin is particularly preferable
because it has superior glossiness exhibiting property and
provides a texture similar to that of an offset paper.
There are several types of kaolin, including
delaminated kaolin, calcined kaolin, and engineered kaolin
made by surface modification. In consideration of glossiness
exhibiting property, 50% by mass or more of the entire kaolin
has a particle size distribution such that 80% by mass or
greater of the particles has a particle size of 2 urn or
smaller.
Preferably, the added amount of kaolin is 50
parts by mass with respect to 100 parts by mass of the entire
pigment in the coating layer. If the added amount of kaolin
is lower than 50 parts by mass, sufficient glossiness may not
be obtained. While there is no specific upper limit to the
amount of kaolin added, the added amount of kaolin is
preferably 90 parts by mass or smaller from the viewpoint of
surface-coating property and in consideration of fluidity of
kaolin, particularly the thickening property of kaolin under a
high shearing force.
Examples of the organic pigment include a water-
soluble dispersion of styrene-acrylic copolymer particles,

styrene-butadiene copolymer particles, polystyrene particles,
and polyethylene particles. Two or more of the above organic
pigments may be used in combination.
Preferably, the added amount of the organic
pigment is 2 to 20 parts by mass with respect to 100 parts by
mass of the entire pigment in the coating layer. Because the
organic pigment has excellent glossiness exhibiting property
and a specific gravity smaller than that of an inorganic
pigment, it provides a thick, high-gloss coating layer having
a good surface-coating property. If the added amount of the
organic pigment is less than 2 parts by mass, the
aforementioned effect may not be obtained. If it exceeds 20
parts by mass, the fluidity of a coating liquid may worsen,
resulting in a decrease in coating process efficiency and a
cost disadvantage.
The organic pigments may be classified by their
particle shapes into the solid-type, the hollow-type, and the
doughnut-shape type. To achieve a good balance among
glossiness, surface-coating property, and fluidity of coating
liquid, preferably the organic pigment has an average particle
size of 0.2 to 3.0 μm. More preferably, the organic pigment
is of the hollow-type with a void percentage of 4 0 percent or
greater.
As the binder, a water-based resin is preferably
used.

As the water-based resin, either a water-soluble
resin or a water-dispersible resin may be suitably used. The
water-soluble resin is not particularly limited and may be
selected depending on the purpose. Examples are polyvinyl
alcohol; a modified polyvinyl alcohol such as anion-modified
polyvinyl alcohol, cation-modified polyvinyl alcohol, and
acetal-modified polyvinyl alcohol; polyurethane; polyvinyl
pyrrolidone; modified polyvinyl pyrrolidone such as polyvinyl
pyrrolidone-vinyl acetate copolymer, vinyl pyrrolidone-
dimethylaminoethyl methacrylate copolymer, quaternized vinyl
pyrrolidone-dimethylaminoethyl methacrylate copolymer, and
vinyl pyrrolidone-methacrylamide propyl trimethyl ammonium
chloride copolymer; cellulose such as carboxymethyl cellulose,
hydroxyethyl cellulose, and hydroxypropylcellulose; modified
cellulose such as cationized hydroxyethyl cellulose;
polyester, polyacrylic acid (ester), melamine resin, and their
modified products; synthetic resin made of polyester-
polyeurethane copolymer; and other substances such as
poly(metha)acrylic acid, poly(metha)acrylamide, oxidized
starch, phosphorylated starch, self-denatured starch,
cationized starch, other modified starches, polyethylene
oxide, polyacrylic acid soda, and alginic acid soda. The
above substances may be used individually or in combination.
Among the above substances, polyvinyl alcohol,
cation-modified polyvinyl alcohol, acetal-modified polyvinyl

alcohol, polyester, polyurethane, and polyester-polyeurethane
copolymer are especially preferable in terms of ink absorbing
property.
The water-dispersible resin is not particularly
limited and may be selected appropriately depending on the
purpose. Examples are polyvinyl acetate, ethylene-polyvinyl
acetate copolymer, polystyrene, styrene-(metha)acrylic ester
copolymer, (metha)acrylic ester polymer, polyvinyl acetate-
(metha)acrylic acid (ester) copolymer, styrene-butadiene
copolymer, ethylene-propylene copolymer, polyvinyl ether, and
silicone-acrylic copolymer. The water-dispersible resin may
contain a cross-linking agent such as methylol melamine,
methylol urea, methylol hydroxypropylene urea, or isocyanate.
The water-dispersible resin may be a self-crosslinking
copolymer containing a unit of N-methylol acrylamide. Two or
more of such water-dispersible resins described above may be
used at the same time.
The added amount of the water-based resin is
preferably 2 to 100 parts by mass and more preferably 3 to 50
parts by mass to 100 parts by mass of the pigment. The added
amount of the water-based resin is determined so that the
liquid absorption property of a recording medium falls within
a desired range.
When a water-dispersible colorant is used as the
coloring agent, the mixing of a cationic organic compound is

optional, and an appropriate cationic organic compound may be
selected and used depending on the purpose. Examples include
primary to tertiary amines that react with sulfonic groups,
carboxyl groups, or amino groups in a direct dye or an acid
dye in a water-soluble ink to form insoluble salt; and a
monomer, oligomer, or polymer of quarternary ammonium salt.
Among these, an oligomer and a polymer are especially
preferable.
Examples of the cationic organic compound include
dimethylamine-epichlorohydrin polycondensate, dimethylamine-
ammonia-epichlorohydrin condensate, poly(trimethyl aminoethyl-
methacrylate methylsulfate) , diallylamine hydrochloride-
acrylamide copolymer, poly(diallylamine hydrochloride-sulfur
dioxide), polyallylamine hydrochlorid, poly(allylamine
hydrochlorid-diallylamine hydrochloride) , acrylarnide-
diallylamine copolymer, polyvinylamine copolymer,
dicyandiamide, dicyandiamide-ammonium chloride-urea-
formaldehyde condensate, polyalkylene polyamine-dicyandiamide
ammonium salt condensate, dimethyl diallyl ammonium chloride,
poly(diallylmethylamine) hydrochloride,
poly(diallyldimethylammoniumchloride),
poly(diallyldimethylammonium chloride-sulfur dioxide),
poly(diallyldimethylammonium chloride-diallyl amine
hydrochloride derivative), acrylamide-diallyldimethylammonium
chloride copolymer, acrylate-acrylamide-diallyl amine

hydrochloride copolymer, polyethylenimine, ethylenimine
derivative such as acrylamine polymer, and modified
polyethylenimine alkylene oxide. The above substances may be
used individually or in combination.
Among those mentioned above, it is preferable to
use a cationic organic compound with a low-molecular weight,
such as dimethylamine-epichlorohydrin polycondensate or
polyallylamine hydrochlorid, in combination with a cationic
organic compound with a relatively-high molecular weight, such
as poly(diallyldimethylammonium chloride). Such a combination
improves image density and reduces feathering compared with a
case where only one substance is used.
The equivalent weight of cation in the cationic
organic compound as measured by the colloid titration method
(performed using polyvinyl potassium sulfate and toluidine
blue) is preferably 3 to 8 meq/g. With the equivalent weight
of cation in this range, good results can be obtained within
the aforementioned range of dry deposit amount.
In the measurement of the equivalent weight of
cation with the aforementioned colloid titration method, the
cationic organic compound is diluted with distillated water so
that the solid content in the solution becomes 0.1% by mass.
No pH control is performed.
The dry deposit amount of the cationic organic
compound is preferably between 0.3 and 2.0 g/m2. If the dry

deposit amount of the cationic organic compound is smaller
than 0.3 g/m2, sufficient improvement in image density may not
be obtained or reduction in feathering may not be achieved.
The surfactant is not particularly limited and
may be appropriately selected depending on the purpose.
Either an anion surfactant, a cation surfactant, an amphoteric
surfactant, or a nonionic surfactant may be used. Among the
above surfactants, a nonionic surfactant is particularly
preferable. Adding a surfactant improves water resistance of
an image and increases image density, and also reduces
bleeding.
Examples of the nonionic surfactants include
higher alcohol ethylene oxide adduct, alkylphenol ethylene
oxide adduct, fatty acid ethylene oxide adduct, polyhydric
alcohol fatty acid ester ethylene oxide adduct, higher
aliphatic amine ethylene oxide adduct, fatty acid amide
ethylene oxide adduct, fatty oil ethylene oxide adduct,
polypropylene glycol ethylene oxide adduct, glycerol fatty
acid ester, pentaerythritol fatty acid ester, sorbitol-
sorbitan fatty acid ester, sucrose fatty acid ester,
polyhydric alcohol alkyl ether, and alkanolamine fatty acid
amide. The above substances may be used individually or in
combination.
The polyhydric alcohol is not particularly
limited and may be appropriately selected depending on the

purpose. Examples are glycerol, trimethylolpropane,
pentaerythrite, sorbitol, and sucrose. With reference to an
ethylene oxide adduct, part of the ethylene oxide may be
substituted with an alkylene oxide such as propylene oxide or
butylene oxide to the extent that water solubility is not
affected. The substitution ratio is preferably 50 percent or
lower. The hydrophile-lipophile balance (HLB) of the nonionic
surfactant is preferably between 4 and 15 and more preferably
between 7 and 13.
The added amount of the surfactant is preferably
0 to 10 parts by mass and more preferably 0.1 to 1.0 part by
mass to 100 parts by mass of the cationic organic compound.
Other components may also be added to the coating
layer to the extent that its advantageous effects are not
undermined. Examples of such other components include
additives such as an alumina powder, a pH adjuster, an
antiseptic agent, and an antioxidant.
The method of forming the coating layer is not
particularly limited and may be appropriately selected
depending on the purpose. One example is a method whereby the
support is impregnated or applied with a coating liquid. The
method of impregnation or application of the coating layer is
not particularly limited and may be selected appropriately
depending on the purpose. For example, a coating machine may
be used. Examples of the coating machine include a

conventional size press, a gate roll size press, a film
transfer size press, a blade coater, a rod coater, an air
knife coater, and a curtain coater. A preferable example from
the viewpoint of cost is a method whereby the support is
impregnated or applied with a coating liquid using a
conventional size press, a gate roll size press, or a film
transfer size press attached to a paper machine so that the
process can be finished on-machine.
The amount of the coating liquid on the support
is not particularly limited and may be appropriately selected
depending on the purpose. Preferably, the solid content of
the coating liquid is 0.5 to 20 g/m2 and more preferably 1 to
15 g/m2. If the solid content is less than 0.5 g/m2, the ink
cannot be sufficiently absorbed, resulting in an overflow of
ink and character bleeding. Conversely, if the solid content
exceeds 20 g/m2, the texture of the paper is adversely
affected, resulting in problems such as the difficulty in
bending of the sheet or writing on it with a writing
instrument.
After the impregnation or application of a
coating liquid, the coating liquid may be dried as needed.
The temperature for this drying process is not particularly
limited and may be appropriately selected depending on the
purpose. Preferably, the temperature is in the range of from
100 to 250 °C.

The recording medium may also have a back layer
formed on the back of the support, and other layers between
the support and the coating layer or between the support and
the back layer. A protective layer may also be provided on
the coating layer. Each of these layers may be composed of
one or more layers.
The recording medium in accordance with the
present embodiment may be commercially available coated paper
for offset printing or coated paper for gravure printing, as
well as a medium used for ink jet recording, as long as their
liquid absorbing property is within the aforementioned range.
Preferably, the basis weight of the recording
medium in accordance with the present embodiment is in the
range of from 50 to 250 g/m2. If the basis weight is less
than 50 g/m2, a transportation defect such as the jamming of
the recording medium in the transportation path becomes more
likely to occur due to lack of strength. If the basis weight
exceeds 250 g/m2, the strength may be too high for the
recording medium to turn a curved part of the transportation
path, also resulting in a transport defect such as the jamming
of the recording medium.
Recording head
Hereafter, an example of a specific recording
head in accordance with the present embodiment is described.

A nozzle plate of the specific recording head is
superior in water or ink repellency, so that, even when ink
with low surface tension is used, ink droplets (i.e., ink
particles) can be formed in a satisfactory manner. This is
due to the fact that the nozzle plate is not wetted too much,
enabling the normal formation of an ink meniscus. When the
meniscus is normally formed, ink does not get pulled in one
direction when ejected. As a result, there is less skewing in
ink ejection, and an image with high dot-position accuracy can
be obtained.
When printing a sheet with low absorbance, the
image quality is gteatly affected by the dot position
accuracy. Namely, because ink does not spread easily on a
sheet with low absorbance, even a small amount of decrease in
dot position accuracy leads to a portion on the sheet that is
not completely filled with ink, i.e., a void. Such an
unfilled portion results in image density nonuniformity or
image density decrease, thus adversely affecting image
quality.
However, because the nozzle plate of the
recording head in accordance with the present embodiment can
provide high dot position accuracy even when the ink has low
surface tension, even a sheet having low absorbance can be
filled with ink. As a result, there is no image density
nonuniformity or image density decrease, so that printed

matter having high image quality can be obtained. Thus, an
image forming method according to an embodiment of the present
invention needs to be used in the absence of the recording
head of the present embodiment.
When ink with a relatively low surface tension is
used, the nozzle plate desirably has excellent water
repellency and ink repellency. This is due to the fact that
by using a nozzle plate having excellent water repellency and
ink repellency, it becomes possible to form an ink meniscus
normally even when the ink has low surface tension, and, as a
result, ink droplets (i.e., ink particles) can be formed in a
satisfactory manner. When the meniscus is normally formed,
the problem of the ink being pulled in one direction upon
ejection can be avoided. As a result, the ink ejection skew
can be reduced and an image with high dot position accuracy
can be obtained.
When printing a medium (sheet) having low
absorbance, the dot position accuracy notably affects image
quality. Specifically, because ink does not easily spread
over a medium with low absorbance, a portion appears on the
medium that is not completely filled with ink, i.e., a void,
if dot position accuracy drops even a little. Such an
unfilled portion leads to image density nonuniformity and a
decrease in image density, thus adversely affecting image
quality.

In accordance with the present embodiment,
because the inkjet head provides high dot position accuracy-
even when ink with low surface tension is used, even a medium
having low absorbance can be fully filled with ink. Thus,
printed matter with high image quality can be obtained having
no image density nonuniformity or image density decrease.
Ink-repellent layer material
The material of the ink-repellent layer may
comprise any material as long as it repels ink. Examples are
fluorine water-repellent material and silicone-based water-
repellent material.
There are many types of fluorine water-repellent
materials. An example is a mixture of perfluoropolyoxetane
and modified perfluoropolyoxetane ("OPTOOL DSX" from Daikin
Industries, Ltd.). Necessary water repellency can be obtained
by depositing it to a thickness of 1-30 A. In an experiment,
no difference was seen in water repellency and wiping
durability when the thickness of OPTOOL DSX was 10, 20, or 30
A. When factors including cost are taken into account, the
thickness is preferably 1 to 20 A. An adhesive tape made of
resin film and applied with adhesive material may be affixed
to the surface of a fluorine water-repellent layer to provide
an auxiliary function during excimer laser processing.

Alternatively, a silicone water-repellent material may be
used.
Examples of silicone water-repellent material
include room-temperature curing liquid silicone resin and
elastomer. Preferably, such a silicone water-repellent
material is applied to a base material surface and left to
stand in the atmosphere at room temperature in order to allow
it to polymerize and cure to form an ink-repellent coating.
The silicone water-repellent material may be thermally cured
liquid silicone resin or elastomer, which may be applied to a
base material surface and heated to cure and form an ink-
repellent coating. Further, the silicone water-repellent
material may be UV curing liquid silicone resin or elastomer,
which may be applied to a base material surface and irradiated
with UV ray to cure and form an ink-repellent coating. The
viscosity of the silicone water-repellent material is
preferably 1,000 cP or lower.
Ink-repellent layer
Surface roughness of the ink-repellent layer is
described. Preferably, the surface roughness Ra of the ink-
repellent layer is 0.2 μm or smaller. By keeping the surface
roughness Ra 0.2 μm or smaller, the amount of ink that remains
after wiping can be reduced.

FIGs. 20 and 21 show cross sections of inkjet
head nozzle plates fabricated in accordance with an
embodiment. In this embodiment, a nozzle plate 2, which is a
base material for an inkjet head, is fabricated by
electroforming of Ni. On the surface of the nozzle plate 2,
there is formed an ink-repellent film 1, which is a silicone
resin coating, having a film thickness of 0.1 μm or greater.
The surface roughness Ra of the ink-repellent film 1 is
preferably 0.2 or smaller. Preferably, the film thickness of
the ink-repellent film 1 is 0.5 μm or greater.
Upon filling with ink 3, a meniscus (liquid
level) P is formed at the boundary between the ink-repellent
film 1, i.e., the silicone resin coating, and the nozzle plate
2, as shown in FIG. 22C.
The ink-repellent film 1 is formed such that the
cross-sectional area of a plane perpendicular to a center line
of the ink discharge opening formed in the inkjet head
gradually increases with increasing distance between the plane
and the base material surface.
Preferably, the profile of the ink-repellent film
1 near the opening is curved.
Preferably, the radius of curvature of the ink-
repellent film near the opening in a cross section taken along
a plane including the center line of the opening is greater
than the thickness of the ink-repellent film.

Preferably, the curve that extends from the edge
of the opening in the ink-repellent film to a region near the
opening in the cross section taken along a plane including the
center line of the opening is substantially circular-arch
shaped. Preferably, the radius of curvature of the arch is
greater than the thickness of the ink-repellent film.
Preferably, in the cross section taken along a
plane including the center line of the opening, a tangent to
the edge of the opening in the ink-repellent film forms an
angle of less than 90° with the surface of the nozzle member
including the edge.
The opening of the nozzle plate 2 is formed in a
substantially circular shape about the center line indicated
by the dotted line in FIGs. 21A through 21C, in a cross
section taken along a plane perpendicular to the center line.
The ink-repellent film 1 is formed on the ink discharge
surface of the nozzle plate 2 such that the cross-sectional
area of the opening in a plane perpendicular to the center
line increases with increasing distance from the nozzle plate
2.
More specifically, the opening of the ink-
repellent film 1 is, as shown in FIG. 21A, the curve at the
opening that extends from the opening edge of the nozzle plate
2 to a portion near the opening has a radius of curvature r.
Preferably, the radius of curvature r is greater than the

thickness d of the ink-repellent film 1 at a portion other
than the opening portion.
The thickness d is a thickness of the ink-
repellent film 1 at a portion other than its rounded portion
at the opening. Preferably, the thickness d may be the
maximum thickness of the ink-repellent film.
Thus, the opening portion of the ink-repellent
film 1 adjacent to the opening of the nozzle plate 2 is
smoothly curved and has substantially no peaks or pointed
portions. In this way, when the nozzle is wiped with a wiper
made of material such as rubber, because there is no pointed
portions that could catch the wiper, the ink-repellent film 1
is prevented from being peeled from the nozzle plate 2.
Preferably, as shown in FIG. 21B, the tangent to
the edge of the opening of the ink-repellent film 1 in the
cross section taken along a plane including the center line of
the opening of the nozzle plate 2 forms an angle 9 of less
than 90° with the surface of the nozzle plate 2 including its
edge adjacent to the opening of the ink-repellent film 1.
Thus, because the angle 9 between the tangent to
the opening edge of the ink-repellent film 1 and the surface
of the nozzle plate 2 is less than 90°, the meniscus (liquid
level) P is stably formed at the boundary between the ink-
repellent film 1 and the nozzle plate 2, as shown in FIG. 21C.

In this way, the probability of the meniscus P being formed at
a different portion can be greatly reduced.
The stable formation of the meniscus enables the
ink to be ejected stably when forming an image with an image
forming apparatus in which an inkjet head including the nozzle
plate 2 is used.
Preferably, a silicone resin that cures at room
temperature, particularly one involving hydrolysis reaction,
is used.
In the following example, SR2411 manufactured by
Dow Corning Toray Co. Ltd. was used.
Table 1 shows the result of evaluation of various
properties of the ink-repellent film 1 in the inkjet head,
including the profile at the edge of the opening of the nozzle
plate 2, the build-up of ink around the nozzle, edge peeling,
and ejection stability.
Table 1

When the edge of the ink-repellent film 1 (at or
near the opening edge) had a substantially pointed portion, a

buildup of ink was observed around the nozzle, and edge
peeling due to wiping occurred.
When the edge was rounded, no buildup of ink was
observed in any of the examples. However, partial peeling of
the edge occurred in a comparative example shown in FIG. 22A
where r 90° as shown in FIG. 22B, the ejection
of droplet was unstable.
An analysis indicates that, as shown in FIG. 22C,
when r 90°, a meniscus (liquid level) P may be
formed at the boundary between the ink-repellent film 1 and
the nozzle plate 2 when filled with ink 3, or a meniscus Q may
be formed at the bulging portion of the ink-repellent film 1'
that extends toward the center of the opening (where the
cross-sectional area perpendicular to the center line of the
opening is minimum). As a result, fluctuations are caused in
ink ejection stability when forming an image in an image
forming apparatus using an inkjet head having such a nozzle
plate 2.
Hereafter, a process of manufacturing the inkjet
head nozzle member according to an embodiment is described.
FIG. 23 shows the ink-repellent film 1 being
formed by applying silicone resin with a dispenser 4 according
to the present embodiment.
The dispenser 4 for applying silicone solution is
disposed on the ink-discharge side of a nozzle 2, which is

made by Ni electroforming. With a predetermined distance
maintained between the nozzle plate 2 and the tip of a needle
5, the dispenser 4 is moved while the silicone is discharged
from the tip of the needle 5. In this way, a silicone resin
coating was selectively formed on the ink discharge surface of
the nozzle plate 2, as shown in FIG. 20 and FIGs. 21A through
21C. The silicone resin used in the present example was the
room-temperature-curing silicone resin SR2411 (by Dow Corning
Toray Co. Ltd.), with the viscosity of 10 mPa.s. It is noted,
however, that some deposition of silicone was observed on the
nozzle openings and the back side of the nozzle plate. The
thickness of the thus selectively formed silicone resin
coating was 1.2 um, and its surface roughness (Ra) was 0.18
urn.
The needle 5 has a coater opening at the tip
which has a width corresponding to the width with which the
nozzle plate 2 is to be coated, as shown in FIG. 24A. Thus,
coating of the necessary portion of the nozzle plate 2 can be
completed in a single scan by the dispenser 4 in a coating
direction.
In other words, the scan for the coating
operation needs to be performed in just one direction, and the
need for changing the scan direction or scanning in the
opposite direction, as shown in FIG. 24B, can be eliminated.

FIG. 24B shows how the nozzle plate 2 is coated
using a conventional needle 5'. Because the tip of the needle
5' in this case is much narrower than the width of the nozzle
plate 2 to be coated, the scan direction needs to be changed
by 90° or reversed in multiple times in order to complete the
coating of the entire area, making it difficult to provide a
coating with a uniform thickness.
In accordance with the present embodiment,
because the coater opening at the tip of the needle 5 has a
width corresponding to the width with which the nozzle plate 2
needs to be coated, it becomes possible to provide a uniform
thickness over the entire surface that needs to be coated,
whereby an accurate surface finish can be achieved.
FIG. 25 illustrates a coating operation performed
by using the dispenser 4 in another embodiment. The present
embodiment differs from the foregoing embodiment illustrated
in FIG. 23 in that silicone is applied while gas 6 is ejected
out of a nozzle opening in the nozzle plate 2. The gas 6 may
be any gas as long as it does not easily chemically react with
the applied silicone. For example, the gas 6 may be air.
By thus performing a coating operation while the
gas 6 is ejected via the nozzle opening, a silicone resin
coating can be formed on the upper surface of the nozzle plate
2 alone excluding the other nozzle opening surfaces.

In another embodiment, similar silicone resin may
be applied without the ejection of the gas 6. In this
embodiment, as shown in FIG. 26, the gas 6 may be ejected via
the nozzle 2 after the silicone resin reached down to a
predetermined depth. In this way, it becomes possible to form
an ink-repellent layer of silicone resin to a desired depth on
the internal surface of the nozzle (such as on the order of
several μm).
Thus, in addition to the above-described ink-
repellent film 1 on the ink discharge surface, a very thin
ink-repellent film la can be formed on the internal surface of
the opening from the opening edge of the nozzle plate 2 down
to a predetermined depth.
The thus fabricated ink-repellent film 1 formed
on the nozzle plate was subjected to wiping with EPDM rubber
(rubber hardness: 50). As a result, the ink-repellent film 1
on the nozzle plate retained good ink repellency after 1000
times of wiping. In another test, a nozzle member formed with
the ink-repellent film was immersed in ink at temperature of
70 'C for 14 days. As a result, the ink-repellent film
retained the same ink repellency as that before the test.
Hereafter, the thickness of the water-repellent
layer film is discussed. FIG. 27 shows an inkjet head
according to an embodiment of the present invention, where a
nozzle opening 44 is formed by excimer laser processing. A

nozzle plate 43 includes a resin member 121 and a high-
stiffness member 125 joined together with thermoplastic cement
126. On the surface of the resin member 121, a SiO2 thin-film
layer 122 and a fluorine water-repellent layer 123 are
successively laminated. A nozzle opening 44 having a required
diameter is formed in the resin member 121. In the high-
stiffness member 125, there is formed a nozzle-communicating
opening 127 that is in communication with the nozzle opening
44. The SiO2 thin-film layer 122 is formed by a relatively
heat-free process, i.e., a process capable of film formation
within a temperature range such that the resin member is not
thermally affected. Suitable examples are sputtering, ion
beam deposition, ion plating, chemical vapor deposition (CVD),
and plasma chemical vapor deposition (P-CVD).
It is advantageous to minimize the film thickness
of the SiO2 thin-film layer 122 to the extent that its
adhesive power can be ensured, from the viewpoint of process
time and material cost. If the film thickness is too much,
problems may develop during the nozzle opening process by an
excimer laser. Specifically, even when the resin member 121
is cleanly processed in the shape of a nozzle opening, part of
the SiO2 thin-film layer 122 may not be sufficiently processed
and remain unprocessed. More specifically, the film thickness
is preferably in the range of from 1 A to 300 A and more
preferably from 10 A to 100 A. In an experiment, sufficient

adhesion was obtained even when the SiO2 film thickness was 30
A and there was no problem in excimer laser processability.
When the film thickness was 300 A, although a small
unprocessed portion remained, there was no practical problems.
When the thickness was beyond 300 A, a rather large
unprocessed portion remained, resulting in such a nozzle
deformity as to render the nozzle unusable.
FIG. 28 shows a configuration of an excimer laser
processing apparatus used for forming a nozzle opening. A
laser oscillator 81 emits an excimer laser beam 82 which is
reflected by mirrors 83, 85, and 88 as it is guided to a
processing table 90. Along the optical path of the laser beam
82 before it reaches the processing table 90, there are
disposed a beam expander 84, a mask 86, a field lens 87, and
imaging optics 8 9 at respectively predetermined positions so
that an optimum beam can reach a processed item 91. The
processed item (nozzle plate) 91, which is disposed on the
processing table 90, receives the laser beam. The processing
table 90, which may consist of a known XYZ table, is
configured such tha.t the processed item 91 can be moved as
required and irradiated at a desired position with the laser
beam. While the laser has been described as being excimer
laser, any type of laser may be used as long as it is a short-
wavelength UV laser capable of abrasion processing.

FIG. 29A through 29F schematically show the steps
of manufacturing a nozzle plate in a process of manufacturing
an inkjet head according to an embodiment of the invention.
FIG. 29A shows a resin film 121 as a base material of a nozzle
forming member. The resin film 121 may comprise a polyimide
film such as Kapton (brand name) by DuPont that contains no
particles. A conventional polyimide film contains particles
of SiO2 (silica), for example, for the sake of ease of
handling (slipperiness) on a roll film handling device.
However, the SiO2 (silica) particles obstruct the process of
nozzle opening formation by an excimer laser and may lead to a
deformation of the nozzle. For this reason, a polyimide film
that does not contain SiO2 (silica) particles is preferable.
FIG. 29B shows the step of forming the SiO2 thin-
film layer on the Surface of the resin film 121. The SiO2
thin-film layer 122 is formed preferably by sputtering in a
vacuum chamber. The thickness of the SiO2 thin-film layer 122
is preferably in the range of from several A to 200 A. In
this example, the thickness of the SiO2 thin-film layer 122 is
between 10 and 50 A. As regards the sputtering method, it has
been learned that by performing Si sputtering and then
bombarding the Si Surface with 02 ions, the adhesion of the
SiO2 thin-film layer 122 to the resin film 121 can be improved
and a uniform and dense film can be obtained. In this way,

the wiping durability of a water-repellent layer can be
improved.
FIG. 29C shows the step of applying a fluorine
water-repellent 123a. Although application methods such as
spin coating, roll coating, screen printing, and spray coating
may be used, vacuum deposition is preferable to improve the
adhesion of the water-repellent layer. Vacuum deposition is
preferably performed in the same vacuum chamber after the
formation of the SiO2 thin-film layer 122, as shown in FIG.
30B. This is believed due to the fact that if the work is
taken out of the vacuum chamber after the formation of the
SiO2 thin-film layer 122, impurities may adhere to the surface
of the SiC>2 thin-film layer 122 to reduce adhesion. While
various fluorine water-repellent materials are known, a
fluorine amorphous compound such as perfluoropolyoxetane,
modified perfluoropolyoxetane, or a mixture thereof may be
preferably used to obtain sufficient water repellency. The
aforementioned "OPTOOL DSX" by Daikin Industries, Ltd. may
also be referred to as alkoxysilane terminus modified
perfluoropolyether.
FIG. 29D shows the step in which the plate is
left to stand in the atmosphere, whereby the fluorine water-
repellent 123a chemically binds to the SiO2 thin-film layer
122 via the moisture in the atmosphere, thereby forming the
fluorine water-repellent layer 123.

FIG. 29E shows the step of affixing an adhesive
tape 124 to the coated surface of the fluorine water-repellent
layer 123. The adhesive tape 124 needs to be affixed such
that no air bubbles are present between the adhesive tape 124
and the fluorine water-repellent layer 123. If bubbles are
present, the quality of a nozzle opening formed in a position
where bubbles are present may be degraded by undesired matter
during processing.
FIG. 29F shows the step of processing the nozzle
opening 44 by excimer laser irradiation from the polyimide
film side. After the nozzle opening 44 is formed, the
adhesive tape 124 is removed. In the foregoing, description
of the high-stiffness member 125, which is used to increase
the rigidity of the nozzle plate 43 as described with
reference to FIG. 27, has been omitted. In another
embodiment, the high-stiffness member 125 may be appropriately
provided between the steps of FIGs. 29D and 29E.
FIG. 30 schematically shows an apparatus 200 that
may be used to manufacture an inkjet head according to an
embodiment of the present invention. The apparatus 200 is
designed to implement a technique called "MetaMode®" developed
by Optical Coating Laboratory, Inc. (OCLI) of the U.S.A. The
MetaMode® process may be used to make
antireflection/antifouling films on displays. As shown, a
drum 201 is surrounded at four locations by an Si sputter

station 202, an 02 ion gun station 203, an Nb sputtering
station 204, and an OPTOOL vapor deposition station 205, which
are all disposed in a chamber that can be vacuumized. First,
the Si sputtering station 202 performs Si sputtering. The O2
ion gun station 203 then bombards the Si with 02 ions to form
SiO2. Then, Nb is provided by the Nb sputter station 204 and
OPTOOL DSX is deposited by the OPTOOL vapor deposition station
205 as needed. In the case of an antireflection film,
deposition takes place after a necessary number of layers of
Nb and SiO2 with predetermined thicknesses are laminated.
Because the function of an antireflection film is not
necessary in the case of various embodiments of the present
invention, Nb is not required and only one layer each of SiO2
and OPTOOL DSX needs to be formed. By using this apparatus,
it becomes possible to deposit OPTOOL DSX in the same vacuum
chamber after the formation of the SiO2 thin-film layer 122,
as mentioned above.
In the following, the critical surface tension of
the ink-repellent layer is described. The critical surface
tension of the ink-repellent layer is preferably 5 to 40 mN/m
and more preferably 5 to 30 mN/m. When the critical surface
tension is greater than 30 mN/m, ink wets the nozzle plate too
much over a long period of use, whereby problems such as ink
discharge skew and abnormal ink drop formation may occur after
repeated printing. When the critical surface tension exceeds

40 mN/m, ink wets the nozzle plate too much from an initial
period, and problems such as ink discharge skew and abnormal
ink drop formation may occur. In an experiment, ink-repellent
materials shown in Table 2 below were applied to an aluminum
substrate, which was then heated to prepare nozzle plates
having ink-repellent layers. Table 2 shows the result of
measuring the critical surface tension of those water-
repellent layers.
Table 2

The critical surface tension can be determined by
the Zisman method. Specifically, droplets of liquids with
known surface tensions are placed onto the ink-repellent
layer, and their contact angles 9 are measured. By plotting
the surface tension of each liquid on the x axis and cosØ on
the y axis, a line sloping to the right (Zisman Plot) is
obtained.
The critical surface tension YC is the surface
tension at which Y = 1 (9=0). The critical surface tension
can be also obtained by other methods, such as the Fowkes

method, the Owens and Wendt method, and the Van Oss method.
In an experiment, inkjet heads were fabricated using nozzle
plates having an ink-repellent layer by the same method as
described above. The cyan ink according to Manufactured
Example 1 (which is described later) was ejected from the
inkjet head. When the trajectory of the ink was recorded in
video and observed, normal particles of the ink were formed in
all of the cases of the nozzle plates, indicating the good
discharge stability of the inkjet heads.
Hereafter, an example of a specific ink according
to an embodiment is described.
Ink
The ink according to the present embodiment
contains at least water, a colorant, and a humectant. It may
also contain a penetrant, a surfactant, and other components
as needed.
The surface tension of the ink is preferably 15
to 40 mN/m and more preferably 20 to 35 mN/m. When the
surface tension is less than 15 mN/m, the ink may wet the
nozzle plate so much that ink droplets are not properly
formed, or significant bleeding may occur on the recording
medium, thus preventing the stable discharge of the ink. When
the surface tension is greater than 40 mN/m, the ink may fail

to penetrate the recording medium sufficiently, resulting in
beading or an extended drying time.
The surface tension of the ink may be measured
with the CBVP-Z surface tensiometer from Kyowa Interface
Science Co., Ltd., using a platinum plate at temperature of
25 °C.
Colorant
Preferably, at least one of a pigment, a dye, and
a colored particle is used as the aforementioned colorant.
Preferably, the aforementioned colored particle
comprises an aqueous dispersion of polymer particles
containing at least a pigment or a dye as a colorant.
That the polymer particles "contain" a colorant
means that the colorant is either encapsulated in the polymer
particles, the colorant is adsorbed on the surface of the
polymer particles, or both. Not all of the colorant needs to
be encapsulated in or adsorbed on the polymer particles; the
colorant may be dispersed in an emulsion as long as the
advantageous effects of various embodiments of the present
invention are not adversely affected. The colorant is not
particularly limited and may be suitably selected depending on
the purpose, as long as it is water-insoluble or poorly water-
soluble and can be adsorbed on the polymer particles.

"Water-insoluble" or "poorly water-soluble"
indicates that no more than 10 parts by mass of the colorant
can be dissolved in 100 parts by mass of water at a
temperature of 20 °C. "Dissolved" means that no separation or
sediment of the colorant is identified in the upper or the
lower layer of the aqueous solution by visual inspection.
Preferably, the volume average particle size of a
polymer particle (colored particle) containing the colorant is
0.01 to 0.16 μm in the ink. When the volume average particle
size is less than 0.01 μm, the polymer particles tend to flow,
resulting in increased bleeding or decrease in light
resistance. When the volume average particle size is more
than 0.16 μm, the nozzle may be clogged or color development
of the ink may be inhibited.
Examples of the colorant include a water-soluble
dye, an oil-soluble dye, a disperse dye, and a pigment. From
the viewpoint of absorbability and encapsulation, an oil-
soluble dye or a disperse dye is preferable. From the
viewpoint of light resistance of an image formed, a pigment is
preferable.
Preferably, the amount of the dye that is
dissolved in an organic solvent, such as a ketone solvent, is
2 g/1 or more and more preferably 20 to 600 g/1 from the
viewpoint of efficient impregnation in the polymer particles.

The aforementioned water-soluble dye may comprise
a dye classified as being an acid dye, a direct dye, a basic
dye, a reactive dye, or a food dye in the Color Index.
Preferably, a dye with high water-resistance and high light
resistance is used.
Humectant
The humectant is not particularly limited and may
be appropriately selected depending on the purpose. A
suitable example is at least one selected from a polyol
compound, a lactam compound, a urea compound, and a
saccharide.
Penetrant
The aforementioned penetrant may comprise a
water-soluble organic solvent such as a polyol compound or a
glycol ether compound. Preferably, a polyol compound or a
glycol ether compound having a carbon number of eight or
larger may be suitably used.
If the carbon number of the polyol compound is
less than eight, sufficient permeability may not be obtained,
resulting in staining the recording medium during both-side
printing. This may also result in decrease in character
quality or image density due to the insufficient spread of ink
over the recording medium and poorer filling of the pixels.

Preferable examples of the polyol compound having
the carbon number of eight or greater include 2-ethyl 1,3-
hexanediol (solubility: 4.2% (25 *C)), and 2,2,4-trimethyl
1,3-pentanediol (solubility: 2.0% (25 °C) ) .
The added amount of the penetrant is not
particularly limited but may be appropriately selected
depending on the purpose. Preferably, the added amount of the
penetrant is 0.1 to 20% by mass and more preferably 0.5 to 10%
by mass.
Surfactant
The surfactant is not particularly limited and
may be appropriately selected depending on the purpose.
Examples are an anion surfactant, a nonionic surfactant, an
amphoteric surfactant, and a fluorine surfactant.
A preferable example of the fluorinated
surfactant is represented by the following general formula:
CF3CF2(CF2CF2)m-CH2CH2O(CH2CH2O)nH (A)
where m is an integer of from 0 to 10, and n is an integer of
from 1 to 40.
Examples of the fluorinated surfactant include a
perfluoroalkyl sulfonic acid compound, a perfluoroalkyl
carvone compound, a perfluoroalkyl phosphoric ester compound,

a perfluoroalkyl ethylene oxide adduct, and a polyoxyalkylene
ether polymer compound having a perfluoroalkylether group as a
side chain. Among those, a polyoxyalkylene ether polymer
compound having a perfluoroalkylether group as a side chain is
particularly preferable from the safety standpoint because it
has a low foaming property and a low fluorine compound
bioaccumulation potential, which is seen as a problem in
recent years.
Examples of the perfluoroalkyl sulfonic acid
compounds include perfluoroalkyl sulfonic acid and
perfluoroalkyl sulfonate.
Examples of the perfluoroalkyl carvone compounds
include perfluoroalkyl carboxylic acid and perfluoroalkyl
carboxylate.
Examples of the perfluoroalkyl phosphoric ester
compounds include perfluoroalkyl phosphoric ester and a salt
of perfluoroalkyl phosphoric ester.
Examples of the polyoxyalkylene ether polymer
compounds having a perfluoroalkylether group as a side chain
include a polyoxyalkylene ether polymer having a
perfluoroalkylether group as a side chain, a sulfate ester
salt of a polyoxyalkylene ether polymer having a
perfluoroalkylether group as a side chain, and a salt of a
polyoxyalkylene ether polymer having a perfluoroalkylether
group as a side chain.

Counter ions of salts in the above fluorinated
surfactants include Li, Na, K, NH4, NH3CH2CH2OH, NH2 (CH2CH2OH) 2,
and NH(CH2CH2OH)3.
The fluorinated surfactant may be appropriately
synthesized, or a commercially available product may be used.
Examples of the commercially available
fluorinated surfactant include Surflon S-lll, S-112, S-113, S-
121, S-131, 53-132, S-141, S-145 (Asahi Glass Co., Ltd.);
Fluorad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430,
FC-431 (Sumitomo 3M Limited); Megafac F-470, F1405, F-
474(Dainippon Ink and Chemicals, Incorporated); Zonyl TBS,
FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (DuPont); FT-
110, FT-250, FT-251, FT-400S, FT-150, FT-400SW (NEOS Co.
Ltd.); and PF-151N (Omnova Solutions, Inc.). Among the above,
Zonyl FS-300, FSN, FSN-100, and FSO (DuPont) are particularly
preferable from the viewpoint of reliability and color
development.
Other components
The aforementioned other components are not
particularly limited and may be appropriately selected as
needed. Examples are a resin emulsion, a pH adjuster, an
antiseptic or a fungicide, a rust inhibitor, an antioxidant,
an ultraviolet absorber, an oxygen absorber, and a light
stabilizer.

Resin emulsion
The resin emulsion is a dispersion of resin
particles in water as a continuous phase. It may contain a
dispersing agent such as a surfactant as needed.
Generally, the content of resin particles as a
disperse phase component (i.e., the content of the resin
particles in the resin emulsion) is preferably 10 to 70% by
mass. The average particle size of the resin particles is
preferably 10 to 1000 nm and more preferably 20 to 300 ran from
the viewpoint of use in an inkjet recording apparatus.
The added amount of resin particles in the resin
emulsion with respect to the ink is preferably 0.1 to 50% by
mass, more preferably 0.5 to 20% by mass, and further more
preferably 1 to 10% by mass. When the added amount is less
than 0.1% by mass, sufficient improvements in clogging
resistance or discharge stability may not be obtained. When
the added amount is more than 50% by mass, the preservation
stability of the ink may be reduced.
The viscosity of the ink is preferably 1 to 30
cPs and more preferably 2 to 20 cPs at temperature of 20 °C.
When the viscosity is higher than 20 cPs, sufficient discharge
stability may not be obtained.
The pH of the ink is preferably 7 to 10.

The color of the ink is not particularly limited
and may be appropriately selected depending on the purpose.
Examples are yellow, magenta, cyan, and black. A multi-color
image can be formed by using an ink set of two or more of such
colors. A full-color image can be formed by using a set of
inks of all of the colors.
In the following, exemplary ink preparations are
described. However, the present invention is not limited to
any of those examples.
Preparation Example 1
- Preparation of dispersion of polymer particles containing
copper phthalocyanine pigment -
The atmosphere of a 1L flask equipped with a
mechanical stirrer, a thermometer, a nitrogen gas inlet tube,
a reflux tube, and a dropping funnel was substituted
sufficiently with nitrogen gas. The 1L flask was then charged
with 11.2 g of styrene, 2.8 g of acrylic acid, 12.0 g of
lauryl methacrylate, 4.0 g of polyethylene glycol
methacrylate, 4.0 g of styrene macromer (Toagosei Co., Ltd.,
brand name: AS-6), and 0.4 g of mercaptoethanol, and the
temperature was raised to 65 °C. Then, a mixture solution of
100.8 g of styrene, 25.2 g of acrylic acid, 108.0 g of lauryl
methacrylate, 36.0 g of polyethylene glycol methacrylate, 60.0
g of hydroxyethyl methacrylate, 36.0 g of styrene macromer

(Toagosei Co., Ltd., brand name: AS-6), 3.6 g of
mercaptoethanol, 2.4 g of azobisdimethylvaleronitrile, and 18
g of methyl ethyl ketone was added dropwise into the flask
over a period of 2.5 hours.
After the dripping was completed, a mixture
solution of 0.8 g of azobisdimethylvaleronitrile and 18 g of
methyl ethyl ketone was added dropwise into the flask over a
period of 0.5 hours. After the resulting solution was matured
for 1 hour at the temperature of 65 °C, 0.8 g of
azobisdimethylvaleronitrile was added, and the solution was
further matured over a period of 1 hour. After the reaction
was over, 364 g of methyl ethyl ketone was put into the flask,
obtaining 800 g of a polymer solution with a concentration of
50% by mass. A portion of the obtained polymer solution was
dried and then measured by gel permeation chromatography
(standard: polystyrene, solvent: tetrahydrofuran). The
weight-average molecular weight (Mw) was 15,000.
Next, 28 g of the obtained polymer solution, 26 g
of copper phthalocyanine pigment, 13.6 g of 1 mol/L potassium
hydroxide solution, 20 g of methyl ethyl ketone, and 30 g of
ion-exchanged water were mixed and stirred sufficiently. The
resulting substance was kneaded 20 times using a tripole roll
mill (NR-84A from Noritake Co., Limited). The obtained paste
was put in 200 g of ion-exchanged water. After sufficiently
stirring, methyl ethyl ketone and water were distilled away

with an evaporator. As a result, 160 g of a blue polymer
particle dispersion having a solid content of 20.0% by mass
was obtained.
The average particle size (D50%) of the resultant
polymer particles as measured with a particle size
distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was
93 ran.
Preparation Example 2
- Preparation of dispersion of polymer particles containing
dimethyl quinacridone pigment -
A purple-red polymer particle dispersion was
prepared in the same manner as in Preparation Example 1 with
the exception that the copper phthalocyanine pigment was
replaced with C. I. Pigment Red 122.
The average particle size (D50%) of the obtained
polymer particles as measured with a particle size
distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was
127 ran.
Preparation Example 3
- Preparation of dispersion of polymer particles containing
monoazo yellow pigment -
A yellow polymer particle dispersion was prepared
in the same manner as in Preparation Example 1 with the

exception that the copper phthalocyanine pigment was replaced
with C. I. Pigment Yellow 74.
The average particle size (D50%) of the resultant
polymer particles as measured with a particle size
distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.) was
7 6 nm.
Preparation Example 4
- Preparation of dispersion of carbon black processed with
sulfonating agent -
150 g of a commercially available carbon black
pigment (Printex #85, Degussa) was well mixed in 400 ml of
sulfolane. After micro-dispersing with a beads mill, 15 g of
amidosulfuric acid was added to the solution, which was then
stirred for 10 hours at 140-150 °C. The resultant slurry was
put in 1000 ml of ion-exchanged water, and the solution was
centrifuged at 12,000 rpm. As a result, a surface-treated
carbon black wet cake was obtained. The obtained carbon black
wet cake was dispersed again in 2,000 ml of ion-exchanged
water. After adjusting the pH with lithium hydroxide, the
solution was desalted/condensed using a ultrafilter, obtaining
a carbon black dispersion with a pigment concentration of 10%
by mass, which was then filtered with a nylon filter with an
average pore diameter of 1 p.

The average particle size (D50%) of the particles
in the carbon black dispersion as measured with a particle
size distribution analyzer (Microtrac UPA, Nikkiso Co., Ltd.)
was 80 ran.
Manufacture Example 1
- Preparation of cyan ink -
20.0% by mass of the dispersion of polymer
particles containing a copper phthalocyanine pigment according
to Preparation Example 1, 23.0% by mass of 3-methyl-l , 3-
butanediol, 8.0% by mass of glycerin, 2.0% by mass of 2-ethyl-
1, 3-hexanediol, 2.5% by mass of FS-300 (DuPont) as a
fluorinated surfactant, 0.2% by mass of Proxel LV (Avecia KK)
as an antiseptic or a fungicide, 0.5% by mass of 2-amino-2-
ethyl-1,3-propanediol, and an appropriate amount of ion-
exchanged water were mixed to a total of 100% by mass. The
mixture was then filtered using a membrane filter with an
average pore diameter of 0.8 μm.
Manufacture Example 2
- Preparation of magenta ink -
20.0% by mass of the dispersion of polymer
particles containing a dimethyl quinacridone pigment according
to Preparation Example 2, 22.5% by mass of 3-methyl-l,3-
butanediol, 9.0% by mass of glycerin, 2.0% by mass of 2-ethyl-

1, 3-hexanediol, 2.5% by mass of FS-300 (DuPont) used as a
fluorinated surfactant, 0.2% by mass of Proxel LV (Avecia KK)
used as an antiseptic or a fungicide, 0.5% by mass of 1-amino-
2,3-propanediol, and an appropriate amount of ion-exchanged
water were mixed to a total of 100% by mass. The mixture was
then filtered using a membrane filter with an average pore
diameter of 0.8 urn.
Manufacture Example 3
- Preparation of yellow ink -
20.0% by mass of the dispersion of polymer
particles containing a monoazo yellow pigment according to
Preparation Example 3, 24.5% by mass of 3-methyl-l,3-
butanediol, 8.0% by mass of glycerin, 2.0% by mass of 2-ethyl-
1, 3-hexanediol, 2.5% by mass of FS-300 (DuPont) as a
fluorinated surfactant, 0.2% by mass of Proxel LV (Avecia KK)
as an antiseptic or a fungicide, 0.5% by mass of 2-amino-2-
methyl-1,3-propanediol, and an appropriate amount of ion-
exchanged water were mixed to a total of 100% by mass. The
mixture was then filtered with a membrane filter with an
average pore diameter of 0.8 μm.
Manufacture Example 4
- Preparation of black ink -

20.0% by mass of the carbon black dispersion
according to Preparation Example 4, 22.5% by mass of 3-methyl-
1,3-butanediol, 7.5% by mass of glycerin, 2.0% by mass of 2-
pyrrolidone, 2.0% by mass of 2-ethyl-l, 3-hexanediol, 2.5% by
mass of FS-300 (DuPont) as a fluorinated surfactant, 0.2% by
mass of Proxel LV (Avecia KK) as an antiseptic or a fungicide,
0.2% by mass of choline, and an appropriate amount of ion-
exchanged water were mixed to a total of 100% by mass. The
mixture was then filtered with a membrane filter with an
average pore diameter of 0.8 urn.
The surface tension and viscosity of the inks
according to Manufacture Examples 1 through 4 were measured as
described below. The results are shown in Table 3.
Table 3

Measurement of viscosity
The viscosity was measured at 25 °C, using the R-
500 Viscometer from Toki Sangyo Co., Ltd. under the conditions
of cone 1° 34', * R24, 60 rpm, and 3 minutes later).
Measurement of surface tensionx

The surface tension was measured at 25 °C, using
a surface tensiometer (CBVP-Z from Kyowa Interface Science Co.,
Ltd.) and a platinum plate.
Fabrication of support member
A support member with a basis weight of 7 9 g/m2
was fabricated by making paper with a fourdrinier from a 0.3%
by mass slurry with the following composition. In the size
press step of the papermaking process, an oxidized starch
solution was applied to the support member such that the
attached amount of solid content on the support member was 1.0
g/m2 per side.
• Leaf bleached kraft pulp (LBKP) 80 parts by mass
• Needle bleached kraft pulp (NBKP) 20 parts by mass
• Precipitated calcium carbonate (brand name: TP-121, Okutama
Kogyo Co., Ltd.) 10 parts by mass
• Aluminum sulfate 1.0 part by mass
• Amphoteric starch (brand name: Cato3210, Nippon NSC Ltd.)
1.0 part by mass
■ Neutral rosin size agent (brand name: NeuSize M-10, Harima
Chemicals, Inc.) 0.3 part by mass
• Yield improving agent (brand name: NR-11LS, HYMO Co.,Ltd.)
0.O2 part by mass

Manufacture Example 5
- Fabrication of Recording Medium 1 -
70 parts by mass of clay as a pigment in which
the proportion of particles with the diameter of 2 una or
smaller was 97% by mass, 30 parts by mass of heavy calcium
carbonate with an average particle size of 1.1 um, 8 parts by
mass of styrene-butadiene copolymer emulsion as an adhesive
having a glass-transition temperature (Tg) of -5 °C, 1 part by
mass of phosphoric esterified starch, and 0.5 part by mass of
calcium stearate as an aid were mixed. Water was further
added, thereby preparing a coating liquid with a solid content
concentration of 60% by mass.
The obtained coating liquid was applied to both
sides of the above support member using a blade coater so that
the attached solid amount per side of the support member was 8
g/m2. After hot-air drying, supercalender process was
performed, thereby obtaining a Recording Medium 1.
Manufacture Example 6
- Fabrication of Recording Medium 2 -
70 parts by mass of clay as a pigment in which
the proportion of particles with the diameter of 2 μm or
smaller was 97% by mass, 30 parts by mass of heavy calcium
carbonate with an average particle size of 1.1 μm, 7 parts by
mass of styrene-butadiene copolymer emulsion as an adhesive

having a glass-transition temperature (Tg) of -5 °C, 0.7 part
by mass of phosphoric esterified starch, and 0.5 part by mass
of calcium stearate as an aid were mixed. Water was further
added, thereby preparing a coating liquid with a solid content
concentration of 60% by mass.
The obtained coating liquid was applied to both
sides of the above support member using a blade coater so that
the attached solid amount was 8 g/m2 per side. After hot-air
drying, supercalender process was performed, thereby obtaining
a Recording Medium 2
Example 1
- Ink set, recording medium, and image recording -
An Ink Set 1 of the black ink according to
Manufacture Example 4, the yellow ink according to Manufacture
Example 3, the magenta ink according to Manufacture Example 2,
and the cyan ink according to Manufacture Example 1 was
prepared a conventional method.
Using Ink Set 1 and Recording Medium 1, printing
was performed using a 300 dpi prototype drop-on-demand printer
having nozzles with resolution of 300 dpi, at an image
resolution of 600 dpi and the maximum ink droplet of 18 p1.
The total amount of the secondary color was limited to 14 0% to
control the attached amount of ink. A solid image and
characters were printed, obtaining an image print.

Example 2
- Ink set, recording medium, and image recording -
Printing was performed in the same manner as in
Example 1 with the exception that Recording Medium 2 was used
as a recording medium, obtaining an image print.
Example 3
- Ink set, recording medium, and image recording -
Printing was performed in the same manner as in
Example 1 with the exception that a coated paper for gravure
printing (brand name: Space DX, basis weight = 56 g/m2, Nippon
Paper Industries Co., Ltd.;hereafter referred to as a
Recording Medium 3) was used as a recording medium, obtaining
an image print.
Comparative Example 1
- Ink set, recording medium, and image recording -
Printing was performed in substantially the same
manner as in Example 1 with the exception that a commercially
available coated paper for offset printing (brand name: Aurora
Coat, basis weight - 104.7 g/m2, Nippon Paper Industries Co.,
Ltd.; to be hereafter referred to as a Recording Medium 4) was
used as a recording medium, obtaining an image print.

Comparative Example 2
- Ink set, recording medium, and image recording -
Printing was performed in the same manner as in
Example 1 with the exception that a commercially available
matt coated paper for inkjet printing (brand name: Superfine,
Seiko Epson Corporation; to be hereafter referred to as a
Recording Medium 5) was used as a recording medium, thereby
obtaining an image print.
Measurement of transferred amounts of pure water and cyan ink
with dynamic scanning absorptometer
For each of the above Recording Media 1-5, the
transfer amount for pure water and cyan ink were measured
using a dynamic scanning absorptometer (K350 series, Type D,
Kyowa Co., Ltd.). The transfer amounts for the contact times
of 100 ms and 400 ms were obtained by interpolation of
measured values of the transfer amounts in adjacent contact
times. The results are shown in Table 4.
Table 4



The image print of each of Examples 1 through 3
was evaluated in terms of beading, bleeding, spur mark, and
glossiness as described below. The results are shown in table
5.
Table 5

Beading
The degree of beading in a solid green image
portion of each image print was visually observed and
evaluated according to the following criteria.
Excellent: No beading is observed and image is uniformly
printed.
Good: Beading is slightly observed.
Poor: Beading is clearly observed.
Bad: Excessive beading is observed.
Bleeding

The degree of bleeding of a black character in
the yellow background in each image print was visually
observed and evaluated according to the following evaluation
criteria.
Excellent: No bleeding is observed and print is clear.
Good: Bleeding is slightly observed.
Poor: Bleeding is clearly observed.
Bad: Outline of the character is obscured by bleeding.
Spur mark
The degree of spur marks in each printed image
was visually observed and evaluated according to the following
criteria.
Excellent: No spur mark is observed.
Good: Spur mark is slightly observed.
Poor: Spur mark is clearly observed.
Bad: Excessive spur mark is observed.
Evaluation of glossiness
The 60° specular gloss (JIS Z8741) of a solid
cyan image portion of each image print was measured.
The results shown in Table 5 indicate that
Examples 1 through 3, each of which contains at least water, a

colorant, and a humectant, and each of which is based on a
combination of an ink having the surface tension of 20 to 35
mN/m at 25 °C with a recording medium having the ink transfer
amount as measured with a dynamic scanning absorptometer of 4
to 15 ml/m2 at the contact time of 100 ms and 7 to 20 ml/m2 at
the contact time of 4 00 ms, are superior to Comparative
Examples 1 and 2 in all of the respects of beading, bleeding,
spur mark, and glossiness.
Although the invention has been described in
detail with reference to certain embodiments, variations and
modifications exist within the scope and spirit of the
invention as described and defined in the following claims.
The present application is based on the Japanese
Priority Application No. 2007-182626 filed July 11, 2007, the
entire contents of which are hereby incorporated by reference.

CLAIMS
1. An image forming apparatus configured to move
a recording head including plural nozzles in a horizontal scan
direction in order to record a recording medium by discharging
ink via the nozzles onto the recording medium, the image
forming apparatus comprising:
a detection unit configured to detect whether one
or more expendable supplies required for image formation are
specific expendable supplies; and
a notifying unit configured to notify an operator
upon detection by the detection unit of a non-specific
expendable supply, and configured to suggest to a user that an
image forming method that is currently set be changed.
2. An image forming apparatus configured to move
a recording head including plural nozzles in a horizontal scan
direction in order to record a recording medium by discharging
ink via the nozzles onto the recording medium, the image
forming apparatus comprising:
a detection unit configured to detect whether one
or more expendable supplies required for image formation are
specific expendable supplies;
a notifying unit configured to notify an operator
upon detection of a non-specific expendable supply; and

an image forming method changing unit configured
to automatically change an image forming method that is
currently set.
3. The image forming apparatus according to
claim 2, wherein the image forming method changing unit is
configured to allow the operator to make a setting regarding
whether the changing of the image forming method is to be made
automatically or not.
4. The image forming apparatus according to any
one of claims 1 through 3, wherein the detection unit is
configured to detect a non-specific expendable supply
automatically using an automatic detection unit or manually
based on an operator input.
5. The image forming apparatus according to
claim 4, wherein the automatic detection unit is configured to
examine an ink cartridge having a storage unit configured to
store information about an ink use period, wherein the
automatic detection unit detects that the ink is not a
specific expendable supply when the use period of the ink is
longer than a specific period.

6. The image forming apparatus according to
claim 4, wherein the automatic detection unit is configured to
examine an ink cartridge having a storage unit configured to
store information about an accumulated amount of the ink used,
wherein the automatic detection unit detects that the ink is
not a specific expendable supply when the accumulated amount
of the ink used is greater than a specific amount.
7. The image forming apparatus according to
claim 4, wherein the automatic detection unit is configured to
examine the recording head and identify a unique ID stored in
a storage unit provided in the recording head, wherein the
automatic detection unit detects that the recording head is
not a specific expendable supply when the unique ID does not
correspond to a specific ID at the start of recording.
8. The image forming apparatus according to
claim 4, wherein the automatic detection unit is configured to
examine a transport path in which a sensor for detecting a
thickness of the recording medium is provided, wherein the
automatic detection unit detects that the recording medium is
not a specific expendable supply when the thickness detected
by the sensor at the start of recording is not within a
specific range of values.

9. The image forming apparatus according to
claim 4, wherein the automatic detection unit is configured to
examine a transport path in which a sensor for detecting a
basis weight of the recording medium is provided, wherein the
automatic detection unit detects that the recording medium is
not a specific expendable supply when the basis weight
detected by the sensor at the start of recording is not within
a specific range of values.
10. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves reducing the speed of movement of the
carriage.
11. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves increasing the number of scan passes
made by the recording head for image formation.
12. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves reducing the number of droplet sizes
for gradation expression.

13. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves changing a bidirectional printing to a
one-directional printing.
14. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves reducing the number of lines in
halftone processing.

15. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves reducing the amount of ink that
attaches to the recording medium per unit area.
16. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves eliminating a use of a color ink when
generating colors of black and gray.
17. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves reducing an amount of a color ink used
for generating colors of black and gray.

18. The image forming apparatus according to any-
one of claims 1 through 3, wherein the changing of the image
forming method involves extending a standby time between
successive vertical scan operations.
19. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves extending a standby time for each of
plural pages that are recorded successively.
20. The image forming apparatus according to any
one of claims 10 through 19, wherein the changing of the image
forming method is carried out near a border of the recording
medium when a borderless printing is performed on the
recording medium.
21. The image forming apparatus according to any
one of claims 1 through 3, wherein the changing of the image
forming method involves extending a standby time that is
provided in an interval between a switching of recording
surfaces when printing both top and bottom surfaces of the
recording medium successively.

An image forming apparatus enables the output of
a high-quality image even when an expendable supply, such as ink, recording head, or recording sheet other than a specific expendable supply, such as one designated by a manufacturer,
is used. The image forming apparatus includes a carriage for moving a recording head having plural recording nozzles in a horizontal scan direction. The recording head discharges ink
onto a recording medium. A detection unit detects whether one or more expendable supplies required for image formation is a specific expendable supply. Upon detection of a non-specific expendable supply, a notifying unit notifies an operator and suggests that the image forming method be changed.

Documents:

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Patent Number 269696
Indian Patent Application Number 625/KOLNP/2009
PG Journal Number 45/2015
Publication Date 06-Nov-2015
Grant Date 02-Nov-2015
Date of Filing 17-Feb-2009
Name of Patentee RICOH COMPANY, LTD.
Applicant Address 3-6, NAKAMAGOME 1-CHOME, OHTA-KU, TOKYO
Inventors:
# Inventor's Name Inventor's Address
1 KIKUCHI, NAOKI 14-27-505, SAKURADAI 3-CHOME, ISEHARA-SHI, KANAGAWA, 259-1132
2 HIRANO, MASANORI 1253-7, SHIMOOGINO, ATSUGI-SHI, KANAGAWA, 243-0203
PCT International Classification Number B41J 2/01,B41J 2/205
PCT International Application Number PCT/JP2008/062126
PCT International Filing date 2008-06-27
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2007-182626 2007-07-11 Japan