Title of Invention

APPARATUS AND METHOD FOR OPTICALLY EXAMINING SECURITY DOCUMENTS

Abstract An apparatus for optical analysis of value documents (BN) possesses a recording area (14) in which a value document (BN) is located during analysis, and a spectrographic device (16). The latter has a spatially dispersing optical device (29) for at least partly decomposing optical radiation coming from the recording area (14) into spectrally separate spectral components propagating in different directions according to the wavelength, a detection device (30) locally resolving in at least one spatial direction for detecting the spectral components, and a collimating and focusing optic (28) for collimating the optical radiation directed from the recording area (14) onto the dispersing device (29) and for focusing at least some of the spectral components formed by means of the dispersing optical device (29) onto the detection device (30).
Full Text Apparatus and method for optical analysis of value documents
[6001] This invention relates to an apparatus and method for optical analysis of
value documents and to apparatuses for processing value documents with an inventive
analysis apparatus.
[0002] Value documents are understood here to mean objects that represent for ex-
ample a monetary value or an authorization and are therefore not to be producible at
will by unauthorized persons. They therefore have features that are not easy to pro-
duce, in particular to copy, whose presence is an indication of authenticity, i.e. produc-
tion by an authorized body. Important examples of such value documents are chip
cards, coupons, vouchers, checks and in particular bank notes.
[0003] An important class of features of such value documents are optically recog-
nizable features, which include in particular features for which luminescent substances
are used that emit luminescence radiation with a characteristic spectrum upon irradia-
tion with optical radiation of a given wavelength. Optical radiation is understood here
to mean electromagnetic radiation in the ultraviolet, visible or infrared range of the
electromagnetic spectrum.
[0004] For checking authenticity, a value document can be irradiated with suitable
optical radiation. It is then checked by means of a suitable sensor device whether the
optical radiation excites luminescence radiation at given places on or in the value
document, for which purpose optical radiation emanating from the value document is
analyzed spectrally. Such a check should proceed as fast as possible and with simple
equipment; to give apparatuses in which an authenticity check is carried out on the
basis of luminescence features as space-saving a design as possible, it is desirable that
an apparatus for checking luminescence features is constructed very compactly but
still possesses a sufficient spectral resolution and sensitivity to permit recognition of
the presence of the characteristic luminescence spectrum.
[0005] The present invention is therefore based on the object of providing an appa-
ratus for optical analysis of value documents that permits a very compact, space-

saving structure, and of providing a corresponding method for analyzing value docu-
ments.
[0006] This object is achieved according to a first alternative by an apparatus for
optical analysis of value documents with a recording area in which a value document
is located during analysis, and a spectrographic device for analysis of optical radiation
coming from the recording area. The spectrographic device comprises a spatially dis-
persing optical device for at least partly decomposing optical radiation coming from
the recording area into spectrally separate spectral components propagating in different
directions according to the wavelength, a detection device locally resolving in at least
one spatial direction for, in particular locally resolved, detection of the spectral com-
ponents, and a collimating and focusing optic for collimating the optical radiation di-
rected from the recording area onto the dispersing device and for focusing at least
some of the spectral components formed by the dispersing device onto the detection
device.
[0007] This object is further achieved according to the first alternative by a method
for optical analysis of a value document wherein optical radiation emanating from the
value document is shaped into a parallel ray bundle by an optic, in particular a colli-
mating and focusing optic, the ray bundle is decomposed at least partly into spectral
components of different wavelengths which propagate in different directions in de-
pendence on the wavelength, at least some of the spectral components are focused by
the optic onto a detection device, and the spectral components focused onto the detec-
tion device are detected.
[0008] The inventive apparatus according to the first alternative uses for analyzing a
value document in the recording area a spectral decomposition of the optical radiation
emanating from the recording area, in particular a value document in the recording
area, which will hereinafter also be designated as detection radiation. For this purpose,
it has the spatially dispersing device which decomposes incident optical radiation at
least partly into spectral components which propagate in spatially different directions
depending on the wavelength of the particular spectral component. The dispersing de-
vice only needs to be able to work in a wavelength range given in dependence on the

given value documents. The presence of optical radiation in a certain spatial direction
and thus of the corresponding spectral component is detected by means of the locally
resolving detection device, whose detection signals can be sent for at least partial re-
cording of a spectrum of the radiation emanating from the recording area to an evalua-
tion device and evaluated there. The recording area can be selected here in particular
such that a given transport device for the value documents, for example driven belts,
can transport value documents to be analyzed into the recording area.
[9009] The detection device can have in particular a plurality of detection elements
for detecting optical radiation impinging in each case thereon so as to form corre-
sponding detection signals, which are preferably disposed in the form of a row. How-
ever, it is also possible to use a two-dimensional array of detection elements.
[0010] The apparatus is characterized in particular by the fact that only one optic,
the collimating and focusing optic, is used for performing two functions, namely firstly
for collimating the optical radiation emanating from the recording area, in particular a
value document therein, and secondly for focusing the spectrally decomposed compo-
nents onto the detection device.
[0011] The proposal of this surprisingly simple structure is based on the observation
that for the purpose of checking value documents a merely moderate spectral resolu-
tion, which can be simply obtained with the proposed means, is sufficient in compari-
son with scientific spectroscopy.
[0012] The use of only one optic for collimation and focusing further permits an at
least singly folded beam path after the optic, which permits good spectral resolution at
the same as a low space requirement.
[0013] Compared with another conceivable solution, namely the use of an imaging
grating, there is the further advantage that the dispersing device and the collimating
and focusing optic are comparatively simple components which are thus easy and eco-
nomical to produce.

[0014] Furthermore, it is only necessary to adjust the collimating and focusing op-
tic, while in constructions with separate optics for collimation and focusing two optics
must be adjusted.
[0015] A further advantage of the proposed arrangement is that a very high numeri-
cal aperture of the beam path between the collimating and focusing optic can be ob-
tained.
[0016] The collimating and focusing optic can fundamentally be configured at will.
For example, it can contain at least one imaging mirror as the collimating and focusing
optical component. However, to permit a beam path as simple as possible and an eco-
nomical structure to be obtained, the collimating and focusing optic preferably has at
least one lens, which may be a refractive lens or a diffractive optical lens.
[0017] To obtain good spectral resolution and permit a simple evaluation and cali-
bration of the detection device, the collimating and focusing optic in the apparatus can
be achromatic. This is understood to mean that said optic is corrected chromatically in
the spectral range in which the spectrographic device works; the focal points for two
different wavelengths in the given spectral range preferably lie one on the other. The
use of an achromatic optic has the advantage that the radiation emanating from the
recording area and directed onto the dispersing device is, in good approximation, not
additionally split spectrally and in particular chromatic aberrations occur at the most to
a small extent upon focusing of the spectral components onto the detection device. To
come as close as possible, when using an entrance diaphragm or an equivalent device,
to the theoretical limit of resolution given by the size of the diaphragm opening, for
example the slit width in the case of a slit diaphragm, it is desirable that the circle of
confusion of a pixel on the detection device resulting from color aberration in the spec-
tral range to be detected or the working spectral range of the apparatus remains smaller
than preferably 1/5, particularly preferably 1/10, of the size of the diaphragm opening.
[0018] The detection device can fundamentally be disposed and aligned at will rela-
tive to the beam path of the radiation from the recording area. However, it is preferred
in the apparatus that the direction of the radiation from the recording area falling on
the collimating and focusing optic is inclined relative to a surface spanned by the spec-

tral components in the area between the collimating and focusing optic and the detec-
tion device. This embodiment permits a particularly space-saving arrangement of the
detection device. In particular in the case that the spectral components span a plane
as the surface, the detection device can comprise a row of detection elements extend-
ing in the direction of the plane, said row extending above or below a plane given by
the beam path of the radiation emanating from the recording area. It is likewise pre-
ferred that the direction of the radiation from the recording area between the collimat-
ing and focusing optic and the dispersing device is inclined relative to a surface
spanned by the spectral components in the area between the collimating and focusing
optic and the dispersing device.
[0019] Further, in the apparatus, a geometric projection of the radiation coming
from the recording area onto a surface spanned and limited by the spectral components
falling on the detection device can be located in said surface, at least in a portion im-
mediately before the collimating and focusing optic. This results in a particularly
space-saving arrangement.
[0020] Further, there can be disposed in the apparatus in the beam path from the re-
cording area to the spectrographic device a diaphragm disposed in the caustic surface
of the collimating and focusing optic and an imaging optic for imaging the recording
area onto the diaphragm. The diaphragm can be embodied in particular by a diaphragm
body with a diaphragm opening or else by a beam-deflecting element or deflecting
element, for example a mirror or a beam splitter, with a surface constituting a dia-
phragm and at least partly reflecting the detection radiation.
[0021] Particularly preferably, the detection device can then be spaced from the
diaphragm in a direction extending orthogonally to the direction in which the spectral
components are split. This results in a particularly compact structure of the apparatus.
[0022] The diaphragm is preferably located laterally beside the detection device
here, regarded in the direction of the spatial splitting of the spectral components. Lat-
erally can also mean above or below here, depending on the alignment of the apparatus
to the ground. If a detection device with a row of detection elements is used, a perpen-
dicular from the diaphragm onto the row preferably intersects the row itself.

[0023] The dispersing device used can fundamentally be any optical component or a
combination of optical components that splits incident radiation at least partly into
spectral components propagating in different directions according to the particular
wavelength. For example, a prism can be used. However, the dispersing optical device
of the apparatus preferably has an optical grating. The spectral components used can
preferably be the spectral components of the first diffraction order, although it is also
possible to use higher diffraction orders. This embodiment has the advantage that grat-
ings are readily and economically available for any ranges of the optical spectrum, in
particular for the infrared range. The grating may be any kind of grating, produced for
example mechanically, lithographically or holographically.
[0024] The grating is preferably a reflection grating which directs the spectral com-
ponents immediately back into the collimating and focusing optic, thereby permitting a
particularly compact structure to be obtained.
[0025] Further, it is preferred that the grating is so aligned and so selected relative
to the detection device that the radiation of the zeroth diffraction order does not fall on
the detection device. This has the advantage that the zeroth diffraction order can op-
tionally be used for other analyses. The grating used can be in particular an echelon
grating. The echelon grating used is particularly preferably a blazed grating. This has
the advantage that corresponding configuration and arrangement of the grating per-
mits the radiation of the diffraction order given for forming the spectral components to
have a particularly high intensity. The grating can be aligned with its dispersively act-
ing line structure orthogonally to the optical axis of the collimating and focusing optic.
In this case the radiation emanating from the recording area must then fall on the grat-
ing at an inclination against the optical axis. However, line structures of the grating are
preferably inclined from the optical axis of the collimating and focusing optic. This
permits a simple mutual adjustment of all components disposed between the recording
area and the collimating and focusing optic.
[0026] Further, the dispersing optical device can be itself reflective or integrated
with a reflective element, thereby reducing the number of optical components. How-
ever, it is also possible that the dispersing device used is an optical device dispersing

in transmission, in which case a deflecting element, for example a mirror, is provided
for reflecting the beam components generated by the device into the collimating and
focusing optic.
[0027] In a particularly preferred development, the detection device has at least two
edge detection elements which are so disposed that at least part of the detection beam
path extends therebetween. The detection beam path from the recording area to the
dispersing device extends thus at least partly through the detection device, which re-
sults in an advantageously space-saving structure.
[0628] This space-saving structure does not only result in the apparatus according to
the first alternative or upon use of the collimating and focusing optic, however.
[0029] The object is instead achieved according to a second alternative more gener-
ally also by an apparatus for optical analysis of value documents with a recording area
in which a value document is located during analysis, and a spectrographic device,
comprising a spatially dispersing optical device for at least partly decomposing optical
radiation coming from the recording area along a detection beam path into spectrally
separate spectral components propagating in different directions according to the
wavelength,
[0030] and a detection device locally resolving in at least one spatial direction for
detecting the spectral components which has at least two edge detection elements
which are so disposed that at least part of the detection beam path extends therebe-
tween.
[0031] The detection device can in both alternatives have not only the two stated
edge detection elements but also further detection elements which are disposed in a
row in each case following the detection elements. The edge detection elements need
not differ, except for their position, from any other detection elements present, al-
though this is possible. The result is then a detection device with two detector rows of
detection elements disposed along a row. The detector rows constitute a gap through
which at least part of the detection beam path runs. The two edge detection elements
are disposed on each side of the gap.

[0032] A particularly compact structure results in both alternatives when the appara-
tus is so configured that in the area of the two edge detection elements the detection
beam path extends parallel to a surface determined by a beam path of the spectral
components. In particular, the detection beam path after the two edge detection ele-
ments and the beam paths of the spectral components can extend at least partly in a
plane, resulting in a particularly flat structure.
[0033] The dispersing device can fundamentally be configured in an apparatus ac-
cording to the second alternative as described in the first alternative, whereby the
changed beam paths must be taken into account. In particular, the dispersing device
can act reflectively. If no collimating and focusing optic is used, it is particularly pref-
erable in an apparatus according to the second alternative that the spatially dispersing
optical device has an imaging dispersing element which focuses optical radiation that
has passed from the recording area between the edge detection elements, split into
spectral components for at least one given spectral range, onto the detection device,
preferably the detection elements thereof including the edge detection elements. This
embodiment offers in particular the advantage that only few parts need to be used.
[0054] For the dispersing device of the apparatus according to the second alterna-
tive, the statements on that of the first alternative apply accordingly. In particular, the
dispersing optical device can preferably have an optical grating which is preferably an
echelon grating, whose steps are so selected that the radiation of the zeroth diffraction
order does not fall on the detection device. The use of a grating permits a particularly
variable adjustment of the splitting of the spectral components. Furthermore, the grat-
ing can be simply executed as a reflection grating, resulting in a structure with few
elements.
[0035] If the grating is a line grating, the line structures of the grating preferably ex-
tend orthogonally to the detection beam path immediately before the optical grating.
This permits the spectral components to be directed onto the detection elements of the
detection device again.
[0036] In the area between the two edge detection elements, no spectral component
is detected. It is therefore preferred in an apparatus according to one of the two alterna-


tives that a beam path from the spatially dispersing device to the detection device ex-
tends such that a spectral component of a given wavelength is directed between the
two edge detection elements. In particular, the detection device, or the detection ele-
ments thereof, and the dispersing device can for this purpose be disposed relative to
each other in a suitable manner. The wavelength can be given depending on the pur-
pose of use of the apparatus. If the apparatus is to be used for example for measuring
luminescence radiation or Raman radiation, the given wavelength is preferably the
wavelength of the excitation radiation with which the luminescence radiation or Ra-
man radiation is excited.
[0037] In particular for checking bank notes it is often desirable to be able to detect
radiation in a spectrally resolved manner in different ranges of the optical spectrum, in
particular in the visible and infrared parts of the optical spectrum. In an apparatus ac-
cording to one of the two alternatives it is therefore preferred that the two edge detec-
tion elements have in each case different spectral detection ranges. If the detection de-
vice has two detector rows at whose opposite ends the two edge detection elements are
disposed, the detection elements of both rows preferably have in each case the same
spectral detection ranges, so that the detection ranges of the detection elements differ
on the opposite sides of the gap. In particular, one detector row can have detection
elements for detecting radiation at least in the visible range of optical radiation, for
example based on silicon, and the other can have detection elements for detecting ra-
diation in the infrared range of optical radiation, preferably with wavelengths greater
than 900 nm, based on indium-gallium-arsenide semiconductors. This offers the ad-
vantage of a spectrally particularly broadband detection while requiring little space. In
particular, the disadvantage can be overcome that detection elements based on silicon
possess too little sensitivity for practical detection purposes in the spectral range with
wavelengths greater than 1100 nm.
[0038] To permit a good signal-to-noise ratio to be obtained at recording times as
short as possible, it is further preferred in an apparatus according to one of the two al-
ternatives that at least some detection elements of the detection device have a sensitive
surface of at least 0.1 mm2. This can in particular yield considerable advantages in


comparison with the use of CCD elements with respect to the signal-to-noise ratio and
the recording time.
[0039] Particularly preferably, the detection device has, in particular in addition to
the two edge detection elements, detection elements for simultaneously generating de-
tection signals which represent a property, in particular the intensity, of the radiation
falling thereon. This embodiment offers the advantage that the detection signals gener-
ated from the spectral components by the detection elements can be recorded simulta-
neously, which allows a high recording speed or repetition rate of the measurement, in
particular in comparison with CCD arrays. In particular, the detection elements can be
readable independently of each other or generate detection signals independently of
each other.
[0040] In this case it is particularly preferable that the apparatus according to one of
the two alternatives has an evaluation device connected to the detection elements via
signal connections which records detection signals formed by means of the detection
elements, in parallel. Such an apparatus can preferably be used to record at least one
spectrum, preferably a temporal sequence of spectra, after emission of only one pulse,
which is advantageous in particular for analyzing luminescence phenomena.
[0041] It proves to be very advantageous here if the evaluation device records
detection signals from the detection elements of the detection device in dependence on
a signal which represents the output of a pulse of illumination radiation onto the re-
cording area. This permits an analysis of luminescence, for example of a bank note, to
be effected very simply and at the same time exactly, since the time interval between
pulse output and recording can be specified.
[0042] To permit a reduction of the signal-to-noise ratios of the detection by extra-
neous radiation to be limited or even avoided, there is disposed in the apparatuses ac-
cording to the two alternatives, preferably in the detection beam path between the re-
cording area and the spatially dispersing optical device, a filter which suppresses ra-
diation in a given spectral range. The given spectral range can again be selected in de-
pendence on the use of the apparatus. If the apparatus is used for example for measur-
ing luminescence radiation or Raman radiation, the given spectral range can be for


example the spectral range of the excitation radiation with which the luminescence
radiation or Raman radiation is excited. It is also possible,, however, to use filters that
pass radiation only in a spectral range given by the spectral components to be detected
but at least strongly attenuate radiation outside the range.
[0043] Further, it is preferred in an apparatus according to one of the two alterna-
tives that there is provided in the beam path between the recording area and a space
formed by the two edge detection elements, or the collimating and focusing optic, a
beam splitter by means of which part of the optical radiation from the recording area
can be coupled out of a beam path to the collimating and focusing optic. This has the
advantage that the radiation emanating from the recording area can not only be spec-
trally analyzed, but also used at least partly for other analyses, for example for imaging
purposes or for spectrum analysis of other spectral ranges not analyzable by means of
the spectrographic device. In a particularly preferred embodiment, the above-
mentioned filter is constituted by the beam splitter, which is accordingly configured
for this purpose.
[0044] Depending on the type of illumination, the apparatus does not necessarily
have to possess an entrance slit or, more generally, an entrance diaphragm or another
device performing the same function. However, the apparatus according to one of the
two alternatives preferably has at least one component performing the function of an
entrance diaphragm.
[0045] Thus the apparatus can for example have an entrance diaphragm located in
the plane of the detection elements at least approximatively, i.e. in the field depth
range of the imaging elements disposed after the entrance slit along the beam path.
Said entrance diaphragm can be provided as a separate component, but it is preferably
constituted by the detection elements and/or one or more carriers for the detection
elements. This results in a particularly simple structure. Upon use of a beam splitter or
a beam-deflecting element in the detection beam path from the recording area to the
dispersing device, the beam splitter or beam-deflecting element, for example a mirror,
can likewise perform the function of the entrance slit. A particularly loss-free transfer
of the detection radiation with simultaneous shielding from extraneous radiation can

be obtained in an apparatus according to one of the two alternatives preferably by a
light guide for guiding the detection radiation being disposed in the detection beam
path, the end thereof being disposed between the two edge detection elements. The end
can preferably likewise perform the function of an entrance diaphragm. A light guide
is understood here in particular also to mean any element for guiding and optionally
also deflecting optical radiation which is recordable in a spectrally resolved manner by
means of the dispersing device and the detection device. Depending on the execution
of these devices, the light guide can thus be designed in particular also for guiding in-
visible optical radiation in the infrared range.
[0046] Although an illumination of the recording area with ambient light is funda-
mentally conceivable, an apparatus according to one of the two alternatives preferably
has a radiation source for emitting optical illumination radiation in at least one given
wavelength range into the recording area. The illumination radiation can be used here
as reflected light or transmitted light.
[0047] An apparatus according to one of the two alternatives preferably has at
least one semiconductor radiation source for illuminating the recording area. The use
of semiconductor radiation sources has a number of advantages. Semiconductor radia-
tion sources thus as a rule have a considerably longer life than other radiation sources.
Moreover, they require less input power for emitting optical radiation of a given power
and generate less waste heat, which considerably reduces the requirements for cooling
the device. Furthermore, semiconductor radiation sources are available for different
wavelength ranges, so that excitation radiation can be generated simply in given wave-
length ranges. Semiconductor radiation sources to be used are for example light-
emitting diodes or superluminescent diodes, but preferably semiconductor lasers.
Semiconductor radiation sources are understood here to mean not only components
based on inorganic semiconductors but also ones based on organic substances, in par-
ticular OLEDs.
[0048] Upon use of an illumination of the recording area in reflected light, the illu-
mination radiation can fundamentally be radiated onto the value document at an incli-
nation therefrom. However, it is preferred that there is disposed in the beam path from

the recording area to the spectrographic device a beam flitter via which optical radia-
tion from the semiconductor radiation source passes, in particular is directed, into or
onto the recording area. This has the advantage that the illumination radiation can be
directed onto the value document orthogonally, so that less scattered radiation occurs
that could hinder detection. It is particularly preferable to use a dichroic beam splitter
for separating radiation in the area of the illumination radiation passing into the re-
cording area from the detection radiation emanating from the value document and ar-
ranged for spectral decomposition, in a given wavelength range, which can be selected
for example in dependence on at least one optical feature of the value document. This
increases the signal-to-noise ratio during detection.
[0049] A further subject of the invention is an apparatus for processing value docu-
ments with an inventive apparatus according to one of the two alternatives for analyz-
ing value documents and a transport path for value documents to be processed which
leads into and/or through the recording area. The transport path can have in particular
a transport device for transporting the value documents, for example driven belts. In
particular, processing apparatuses that can be used are apparatuses for counting and/or
sorting bank notes, automatic tellers for accepting and dispensing value documents, in
particular bank notes, and apparatuses for checking the authenticity of value docu-
ments.
[0050] The invention will hereinafter be explained further by way of example with
reference to the drawings. The figures show:
Fig. 1 a schematic representation of a bank-note sorting apparatus.
Fig. 2 a schematic plan view of an apparatus for analyzing bank notes according
to a first preferred embodiment of the invention,
Fig. 3 a schematic, partial side view of the apparatus in Fig. 2,
Fig. 4 a schematic plan view of an apparatus for analyzing bank notes according
to a second preferred embodiment of the invention,
Fig. 5 a schematic, partial side view of the apparatus in Fig. 4,

Fig. 6 a schematic plan view of an apparatus for analyzing bank notes according
to a further preferred embodiment of the invention,
Fig. 7 a schematic, partial side view of the apparatus in Fig. 6,
Fig. 8 a schematic plan view of an apparatus for analyzing bank notes according
to yet another preferred embodiment of the invention,
Fig. 9 a schematic, partial side view of the apparatus in Fig. 8,
Fig. 10 a schematic plan view of an apparatus for analyzing bank notes according
to a further preferred embodiment of the invention,
Fig. 11 a schematic, partial sectional view of the apparatus in Fig. 10,
Fig. 12 a schematic perspective view of a detector arrangement with a light guide
of the apparatus in Fig. 10,
Fig. 13 a schematic plan view of an apparatus for analyzing bank notes according
to yet another embodiment of the invention; and
Fig. 14 a schematic representation of an arrangement of detection elements with
different widths.
[0051] Fig. 1 shows as an example of an apparatus for processing value docu-
ments a bank-note sorting apparatus 1 with an analysis apparatus according to a first
preferred embodiment of the invention.
[0052] The bank-note sorting apparatus 1 has in a housing 2 an input pocket 3 for
bank notes BN into which bank notes BN to be processed can be supplied as bundles
either manually or automatically, optionally after a previous debanding, and then form
a stack there. The bank notes BN inserted into the input pocket 3 are removed singly
from the stack by a singler 4 and transported by means of a transport device 5, which
defines a transport path, through a sensor device 6 which serves to analyze the bank
notes. The sensor device 6 has in this exemplary embodiment a plurality of sensor
modules accommodated in a common housing. The sensor modules serve to check the

authenticity, state and nominal value of the checked bank notes BN. After traversing
the sensor device 6 the checked bank notes BN are output in sorted fashion in depend-
ence on the analysis results or test results of the sensor device 6 and on given sorting
criteria via gates 7, which are in each case switchable back and forth between two dif-
ferent positions via gate-switching signals, and associated spiral slot stackers 8 into
output pockets 9, from which they can be either manually removed or automatically
carried off. The control of the bank-note sorting apparatus 1, in particular the conver-
sion of analysis signals from the sensor device 6 into gate-switching signals for the
gates 7, is effected by means of a control device 10.
[0053] As mentioned above, the sensor device 6 has in this exemplary embodiment
different sensor modules, of which only the sensor module 11, an apparatus for analyz-
ing value documents, in the example bank notes BN, according to a preferred em-
bodiment of the invention, designated hereinafter as the analysis apparatus, is shown in
the figures and described more exactly hereinafter. The sensor modules for recogniz-
ing the state, i.e. the fitness for circulation, and the nominal value or denomination of
the bank notes BN are usual sensor modules known to the person skilled in the art and
therefore need not be described more precisely.
[0054] The analysis apparatus 11 is designed in this exemplary embodiment for de-
tecting and analyzing luminescence radiation which is excited upon illumination of
given bank notes with optical radiation of a given wavelength, in the example in the
infrared range of the spectrum.
[0055] The analysis apparatus 11 has a sensor housing 12 with a disk 13 transparent
to the optical radiation used for analysis, which seals a window to a recording area 14
in which a bank note BN is at least partly located during an analysis. The sensor hous-
ing 12 with the disk 13 is so configured and in particular sealed that unauthorized ac-
cess to the components contained therein is not possible without damaging the sensor
housing 12 and/or the disk 13.
[0056] The recording area 14 delimited among other things by the arrangement and
properties of the optical components of the analysis apparatus 11 is limited on the side
opposite the sensor housing 12 by a fundamentally optional plate 33, so that a bank

note BN can be transported, by means of the transport device 5 not shown in Fig. 2,
past the disk 13 in a direction T extending orthogonally to the drawing plane in Fig. 2.
[0057] The analysis apparatus 11 has an illumination device 15 for emitting illumi-
nation radiation into the recording area 14 and in particular onto a value document, in
the example a bank note BN, located at least partly in the recording area 14, and a
spectrographic device 16 for analysis and in particular spectrally resolved detection of
optical radiation emanating from the recording area 14 or a value document therein. In
the example, the detection radiation comprises luminescence radiation in a wavelength
range given by the type of value document, for example infrared luminescence radia-
tion. This optical radiation emanating from the recording area 14 in the direction of the
disk 13 will be hereinafter also designated as detection radiation. A detection optic 17
serves to couple optical radiation passing from the recording area 14 through the disk
13 into the sensor housing 12, i.e. the detection radiation, into the spectrographic de-
vice 16.
[0058] The illumination device 15 has a semiconductor radiation source 18 in the
form of a semiconductor laser which, in the example, emits optical radiation in the
visible range, and an illumination optic. In other exemplary embodiments the semi-
conductor laser can also be designed to emit radiation in the infrared range. The illu-
mination optic possesses, in an illumination beam path, a first collimator optic 19 for
forming an illumination beam or parallel illumination ray bundle 20 from the optical
radiation emitted by the semiconductor radiation source 18, a dichroic beam splitter 21
which is reflective to the radiation of the illumination beam or illumination ray bundle
20 and deflects the illumination beam or illumination ray bundle 20 by 90°, in the ex-
ample, onto the disk 13, and a first condenser optic 22 for focusing the illumination
radiation through the disk 13 likewise constituting part of the illumination optic into
the recording area 14, in particular a value document BN in the recording area 14.
[0059] The detection optic 17 comprises, along a detection beam path extending
from the recording area 14 or the value document BN therein to the spectrographic
device 16 and thereinto, besides the disk 13 the first condenser optic 22 which gathers
radiation emanating from a point on the value document BN in the recording area 14

into a parallel ray bundle, the beam splitter 21 which is transparent to the radiation to
be supplied to the spectrographic device 16 but filters illumination radiation passing
into the detection beam path as scattered radiation out of the detection beam path by
reflection, and a second condenser optic 23 for focusing the parallel detection radiation
onto an entrance opening of the spectrographic device 16. Between the second con-
denser optic 23 and the spectrographic device 16 there are optionally disposed a filter
24 for filtering undesirable spectral components out of the detection beam path, in par-
ticular in the wavelength range of the illumination radiation, and a deflecting element
25, in the example a mirror, for deflecting the detection radiation by a given angle, in
the example 90°. In other exemplary embodiments, the filter 24 can be disposed in the
parallel beam path before the second condenser optic 23. This has the advantage that
interference filters can be simply used, for example.
[0060] The spectrographic device 16 has an entrance diaphragm 26 with a dia-
phragm opening 27 which is slit-shaped in the exemplary embodiment, whose longitu-
dinal extension extends at least approximatively orthogonally to the plane defined by
the detection beam path.
[0061] Detection radiation entering through the diaphragm opening 27 is bundled
by a collimating and focusing optic 28, which is achromatic in the example, of the
spectrographic device 16. The collimating and focusing optic 28 is shown in the fig-
ures only symbolically as a lens, but is actually frequently executed as a combination
of lenses. That said optic is achromatic is understood to mean that it is corrected with
respect to chromatic aberrations in the wavelength range in which the spectrographic
device 16 works. A corresponding correction in other wavelength ranges is unneces-
sary. The entrance diaphragm 26 and the collimating and focusing optic 28 are so dis-
posed that the diaphragm opening 27 is located at least in good approximation in the
caustic surface of the collimating and focusing optic 28 on the entrance-diaphragm
side.
[0062] The spectrographic device 16 further has a spatially dispersing device 29, in
the example an optical grating, which decomposes incident detection radiation, i.e.

optical radiation coming from the recording area, at least partly into spectrally separate
spectral components propagating in different directions according to the wavelength.
[0063] A detection device 30 of the spectrographic device 16 is used for detection
of the spectral components that is locally resolving in at least one spatial direction.
Detection signals formed upon detection are supplied to an evaluation device 31 of the
spectrographic device 16, which records the detection signals and performs a compari-
son of the recorded spectrum with given spectra on the basis of the detection signals.
The evaluation device 31 is connected to the control device 10 to transmit the result of
the comparison thereto via corresponding signals.
[0064] The spatially dispersing device 29 is, in the present example, a reflection
grating with a line structure whose lines extend parallel to a plane through the longitu-
dinal direction of the diaphragm opening 27 and an optical axis of the collimating and
focusing optic 28. The line spacing is so selected that the detection radiation can be
spectrally decomposed in a given spectral range, in the example in the infrared. The
dispersing device 29 is for this purpose so aligned that the separate spectral compo-
nents, in the example the first diffraction order, are focused by the collimating and fo-
cusing optic 28 onto the detection device 30. To obtain as good a signal-to-noise ratio
as possible, the line spacing and the position of the dispersing device 29 are so se-
lected that spectrally undecomposed components of the detection radiation, in the ex-
ample the zeroth diffraction order, do not fall into the collimating and focusing optic
28 but onto a radiation trap not shown in the figures, for example a plate absorbent to
the detection radiation.
[0065] The detection device 30 has a row-type arrangement of detection elements
32 for the spectral components, for example a row of CCD elements, which is aligned
at least approximatively parallel to the direction of spatial splitting of the spectral
components, i.e. here the surface S spanned by the spectral components, in this case
more precisely a plane. The plane S is illustrated in Fig. 3 by a dashed line.
[0066] To obtain as compact a structure as possible, the dispersing device 29 is
firstly inclined in two directions from the detection device 30 and the direction of inci-
dent detection radiation between the collimating and focusing optic and the reflective

component causing a folding of the beam path, here the dispersing device 29. Since the
direction of the detection radiation between the collimating and focusing optic 28 and
the reflective component, i.e. the dispersing device 29, extends parallel to the optical
axis O of the collimating and focusing optic 28 in the exemplary embodiment, the pla-
ne reflection grating 29 and thus also the line structure thereof is firstly inclined from
the optical axis O of the collimating and focusing optic 28 in the plane of the detection
beam path. Therefore the surface S, in the example a plane, generated by the spectral
components is inclined by the angle β from the direction of the detection radiation or
the optical axis O of the collimating and focusing optic at least in the area between the
dispersing device 29 and the collimating and focusing optic 28. In particular, a normal
onto the plane reflection grating 29 in the plane of the detection beam path is inclined
by an angle |3 from the optical axis O of the collimating and focusing optic 28 (cf. Fig.
3). Secondly, the dispersing device 16, more precisely the perpendicular of incidence
for specular reflection, i.e. here the normal onto the plane of the line structure of the
reflection grating 29, is inclined by an angle a from the direction of the detection ra-
diation or the optical axis O between the collimating and focusing optic 28 and the
dispersing device 29.
[0067] Secondly, the row of detection elements 32 of the detection device 30 is dis-
posed at least approximatively in a plane with the diaphragm opening 27 and in a di-
rection orthogonal to the plane S defined by the directions of propagation of the spec-
tral components, spaced from the diaphragm opening 27, in Fig. 3 above the dia-
phragm opening 27. In Figures 2 and 3 the entrance diaphragm 26 and the receiving
surfaces of the detection elements 32 are shown for clarity's sake spaced apart parallel
to the focal plane of the collimating and focusing optic 28, but they are actually lo-
cated substantially in a common plane in this example. The diaphragm opening 27 is
located approximately in the middle of the row, regarded in the direction parallel to the
row of detection elements 32.
[0068] It thus also results, as to be taken from Fig. 2, that in the portion between the
entrance diaphragm 26 and the collimating and focusing optic 28, i.e. in particular also
immediately before the collimating and focusing optic 28, a geometric projection of
the detection radiation coming from the recording area 14 onto a surface A spanned

and limited by the spectral components falling on the detection device 30, said surface
being trapezoidal in this case, is located in said surface. This results in a particularly
space-saving arrangement.
[0069] In this exemplary embodiment, the detection device 30, the entrance dia-
phragm 26, the collimating and focusing optic 28 and the dispersing device 29 are so
configured and disposed that they are located in a circular cylindrical spatial area
whose cylinder axis is given by the optical axis of the collimating and focusing optic
28, and whose cylinder diameter by the diameter of the collimating and focusing optic
28, or that of the lens or largest lens therein. The length of the circular cylindrical spa-
tial area is preferably smaller than 50 mm, in the example 40 mm. There thus results a
particularly small space requirement for the spectrographic device, while at the same
time a large numerical aperture in comparison with the extension can be obtained.
[0070] For optical analysis of a value document, here a bank note BN in the re-
cording area 14, the value document is illuminated with illumination radiation, in the
example optical radiation suitable for exciting luminescence radiation from the semi-
conductor radiation source 18, and the optical radiation emanating from the value
document, here luminescence radiation, is shaped by the detection optic 17 and the
collimating and focusing optic 28 into a parallel detection ray bundle. The latter is de-
composed at least partly into spectral components of different wavelengths which
propagate in different directions in dependence on the wavelength. In Fig. 2 the zeroth
diffraction order which is reflected without spectral splitting is shown by a continuous
line, and spectral components given by the first diffraction order by dotted and dashed
lines for two different wavelengths. The spectral components are focused by the colli-
mating and focusing optic 28 onto the detection device 30, more precisely the row of
detection elements 32, and detected thereby in spatially resolved fashion. Each detec-
tion element 32 is associated with a direction of propagation and thus to a spectral
component in dependence on the wavelength. The evaluation device 31 therefore
forms in each case from the positions of the detection elements 32 and the particular
intensities recorded thereby a spectrum which can then be compared with comparison
spectrums.

[0071] A second preferred embodiment in Figures 4 and 5 differs from the first ex-
emplary embodiment firstly in the type of dispersing device and secondly in the ar-
rangement of the illumination device. The same reference signs are therefore used for
the same components and the comments on the first exemplary embodiment apply ac-
cordingly here too.
[0072] Instead of the plane reflection grating 29 there is now used a blazed grating
29' whose steps are so inclined that the first diffraction order arises in the direction of
specular reflection. This permits a higher intensity of the spectral components to be
obtained.
[0073] In the first exemplary embodiment the illumination device can fundamen-
tally be rotated around the optical axis of the first condenser optic 22 without the func-
tion changing. To permit as compact a design as possible to be obtained, the semicon-
ductor radiation source 18 and the collimator optic 19 are therefore disposed beside the
collimating and focusing optic 28 in this exemplary embodiment.
[0074] Further exemplary embodiments differ from the first and second exemplary
embodiments in that instead of the deflecting element 25 a deflecting element 25' is
used which replaces the entrance diaphragm 26. A corresponding modification of the
first exemplary embodiment is shown in Fig. 6 and Fig. 7. Therein the same reference
signs as in the first exemplary embodiment are used for the same elements and the
comments thereon in the first exemplary embodiment apply here too. The deflecting
element 25' is now a mirror of the size of the diaphragm opening 27 in the first exem-
plary embodiment and disposed in the focal plane of the collimating and focusing op-
tic 28.
[0075] Further preferred embodiments differ from the above-described embodi-
ments in that the detection device 30 and the entrance diaphragm 26 are integrated. For
this purpose the diaphragm opening is configured in a circuit board which also bears
the detection elements 32.

[0076] In other exemplary embodiments the illumination device 15 possesses as a
radiation source, instead of the laser diode 18, a light-emitting diode, a superlumines-
cent diode or an OLED.
[0077] Further, the illumination device 15 can, in other exemplary embodiments,
have at least two semiconductor radiation sources which emit optical radiation at dif-
ferent centroid wavelengths, i.e. the average across the emission wavelengths weighted
with the emission intensity, and are switchable on and off independently of each other.
This permits analyses at different wavelengths to be performed successively.
[0078] In other preferred exemplary embodiments, the entrance diaphragm 26 can
be completely omitted. The illumination device 15 is then so configured that it illumi-
nates only a narrow, elongate area in the recording area, for which purpose the first
condenser optic 19 can contain a cylindrical lens.
[0079] Further exemplary embodiments differ from the above-described exemplary
embodiments in that further lenses are disposed in the detection beam path for reduc-
ing aberrations through the elements of the detection optic and the collimating and fo-
cusing optic 28 or improving the illumination.
[0080] Further exemplary embodiments differ from the above-described exemplary
embodiments in that the deflecting element 25 or 25' is a beam splitter, so that compo-
nents of the detection radiation passing therethrough can be coupled out for example
for producing an image of the value document.
[0081] In further exemplary embodiments, an illumination in transmission can also
be used.
[0082] Further, it is not absolutely necessary to use a reflective dispersing optical
device, such as the reflection grating 29. It is thus possible in a further exemplary em-
bodiment, which differs from the exemplary embodiment in Figs. 6 and 7 only in this
regard, to dispose in the detection beam path after the collimating and focusing optic
28 a transmission grating 29" which decomposes the detection radiation at least partly
into spectral components. The spectral components can then be reflected into the col-

limating and focusing optic 28 by means of at least one reflective component 34, for
example a mirror, which is inclined against the plane spanned by the spectral compo-
nents.
[0083] The folding of the beam path after the collimating and focusing optic makes
it possible to obtain a considerably more compact design than in an also possible appa-
ratus wherein a focusing optic and the detection device are disposed behind the trans-
mission grating instead of the mirror.
[0084] In other exemplary embodiments, the sensor housing 12 and/or the plate 33
can also be configured differently or completely omitted.
[0085] Further, in other exemplary embodiments the evaluation device 31 can be in-
tegrated into the control device 10.
[0086] Other preferred embodiments differ from the above-described exemplary
embodiments in that the detection device has, instead of a row of CCD elements, a
row-type arrangement of photodetection elements, for example CMOS elements, or
photodetection elements for detecting optical radiation in other wavelength ranges.
[0087] An exemplary embodiment for such an analysis apparatus, which can be
used like all other described analysis apparatuses for example in the apparatus for
processing value documents in Fig. 1, is shown in Figures 10 to 12.
[0088] The analysis apparatus 11" differs from the analysis apparatus 11 in Fig. 1,
besides the type of detection elements, in that the detection beam path now passes be-
tween two edge detection elements of a detection device to reach the dispersing de-
vice. In particular, the analysis apparatuses differ only in that the detection device 30 is
replaced by a detection device 34, the deflecting element 25 by a light guide 35 and
the evaluation device 31 by a modified evaluation device 31'. Furthermore, the dis-
persing device 29 is aligned differently relative to the detection device 30. Since the
analysis apparatus otherwise does not differ from that of the first exemplary embodi-
ment, the same reference signs are used for the same components and the statements

thereon in the description of the first exemplary embodiment apply accordingly here
too.
[0089] The detection device 34 shown more precisely in Fig. 12 now has a carrier
36, in the example a ceramic substrate, on which first detection elements 37 are dis-
posed in a first row-type arrangement 39, and second detection elements 38 in a sec-
ond row-type arrangement 39'. In this exemplary embodiment the detection elements
37 and 38 are disposed along only one straight line. In Fig. 12 below the detection
elements 37 or 38 there are located contacting elements 40 connected electrically to
the detection elements via an amplifier stage configured on the carrier, and connected
to signal connections to form evaluation circuits or evaluation devices.
[0090] The detection elements 37 and 38 are located on opposite sides of a recess or
opening 41, which is configured rectangularly in this exemplary embodiment, in the
carrier 36. Between the two edge detection elements 42 and 43 there is thus a gap.
[0091] The detection elements 37 differ from the detection elements 38 by their
spectral detection range.
[0092] The detection elements 37 are detection elements for detecting optical radia-
tion in the visible spectrum and in the near infrared, i.e. up to a wavelength of 1100
run. They have in this exemplary embodiment a useful spectral detection range be-
tween 400 nm and 1100 nm. It is possible to use for example silicon-based detection
elements here.
[0093] The detection elements 38 are detection elements for detecting optical radia-
tion in the infrared. The useful spectral detection range thereof is between 900 nm and
1700 nm in the exemplary embodiment. It is possible to use for example InGaAs-
based detection elements here, which are sensitive in the spectral range above 900 nm.
[0094] The detection elements 37 and 38 are so disposed relative to the dispersing
device 29 that spectral components from the dispersing device with wavelengths above
900 nm are directed onto the detection elements 38 and those with wavelengths below
900 nm onto the detection elements 37.

[0095] In comparison with CCD arrays, only a considerably smaller number of de-
tection elements 37 or 38, for example between ten and thirty, are used, but they pos-
sess a larger detection area and a reduced proportion of non-photosensitive areas. The
detection area is determined here by only optical radiation impinging thereon being
recorded.
[0096] The detection areas preferably have a surface area of at least 0.1 mm2; in the
example they have a height of 2 mm and a width of 1 mm, whereby non-
photosensitive areas between adjacent detection elements have an extension of about
50 µm.
[0097] In this exemplary embodiment the detection elements 37 and 38 are readable
singly independently of each other and in particular in parallel.
[0098] In this exemplary embodiment, the abovementioned amplifier stage com-
prises for this purpose an analog-digital converter for each of the detection elements,
which converts analog signals from the particular detection element into a digital de-
tection signal which represents the intensity of the radiation that has fallen on the de-
tection area.
[0099] In the detection beam path there is disposed the light guide 35 made of a
suitable transparent material, which guides entering detection radiation at least in the
spectral range detectable by the analysis apparatus and deflects it in the direction of the
dispersing device 29.
[0100] One end 44 of the light guide 35 through which the detection radiation exits
therefrom is disposed in the opening 41 and thus in the caustic surface of the collimat-
ing and focusing optic 28. The detection beam path therefore extends between the two
edge detection elements 42 and 43. The exit surface or the end 44 of the light guide 35
constitutes an entrance diaphragm or an entrance slit for the spectrographic device.
[0101] The light guide 35 is aligned relative to the optical axis O of the collimating
and focusing optic 28 such that the radiation emitted through the end 44, averaged
across the ray-bundle cross section, extends at least approximatively parallel to the

optical axis O and orthogonally to the surface of the carrier 36 and in.particular to the
row-type arrangements of the detection elements.
[0102] As recognizable in Fig. 11, the dispersing device 29, in particular the grating
lines thereof, are aligned orthogonally to the optical axis O in the plane shown in Fig.
11. In the plane shown in Fig. 10 orthogonal to the plane in Fig. 11, in contrast, the
line structure given by the grating lines is inclined against the optical axis O.
[0103] The spectral components generated by the dispersing device 29 are therefore
focused by the collimating and focusing optic 28 onto the detection device 34, more
precisely the detection elements 37 and 38, which then detect the corresponding spec-
tral components.
[0104] By the selected arrangement of light guide 35, collimating and focusing op-
tic 28, dispersing device 29 and detection device 34 it is achieved that the detection
beam path extends parallel or partly in the surface determined by the spectral compo-
nents which are generated by means of the dispersing device 29.
[0105] The angle a is selected here so that a spectral component according to a
given wavelength, in this example given by the application for luminescence meas-
urements, the excitation wavelength for the luminescence, is focused into the gap be-
tween the two edge detection elements 42 and 43 and thus not detected.
[0106] As an option, the evaluation device 31' is modified relative to the evaluation
device 31 firstly in that the detection signals from the detection elements or the detec-
tion device are recordable substantially in parallel. Substantially in parallel is under-
stood here to mean that the detection signals can differ in their time slots at least inso-
far as is necessary for the transfer to the evaluation device 311 for example by means of
multiplexing via a bus.
[0107] Further, the evaluation device 31' is configured to record the detection sig-
nals from the detection device 34 upon a pulse output signal for the semiconductor
radiation source 18 after a period of time given in dependence on the expected lumi-
nescence.

[0108] The thereby permitted parallel readout of the detection elements 37 and 38
permits short integration times and in particular a high repetition frequency of the
measurements. This measure likewise contributes to an increase in the signal-to-noise
ratio.
[0109] In particular, this analysis apparatus can be used for carrying out a so-called
single-shot measurement by which a single measurement of the spectral properties of
the luminescence radiation is carried out upon only one illumination or excitation
pulse, said measurement having a precision sufficient for evaluation.
[0110] Further, the evaluation device 31' can optionally be so configured that the
analysis apparatus can be used for recording multiply in time sequence the detection
signals from the detection elements and thus a plurality of spectra after output of an
excitation pulse by the semiconductor radiation source, and thus for carrying out an
evaluation of the time development of the spectrum.
[0111] Yet another embodiment in Fig. 13 differs from the last-described exemplary
embodiment in Figures 10 to 12 only in that the collimating and focusing optic 28 and
the dispersing device 29 in the form of a plane reflection grating are replaced by an
imaging dispersing element 45 which performs the function thereof. All other parts
and components are unchanged so that the same reference signs are used therefor and
the statements on the last exemplary embodiment apply here too.
[0112] The imaging dispersing element now used is a holographic grating 45 which
images the entrance diaphragm 44, in the example the end 44 of the light guide 35,
onto the detection elements 37 or 38 in a spectrally resolved manner.
[0113] The imaging grating 45 has in the example preferably more than about 300,
particularly preferably more than about 500, lines per mm, i.e. diffraction elements, to
permit a sufficient dispersion of the luminescence radiation onto the detector element
21 despite the compact structure. The distance between imaging grating 45 and the
detection device 34 is preferably less than about 70 mm, particularly preferably less
than about 50 mm.

[0114] In other exemplary embodiments, it can also be provided that individual de-
tection elements 45 have different dimensions, in particular in the dispersion direction
of the spectral components, as shown in Fig. 14 by way of example. Since normally
not all wavelengths of the spectrum or only wavelength ranges of equal width are
evaluated, but rather selectively only individual wavelengths or wavelength ranges
also of different width, the detection elements can be designed to be adapted in their
width, parallel to the plane defined by the spectral components, to the particular wave-
lengths or wavelength ranges to be evaluated.
[0115] In yet other exemplary embodiments, in particular in ones where a collimat-
ing and focusing optic is used, there can be disposed before the detection device or a
row of detection elements a cylindrical lens which focuses detection radiation onto the
detection elements and whose cylinder axis is aligned for this purpose parallel to the
row.
[0116] By means of such a cylindrical lens the portion of the recording area used for
detection can be enlarged in a direction corresponding to a direction orthogonal to the
cylinder axis of the cylindrical lens, thereby increasing the intensity available for de-
tection.

Claims
1. An apparatus for optical analysis of value documents (BN) with a recording area
(14) in which a value document (BN) is located during analysis, and a spectro-
graphic device (16) which has:
a spatially dispersing optical device (29) for at least partly decomposing optical
radiation coming from the recording area (14) into spectrally separate spectral
components propagating in different directions according to the wavelength,
a detection device (30; 34) spatially resolving in at least one spatial direction for
detecting the spectral components, and
a collimating and focusing optic (28) for collimating the optical radiation di-
rected from the recording area (14) onto the dispersing device (29) and for focus-
ing at least some of the spectral components formed by means of the dispersing
optical device (29) onto the detection device (30; 34).
2. The apparatus according to claim 1, wherein the collimating and focusing optic
(28) is achromatic.
3. The apparatus according to any of the previous claims, wherein the direction of
the radiation from the recording area (14) impinging on the collimating and fo-
cusing optic (28) is inclined from a surface formed by the spectral components in
the area between the collimating and focusing optic (28) and the detection device
(30).
4. The apparatus according to any of the previous claims, wherein at least in a por-
tion immediately before the collimating and focusing optic (28), a geometric pro-
jection of the radiation coming from the recording area (14) onto a surface (A)
formed and limited by the spectral components impinging on the detection device
(30) is located in said surface.
5. The apparatus according to any of the previous claims, wherein a diaphragm (26)
disposed in the focal surface of the collimating and focusing optic (28) and an
imaging optic (22, 23) for imaging the recording area (14) onto the diaphragm

(26) are disposed in the beam path from the recording area (14) to the spectro-
graphic device (16).
6. The apparatus according to any of the previous claims, wherein the detection de-
vice (30; 34) is spaced from the diaphragm (26) in a direction which extends or-
thogonally to the direction in which the spectral components are separated.
7. The apparatus according to any of the previous claims, wherein the dispersing
optical device (29) has an optical grating.
8. The apparatus according to claim 7, wherein the grating (29) is so configured and
so selected that the radiation of the zeroth diffraction order does not impinge on
the detection device (30; 34).
9. The apparatus according to claim 7 or claim 8, wherein the line structures of the
grating (29) are inclined from the optical axis (O) of the collimating and focusing
optic (28).
10. The apparatus according to any of claims 1 to 9, wherein the detection device
(30; 34) has at least two edge detection elements (42, 43) which are so disposed
that at least part of the detection beam path extends therebetween.
11. An apparatus for optical analysis of value documents with a recording area (14)
in which a value document (BN) is located during analysis, and a spectrographic
device (16) which has:
a spatially dispersing optical device (29) for at least partly decomposing optical
radiation coming from the recording area (14) along a detection beam path into
spectrally separate spectral components propagating in different directions ac-
cording to the wavelength, and
a detection device (34) spatially resolving in at least one spatial direction for de-
tecting the spectral components which has at least two edge detection elements
(42, 43) which are so disposed that at least part of the detection beam path ex-
tends therebetween.

12. The apparatus according to any of claims 10 and 11, wherein in the area of the
two edge detection elements (42, 43) the detection beam path extends parallel to
a surface determined by a beam path of the spectral components.
13. The apparatus according to claim 11 or claim 12, wherein the spatially dispersing
optical device has an imaging dispersing element which focuses optical radiation
that has passed from the recording area between the edge detection elements,
split into spectral components for at least one given spectral range, onto the de-
tection device.
14. The apparatus according to any of claims 10 to 13, wherein the dispersing optical
device (29) has an optical grating which is so aligned and so selected that the ra-
diation of the zeroth diffraction order of the grating (29) does not impinge on the
detection device (30; 34), the grating preferably being an echelon grating.
15. The apparatus according to any of claims 10 to 14, wherein a beam path from the
spatially dispersing device (29) to the detection device (30; 34) extends such that
a spectral component of a given wavelength is directed between the two edge de-
tection elements (42, 43).
16. The apparatus according to any of claims 10 to 15, wherein the at least two edge
detection elements (42, 43) have in each case different spectral detection ranges.
17. The apparatus according to any of the previous claims, wherein a filter which
suppresses radiation in a given spectral range is disposed in the detection beam
path between the recording area and the spatially dispersing optical device (29).
18. The apparatus according to any of the previous claims, wherein a beam splitter
(25) by means of which part of the optical radiation from the recording area (14)
can be coupled out of the detection beam path is provided in the detection beam
path between the recording area (14) and a space formed by the two edge detec-
tion elements (42, 43), or the collimating and focusing optic (28).

19. The apparatus according to any of claims 10 to 18, wherein a light guide for
guiding the detection radiation is disposed in the detection beam path, the end of
said light guide being disposed between the two edge detection elements.
20. The apparatus according to any of the previous claims, wherein at least some of
the detection elements (32; 37, 38, 42,43) of the detection device (30; 34) have a
sensitive surface area of at least 0.1 mm2.
21. The apparatus according to any of the previous claims, wherein the detection de-
vice (34) has, in particular in addition to the two edge detection elements (42,
43), detection elements (32, 37, 38, 42, 43) for simultaneously generating detec-
tion signals which represent a property, in particular the intensity, of the radiation
impinging thereon.
22. The apparatus according to any of the previous claims, which has an evaluation
device (11; 111; 11") connected to the detection elements (32; 37, 38, 42, 43) via
signal connections and which in parallel records detection signals formed by
means of the detection elements (32; 37, 38, 42, 43).
23. The apparatus according to any of the previous claims, wherein the evaluation
device records detection signals from the detection elements (32; 37, 38, 42, 43)
of the detection device (30; 34) in dependence on a signal which represents the
output of a pulse of illumination radiation onto the recording area.
24. The apparatus according to any of the previous claims, which has at least one
semiconductor radiation source (18) for illuminating the recording area (14).
25. The apparatus according to any of the previous claims, wherein a beam splitter
(21) via which optical radiation from the semiconductor radiation source (18)
passes into or onto the recording area (14) is disposed in the beam path from the
recording area (14) to the spectrographic device (16).
26. An apparatus for processing value documents (BN) with an apparatus according
to any of the previous claims and a transport path (5) for value documents to be
processed (BN) which leads into and/or through the recording area (14).

27. A method for optical analysis of a value document (BN), wherein optical radia-
tion emanating from the value document (BN) is shaped into a parallel ray bun-
dle by an optic (28), the ray bundle is decomposed at least partly into spectral
components of different wavelengths which propagate in different directions in
dependence on the wavelength, at least some of the spectral components are fo-
cused by the optic (28) onto a detection device (30; 34), and the spectral compo-
nents focused onto the detection device (30; 34) are detected.

An apparatus for optical analysis of value documents (BN) possesses a recording area (14) in which a value document (BN) is located during analysis, and a spectrographic device (16). The latter has a spatially dispersing optical device (29) for at least partly decomposing optical radiation coming from the recording area (14) into spectrally separate spectral components propagating in different directions according to the wavelength, a detection device (30) locally resolving in at least one spatial direction
for detecting the spectral components, and a collimating and focusing optic (28) for
collimating the optical radiation directed from the recording area (14) onto the dispersing
device (29) and for focusing at least some of the spectral components formed by means of the dispersing optical device (29) onto the detection device (30).

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=B/FS3OIDsnJl2H1JOJIG+A==&loc=wDBSZCsAt7zoiVrqcFJsRw==


Patent Number 278174
Indian Patent Application Number 4027/KOLNP/2008
PG Journal Number 53/2016
Publication Date 23-Dec-2016
Grant Date 15-Dec-2016
Date of Filing 03-Oct-2008
Name of Patentee GIESECKE & DEVRIENT GMBH
Applicant Address PRINZREGENTENSTRASSE 159, MUNCHEN
Inventors:
# Inventor's Name Inventor's Address
1 CLARA, MARTIN KAISERSTRASSE 47, 80801, MUNCHEN
2 BLOSS, MICHAEL BAD-ISCHLER-STRASSE 2/B, 81241 MUNCHEN
3 DECKENBACH, WOLFGANG BIRKENWEG 15, 83135 SCHECHEN
PCT International Classification Number G07D 7/12
PCT International Application Number PCT/EP2007/003220
PCT International Filing date 2007-04-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2006 017 256.6 2006-04-12 Germany
2 10 2006 045 624.6 2006-09-27 Germany