Title of Invention	A CONTAINER CONNECTABLE TO A RECORDING HEAD FOR AN INK JET RECORDING APPARATUS, AN INK JET HEAD ASSEMBLY AND A PRINTER
Abstract	The present invention relates to a container connectable to a recording head for an ink jet recording apparatus, comprising: a first chamber containing liquid retaining material and having an air vent for allowing ambient air into the container; and a second chamber which provides a liquid reservoir for the first chamber and which is substantially closed except for a communication port defmed by a bottom wall common to the fIrst and second chambers and a partition wall between the fIrst and second chambers and by which the fIrst and second chambers communicate, wherein said liquid retaining material extends partly into said communication port and is not substantially compressed by an end of the partition wall. The present invention also relates to an ink jet head assembly and a printer.

Title of Invention

A CONTAINER CONNECTABLE TO A RECORDING HEAD FOR AN INK JET RECORDING APPARATUS, AN INK JET HEAD ASSEMBLY AND A PRINTER

Abstract

The present invention relates to a container connectable to a recording head for an ink jet recording apparatus, comprising: a first chamber containing liquid retaining material and having an air vent for allowing ambient air into the container; and a second chamber which provides a liquid reservoir for the first chamber and which is substantially closed except for a communication port defmed by a bottom wall common to the fIrst and second chambers and a partition wall between the fIrst and second chambers and by which the fIrst and second chambers communicate, wherein said liquid retaining material extends partly into said communication port and is not substantially compressed by an end of the partition wall. The present invention also relates to an ink jet head assembly and a printer.

Full Text	INK JET CARTRIDGE, INK JET HEAD AND PRINTER FIELD_ OF THE__IN VENT ION AND RELATED ART The present invention relates to an ink jet cartridge containing liquid ink, manufacturing method thereof, an ink jet head and printer using the cartridge, and is usable with a copying machine, a facsimile machine or another recording apparatus, communicati on apparatus, office equipment, combined machi no or printer. Heretofore, an,ink cartridge for an ink jet recording apparatus is integrally formed with an ink jjet head, and when the ink in the cartridge is used up, the unified end and the container are disposed of. The quantity of the ink remaining in the cartridge is decided by the ink retaining capacity of a spongd (vacuum producing material) occupying the entirety of the space in the cartridge, and it is relatively, large. Jnpanv&e Laid-Open Patent Application No. 63242/1988 discloses such an ink container. The ink i contai nor contains a foamed material, and it is integral wi1h an ink let recording head having a plurality of ink ejection orifices. In such an ink contain^/, in order to accommodate the ink in the porous mat oria 1 such as foamed polyurethane material, the production of the vacuum and the ink retention (prevent i on of the ink leakage from the ink container) are accomplished by the capillary force of the foamed material. However, the foamed material is required to be f i 1 Jed in the enti ret y of tlie ink container, and therefore, the quantity of the ink therein is limited, and the quantity of the non-usable ink is relatively large. This means that the ink use efficiency is low. It is difficult: to detect the remaining amount of the ink therein. In addition, during the ink consumption period, the negative pressure gradually changes, and therefore, it is difficult to maintain a substantially constant vacuum. Japanese Laid-Open Patent Application No, i 522/1990 discloses that the ink cartridge contains substantially only the ink. More particularly, it discloses an integral ink jet recording head and ink cont.ai nor, comprising a primary ink container for containing a large amount of the ink at an upper position, and a small porous material between the ink i jet recording head therebelow. It is stated thkt the i ink use efficiency is improved because only the! ink is disposed in the ink passage without the porous ! i material contained in the ink container. In addition, a secondary ink container capable of containing the ink is provided at a side of the porous material, whi ch is ef feeti ve to receive the ink flowed from the primary ink container due to expansion of the air in the primary i nk container upon temperature rise (pressure decrease), so as to maintain a substantially constant negative pressure of the recording head dur ing the recording operation - In this structure, when the recording operation is not carried out, the porous material is filled with a very large amount of the ink from the primary ink container containing a large amount of the ink above the porous material, and therefore, the porous material itself can hardly produce the iiegative pressure. For this reason, the ink leaks out of the i orifice of the ink jet recording head by small impact, and therefore, it is not practical. If this dontainer is used as a exchangeable ink cartridge to be mounted to an ink jet recording head, the ink can leaks out of the porous material, and therefore, it is still not \| practical. I : In an i nk cart ri dgn, the ink is sealingly i l ! ! . contained in a bladder, and the negative pressure of the bladder i s maintained constant using a spring i structure, but this is expensive, and it is difficult to mass-produce with the correct performance of the spring structure. In the field of the ink jet printing (non-contact type printing) inexpensive ink cartridge having proper performance has not been accomplished, and has long been desired. The inventors have investigated from the standpoint of capability of properly supplying the ink cor responding to the eject, ion of the ink from the recording head during the printing operation and also front the standpoint of capability of preventing ink leakage through the ejection outlet when the printing operation is not carried out. As a result, it has been found that the fundamental structure comprises a first container containing a vacuum producing material and provided with an air vent and a second container for containing substantially only the ink to be suppl iod to the first container, the second container being substantially hermetically closed with the exception of the communication with the first container. Japanese Laid-Open Patent Application No. 16385/1985 discloses a recording pen having a recording tip which is contacted to a recording material during the recording operation. The recording tip has ink absorbing and retaining nature, i i and the ink is supplied thereto. Therefore, the recording tip is exposed to the ambience, as i i contrasted to the ink jet recording apparatus. The Japanese Laid-Open Patent Appli cation is directed only to the overflow of the ink through the recording tip. It comprises as essential elements a first liquid absorbing material, and a second absorbing material which absorbs less ink than the first absorbing material although it absorbing a small amount of the ink, the second absorbing material being disposed above the first absorbing material at a posi tion closer to the ai r vent, a central chamber from which the recording tip is projected downwardly, and hermetically closed in accommodating chamber to supply the ink to opposite sides of the chamber. With this structure, when the air in the closed ink container expands due to the ambient temperature rise with the result of the ink in the ink container into the first absorbing material, the ink incapable of being retained by the first absorbing material, is absorbed by the second absorbing material, so that the overflowing droplets of ink from the writing tip can be prevented. It also discloses provision of a constant width groove which is effective, when one of the two closed ink container contains only air, to permit the expanded air to escape through the air vent. The groove is extended from the bottom end to the top end on a si do sur face which is different from a partition wal1 between the central chamber and the c:l osed i nk container . When this structure is used for an ink jet recording head, the ink leakage through the air vent has been confir med, as has been expected because of the fundamental difference between the contact recording and the non-contact recording. This problem is not recognized in the field of the recording pen. In addition, the constant width groove servos to promote the discharge of the ink together with the air, and therefore, the leak of the ink through the air vent has been promoted. Additionally, the ink consumptions of the two ink containers are not the same. If one of the containers becomes empty first, the ink jet recording operation became no longer possible despite the fact that a 1arge amount of the ink is remaining in the other ink container. This is because a large amount of the air is introduced into the first absorbing material with the result of incapability of the ink supply. This is against the aim of this invention* SUMMARY Of^HE INVENTION Accordingly, it is a principal object of the present invention to provide an improvement to the fundamental structure having the first contained containing the vacuum producing material and provided wi l.h the air vent for communication with the ambience, i and a second container for substantially only the ink to be supplied to the fi rst container, the secohd container being substantially hermetically closed with the exception of the communication with the first hoad and a printer usinq the same capable of effecting high speed recording, while the vacuum can be maintained substantially constant in a large part of the period from the start of the use to the end thereof of the ink cartridge. It is another object of the present invention to provide an exchangeable ink cartridge in which the vacuum is produced in the ink cartridge when the recording operation is not effected, thus preventing ink leakage through an opening upon small impact. It is a further object of the present invention to provide an ink cartridge in which ;the i i remaining non-usable ink is minimized. It is a yet further object of the present i invention to provide a.n exchangeable ink cartridge which is less expensive and from which the ink does not leak out during transportation of itself. According to an aspect of the present : invention, a region of the vacuum producing material that adjacent to air introduction passage does not ronl.iin the ink. By doing so, the leakage of the ink through the a i r vent ftorn the ink cartridge can be prevented against the ambient condition change. Part i nilarly when a sealing member is used to seal the a i r '/r»nt, thi s aspect of the invention is effective to prevent removal of the sealing member. During the use of the ink cartridge, this region is effective to the proper amount of the air is introduced into the ink cartridge, thus suppressing variation of the vacuum in the ink jet cartridge. The region adjacent the air introduction passage is completely free from being wetted by the ink, the ink seeping speed is reduced, and therefore, it is desirable. However, it is a possiblo alternative that the region is once wetted by the ink, and the ink is thereafter removed. Acco/djriii In .mot hei. aspect of the invention baser I on the abovo-deser i bed fundamental structure, the vacuum or negative pressure producing material is compressed or capable of being compressed in the region adjacent an ink supply opening or an ink supply pipe which is provided at a side opposite from the partition wall having a small communication part between the first container and the second container. i My doinq so, a stabi)ized ink path can be assurfed in i i the vacuum produci ng material from the second ink , contairu^r. h'nr l;he purpose of t he further stabi1j nation, the i nk supply opening is disposed above the sma11 communi cat i on part relative to the bottom surface of the ink cartridge. Here, the supply pipe incIudes an inser f i on in pe peculiar to the ink jet recording or pri nt i nq, and a valve structure or connect i ng member mounted on the cartridge compressing the vacuum producing membr r. By doing so, the ink movement direction can be substantially stabilized, so that; a 11 of the ink in the second container can be used up. After it is used up, the air moves from the parti tion wall toward the ink supply opening, thus permitting consumption of the ink in the vacuum producing material, and therefore, the amount of the non-usable remaining ink can be minimized. According to a further aspect of the present invention, a region of the vacuum producing material not compressed by the supply pipe, and the region i compressed by the supply pipe are formed in the order named from the partition wall forming the fine communication part to the opposite wall, by which one i way ink supply path is formed in the non-compressed region, and in addition, the remaining non-usable ink amount can be further reduced by the ink retaining capacity in the compressed region, i The present invention includes a structure containing one or more of the above-described Aspects. The ink jet cartridge of this invention is usually handled by an operator, and therefore, \| it is po.ss i b 1 r» tha t ?-;l r ong J or re is appl ied thereto wi th the result of deformation of the ink container wall- In vi r»w o\ this, i 1: is preferable that an additional partition wall providing a larger clearance than the fine communication part: in the ink container for contni ni ng substantial 1y only the ink. When the cartridge is made of resin material, it is preferable that the thickness of the wall containing substantially only of the ink is 0.8 mm (Ti, G in Fi guro 29) or more and t hat the wal 1 thickness of the container containing the vacuum producing material such as sponge is 1.3 mm (Ts, J in Figure 20) from the standpoint of the prevention of the deformation. In the ink jet printer of this invention, the ink is forced discharged by sucking the ink by the sucking means and by ejecting the ink by ejecting means automatically or manually upon mounting of the cartridge on the ink jet printer. This is preferable because the state of the ink in the vacuum generating material can be adjusted before the start of the pri nt.i ng operation, and therefore, the printing function can be performed wi thout influence of; the ink i cartridge keeping state. i average pore size of the vacuum producing material (preferably the average' pore size in the region adjacent the fine communication part) (practically not less than 0.1 mm), and it is preferably not less than 5 mm. If it is less than 3 nun, the further stabilization can be expected. The volume ratio of the vacuum producing material container and the ink container is not less than 1:1 and not more than 1:3, practi cally. These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the i i accompanying drawings. i i BR IEF HESCR IJPTIPN..OF THE DRAWINGS Figure 1 i s a schematic partly broken perspective view of an ink container according to a first embodiment of the present invention. * Figure 2 is a sectional view of the ink conta i na.r of F1 gure 1 . Figure 3 shows examples of connection between the cartridge and the supply pipe. Figure 4 i1 lust rates a comparison example. Figure S i 1 lust rates ink supply part used in thi s i nvonf: ion . Figure 6 illustrates a positional relationship between an ink supply portion and the fine communication part. Figure 7 illustrates the structure of the fine communication part. Figure 8 illustrates configuration of the partition wall at a side of the fine communication part. Figure 9 illustrates state of the absorbing material at an end adjacent the partition wall. Figure 10 illustrates the state of inside of the absorbing material against ambient condition change. \| Figure 11 illustrates a manufacturing method according to an embodiment of the present invention, and illustrates an ink jet head. Figure 12 illustrates an ink jet printer and an ink cartridge usable therewith. Figure 13 illustrates modified embodiments of trhr* present invention. Figure 14 is a sectional view illustrating permissible inclination in use, of the ink cartridge. Figure 15 shows configuration in an erobodi UHMI! of the present invent i on. Figure 16 illustrates the change in the pr in I i tiff opera t i on . Figure 17 111ustrates pressure to the extoinal wall of the cartridge according to an embodiment of the present invention. Figure 18 is a sectional view of a modified example of an ink cartridge according to an embodiment of the present invention. Figure 19 is a perspective view of a color ink container according to an embodiment of the present invention, Figure 20 is a graph showing a relation between the thickness of the wall and ink leakage by ! the external pressure. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figures 1-6, there is shown an ink container having an ink supply opening formed In a I 1 wall of a vacuum producing material container that is facncl to a pari i lion wal ] 5 which is cooperative with a bottom surface of the cartridge to form a fine communicati on part M. Fi gu i e I is a pe r spec I i ve view of the i nk container according to a f irst embodiment, and Figure -.2 is a .sectional vinw of the i nk container according to [ he I. i rst embodiment . As shown in Figures 1 and 2, the ink carlridge main body 1 of his embodiment is provided w i l.h an open i ng /* I or commun i cat ion with an ink jet r ecor communication part in i hn form of a clearance 8. It comprises a vacuum producing material container 4 for containing the vacuum producing material 3 and enn ink container 6 for containing substantially only the ink, which communicates with the container 4 at a bottom portion 11 through the clearance 8 provided by the partition wal1 5. With this structure, the air is supplied through the opening 2. However, what is important is the ink is supplied assuredly from the ink container 6 i through the communication part 8 toward the opening 2 along the bottom 11 of the ink cartridge. With the ink supply, the air is introduced in place of the ink in the ink container 6. The description will be made as to the compressing deformation of the vacuum or negative pressure producing material by the supply pipe in the compressing deformation capable region adjacent the opening. In Figure 3, a joint member 7 functioning as a supply pipe for supplying the ink to the ink jet recording head has been inserted into an exchangeable ink cartii dge according to this embodiment. With this state, the joint member 7 is press-contacted to tho vacuum producing member, and the i f I k jot record i rig apparatus is operable in this ;respect. A filter may he provided at an end of the joinI member to remove the fore ign matter in the ink car t r i dgo . When the ink jet recording apparatus is operated, the ink is ejected out through orifices of the ink jet recording head with the result of ink absorbing force in the ink cartridge. The ink 9 is supplied by the absorbing force from the ink container 6 through the clearance B between the bottom end of the partition and the bottom of the ink cartridge 11 to the vacuum producing material container 4, and to the ink jet recording head through the vacuum producing material 3 and the joint member 7. By this ink supply, the internal pressure of the ink container 6 which is closed except for the i ! '■ clearance 8 reduces with the result of pressure difference between the ink container 6 and the vacuum i producing material container 4. With the continuing recording operation, the pressure difference cdntinues to i ncreaso. However, since the vaciium producing material is open to the ambience by a clearance 10 i between the joint member and the opening. The air is i introduced into the ink container 4 through th recording, various color inks (black, yellow, magenta and cyan) may be accommodated in separate exchangeable ink cartridges, respectively. These ink cartridges may be unified as shown in Figure 19A. The exchangeable ink cartridge may comprise a black - con tai ner exchangeable ink cartridge which is frequently used and one another color exchangeable cartridge, as shown in Figure 19, (B). Any combination is possible in consideration of the ink jet apparatus. In the exchangeable ink cartridge accord i ng to thi s embodiment, in ord^r to control the vacuum, the following is preferably optimized:! material, configuration and dimensions of the vacuum i producing material 3, configuration and dimensions of rib end 8, configuration and dimensions of the I clearance 8 between the rib end 8 and the ink i container bottom 11, volume ratio between the vacuum prod i in" ng mater i a 1 con t.ai ner 4 and the ink container l>, con I iguiation The material of the vacuum producing member may be any known material i f it can retain the ink despite the weight thereof, the weight of the liquid ( i nk ) and smal1 vi brat ion. For example, there are sponge i i ke materia 1 made of f i hers and porous functioning also as the air introduction opening, and therefore, the structure is simple. The amount of insertion of the joint member 7 into the exchangeable ink cartridge is properly determined by the ordinary skilled in the art so as to provide a compression region of the vacuum producing member to prevent ink leakage upon the insertion and to prevent ink supply stop during the recording operation, in consideration of the configuration of the joint member, the vacuum j producing material and the configuration of the ink cartridge. In the foregoing embodiment, it is effective to provide an air vent in the vacuum producing material container, since then the region of the vacuum producing material that does not contain the ink is easily located adjacent the air introduction ■ i passage. The reliabi1i ty in the ink jet recording appa ratus against the ambient condition change is improved . The con f i .gur atton and dimensions of the clearance 8 between t he end of the partition wall and tho ink cart ridge bottom, a re net 1imited. However, if it is too srnal 1, the meniscus force with the ink is too strong, and although the ink leakage can be prevented through the joint opening, but the ihk supply to the vacuum producing material contaiher is di f f i mi It, with the possi hie result of ink supply stop during the use. If it is too large, the opposite The r:l (Mrancn H i s a 1 ;u> determined in considoration of the posttion of the joint opening. Reforri nq to Fiqure 10, (a) and (b) , the partition wall end is at a position lower than the bottom end of the joint opening in Example (a), and the ink retained in the vacuum producing material is lower than the bottom end of the -joint opening, and therefore, the leakage preventing effect is sufficient. In Example (b), the end of the partition wall is at a position higher than the bottom end of the joint opening, and the ink retained in the vacuum producing material is above the bottom end of !the 30int. opening, and therefore, the ink leakage suppressing effect is not sufficient. Therefore, it 1 is preferable to stabilize the advantageous effect of i the present invention that the position of thje end of the partition wall is not higher than the botftom end i of the joint opening by properly determining ithe dimension of the clearance 8. Although it id . i dependent on the configuration and dimensions of the i exchangeable ink cartridge, the height of the clearance 8 is selected in the range of 0.1 - 20 nun. Further preferably it ranges from 0.5 - 5 mm approximately. The conl iqurati on of an end of the parti tion wai 1 tuny bo any i f the consideration is paid In the position relative t.o the joint opening, as will be understood f rom Fi qure M, (a) - {h). As regards the boundary between the end of the partition wall 5 and the vacuum producing material 1, various structures are consi dered. This is shown in Figure 9. In the structure of Figure 9, (a) - (d), I the vacuum producing material is not compressed by the end of the partition wall, and the density of the vacuum producing material is not: locally increased, and therefore, the flow of the ink and the air is relatively smooth, and for this reason, it is preferable for a high speed recording or color recording. On the other hand, the examples of Figures 9, (e), (f), the vacuum producing material 3 compressed by the end of the partition wall, and the density of the material is increased, and therefore, i the flow of the ink and the air is obstructed, but the ink leakage or the like can be effectively prevented * against siight ambient condi tion change. Therefore, they ara properly determined by one skilled in the art, on the basis ot the ink jet recording apparatus with which the ink cartridge is used &nd the ambient condi t i on under which the i nk cartridge is used. The volume ratio between the vacuum producing material container 4 and the ink container 6, iS determined in considerat ion of the ambient condition under which the ink cartridge is used and the ink jet recording apparatus with which it is used. Also, the relation wi th the used vacuum producing material is important. In order to improve the use efficiency of the ink, it is desirable to increase the volume of the ink container. In that case, a vacuum producing material capable of producing high vacuum (high compression ratio sponge), is effective. Therefore, the preferable ratio ranges from 1:1 - 1:3 practical ly. In this casn', the vacuum producing performance of the vacuum producing member is inci r^ased with increase ol the relative volume of the ink container. The configuration, dimension and mesh of the i filter 11 can be properly determined by one skilled in . i i the art depending on the ink jet recording apparatus i > i with which the ink cartridge is used. However,jin s order to prevent the nozzle from being clogged by the foreign matter introduced from the ink cartridge, the passing area thereof is smaller than the size Of the ,'i ori fice. ; The quantity ol" the ink in the ink cartridge is not Iimi ted except for the internal volume of the ink cartridge. In order to maintain the proper negative structure immediate]y after the exchangeable ink cartridge is unpacked, the ink may be contained to the extent of the volume 1imit i n the ink container. However, the vacuum producing material is preferably lower than the ink retaining capacity of the material. Here, the ink retaining capacity which can be retained solely by the material when tho ink is contained therein. In the ink cart ri dge having a closed system ink container, when an external ambient condition change such as temperature rise or pressure reduction, occurs when it is loaded in the ink jet recording apparatus, the air and the ink expands in the ink container to push the remaining ink out of the ink cartridge with the possible result of ink leakage. However, in the exchangeable ink cartridge of this invention, the volume of air expansion in the Closed ink container, inclTiding i nk expansion (although the amount is small) in accordance with the worst ambient condition change, is estimated, and the amount of the displaced ink from the ink container is to be accommodated in the vacuum producing material container. In this case, it is very effective to provide the vacuum producing material contained with an air vent in addition to the joint opening, as shown in Figure JO, ( r ) and from the joint opening, i t is preferably away from the joint opening. The number, configuration and size of the ait vent are properly determined by skilled in the art in consideration of the ink evaporation or the like. Dur i nr\ transports I i on of the ink cartridge itself, it is preferable that the joint opening and/or the air vent is hermetically shield by a sealing member to prevent ink evaporation or to be prepared for the expansion of the air in the ink cartridge. : : j The sealing member may be a single layer barriejr which is so-called barrier material in the packing field, a compound plastic film having several layers, or such i material reinforced by paper or cloth or ahothdr reinforcing material or aluminum foil, are preferable. It is further preferable that a bonding layer of the same mater ial a:-; the main body of the ink cartridge is used to fuse fixing the hairier material, thus improvi nq the hermetica1 seali ng property. In or He r to snpi i same barrier material as described with respect to the sea 1 i ng rnombe r in cons i r f * • r a 1 i on of the permeabi 1 i ties of the liquid and the t?i By such propei so Loci ion of the packing, the ink doos not Ionic out during HIP t rnnRpnrl aI; i on of l:ho ink cartridge itself. The material of the main body of the ink cartridge may be any known moldable material ifj it 1 i '; doriH not li;iv(! «jny KJVOI«NO inl luonce to the, ink jet i oooi d i iig i file 01 if i I h.r; boon I i o from plastic resin material, respectively. Th6 vacujim i ■' ! h producing material is inserted thereihto, and ! ■ ! ! thereafter, the bottom portion and up^er pOrtioh are fuse-bonded, thus providing the main body of thte ink 1 ; i cartridge. If the plastic material is transparent or i semitransparent, the ink in the ink container can be, observed externally, and therefore, the timing of ink 1 i cartridge change may be expected. In;order to The ink can be loaded through pressurizing or pressure- reduction mo thod . 1' rovi si on of ink fil ling opening in either of the containers of the containing main assembly is preferable since then the ink cartridqe opening is not contaminated. After the filling, the ink filling opening is plugged by plastic or metal plug. The configuration, dimension or the like of the ink cartridge according to this invention can be modified without departing from the sprit of the present invention. As described in the foregoing, the exchangeable ink cartridge is reliable during the transportation thereof, and a high use efficiency ink , i cartridge can be provided with simple structure!. i The proper vacuum is maintained from the start to the end of the use can be maintained when the recording operation is carried out or is not cajrried! I ; l out, while permitting high speed recording. Under the i use ambient condition of the ink -jet recording ; apparatus, the possibility of the ink leakage can be i minimized. !. The exchangeable ink cartridge of this' invention is easy to handle .so I hat the ink does not leak out when i t. is loaded into the ink jet recording apparatus, and the possibi1i ty of erroneous operation can he avoi ded. Figure 1 1 i 1J list lates a manufacturing method ~>f an i nk contai ner cart i j dqe . A main body of the -:art ridge (left down hatchi rig) comprises a partition plate 61 and two containers separated by the partition wall 5. An ink absorbing material 4 functioning as the vacuum producing material is inserted into the container portion which is close to the opening 2« Thereafter, a bottom member 11 functioning as the covering member is unified to the main body. This Figure also shows the state in which the recording head HD is loaded in the ink container 1. The ink container 1 is constituted by a container partitioned into two chambers by a partition wall 5, and the bottom portion is covered by a flat bottom member 11 j constituting the bottom of the ink container, >Thus, by the simple structure, the fine cortimunication part 8 i ; .] ;i can be provided by the end of the pattitidn wall. The air vent 10 is disposed on the saihe !! surface as having the opening 2, but above the! !; opening. j ' The joint port ion 7 functioning as the supply ' : it pipe is inserted into the opening of the ink \ container, and the recording head is;mounted thereto, i I The joint portion 7 is i. ncl ined so that the top portion is more front than the bottom portion. The ink passage in the joint is in the form of a horn opening upwardly in the Figure. With this structure, the i nk can be properly supplied to the recording head from the ink absorbing material. The ink jet recording apparatus comprises heat generating element 7 2 for producing thermal energy to eject the ink through ejection outlets 71 of the nozzles 73, wherein the thermal energy is effective to cause state change in the ink. In this case, a high density and fine images can be provided by the stabi1ized ink supply performance, particularly in the case of color recording. As described in the foregoing, the ink cartridge according to this invention, the high reliability is maintained during the transportation thereof, and the use efficiency of the ink is high. , i In addition, the proper vacuum is maintained from the start to the end of the use thereof when the I ! I recording operation is carried out or is not carried i out, when permitting high speed recording operation. i In addition, the ink leakage can be prevented tender the use condi ti on of the ink jet recording apparatus. Additionally, the exchangeable ink cartridge I ;. i ; i according to this invention is easy to handle, The manufacturing method of the ink cartridge will be described further. When the closed structure ink conUtinf-r ( ,i I I hough I 'KM e is fine communication part be t ween th i nk conl ai n i ng chamber or container and the negative pressure producing material containing chamber, but the ink is discharged only when the air and the ink are exchanged with each other), and the vacuum producing material containing chamber are integrally molded, the ink is filled through an opening 13 at the ink container chamber side in the covering member 11. When the ink is supplied in this manner, a substantial part of the vacuum producing material 4 receives the ink through the fine communication part. However, the region of the vacuum producing material 4 adjacent the air vent is not supplied with the ink to provide ink-free region. Thereaftet, the i opening 13 is sealed by a ball 14. Then, the (opening 2 and the air -v^nt are sealed by the same sealing member S (it may be separate members). i Figure 12 shows such an ink jet cartridge before start of use. In this Figure, the ink container 6 is filled with an ink. Figure 12 shows the closed state ink ijet cartridge 1 with the printer which is used therewith. A region 3A of the vacuum producing material adjacent to the air vent portion 10 does not contain the ink at an upper portion of the cartridge. A region 3B of the vacuum producing material below the region 3A is compr essod by insert i on of t;hn i nk supply pipe (not shown). The vacuum produci ng material portion other than those roqions 1A and ID, are not externally influenced and simply functions to retain the ink. The region 3B is faced to the opening 2 for the ink supply to the recording head provided on the same surface but below the air vent 10. The opening is above the fine communication part 8, and the above-described structure is used. The cartridge 1 of Figure 12 becomes usable by removing the sealing member S. Since the region A does not retain the ink, the ink does not leak out even if the vibration or pressure change is imparted upon the removal 6f the sea1ing member, In the ink container of this invention, the 1 i ink is not retained in the region of the vacuiim producing member that is close to trie air vent or air communication part, irrespective of whether the ink cartridge is being used or not used. By doing so, the leakage of the ink from the ink cartridge thrdugh the air vent can be prevented even when the ambient condition varies. Particularly, when the sealing member closes the air vent:, the sealing member can be prevented from peeling off. During the use, the region is effective to permit air supply^ corresponding to the consumption of the i nk, so that the change of the varuum in the ink cartridge can be suppressed. If the region oi the vacuum producing material adjacent t o t h all, i t is preferable to «iecelerate the ink seeping speed- However, the region thereof may be wetted by the ink beforehand, and thereafter, the ink may be removed from this region. In the embodiment of this invention, the ink supply opening or the compressed part of the vacuum prorluci ng material (compressible) by the ink supply pipe is present at a side opposed to the partition wall constituting the fine communication part, by which the effective ink supply path can be stably provided in the vacuum producing material in the second accommodation chamber. This can be further stabilized by placing the ink supply opening above the fine communication part relative to the bottom surface of the ink cartridge. i Because of this arrangement, the ink moving ! direction can be substantially made constant, and therefore, the ink can be completely consumed ifrom the second chamber, hat i There are provided a region of the vacuum produe i ng material not. compressed by the supply pipe and the region thereof compressed by the supply pipe in this order in a di root ion from the partition wal1 constituting the fine communication part to the side iace thereto, and therefore, the non-compressed region provided one-way ink path, and the ink retaining capaci t y oi the compressed region can further reduce the remaining amount of the ink. The ink jet printer is provided with a recording head recovery means HR which carries out ink ejection or ink sucking by sucking means automatically or manually in response to mounting of the cartridge 1 thereto. By doing so, the state of the ink in the i vacuum producing material can be corrected before the i start of the printi ng operation, Therefore, the cartridge performance can be used form the start of the printing i rrespect ive of the state in which cartridge has been placed. ! In Figure 12, t ho i nk container 1 bounted to the ink jet head HD mounted on a scanning type carriage CR has been deprived the sealing tape. The container mounted on the carriage CR receives through the opening 2 the ink supply pipe, by which the vacuum producing material 3 is compressed in the compressible region .\h. In this embod iment, the vacuum producing rnomber 1 is deformed toward the fine communication part H. At this time, tho mounting of the container is dot noted by detecting means (not shown) in the form of mechanical or electrical detecting means, which produces mounting signal IT into the printer control means CC. In response thereto, the recovery means HR is actuated before the start of the recording operation to discharge the ink in the ink container, thus improving the state of the ink in the ink container. In Figure 13, (A), there is shown an ink jet cartridge which is a modification of that of Figure 12 , in which the inside surface of the ink accommodating i chamber is modified, and the top part thereof is 1 correspondingly modified into a space 22. The inside surface 20 provides a curved surface which rises away from the fine communication part 8. This structure is effective to supply into the vacuum producing material 3 fine droplets of ink remaining on the wall of the inside surface 20 by the surface tension of the; ink, and also to provide a grip 21 for the operator,! thus preventing deformation of the ink container upon manipulation thereof. Figure 13, (D) shows another modification in which the partition wall 51 is inclined so that the capacity is larger in the ink accommodating chamber or ink container than in the vacuum producing material front ai tier . Fi gure 13, (c ) shows an embodiment which has been produced by the manufacturing method described hereinbefore. A covering member 11 constituting the clearance or gap 8 with the partition wal1 5 i s lnserted and fi xed between side plates 101 and 100 of the cartridge main body. Designated by a reference 5E is an end of the covering member 11. In the case of Figure 13f (C), the clearance SP is not constant i f the bonding is not uniform. In view of this, it is preferable that spacers 110 contacting to the end 5E of the partition wall, as shown in Figure 13, (D), at the opposite ends. The spacer 110 IR preferably provided ori the covering member 11. Projections 30 in the space SP may be provided on the covering member to enhance the collection of the air i nto the ink container. Figure 14, (A) and (B) show an inclination i range capable? of printing operation or ink supply. Designated by a reference numeral 40 is a horizontal line. It is preferable that the fine communication pari i s at a lower position. ideally, bottom surface of l he cartridge is par.il lei with the horizontal plane 40. Practically, however, in the case of two chamber struct ure as in this embodiment, the inclination is permissi ble i n the range 0 . is reci procated on a scanning carriage, it is preferably 0 The vacuum producing material used in this embodiment may be const i tuted by a plurality of vacuum filter to remove foreign matters in the ink cartridge. i When the ink jet recording apparatus is operated, the ink is ejected through the orifice of the ink jet recording head, so that ink absorbing force is produced i n the ink contained. The ink 9 is suppJ ir-? (J to the; ink je I recording head from the ink container () through IJir clfMf.iiicc H between an end of i the rib b and the bottom ol l;lie ink cartridge 11 to the vacuum producing mate rial container 4, and through the vacuum producing material 3 to the joint member 7. By this, the pressure of the ink container 6 which is closed except for the clearance 8, reduces with the result of pressure difference between the ink container 6 and the vacuum producing material container 4. With the- continued recording operation, the pressure difference continues to increase, however s i nee I he vacuum produe i iig ma tor i a 1 container 4 is open to the ai r through the ai r vent 10. As shown in Figure 1 f>, (b) , the ai ? enters the ink container 6 through the vacuum producing material 3 and the \ clearance 8. by this, the pressure difference between the ink container 6 and the vacuum producing material contain^1!: 4 is removed. During the ink jet recording operation, this is repeated, so that a constant certain level of vacuum is maintained in the ink cartridge. All nf the ink in the ink container 6 can be used up, except for f he ink r"eposi ted on the WE CLAIM : 1, A container connectable to a recording head for an ink jet recording apparatus, comprising : a first chamber containing liquid retaining material and having an air vent for allowing ambinent air into the container; and a second chamber which provides a liquid reservoir for the first chamber and is substantially closed apart from a communication port communicating with the first chamber, wherein said liquid retaining material extends partly into said communication part and is, substantially, not compressed by the end of the partition between the first and second chambers which defines the communication port. 2. A container according to claim 1, wherein said communication port is formed between the partition wal1 and an inside surface of said container, a wall of said first chamber facing said partition wal 1 is provided with an opening for supplying printing 1iquid from the container and means are provided for sealing the supply opening and said air vent prior to use of the container. 3. A container according to claims 1 or 2, wherein the volume ratio of said first chamber to said second chamber is from 1 : 3 to 1:1. 4. A container according to anyone^-of-~the claims 1 to 3, wherein the communication port is larger than the average pore size of said liquid retaining material in said firat chamber, and is not less than 5 mm. 5. A container according to claims 1 or 2, wherein said second chamber is enlarged so as to extend beyond the first chamber in a direction which is upward in use of the container. 6. A container according to any one of the preceding claims, wherein the container contains ink. 7. A container according to claim 1 or 6, wherein the negative pressure producing material has a portion not filled with the 1iquid adjacent to said air vent. 8. A container according to claim 1 or 6, wherein when said ink cartridge is connected with the ink jet head, the negative pressure producing material is compressed by an ink supply tube of the ink jet head adjacent to the ink outlet, 9. An ink jet head assembly comprising a container in accordance with any of claims 1 to 6. 10. A printer comprising an ink jet head according to claim 7. 11- A container connectable to a recording head for an ink jet recording apparatus, substantially as hereinabove described and i1 lustrated with reference to the accompanying drawings.

Full Text

INK JET CARTRIDGE, INK JET HEAD AND PRINTER
FIELD_ OF THE__IN VENT ION AND RELATED ART
The present invention relates to an ink jet cartridge containing liquid ink, manufacturing method thereof, an ink jet head and printer using the cartridge, and is usable with a copying machine, a facsimile machine or another recording apparatus, communicati on apparatus, office equipment, combined machi no or printer.
Heretofore, an,ink cartridge for an ink jet recording apparatus is integrally formed with an ink jjet head, and when the ink in the cartridge is used up, the unified end and the container are disposed of. The quantity of the ink remaining in the cartridge is decided by the ink retaining capacity of a spongd (vacuum producing material) occupying the entirety of the space in the cartridge, and it is relatively, large. Jnpanv&e Laid-Open Patent Application No.
63242/1988 discloses such an ink container. The ink
i
contai nor contains a foamed material, and it is integral wi1h an ink let recording head having a plurality of ink ejection orifices. In such an ink contain^/, in order to accommodate the ink in the porous mat oria 1 such as foamed polyurethane material, the production of the vacuum and the ink retention (prevent i on of the ink leakage from the ink container)

are accomplished by the capillary force of the foamed material. However, the foamed material is required to be f i 1 Jed in the enti ret y of tlie ink container, and therefore, the quantity of the ink therein is limited, and the quantity of the non-usable ink is relatively large. This means that the ink use efficiency is low. It is difficult: to detect the remaining amount of the ink therein. In addition, during the ink consumption period, the negative pressure gradually changes, and therefore, it is difficult to maintain a substantially constant vacuum.
Japanese Laid-Open Patent Application No,
i
522/1990 discloses that the ink cartridge contains substantially only the ink. More particularly, it discloses an integral ink jet recording head and ink cont.ai nor, comprising a primary ink container for containing a large amount of the ink at an upper
position, and a small porous material between the ink
i jet recording head therebelow. It is stated thkt the
i ink use efficiency is improved because only the! ink is
disposed in the ink passage without the porous !
i
material contained in the ink container. In addition, a secondary ink container capable of containing the ink is provided at a side of the porous material, whi ch is ef feeti ve to receive the ink flowed from the primary ink container due to expansion of the air in the primary i nk container upon temperature rise

(pressure decrease), so as to maintain a substantially constant negative pressure of the recording head dur ing the recording operation -
In this structure, when the recording operation is not carried out, the porous material is filled with a very large amount of the ink from the primary ink container containing a large amount of the ink above the porous material, and therefore, the porous material itself can hardly produce the iiegative
pressure. For this reason, the ink leaks out of the
i orifice of the ink jet recording head by small impact,
and therefore, it is not practical. If this dontainer
is used as a exchangeable ink cartridge to be mounted
to an ink jet recording head, the ink can leaks out of
the porous material, and therefore, it is still not
| practical.
I :
In an i nk cart ri dgn, the ink is sealingly
i l
! !
. contained in a bladder, and the negative pressure of
the bladder i s maintained constant using a spring
i structure, but this is expensive, and it is difficult
to mass-produce with the correct performance of the
spring structure. In the field of the ink jet
printing (non-contact type printing) inexpensive ink
cartridge having proper performance has not been
accomplished, and has long been desired.
The inventors have investigated from the
standpoint of capability of properly supplying the ink

cor responding to the eject, ion of the ink from the recording head during the printing operation and also front the standpoint of capability of preventing ink leakage through the ejection outlet when the printing operation is not carried out. As a result, it has been found that the fundamental structure comprises a first container containing a vacuum producing material and provided with an air vent and a second container for containing substantially only the ink to be suppl iod to the first container, the second container being substantially hermetically closed with the exception of the communication with the first container.
Japanese Laid-Open Patent Application No. 16385/1985 discloses a recording pen having a recording tip which is contacted to a recording material during the recording operation. The
recording tip has ink absorbing and retaining nature,
i i
and the ink is supplied thereto. Therefore, the
recording tip is exposed to the ambience, as i i
contrasted to the ink jet recording apparatus. The Japanese Laid-Open Patent Appli cation is directed only to the overflow of the ink through the recording tip.
It comprises as essential elements a first liquid absorbing material, and a second absorbing material which absorbs less ink than the first absorbing material although it absorbing a small

amount of the ink, the second absorbing material being disposed above the first absorbing material at a posi tion closer to the ai r vent, a central chamber from which the recording tip is projected downwardly, and hermetically closed in accommodating chamber to supply the ink to opposite sides of the chamber. With this structure, when the air in the closed ink container expands due to the ambient temperature rise with the result of the ink in the ink container into the first absorbing material, the ink incapable of being retained by the first absorbing material, is absorbed by the second absorbing material, so that the overflowing droplets of ink from the writing tip can be prevented. It also discloses provision of a constant width groove which is effective, when one of the two closed ink container contains only air, to permit the expanded air to escape through the air vent. The groove is extended from the bottom end to the top end on a si do sur face which is different from a partition wal1 between the central chamber and the c:l osed i nk container . When this structure is used for an ink jet recording head, the ink leakage through the air vent has been confir med, as has been expected because of the fundamental difference between the contact recording and the non-contact recording. This problem is not recognized in the field of the recording pen. In addition, the constant width groove

servos to promote the discharge of the ink together with the air, and therefore, the leak of the ink through the air vent has been promoted.
Additionally, the ink consumptions of the two ink containers are not the same. If one of the containers becomes empty first, the ink jet recording operation became no longer possible despite the fact that a 1arge amount of the ink is remaining in the other ink container. This is because a large amount of the air is introduced into the first absorbing material with the result of incapability of the ink supply. This is against the aim of this invention*
SUMMARY Of^HE INVENTION
Accordingly, it is a principal object of the present invention to provide an improvement to the fundamental structure having the first contained containing the vacuum producing material and provided
wi l.h the air vent for communication with the ambience,
i
and a second container for substantially only the ink to be supplied to the fi rst container, the secohd container being substantially hermetically closed with the exception of the communication with the first

hoad and a printer usinq the same capable of effecting high speed recording, while the vacuum can be maintained substantially constant in a large part of the period from the start of the use to the end thereof of the ink cartridge.
It is another object of the present invention to provide an exchangeable ink cartridge in which the vacuum is produced in the ink cartridge when the recording operation is not effected, thus preventing ink leakage through an opening upon small impact.
It is a further object of the present
invention to provide an ink cartridge in which ;the
i i
remaining non-usable ink is minimized.
It is a yet further object of the present
i
invention to provide a.n exchangeable ink cartridge which is less expensive and from which the ink does not leak out during transportation of itself. According to an aspect of the present : invention, a region of the vacuum producing material that adjacent to air introduction passage does not ronl.iin the ink. By doing so, the leakage of the ink through the a i r vent ftorn the ink cartridge can be prevented against the ambient condition change. Part i nilarly when a sealing member is used to seal the a i r '/r»nt, thi s aspect of the invention is effective to prevent removal of the sealing member. During the use of the ink cartridge, this region is effective to the

proper amount of the air is introduced into the ink cartridge, thus suppressing variation of the vacuum in the ink jet cartridge. The region adjacent the air introduction passage is completely free from being wetted by the ink, the ink seeping speed is reduced, and therefore, it is desirable. However, it is a possiblo alternative that the region is once wetted by the ink, and the ink is thereafter removed.
Acco/djriii In .mot hei. aspect of the invention baser I on the abovo-deser i bed fundamental structure, the vacuum or negative pressure producing material is compressed or capable of being compressed in the region adjacent an ink supply opening or an ink supply pipe which is provided at a side opposite from the partition wall having a small communication part
between the first container and the second container.
i
My doinq so, a stabi)ized ink path can be assurfed in
i i
the vacuum produci ng material from the second ink , contairu^r. h'nr l;he purpose of t he further stabi1j nation, the i nk supply opening is disposed above the sma11 communi cat i on part relative to the bottom surface of the ink cartridge. Here, the supply pipe incIudes an inser f i on in pe peculiar to the ink jet recording or pri nt i nq, and a valve structure or connect i ng member mounted on the cartridge compressing the vacuum producing membr r. By doing so, the ink movement direction can be substantially stabilized, so

that; a 11 of the ink in the second container can be used up. After it is used up, the air moves from the parti tion wall toward the ink supply opening, thus permitting consumption of the ink in the vacuum producing material, and therefore, the amount of the non-usable remaining ink can be minimized.
According to a further aspect of the present invention, a region of the vacuum producing material
not compressed by the supply pipe, and the region
i
compressed by the supply pipe are formed in the order named from the partition wall forming the fine
communication part to the opposite wall, by which one
i
way ink supply path is formed in the non-compressed region, and in addition, the remaining non-usable ink amount can be further reduced by the ink retaining
capacity in the compressed region,
i
The present invention includes a structure containing one or more of the above-described Aspects.
The ink jet cartridge of this invention is usually handled by an operator, and therefore, | it is po.ss i b 1 r» tha t ?-;l r ong J or re is appl ied thereto wi th the result of deformation of the ink container wall- In vi r»w o\ this, i 1: is preferable that an additional partition wall providing a larger clearance than the fine communication part: in the ink container for contni ni ng substantial 1y only the ink. When the cartridge is made of resin material, it is preferable

that the thickness of the wall containing substantially only of the ink is 0.8 mm (Ti, G in Fi guro 29) or more and t hat the wal 1 thickness of the container containing the vacuum producing material such as sponge is 1.3 mm (Ts, J in Figure 20) from the standpoint of the prevention of the deformation. In the ink jet printer of this invention, the ink is forced discharged by sucking the ink by the sucking means and by ejecting the ink by ejecting means automatically or manually upon mounting of the cartridge on the ink jet printer. This is preferable because the state of the ink in the vacuum generating material can be adjusted before the start of the pri nt.i ng operation, and therefore, the printing
function can be performed wi thout influence of; the ink
i
cartridge keeping state. i

average pore size of the vacuum producing material (preferably the average' pore size in the region adjacent the fine communication part) (practically not less than 0.1 mm), and it is preferably not less than 5 mm. If it is less than 3 nun, the further stabilization can be expected. The volume ratio of the vacuum producing material container and the ink container is not less than 1:1 and not more than 1:3, practi cally.
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the
present invention taken in conjunction with the
i i
accompanying drawings.
i
i BR IEF HESCR IJPTIPN..OF THE DRAWINGS
Figure 1 i s a schematic partly broken perspective view of an ink container according to a first embodiment of the present invention. * Figure 2 is a sectional view of the ink conta i na.r of F1 gure 1 .
Figure 3 shows examples of connection between the cartridge and the supply pipe.
Figure 4 i1 lust rates a comparison example.
Figure S i 1 lust rates ink supply part used in thi s i nvonf: ion .

Figure 6 illustrates a positional relationship between an ink supply portion and the fine communication part.
Figure 7 illustrates the structure of the fine communication part.
Figure 8 illustrates configuration of the partition wall at a side of the fine communication part.
Figure 9 illustrates state of the absorbing material at an end adjacent the partition wall.
Figure 10 illustrates the state of inside of
the absorbing material against ambient condition
change. |
Figure 11 illustrates a manufacturing method according to an embodiment of the present invention, and illustrates an ink jet head.
Figure 12 illustrates an ink jet printer and an ink cartridge usable therewith.
Figure 13 illustrates modified embodiments of trhr* present invention.
Figure 14 is a sectional view illustrating permissible inclination in use, of the ink cartridge.
Figure 15 shows configuration in an erobodi UHMI! of the present invent i on.
Figure 16 illustrates the change in the pr in I i tiff opera t i on .
Figure 17 111ustrates pressure to the

extoinal wall of the cartridge according to an embodiment of the present invention.
Figure 18 is a sectional view of a modified example of an ink cartridge according to an embodiment of the present invention.
Figure 19 is a perspective view of a color ink container according to an embodiment of the present invention,
Figure 20 is a graph showing a relation between the thickness of the wall and ink leakage by
!
the external pressure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figures 1-6, there is shown an ink container having an ink supply opening formed In a
I 1
wall of a vacuum producing material container that is facncl to a pari i lion wal ] 5 which is cooperative with a bottom surface of the cartridge to form a fine communicati on part M.
Fi gu i e I is a pe r spec I i ve view of the i nk container according to a f irst embodiment, and Figure -.2 is a .sectional vinw of the i nk container according to [ he I. i rst embodiment .
As shown in Figures 1 and 2, the ink carlridge main body 1 of his embodiment is provided w i l.h an open i ng /* I or commun i cat ion with an ink jet r ecor
communication part in i hn form of a clearance 8. It comprises a vacuum producing material container 4 for containing the vacuum producing material 3 and enn ink container 6 for containing substantially only the ink, which communicates with the container 4 at a bottom portion 11 through the clearance 8 provided by the partition wal1 5.
With this structure, the air is supplied through the opening 2. However, what is important is
the ink is supplied assuredly from the ink container 6
i through the communication part 8 toward the opening 2
along the bottom 11 of the ink cartridge. With the
ink supply, the air is introduced in place of the ink
in the ink container 6. The description will be made
as to the compressing deformation of the vacuum or
negative pressure producing material by the supply
pipe in the compressing deformation capable region
adjacent the opening. In Figure 3, a joint member 7
functioning as a supply pipe for supplying the ink to
the ink jet recording head has been inserted into an
exchangeable ink cartii dge according to this
embodiment. With this state, the joint member 7 is
press-contacted to tho vacuum producing member, and
the i f I k jot record i rig apparatus is operable in this
;respect. A filter may he provided at an end of the
joinI member to remove the fore ign matter in the ink
car t r i dgo .

When the ink jet recording apparatus is operated, the ink is ejected out through orifices of the ink jet recording head with the result of ink absorbing force in the ink cartridge. The ink 9 is supplied by the absorbing force from the ink container 6 through the clearance B between the bottom end of the partition and the bottom of the ink cartridge 11 to the vacuum producing material container 4, and to the ink jet recording head through the vacuum producing material 3 and the joint member 7.
By this ink supply, the internal pressure of
the ink container 6 which is closed except for the
i
! '■
clearance 8 reduces with the result of pressure
difference between the ink container 6 and the vacuum
i producing material container 4. With the continuing
recording operation, the pressure difference cdntinues to i ncreaso. However, since the vaciium producing
material is open to the ambience by a clearance 10
i
between the joint member and the opening. The air is
i
introduced into the ink container 4 through th

recording, various color inks (black, yellow, magenta and cyan) may be accommodated in separate exchangeable ink cartridges, respectively. These ink cartridges may be unified as shown in Figure 19A. The exchangeable ink cartridge may comprise a black - con tai ner exchangeable ink cartridge which is
frequently used and one another color exchangeable cartridge, as shown in Figure 19, (B). Any combination is possible in consideration of the ink jet apparatus. In the exchangeable ink cartridge accord i ng to thi s embodiment, in ord^r to control the vacuum, the following is preferably optimized:!
material, configuration and dimensions of the vacuum
i producing material 3, configuration and dimensions of
rib end 8, configuration and dimensions of the I
clearance 8 between the rib end 8 and the ink i
container bottom 11, volume ratio between the vacuum prod i in" ng mater i a 1 con t.ai ner 4 and the ink container l>, con I iguiation The material of the vacuum producing member may be any known material i f it can retain the ink despite the weight thereof, the weight of the liquid ( i nk ) and smal1 vi brat ion. For example, there are sponge i i ke materia 1 made of f i hers and porous

functioning also as the air introduction opening, and therefore, the structure is simple. The amount of insertion of the joint member 7 into the exchangeable ink cartridge is properly determined by the ordinary skilled in the art so as to provide a compression region of the vacuum producing member to prevent ink leakage upon the insertion and to prevent ink supply stop during the recording operation, in consideration of the configuration of the joint member, the vacuum j producing material and the configuration of the ink cartridge.
In the foregoing embodiment, it is effective to provide an air vent in the vacuum producing material container, since then the region of the vacuum producing material that does not contain the
ink is easily located adjacent the air introduction
■ i passage. The reliabi1i ty in the ink jet recording
appa ratus against the ambient condition change is
improved . The con f i .gur atton and dimensions of the
clearance 8 between t he end of the partition wall and
tho ink cart ridge bottom, a re net 1imited. However,
if it is too srnal 1, the meniscus force with the ink is
too strong, and although the ink leakage can be
prevented through the joint opening, but the ihk
supply to the vacuum producing material contaiher is
di f f i mi It, with the possi hie result of ink supply stop
during the use. If it is too large, the opposite

The r:l (Mrancn H i s a 1 ;u> determined in considoration of the posttion of the joint opening. Reforri nq to Fiqure 10, (a) and (b) , the partition wall end is at a position lower than the bottom end of the joint opening in Example (a), and the ink retained in the vacuum producing material is lower than the bottom end of the -joint opening, and therefore, the leakage preventing effect is sufficient. In Example (b), the end of the partition wall is at a position higher than the bottom end of the joint opening, and the ink retained in the vacuum producing material is above the bottom end of !the 30int. opening, and therefore, the ink leakage
suppressing effect is not sufficient. Therefore, it
1
is preferable to stabilize the advantageous effect of
i the present invention that the position of thje end of
the partition wall is not higher than the botftom end
i
of the joint opening by properly determining ithe dimension of the clearance 8. Although it id
. i
dependent on the configuration and dimensions of the
i
exchangeable ink cartridge, the height of the clearance 8 is selected in the range of 0.1 - 20 nun. Further preferably it ranges from 0.5 - 5 mm approximately. The conl iqurati on of an end of the parti tion wai 1 tuny bo any i f the consideration is paid In the position relative t.o the joint opening, as will be understood f rom Fi qure M, (a) - {h).

As regards the boundary between the end of the partition wall 5 and the vacuum producing material 1, various structures are consi dered. This is shown in Figure 9. In the structure of Figure 9, (a) - (d), I the vacuum producing material is not compressed by the end of the partition wall, and the density of the vacuum producing material is not: locally increased, and therefore, the flow of the ink and the air is relatively smooth, and for this reason, it is preferable for a high speed recording or color recording. On the other hand, the examples of Figures 9, (e), (f), the vacuum producing material 3 compressed by the end of the partition wall, and the
density of the material is increased, and therefore,
i the flow of the ink and the air is obstructed, but the
ink leakage or the like can be effectively prevented
* against siight ambient condi tion change. Therefore,
they ara properly determined by one skilled in the
art, on the basis ot the ink jet recording apparatus
with which the ink cartridge is used &nd the ambient
condi t i on under which the i nk cartridge is used.
The volume ratio between the vacuum producing
material container 4 and the ink container 6, iS
determined in considerat ion of the ambient condition
under which the ink cartridge is used and the ink jet
recording apparatus with which it is used. Also, the
relation wi th the used vacuum producing material is

important. In order to improve the use efficiency of the ink, it is desirable to increase the volume of the ink container. In that case, a vacuum producing material capable of producing high vacuum (high compression ratio sponge), is effective. Therefore, the preferable ratio ranges from 1:1 - 1:3 practical ly. In this casn', the vacuum producing performance of the vacuum producing member is inci r^ased with increase ol the relative volume of the ink container.
The configuration, dimension and mesh of the
i
filter 11 can be properly determined by one skilled in
. i i
the art depending on the ink jet recording apparatus
i
> i
with which the ink cartridge is used. However,jin
s
order to prevent the nozzle from being clogged by the foreign matter introduced from the ink cartridge, the
passing area thereof is smaller than the size Of the
,'i
ori fice. ;
The quantity ol" the ink in the ink cartridge
is not Iimi ted except for the internal volume of the
ink cartridge. In order to maintain the proper
negative structure immediate]y after the exchangeable
ink cartridge is unpacked, the ink may be contained to
the extent of the volume 1imit i n the ink container.
However, the vacuum producing material is preferably
lower than the ink retaining capacity of the material.
Here, the ink retaining capacity which can be retained

solely by the material when tho ink is contained therein.
In the ink cart ri dge having a closed system ink container, when an external ambient condition change such as temperature rise or pressure reduction, occurs when it is loaded in the ink jet recording apparatus, the air and the ink expands in the ink container to push the remaining ink out of the ink cartridge with the possible result of ink leakage. However, in the exchangeable ink cartridge of this invention, the volume of air expansion in the Closed ink container, inclTiding i nk expansion (although the amount is small) in accordance with the worst ambient condition change, is estimated, and the amount of the displaced ink from the ink container is to be accommodated in the vacuum producing material container. In this case, it is very effective to provide the vacuum producing material contained with an air vent in addition to the joint opening, as shown in Figure JO, ( r ) and
from the joint opening, i t is preferably away from the joint opening. The number, configuration and size of the ait vent are properly determined by skilled in the art in consideration of the ink evaporation or the like.
Dur i nr\ transports I i on of the ink cartridge itself, it is preferable that the joint opening and/or the air vent is hermetically shield by a sealing member to prevent ink evaporation or to be prepared for the expansion of the air in the ink cartridge.
: : j
The sealing member may be a single layer barriejr which is so-called barrier material in the packing field, a
compound plastic film having several layers, or such
i
material reinforced by paper or cloth or ahothdr reinforcing material or aluminum foil, are preferable. It is further preferable that a bonding layer of the same mater ial a:-; the main body of the ink cartridge is used to fuse fixing the hairier material, thus improvi nq the hermetica1 seali ng property.
In or He r to snpi i same barrier material as described with respect to the sea 1 i ng rnombe r in cons i r f * • r a 1 i on of the permeabi 1 i ties of the liquid and the t?i

By such propei so Loci ion of the packing, the ink doos not Ionic out during HIP t rnnRpnrl aI; i on of l:ho ink cartridge itself.
The material of the main body of the ink cartridge may be any known moldable material ifj it
1 i ';
doriH not li;iv(! «jny *KJVOI«NO inl luonce to the, ink jet i oooi d i iig i file 01 if i I h.r; boon I i o from plastic resin material, respectively. Th6 vacujim
i ■'
! h
producing material is inserted thereihto, and !
■ ! !
thereafter, the bottom portion and up^er pOrtioh are
fuse-bonded, thus providing the main body of thte ink
1 ; i cartridge. If the plastic material is transparent or
i
semitransparent, the ink in the ink container can be,
observed externally, and therefore, the timing of ink
1 i
cartridge change may be expected. In;order to The ink can be loaded through pressurizing or pressure- reduction mo thod . 1' rovi si on of ink fil ling opening in either of the containers of the containing

main assembly is preferable since then the ink cartridqe opening is not contaminated. After the filling, the ink filling opening is plugged by plastic or metal plug.
The configuration, dimension or the like of the ink cartridge according to this invention can be modified without departing from the sprit of the present invention.
As described in the foregoing, the exchangeable ink cartridge is reliable during the
transportation thereof, and a high use efficiency ink
, i
cartridge can be provided with simple structure!.
i
The proper vacuum is maintained from the start to the end of the use can be maintained when the recording operation is carried out or is not cajrried!
I ;
l
out, while permitting high speed recording. Under the
i use ambient condition of the ink -jet recording ;
apparatus, the possibility of the ink leakage can be
i
minimized. !.
The exchangeable ink cartridge of this'
invention is easy to handle .so I hat the ink does not
leak out when i t. is loaded into the ink jet recording
apparatus, and the possibi1i ty of erroneous operation
can he avoi ded.
Figure 1 1 i 1J list lates a manufacturing method ~>f an i nk contai ner cart i j dqe . A main body of the -:art ridge (left down hatchi rig) comprises a partition

plate 61 and two containers separated by the partition wall 5. An ink absorbing material 4 functioning as the vacuum producing material is inserted into the container portion which is close to the opening 2« Thereafter, a bottom member 11 functioning as the covering member is unified to the main body. This Figure also shows the state in which the recording head HD is loaded in the ink container 1. The ink container 1 is constituted by a container partitioned into two chambers by a partition wall 5, and the
bottom portion is covered by a flat bottom member 11
j
constituting the bottom of the ink container, >Thus,
by the simple structure, the fine cortimunication part 8
i ; .] ;i can be provided by the end of the pattitidn wall.
The air vent 10 is disposed on the saihe !!
surface as having the opening 2, but above the! !;
opening. j '
The joint port ion 7 functioning as the supply
' : it
pipe is inserted into the opening of the ink \ container, and the recording head is;mounted thereto,
i I
The joint portion 7 is i. ncl ined so that the top portion is more front than the bottom portion. The ink passage in the joint is in the form of a horn opening upwardly in the Figure. With this structure, the i nk can be properly supplied to the recording head from the ink absorbing material.
The ink jet recording apparatus comprises

heat generating element 7 2 for producing thermal energy to eject the ink through ejection outlets 71 of the nozzles 73, wherein the thermal energy is effective to cause state change in the ink. In this case, a high density and fine images can be provided by the stabi1ized ink supply performance, particularly in the case of color recording.
As described in the foregoing, the ink cartridge according to this invention, the high reliability is maintained during the transportation
thereof, and the use efficiency of the ink is high. ,
i In addition, the proper vacuum is maintained
from the start to the end of the use thereof when the
I !
I
recording operation is carried out or is not carried
i
out, when permitting high speed recording operation.
i
In addition, the ink leakage can be prevented tender the use condi ti on of the ink jet recording apparatus. Additionally, the exchangeable ink cartridge
I ;.
i ; i
according to this invention is easy to handle, The manufacturing method of the ink cartridge will be described further. When the closed structure ink conUtinf-r ( ,i I I hough I 'KM e is fine communication part be t ween th i nk conl ai n i ng chamber or container

and the negative pressure producing material containing chamber, but the ink is discharged only when the air and the ink are exchanged with each other), and the vacuum producing material containing chamber are integrally molded, the ink is filled through an opening 13 at the ink container chamber side in the covering member 11. When the ink is supplied in this manner, a substantial part of the vacuum producing material 4 receives the ink through the fine communication part.
However, the region of the vacuum producing material 4 adjacent the air vent is not supplied with
the ink to provide ink-free region. Thereaftet, the
i opening 13 is sealed by a ball 14. Then, the (opening
2 and the air -v^nt are sealed by the same sealing
member S (it may be separate members).
i Figure 12 shows such an ink jet cartridge
before start of use. In this Figure, the ink
container 6 is filled with an ink.
Figure 12 shows the closed state ink ijet
cartridge 1 with the printer which is used therewith.
A region 3A of the vacuum producing material adjacent
to the air vent portion 10 does not contain the ink at
an upper portion of the cartridge. A region 3B of the
vacuum producing material below the region 3A is
compr essod by insert i on of t;hn i nk supply pipe (not
shown). The vacuum produci ng material portion other

than those roqions 1A and ID, are not externally influenced and simply functions to retain the ink. The region 3B is faced to the opening 2 for the ink supply to the recording head provided on the same surface but below the air vent 10. The opening is above the fine communication part 8, and the above-described structure is used. The cartridge 1 of Figure 12 becomes usable by removing the sealing member S. Since the region A does not retain the ink, the ink does not leak out even if the vibration or pressure change is imparted upon the removal 6f the sea1ing member,
In the ink container of this invention, the
1 i
ink is not retained in the region of the vacuiim producing member that is close to trie air vent or air communication part, irrespective of whether the ink cartridge is being used or not used. By doing so, the leakage of the ink from the ink cartridge thrdugh the air vent can be prevented even when the ambient condition varies. Particularly, when the sealing member closes the air vent:, the sealing member can be prevented from peeling off. During the use, the region is effective to permit air supply^ corresponding to the consumption of the i nk, so that the change of the varuum in the ink cartridge can be suppressed. If the region oi the vacuum producing material adjacent t o t h
all, i t is preferable to «iecelerate the ink seeping speed- However, the region thereof may be wetted by the ink beforehand, and thereafter, the ink may be removed from this region.
In the embodiment of this invention, the ink supply opening or the compressed part of the vacuum prorluci ng material (compressible) by the ink supply pipe is present at a side opposed to the partition wall constituting the fine communication part, by which the effective ink supply path can be stably provided in the vacuum producing material in the second accommodation chamber. This can be further stabilized by placing the ink supply opening above the fine communication part relative to the bottom surface
of the ink cartridge.
i Because of this arrangement, the ink moving
!
direction can be substantially made constant, and therefore, the ink can be completely consumed ifrom the second chamber, * hat i There are provided a region of the vacuum

produe i ng material not. compressed by the supply pipe and the region thereof compressed by the supply pipe in this order in a di root ion from the partition wal1 constituting the fine communication part to the side iace thereto, and therefore, the non-compressed region provided one-way ink path, and the ink retaining capaci t y oi the compressed region can further reduce the remaining amount of the ink.
The ink jet printer is provided with a recording head recovery means HR which carries out ink ejection or ink sucking by sucking means automatically or manually in response to mounting of the cartridge 1
thereto. By doing so, the state of the ink in the
i
vacuum producing material can be corrected before the
i start of the printi ng operation, Therefore, the
cartridge performance can be used form the start of
the printing i rrespect ive of the state in which cartridge has been placed.
!
In Figure 12, t ho i nk container 1 bounted to the ink jet head HD mounted on a scanning type carriage CR has been deprived the sealing tape. The container mounted on the carriage CR receives through the opening 2 the ink supply pipe, by which the vacuum producing material 3 is compressed in the compressible region .\h. In this embod iment, the vacuum producing rnomber 1 is deformed toward the fine communication part H. At this time, tho mounting of the container

is dot noted by detecting means (not shown) in the form of mechanical or electrical detecting means, which produces mounting signal IT into the printer control means CC. In response thereto, the recovery means HR is actuated before the start of the recording operation to discharge the ink in the ink container, thus improving the state of the ink in the ink container.
In Figure 13, (A), there is shown an ink jet cartridge which is a modification of that of Figure 12 , in which the inside surface of the ink accommodating i chamber is modified, and the top part thereof is 1 correspondingly modified into a space 22. The inside surface 20 provides a curved surface which rises away from the fine communication part 8. This structure is effective to supply into the vacuum producing material 3 fine droplets of ink remaining on the wall of the inside surface 20 by the surface tension of the; ink, and also to provide a grip 21 for the operator,! thus preventing deformation of the ink container upon manipulation thereof.
Figure 13, (D) shows another modification in which the partition wall 51 is inclined so that the capacity is larger in the ink accommodating chamber or ink container than in the vacuum producing material front ai tier . Fi gure 13, (c ) shows an embodiment which has been produced by the manufacturing method

described hereinbefore. A covering member 11 constituting the clearance or gap 8 with the partition wal1 5 i s lnserted and fi xed between side plates 101 and 100 of the cartridge main body. Designated by a reference 5E is an end of the covering member 11. In the case of Figure 13f (C), the clearance SP is not constant i f the bonding is not uniform.
In view of this, it is preferable that spacers 110 contacting to the end 5E of the partition wall, as shown in Figure 13, (D), at the opposite ends. The spacer 110 IR preferably provided ori the covering member 11. Projections 30 in the space SP may be provided on the covering member to enhance the collection of the air i nto the ink container.
Figure 14, (A) and (B) show an inclination
i range capable? of printing operation or ink supply.
Designated by a reference numeral 40 is a horizontal
line. It is preferable that the fine communication
pari i s at a lower position. ideally, bottom surface
of l he cartridge is par.il lei with the horizontal plane
40. Practically, however, in the case of two chamber
struct ure as in this embodiment, the inclination is
permissi ble i n the range 0 . is reci procated on a scanning carriage, it is
preferably 0 The vacuum producing material used in this
embodiment may be const i tuted by a plurality of vacuum

filter to remove foreign matters in the ink cartridge.
i
When the ink jet recording apparatus is
operated, the ink is ejected through the orifice of
the ink jet recording head, so that ink absorbing
force is produced i n the ink contained. The ink 9 is
suppJ ir-? (J to the; ink je I recording head from the ink
container () through IJir clfMf.iiicc H between an end of
i the rib b and the bottom ol l;lie ink cartridge 11 to
the vacuum producing mate rial container 4, and through the vacuum producing material 3 to the joint member 7. By this, the pressure of the ink container 6 which is closed except for the clearance 8, reduces with the result of pressure difference between the ink container 6 and the vacuum producing material container 4. With the- continued recording operation, the pressure difference continues to increase, however s i nee I he vacuum produe i iig ma tor i a 1 container 4 is open to the ai r through the ai r vent 10. As shown in Figure 1 f>, (b) , the ai ? enters the ink container 6 through the vacuum producing material 3 and the \ clearance 8. by this, the pressure difference between the ink container 6 and the vacuum producing material contain^1!: 4 is removed. During the ink jet recording operation, this is repeated, so that a constant certain level of vacuum is maintained in the ink cartridge. All nf the ink in the ink container 6 can be used up, except for f he ink r"eposi ted on the

WE CLAIM :
1, A container connectable to a recording head for an ink jet recording apparatus, comprising : a first chamber containing liquid retaining material and having an air vent for allowing ambinent air into the container; and a second chamber which provides a liquid reservoir for the first chamber and is substantially closed apart from a communication port communicating with the first chamber, wherein said liquid retaining material extends partly into said communication part and is, substantially, not compressed by the end of the partition between the first and second chambers which defines the communication port.
2. A container according to claim 1, wherein said communication
port is formed between the partition wal1 and an inside surface
of said container, a wall of said first chamber facing said
partition wal 1 is provided with an opening for supplying printing
1iquid from the container and means are provided for sealing the
supply opening and said air vent prior to use of the container.
3. A container according to claims 1 or 2, wherein the volume
ratio of said first chamber to said second chamber is from 1 : 3
to 1:1.

4. A container according to anyone^-of-~the claims 1 to 3,
wherein the communication port is larger than the average pore
size of said liquid retaining material in said firat chamber, and
is not less than 5 mm.
5. A container according to claims 1 or 2, wherein said second
chamber is enlarged so as to extend beyond the first chamber in a
direction which is upward in use of the container.
6. A container according to any one of the preceding claims,
wherein the container contains ink.
7. A container according to claim 1 or 6, wherein the negative
pressure producing material has a portion not filled with the
1iquid adjacent to said air vent.
8. A container according to claim 1 or 6, wherein when said
ink cartridge is connected with the ink jet head, the negative
pressure producing material is compressed by an ink supply tube
of the ink jet head adjacent to the ink outlet,
9. An ink jet head assembly comprising a container in accordance
with any of claims 1 to 6.
10. A printer comprising an ink jet head according to claim 7.

11- A container connectable to a recording head for an ink jet recording apparatus, substantially as hereinabove described and i1 lustrated with reference to the accompanying drawings.

Documents:

1348-mas-1998-abstract.pdf

1348-mas-1998-claims duplicate.pdf

1348-mas-1998-claims original.pdf

1348-mas-1998-correspondence othres.pdf

1348-mas-1998-correspondence po.pdf

1348-mas-1998-description complete duplicate.pdf

1348-mas-1998-description complete original.pdf

1348-mas-1998-drawings.pdf

1348-mas-1998-form 1.pdf

1348-mas-1998-form 26.pdf

1348-mas-1998-form 3.pdf

1348-mas-1998-other documents.pdf

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Patent Number

207922

Indian Patent Application Number

1348/MAS/1998

PG Journal Number

26/2007

Publication Date

29-Jun-2007

Grant Date

02-Jul-2007

Date of Filing

19-Jun-1998

Name of Patentee

CANON KABUSHIKI KAISHA

Applicant Address

3-30-2 SHIMOMARUKO, OHTA-KU.TOKYO.

Inventors:

#	Inventor's Name	Inventor's Address
1	MASAHIKO HIGUMA	2-18-11 HIYOSHIDAI,TOHGANE-SHI.

PCT International Classification Number

B41J02/175

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	198474/1992	1992-07-24	Japan