JP2011148221A - Ink storage container and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that poor discharging occurs due to the shortage of ink supply which is caused by the reduction of the effective area for removing impurities resulting from the adhering of bubbles to a filter. <P>SOLUTION: An ink cartridge 1 includes an ink bag 2 for holding an ink, and a supply opening part 23 where a hollow needle is run through from the side of an image forming apparatus and which feeds the ink to the apparatus body. A filter member 30 is arranged in a holding member 22 with a bag body 21 of a channel 25 in the supply opening part 23. The filter member 30 is formed of resin fibers containing an oxygen absorbent. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an ink storage container and an image forming apparatus, and more particularly to an image forming apparatus including a recording head for ejecting liquid droplets and an ink storage container used in the image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. As an apparatus, an ink jet recording apparatus or the like is known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials, resins and the like are also included. In addition, the “image” is not limited to a planar one, but includes an image given to a three-dimensionally formed image, and an image formed by three-dimensionally modeling a solid itself.

  As an ink supply method in such an ink jet recording apparatus used as an image forming apparatus, a method of supplying ink by detachably connecting an ink cartridge to the recording head side (direct connection method) and a sub tank (buffer) on the recording head side are provided. Tank, head tank, etc. are also synonymous.) The main tank is arranged on the main body side, the ink is supplied from the main tank to the sub tank, and the ink is supplied from the sub tank to the recording head (sub tank system). Are known.

  By the way, many of the ink cartridges used in the conventional direct connection system include an ink absorber made of a porous material for forming a negative pressure therein, and remove foreign matter from the ink supply port to the head. A filter member is provided.

  However, in order to increase the capacity of the ink tank and increase the printing speed, the direct connection method cannot be used, and the sub tank method has been adopted. However, the filter member is provided between the head tank and the head. In many cases, the main tank has a configuration in which no filter member is provided for cost reduction.

  As a conventional filter member, a sintered nonwoven fabric made of metal fibers having a high porosity and a small mesh size is known (Patent Document 1).

JP 09-187955 A

  If a filter member is provided in the ink supply path (the ink supply path from the main tank or ink cartridge to the head) to remove foreign matters in the ink, air bubbles mixed in the ink supply path When trapped by the filter member, the effective area of the filter (effective area for performing the filter function) is reduced.

  As a result, particularly when performing high-speed recording, there is a problem in that the amount of ink supplied to the head cannot catch up with the droplet ejection from the head, resulting in a droplet ejection failure.

  The present invention has been made in view of the above problems, and an object of the present invention is to enable stable ink supply by suppressing a decrease in effective area due to a bubble trap of a filter member.

In order to solve the above-described problems, an ink container according to the present invention includes:
In an ink container that contains ink to be supplied to a head that discharges droplets,
A supply port for supplying the ink;
The supply port is provided with a filter member,
The said filter member was set as the structure formed with the resin fiber containing an oxygen absorber.

  Here, the ink may be filled from a filling port different from the supply port.

  Further, the image forming apparatus main body can be detachably mounted.

  Further, the head can be detachably connected to the head.

The liquid discharge head unit according to the present invention is
In a liquid discharge head unit comprising a head for discharging droplets and a head tank for supplying ink to the head,
A filter member is provided between the head tank and the head,
The said filter member was set as the structure formed with the resin fiber containing an oxygen absorber.

  The image forming apparatus according to the present invention includes the ink container according to the present invention.

  The image forming apparatus according to the present invention is configured to include the liquid discharge head unit according to the present invention.

  According to the ink container and the liquid discharge head unit of the present invention, since the filter member formed of the resin fiber containing the oxygen absorbent is provided, the bubble is trapped when the bubble is trapped in the filter member. Absorption can be eliminated, the decrease in effective area can be suppressed, and stable ink supply can be performed.

  The image forming apparatus according to the present invention includes the ink container or the liquid discharge head unit according to the present invention, so that stable ink supply is performed and a high-quality image can be formed at high speed. .

FIG. 2 is an explanatory perspective view of the appearance of an ink cartridge as an ink container according to the present invention. It is front explanatory drawing of the ink bag of the ink cartridge. 2 is an enlarged cross-sectional explanatory view of a supply port portion of the ink cartridge. FIG. It is typical explanatory drawing of a filter member. It is front explanatory drawing which shows the other example of the ink bag of the ink cartridge. FIG. 3 is an exploded perspective view showing an example of a liquid discharge head unit according to the present invention. FIG. 10 is a schematic cross-sectional explanatory view of another example of a liquid discharge head unit including an ink container according to the present invention. FIG. 8 is a cross-sectional explanatory view taken along line AA in FIG. 7. It is a perspective explanatory view showing an example of an image forming apparatus concerning the present invention provided with an ink storage container concerning the present invention. It is side explanatory drawing which shows the outline | summary of the mechanism part of the apparatus. Similarly it is principal part plane explanatory drawing.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an ink cartridge as an ink container according to the present invention will be described with reference to FIGS. 1 is an external perspective view of the ink cartridge, FIG. 2 is a front view of the ink bag of the ink cartridge, and FIG. 3 is an enlarged cross-sectional view of the supply port of the ink cartridge.
The ink cartridge 1 is a cartridge case 11 that is divided into a case 11A and a case 11B, and an ink bag 12 that is a liquid containing member that contains ink.

  On the front side of the cartridge case 11 (the front side of the ink cartridge means the front side when the ink cartridge is inserted into the image forming apparatus main body in the attaching / detaching direction of the ink cartridge, and the opposite side of the front side is called the back side). An opening 14 is formed through which a hollow needle as a liquid suction means from the apparatus main body side passes.

  The ink bag 12 is obtained by joining a holding member 22 to a bag body 21 which is a sealed bag-shaped member made of, for example, a flexible film member. The material of the bag body 21 of the ink bag 12 is preferably a flexible film member. In this case, a film member made of one kind of resin composition or a film member having a layer structure made of plural kinds of resin compositions may be used. Moreover, the structure which has a metal thin film layer in the surface or an intermediate | middle layer may be sufficient. A good resin composition is an olefin resin composition, and a polyethylene film is particularly good because of its wettability with ink. Moreover, as a metal thin film layer, what suppresses the moisture permeability of a film or gives the rigidity of a film is preferable, for example, an aluminum thin film is especially preferable.

  The holding member 22 is filled with a supply port 23 through which a hollow needle is pierced from the apparatus main body side to supply ink in the bag main body 21 to the apparatus main body side, and ink that is a liquid in the bag main body 21. An ink filling port portion 24 that is a cylindrical liquid filling port portion and the like are provided. The ink filling port portion 24 is formed with a sealing portion 25 that is sealed by thermal welding by a sealing device of a liquid filling device according to the present invention described later.

  The supply port portion 23 has a cylindrical internal flow path 25, an elastic member 26 is fitted on the front side and held by the cap member 27, and the filter member 30 held in the holding member 22 on the rear side. Is provided.

  Here, as the elastic member 26, a rubber member is preferable. As the composition, silicon rubber, fluorine rubber, butyl rubber, ethylene propylene rubber (EPM and EPDM) and the like can be used. In particular, considering the liquid contact property with ink, EPDM is preferable because it is excellent in heat resistance, weather resistance, and ozone resistance, although it depends on the composition of the ink. In the case of a structure that is in contact with ink for a long period of time, a vulcanizing agent, a vulcanization accelerator, a vulcanization acceleration aid, a filler, an antioxidant, and the like can be added to the elastic member.

  The outer circumference of the elastic member 26 is preferably slightly larger than the inner diameter of the supply port portion 23 formed in the holding member 22. Thereby, the elastic member 26 can be press-fitted and ink leakage can be prevented even when the hollow needle is inserted and removed.

  As shown in FIG. 4, the filter member 30 is formed of resin fibers 32 containing an oxygen absorbent 31.

  As the oxygen absorbent 31, in the case of inorganic type, as reducing metal powder, reducing iron, reducing tin powder, reducing zinc, as oxide, ferrous oxide, iron trioxide, etc., metal Examples of the compound include iron carbide, silicon iron, carbonyl iron, and iron hydroxide. Other inorganic oxygen absorbers include sodium sulfite, potassium sulfite, and the like. However, since these can form water as a reaction by-product, they are not preferred for use as a filter for an ink container. Examples of organic compounds include ascorbic acids, nylon / cobalt salt catalyst systems, ethylenically unsaturated hydrocarbon / cobalt salt catalyst systems, cyclohexene side chain polymer systems, and polymer compound systems having polyvalent phenols. It is done.

  Although it will not specifically limit if it is a combination which is easy to shape | mold as an oxygen absorber used by this invention, Iron powder is mentioned as an especially preferable thing from the surface of a moldability or a price. Particularly preferable examples include mixed powder of iron powder and metal halide.

  Examples of the resin 32 containing an oxygen absorbent used in the present invention include polyolefin resins such as polyethylene and polypropylene for ease of molding and the like, and an oxygen absorbent made of iron powder is kneaded into them. Can be preferably used.

  As a method of making a resin containing an oxygen absorbent into a fibrous form, generally, an oxygen absorbent and a resin material previously kneaded and pelletized are molded into a fibrous form by a melt blow method or the like. Is possible. As an example of production, polypropylene mixed with iron powder classified to a size of 10 μm or less is heated to a temperature of 200 to 250 ° C. with nozzles having a pore diameter of 0.3 to 0.5 mm arranged at a pitch of 0.8 to 1 mm. An ultrafine fiber structure can be manufactured by discharging fibers from the nozzle array thus formed at a rate of 0.1 to 1.0 g / min per nozzle.

  In addition, as a method for producing ultrafine fibers, a method called electrospinning has recently been adopted. In this method, a high voltage is applied to the polymer solution and ejected from the tip of the capillary to make a non-woven ultrafine fiber.

  As described above, the method for producing ultrafine fibers may be produced from a kneaded oxygen absorbent as described above. A sandwiching method is also possible.

  The fiber diameter of the resin fiber 32 is preferably 0.5 to 20 μm, more preferably 1 to 10 μm. Since the fiber diameter affects the filtration efficiency and the filter life, it is generally preferable that the fiber diameter is thin. However, considering the processing cost and durability, the fiber diameter is preferably about 10 μm. Processing into a filter is made by compressing and pressing these fibers after integration. In order to obtain the desired filtration accuracy, not only the fiber diameter of the filter but also the thickness and configuration (layered or single layer) can be selected according to the ink to be used.

  In addition, since the life of the filter member 30 also correlates with the porosity of the filter, it is important to select a filter having a porosity that matches the characteristics of the ink amount filled in the ink container and the coarse particles in the ink. It is. When the porosity cannot be selected, the filter porosity increases by increasing the filter thickness. Therefore, the filter life can be ensured by adopting a configuration capable of ensuring the filter thickness.

  The ink filled in the ink bag 21 is not particularly limited. The number of coarse particles in the ink varies depending on the type of colorant used in the ink, the type of resin added to improve fixing and weather resistance, and the amount of the resin added. Therefore, the filter member 30 is adjusted to the characteristics of the ink. It is necessary to select In addition, it is preferable that the ink is normally deaerated and then filled into the ink container. However, since the filter member 30 of the present invention has an oxygen absorbing ability, even if the deaeration degree of the ink is insufficient, Highly reliable ink supply is possible.

  As described above, according to the ink cartridge (main tank) as the ink container, since the filter member formed of the resin fiber containing the oxygen absorbent is provided, when bubbles are trapped in the filter member In addition, the bubbles can be absorbed and removed, the reduction of the effective area can be suppressed, and stable ink supply can be performed.

  In the above-described embodiment, the filter member is disposed on the inlet side of the supply port portion that supplies ink. However, the filter member may be disposed in the flow path 25 of the above-described embodiment. Further, in the above embodiment, an example in which the filling port portion is provided separately from the supply port portion is described. However, as shown in FIG. 5, after the ink is filled from the part 21 a of the bag body 21 of the ink bag 12. It can also be sealed by heat welding. Further, the configuration of the case main body and the liquid storage member of the ink cartridge is not limited to the above embodiment. For example, a blow molded container (liquid storage member) filled with ink may be used.

Next, an example of the liquid discharge head unit according to the present invention will be described with reference to FIG. FIG. 6 is an exploded perspective view of the head unit.
In the liquid discharge head unit 50, a head 51 that discharges droplets and a head tank (sub tank) 52 that supplies the head 51 are integrated via a filter unit 53 having a filter member 54. The filter member 54 constituting the filter unit 53 is the same as that described in the ink container.

Next, another embodiment of the liquid discharge head unit including the ink container according to the present invention will be described with reference to FIGS. 8 is a schematic cross-sectional explanatory view of the head unit, and FIG. 8 is a cross-sectional explanatory view taken along the line AA of FIG.
Here, the head 101 is common to a plurality of nozzles 111 that discharge droplets, a liquid chamber 112 that communicates with each nozzle 111, and a common liquid chamber (common flow path) 113 that supplies ink to each liquid chamber 112. A supply port (ink supply port) 114 for supplying (introducing) ink into the liquid chamber 113 and a discharge port (ink discharge port) 115 for discharging ink from the common liquid chamber 113 are provided.

  The head tank 102 which is an ink storage container is provided with a storage portion 123 for storing ink supplied in a tank case (tank main body) 121, and a filter member 124 for removing impurities and the like in the ink in the storage portion 123. Are arranged in a direction (longitudinal direction) along the droplet discharge direction, and the accommodating portion 123 is divided into a filter upstream chamber 123A and a filter downstream chamber 123B, and the upstream chamber 123A is connected to an ink supply port 125 connected to the ink supply tube. The downstream chamber 123B communicates with an ink supply channel 126 that communicates with the supply port 114 of the head 101.

  Further, in the tank case 121, there is provided a discharge path 128 that communicates with the discharge port portion 115 of the head 101 and discharges ink discharged from the discharge port portion 115, and the discharge path 128 is an ink to which an ink discharge tube is connected. It communicates with the discharge port 129.

  Here, the filter member 124 is the same as that described for the ink container. Further, by arranging the filter member 124 in the vertical direction, the effective area of the filter member 124 (area from which impurities can be removed) can be increased, and the width of the head tank 102 can be reduced, thereby reducing the size of the liquid discharge head unit. Can be realized.

Next, an example of the image forming apparatus according to the present invention using the ink cartridge according to the present invention will be described with reference to FIGS. FIG. 9 is an external perspective view of the image forming apparatus, FIG. 10 is a side explanatory view showing an outline of a mechanism part of the image forming apparatus, and FIG.
This image forming apparatus is a serial type ink jet recording apparatus, and also serves as an apparatus main body 201, a paper feed cassette 202 that can be pulled out to a predetermined paper supply position while being attached to the apparatus main body 201, and a lid member of the paper feed cassette 202. A paper discharge tray 203 that is swingably mounted on the apparatus main body 201 and that can open and close above the paper feed cassette 202 is provided. The paper feed cassette 202 stocks paper to be fed into the apparatus main body 1, and the paper discharge tray 203 stocks paper on which an image is recorded (formed). Furthermore, a cartridge loading unit 204 for loading an ink cartridge, which is an ink container according to the present invention, is provided on one end of the front surface of the apparatus main body 201. The upper surface of the cartridge loading unit 204 has an operation button and a display. The operation / display unit 205 is provided with a device.

  In the apparatus main body 201, the carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B. It moves and scans in the direction of the arrow (carriage main scanning direction) via the timing belt.

  The carriage 233 has recording heads 234a and 234b (which are composed of liquid ejection heads according to the present invention for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). When not distinguished, it is referred to as “recording head 234”). A nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward.

  Each of the recording heads 234 has two nozzle rows. One nozzle row of the recording head 234a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 234b has one nozzle row. One nozzle row ejects magenta (M) droplets, and the other nozzle row ejects yellow (Y) droplets.

  The carriage 233 is equipped with head tanks 235a and 235b (referred to as “head tank 235” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the recording head 234. The sub tank 235 is supplied with ink of each color from the ink cartridge 1 of each color (shown in the hard case storage type in FIG. 7) via the supply tube 236 of each color.

  On the other hand, as a paper feeding unit for feeding the paper 242 stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon roller (feeding) that separates and feeds the paper 242 one by one from the paper stacking unit 241. A separation pad 244 made of a material having a large coefficient of friction is provided opposite to the sheet roller 243 and the sheet feeding roller 243, and the separation pad 244 is urged toward the sheet feeding roller 243 side.

  In order to feed the sheet 242 fed from the sheet feeding unit to the lower side of the recording head 234, a guide member 245 for guiding the sheet 242, a counter roller 246, a conveyance guide member 247, and a tip pressure roller. And a conveying belt 251 which is a conveying means for electrostatically attracting the fed paper 242 and conveying it at a position facing the recording head 234.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction). In addition, a charging roller 256 that is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 256 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251. The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 242 recorded by the recording head 234, a separation claw 261 for separating the paper 242 from the transport belt 251, a paper discharge roller 262, and a paper discharge roller 263 are provided. A paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body 201. The duplex unit 271 takes in the paper 242 returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, a maintenance / recovery mechanism 281 that is a head maintenance / recovery device according to the present invention includes a recovery means for maintaining and recovering the nozzle state of the recording head 234 in the non-printing area on one side of the carriage 233 in the scanning direction. Is arranged. The maintenance / recovery mechanism 281 includes caps 282a and 282b for capping each nozzle surface of the recording head 234 (referred to as “cap 282” when not distinguished) and a wiper that is a blade member for wiping the nozzle surface. A blade 283 and an idle discharge receptacle 284 for receiving droplets when performing idle discharge for discharging droplets that do not contribute to recording in order to discharge the thickened recording liquid are provided.

  In addition, in the non-printing area on the other side in the scanning direction of the carriage 233, the liquid that receives liquid droplets when performing idle ejection that ejects liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink recovery unit (empty discharge receiver) 288 that is a recovery container is disposed, and the ink recovery unit 288 includes an opening 289 along the nozzle row direction of the recording head 234 and the like.

  In this image forming apparatus configured as described above, the sheets 242 are separated and fed one by one from the sheet feeding tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and is conveyed to the conveyor belt 251 and the counter. The roller 246 is sandwiched between the rollers 246, and the leading end is guided by the conveying guide 237 and pressed against the conveying belt 251 by the tip pressure roller 249. The conveying direction is changed by approximately 90 °, and the charged conveying belt 251 is moved. The sheet 242 is conveyed in the sub-scanning direction by the circular movement of the conveying belt 251.

  Therefore, by driving the recording head 234 according to the image signal while moving the carriage 233, ink droplets are ejected onto the stopped paper 242 to record one line, and after the paper 242 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 242 has reached the recording area, the recording operation is finished and the paper 242 is discharged onto the paper discharge tray 203.

  Since this image forming apparatus is detachably mounted with an ink cartridge as an ink container according to the present invention, stable image ejection can be performed and a high quality image can be formed at high speed. Although an example in which an ink cartridge is mounted is described here, other liquid discharge head units or a direct connection type ink container can be used.

DESCRIPTION OF SYMBOLS 1 Ink cartridge 12 Ink bag 21 Bag main body 22 Holding member 23 Supply port part 30 Filter member 50 Liquid discharge head unit 51 Head 52 Head tank 53 Filter unit 54 Filter member 101 Head 102 Head tank 124 Filter member 201 Apparatus main body 202 ... Paper feed Tray 203 ... Discharge tray 204 ... Cartridge loading unit 233 ... Carriage 234 ... Recording head

Claims (7)

In an ink container that contains ink to be supplied to a head that discharges droplets,
A supply port for supplying the ink;
The supply port is provided with a filter member,
The ink container is characterized in that the filter member is formed of a resin fiber containing an oxygen absorbent.   The ink container according to claim 1, wherein the ink is filled from a filling port different from the supply port.   The ink container according to claim 1, wherein the ink container is detachably attached to the main body of the image forming apparatus.   The ink container according to claim 1, wherein the ink container is detachably connected to the head. In a liquid discharge head unit comprising a head for discharging droplets and a head tank for supplying ink to the head,
A filter member is provided between the head tank and the head,
The liquid discharge head unit, wherein the filter member is formed of a resin fiber containing an oxygen absorbent.   An image forming apparatus comprising the ink container according to claim 1.   An image forming apparatus comprising the liquid discharge head unit according to claim 5.

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