JP5251474B2 - Liquid ejecting apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus that ejects liquid from a head, and can be used in an image forming apparatus such as an ink jet printer that forms an image with ink ejected from the head when ink is used as the liquid. The present invention relates to such an image forming apparatus.

Conventionally, such a liquid ejecting apparatus and an image forming apparatus generally take into account that if the liquid contains impurities, the impurities cause clogging of the head and the image quality is deteriorated. And the filter for filtering this impurity is provided (for example, refer to [patent document 1]-[patent document 3]). Since the particle size of such impurities is relatively small, it is necessary to reduce the supplemental particle size of the filter, so-called eye size, accordingly.
However, when the size of the filter is reduced, bubbles are generated in the liquid when the liquid passes through the filter. Therefore, in the configuration in which the filter is provided immediately before the head (for example, see Patent Document 1), the bubbles are generated. May enter the head and cause image quality to deteriorate.
Therefore, in order to avoid such a problem, a technique has been proposed in which a liquid channel is provided between the filter and the head, and a configuration for removing such bubbles is provided in the channel (for example, [Patent Literature 2] and [Patent Literature 3]).

  On the other hand, such a liquid ejecting apparatus and an image forming apparatus are known that include a liquid storage unit that stores the liquid supplied from the main tank and supplies the stored liquid directly to the head (for example, [See Patent Document 1] and [Patent Document 2]). It is known that such a liquid ejecting apparatus is used in an electronic circuit forming apparatus that forms a conductive path by the liquid ejected from the head.

JP 2008-168563 A JP 2007-75753 A Japanese Patent Laid-Open No. 11-42795

However, if the above-described technique is applied to such a liquid ejection apparatus and image forming apparatus (see, for example, [Patent Document 2]), the impurities generated in the liquid container cannot be filtered. May cause clogging of the head and reduce image quality.
However, if the filter is simply inserted between the liquid container and the head, as described above, bubbles generated when the liquid passes through the filter enter the head and cause deterioration in the function such as image quality. Can be.

  The present invention relates to a liquid ejecting apparatus that can be used in an image forming apparatus such as an ink jet printer that forms an image with ink ejected from a head when ink is used as the liquid, and is generated when the liquid passes through a filter An object of the present invention is to provide a liquid ejecting apparatus capable of avoiding bubbles from entering the head and avoiding entry of impurities into the head, and such an image forming apparatus.

In order to achieve the above object, the invention described in claim 1 includes a plurality of heads for discharging liquid, a liquid supply unit for supplying liquid supplied from a main tank side for storing liquid to the head, and the main tank. A first filter for liquid flowing into the liquid supply unit from the side, a second filter for liquid flowing into the head from the liquid supply unit side, and exhausting the liquid that has passed through the first filter And an exhaust means for performing before passing through the second filter. The second filter is provided for removing impurities caused by the liquid supply unit, and the supplemental particle diameter is supplemental to the first filter. rather larger than the particle diameter, the liquid supply unit is a distributor to distribute the liquid supplied from the main tank to the head, the distributor, first off The liquid that has passed through the filter flows in from below, and has a storage portion that stores the liquid that has flowed in. The storage portion is inclined so that the position where the liquid that has passed through the first filter flows in occupies the upper position. The top of the ceiling surface has a ceiling surface, and the exhaust means is located at a position facing the position above the position where the liquid that has passed through the first filter flows into the housing section. Is connected to the top, exhausts the liquid in the storage portion from the top, the position of the storage portion where the liquid that has passed through the first filter flows into the storage portion and the top portion of the storage portion, The liquid ejecting apparatus is located upstream of the position where the liquid flows from the distributor toward the head in the direction in which the liquid flows .

  According to a second aspect of the present invention, in the liquid ejection apparatus according to the first aspect, the first filter is detachable so as to be replaceable.

According to a third aspect of the present invention, in the liquid ejecting apparatus according to the first or second aspect , the liquid supply apparatus includes a sub tank that supplies the liquid supplied from the main tank side to the liquid supply unit, and the liquid level in the sub tank is The height of the nozzle surface of the head has a water head difference in height at which the liquid in the sub tank is naturally supplied to the head.

According to a fourth aspect of the present invention, there is provided an image forming apparatus that uses ink as a liquid and forms an image with the ink ejected from the head using the liquid ejecting apparatus according to any one of the first to third aspects. .

The present invention relates to a plurality of heads that discharge liquid, a liquid supply unit that supplies liquid supplied from the main tank side that stores liquid to the head, and liquid that flows into the liquid supply unit from the main tank side. a first filter, a second filter for liquid flowing into the head from the liquid supply side, the exhaust gas exhaust of the liquid that has passed through the first filter is the liquid conducted before passing through the second filter comprising a means, second filter, the is provided with in order to remove impurities resulting from the liquid supply portion, the supplementary particle diameter rather larger than supplements particle diameter of the first filter, the liquid supply unit The distributor distributes the liquid supplied from the main tank side to the head, and the distributor flows the liquid that has passed through the first filter from below to flow. And the storage unit has a ceiling surface that is inclined so that the position where the liquid that has passed through the first filter flows in is higher. The container is connected to the top of the ceiling surface at a position facing the position above the position where the liquid that has passed through the first filter flows into the container, and from the top to the inside of the container The position where the liquid that has passed through the first filter flows into the housing portion and the top portion of the housing portion is exhausted from the distributor, and the liquid is supplied from the distributor of the housing portion to the head. Since the liquid discharge device is located on the upstream side in the direction in which the liquid flows in the container , the impurities can be removed when the liquid passes through the first filter. With bubbles By occur even where the head is effectively exhausted in the process of passing through the distributor by using a distributor which is often used when a plurality to avoid air bubbles while suppressing the size of the apparatus enters the head By obtaining the liquid, the liquid in a good state can be supplied to the head by being able to avoid the entry of impurities and bubbles into the head, and the liquid can be stably and satisfactorily discharged by the head, and good image formation can be achieved. It is possible to provide a liquid ejection device that can contribute to the formation of an electric circuit.

  If the first filter is removable so that it can be exchanged, impurities can be removed when the liquid passes through the first filter, and even if bubbles are generated, this is in the head. By being able to avoid the entry of impurities and bubbles into the head by being able to avoid entering, the liquid in a good state can be supplied to the head, and the liquid can be stably and satisfactorily discharged by the head. In addition, it is possible to provide a liquid ejection device that can contribute to good image formation, electronic circuit formation, and the like, in which the first filter can be easily replaced and has excellent maintainability.

  A sub tank for supplying the liquid supplied from the main tank side to the liquid supply unit, and the liquid level in the sub tank is equal to the height of the nozzle surface of the head. If the head has a height difference that is naturally supplied to the head, it is possible to remove impurities when the liquid passes through the first filter, and even if bubbles are generated, this will enter the head. By avoiding the entry of impurities and bubbles into the head, liquid in a good state is supplied to the head satisfactorily using such a water head difference, and stable liquid discharge by the head can be avoided. Thus, it is possible to provide a liquid ejection apparatus that can perform well and contribute to good image formation, formation of an electric circuit, and the like.

  The present invention is an image forming apparatus that uses ink as a liquid and forms an image with the ink ejected from the head using the liquid ejecting apparatus, so that impurities are removed when the ink passes through the first filter. In addition, even if bubbles are generated, it can be prevented from entering the head, so that impurities and bubbles can be prevented from entering the head. In addition, it is possible to provide an image forming apparatus that can stably and satisfactorily discharge ink with the head and can perform good image formation.

  FIG. 1 shows an outline of an image forming apparatus to which the present invention is applied. The image forming apparatus 100 is a printer as an ink jet printer and can perform full-color image formation. The image forming apparatus 100 performs an image forming process based on an image signal corresponding to image information received from the outside.

  The image forming apparatus 100 can form an image on a sheet-like recording medium using not only plain paper generally used for copying, but also OHP sheets, cardboard, cardboard, cardboard, and envelopes. It is. The image forming apparatus 100 is a single-sided image forming apparatus capable of forming an image on one side of a transfer sheet S that is a recording medium as a recording medium, but is a double-sided image forming apparatus capable of forming an image on both sides of the transfer sheet S. There may be.

  The image forming apparatus 100 is a liquid ejecting body that ejects ink of a color as a liquid that can form an image as an image corresponding to each color separated into yellow, magenta, cyan, and black. The heads 61Y, 61M, 61C and 61BK which are print heads which are ink heads as ink discharge bodies which are droplet discharge bodies are provided. The image forming apparatus 100 has a tandem structure in which heads 61Y, 61M, 61C, and 61BK are arranged in parallel in the horizontal direction.

  The heads 61Y, 61M, 61C, 61BK are located above the belt 11 serving as an endless belt disposed as an endless belt disposed substantially at the center of the main body 99 of the image forming apparatus 100, and the outer peripheral surface of the belt 11. It is arrange | positioned in the position facing. The heads 61Y, 61M, 61C and 61BK are arranged in this order from the upstream side in the A1 direction which is the moving direction of the belt 11 and is the counterclockwise direction in FIG. In the drawing, Y, M, C, and BK added after the numerals of the reference numerals indicate members for yellow, magenta, cyan, and black.

  The heads 61Y, 61M, 61C, and 61BK are respectively ink ejection devices 60Y, 60M, and 60C as liquid ejection devices for forming yellow (Y), magenta (M), cyan (C), and black (BK) images. , 60BK. Each of the heads 61Y, 61M, 61C, 61BK has a plurality in the main scanning direction parallel to the horizontal direction in FIG. 2, corresponding to the direction perpendicular to the paper surface of FIG. 1, as indicated by reference numeral 61 in FIG. The ink ejection devices 60Y, 60M, 60C, and 60BK are provided in a side-by-side manner.

  The belt 11 holds the transfer sheet S on the outer peripheral surface and conveys it in the A1 direction while facing the heads 61Y, 61M, 61C, 61BK, and in this process, the heads 61Y, 61M, 61C, 61BK, yellow, magenta, Cyan and black inks are ejected in such a manner that they are sequentially superimposed, and an image is formed on the transfer paper S. The belt 11 is formed with a number of holes (not shown) for attracting and holding the transfer paper S as will be described later.

  The ejection of ink onto the transfer paper S by the heads 61Y, 61M, 61C, 61BK is directed from the upstream side in the A1 direction to the downstream side so that the image areas of each color of yellow, magenta, cyan, and black overlap the same position on the transfer paper S. This is done at different timings.

  As shown in FIG. 1, the image forming apparatus 100 includes ink ejection devices 60Y, 60M, 60C, and 60BK that include heads 61Y, 61M, 61C, and 61BK, and a belt 11 that attracts and holds the transfer sheet S on the belt 11. The transport unit 10 serving as a paper transport unit that transports the sheet in a state in which the transfer sheet S is transported, and a large number of transfer sheets S can be stacked, and only the uppermost transfer sheet S among the stacked transfer sheets S is fed toward the transport unit 10. The paper unit 20 is disposed between the transport unit 10 and the paper discharge table 30, and a paper discharge table 30 on which a large number of printed transfer sheets S conveyed by the transport unit 10 can be stacked. In addition, the cleaning unit 40 for cleaning the heads 61Y, 61M, 61C, and 61BK is provided.

  The image forming apparatus 100 also includes a carriage 50 as a head support body that integrally supports the heads 61Y, 61M, 61C, and 61BK, and a home position and a cleaning unit 40 shown in FIG. 2 includes a head displacement driving unit (not shown) including a motor (not shown) as a driving source (not shown) that is positioned at any of the cleaning positions facing the CPU, a CPU (not shown), a memory, and the like that control the overall operation of the image forming apparatus 100. And a control unit 70 as control means shown in FIG.

  In addition to the belt 11, the transport unit 10 is formed on the belt 11, a driving roller 12 that is a driving member around which the belt 11 is wound, a tension roller 13 that is a driven member, and a belt 11 disposed below these. A fan 14 as an air suction fan that forms an air flow in a direction to generate a negative pressure between the outer peripheral surface of the belt 11 and the transfer paper S through the holes and sucks and holds the back surface of the transfer paper S on the upper surface of the belt 11; And a motor or the like as a driving means (not shown) for rotationally driving the driving roller 72.

  The paper feed unit 20 feeds only the uppermost transfer paper S among the paper feed tray 21 on which a large number of transfer papers S can be stacked and the transfer paper S stacked on the paper feed tray 21 toward the transport unit 10. The sheet feeding roller 22, the casing 23 supporting the sheet feeding tray 21 and the sheet feeding roller 22, and the sheet feeding roller 22 are rotationally driven so as to match the ink discharge timing in the heads 61Y, 61M, 61C, 61BK. And a motor or the like as drive means (not shown) for feeding the transfer paper S.

  The cleaning unit 40 includes a guide plate 41 serving as a conveyance guide plate that guides the transfer sheet S on which image formation has been performed through the conveyance unit 10, toward the sheet discharge table 30, and a carriage 50 disposed below the guide plate 41. The cleaning unit 42 having a pump suction unit (not shown) for sucking ink in the heads 61Y, 61M, 61C, 61BK and cleaning the heads 61Y, 61M, 61C, 61BK in a state where the cleaning position is occupied. 42 has an opening / closing drive means (not shown) for opening and closing the guide plate 41 so that the cleaning plate 42 is exposed by opening the guide plate 41 when the heads 61Y, 61M, 61C, 61BK are cleaned.

  The carriage 50 can be replaced with a new one when the heads 61Y, 61M, 61C, 61BK are deteriorated, and in order to facilitate maintenance, the heads 61Y, 61M, 61C, 61BK, It can be attached to and detached from the main body 99 integrally with 61BK. Each of the heads 61Y, 61M, 61C, 61BK can be independently attached to and detached from the main body 99 so that it can be replaced with a new one when deterioration or the like occurs and for easy maintenance. ing. This facilitates replacement work and maintenance work.

  In the image forming apparatus 100 having such a configuration, a sheet of transfer paper S is supplied from the paper supply unit 20 to the transport unit 10 in response to the input of a predetermined signal to start image formation. The transfer sheet S supplied to the transport unit 10 is sucked and held on the upper surface of the belt 11 by driving the fan 14, and the surface of the transfer sheet S is moved to the heads 61Y, 61M, 61C, 61BK by the movement of the belt 11 in the A1 direction. It moves in the A1 direction while facing each other. In this process, ink is ejected from the heads 61Y, 61M, 61C, 61BK according to the image to be formed, and an image is formed on the surface of the transfer paper S. The transfer sheet S on which the image is formed passes over the upper surface of the guide plate 41, is guided to the paper discharge table 30, and is stacked on the paper discharge table 30.

  If the heads 61Y, 61M, 61C, 61BK are in a state to be cleaned due to ink clogging while repeating such an image, the guide plate 41 is opened, and the cleaning unit 42 is exposed. 50 moves to the cleaning position. When the carriage 50 moves to the cleaning position, the heads 61Y, 61M, 61C, and 61BK are cleaned by, for example, performing an ink suction operation by driving the cleaning unit. When the cleaning is completed, the carriage returns to the home position, the guide plate 41 is closed, and ink can be ejected from the heads 61Y, 61M, 61C, 61BK. In other words, image formation, in other words, printing is possible.

  The ink ejection devices 60Y, 60M, 60C, and 60BK will be described with reference to FIG. Although the ink discharge devices 60Y, 60M, 60C, and 60BK have different ink colors, they have substantially the same configuration in the other points. Therefore, the ink discharge devices 60Y, 60M, 60C, and 60BK in FIG. Will be described as an ink ejection device 60. Accordingly, Y, M, C, and BK added after the numerals of the respective symbols are omitted.

  The ink discharge device 60 includes a plurality of heads 61 arranged in parallel in the main scanning direction, and an ink supply device 80 as a liquid supply device that forms a supply system that supplies ink to the plurality of heads 61. Since the plurality of heads 61 are arranged in the main scanning direction, the ink ejection device 60 and the image forming apparatus 100 are of a line type.

  The ink supply device 80 includes an ink cartridge 81 as a main tank that is a liquid tank that stores ink of the color supplied to the plurality of heads 61, and a sealed type in which ink in the ink cartridge 81 is supplied and temporarily stored. Sub-tank 82, a pump 83 as a supply pump for pumping and feeding ink once stored in the sub-tank 82 toward each head 61, and the pump 83 from the ink cartridge 81 side through the sub-tank 82. It has a distributor tank 84 as a distributor as an ink supply unit that is a liquid supply unit that distributes and supplies the supplied ink to each head 61.

  The ink supply device 80 also includes an ink amount detection sensor 85 as a liquid amount detection sensor serving as an ink amount detection unit, which is a liquid amount detection unit that detects the ink amount in order to detect an ink amount shortage in the distributor tank 84. , An exhaust means 86 for exhausting the air in the distributor tank 84 to the outside, a pipe 87 that forms an ink feeding path between the ink cartridge 81 and the distributor tank 84 together with the sub tank 82 and the pump 83, and the distributor tank 84 and a plurality of pipes 88 forming an ink feed path between the heads 61.

  The ink supply device 80 is also arranged near the distributor tank from the ink cartridge 81 side disposed near the ink inlet as a liquid inlet to the distributor tank 84 at a position between the pump 83 and the distributor tank 84 of the pipe 87. A first filter 89 serving as an upstream filter for the ink flowing into 84, and a downstream side for the ink flowing into each head 61 from the distributor tank 84 side disposed at the downstream end of each pipe 88 in the direction of ink flow. It has a second filter 90 as a filter, and joints 91 and 91 disposed in the middle of the pipe 87 at positions on both sides of the first filter 89 in the direction of ink flow.

  The ink cartridge 81 is detachable from the main body 99 so that the ink cartridge 81 can be replaced with a new one when the ink in the inside is consumed or when the remaining amount is low, or in order to facilitate maintenance. It has become.

  The sub tank 82 has a flexible film (not shown) that forms the liquid level of the ink. On the other hand, the ink in the sub tank 82 has a water head difference of a height at which the ink is naturally supplied to each head 61. Therefore, the ink discharge device 60 and the ink supply device 80 adopt a natural supply method as an ink supply method as a liquid supply method.

  The operation of the pump 83 is controlled by the control unit 70. Specifically, this shortage occurs when the ink discharge by the head 61 is stopped on the condition that the ink amount detection sensor 85 detects that the ink amount in the distributor tank 84 is insufficient, as will be described later. It is driven until it is not detected, and the ink in the sub tank 82 is supplied to the distributor tank 84. In this respect, the control unit 70 functions as an ink supply control unit that is a liquid supply control unit. The control unit 70 controls the driving of the driven configuration even if not specifically described.

  The distributor tank 84 supplies ink directly to each head 61. The distributor tank 84 includes an ink storage portion 84 a connected to the end of the pipe 87 in the vicinity of the end in the horizontal direction. Ink is supplied into the portion 84a. In the distributor tank 84, the ceiling surface 84b of the inner surface of the accommodating portion 84a is inclined so that the end on the side to which the pipe 87 is connected, in other words, the first filter 89 side in the direction of ink flow occupies the upper side. .

  The ink amount detection sensor 85 is a liquid level detection sensor that detects the liquid level of the ink in the storage portion 84a, and inputs a signal regarding whether or not the ink amount detection sensor 85 is immersed in the ink to the control unit 70. The state in which the ink amount detection sensor 85a is not immersed in the ink is a state in which the ink is insufficient, and the ink should be supplied into the storage portion 84a. Based on the signal, the control unit 70 determines that the ink in the container 84a is insufficient when the ink amount detection sensor 85a is not immersed in the ink.

The exhaust means 86 includes a pipe 86a disposed so as to communicate with the space inside and outside the accommodating portion 84a at a position where the ceiling surface 84b occupies the highest position, or in the vicinity thereof, that is, at the top, and an accommodating portion disposed in the middle of the pipe 86a. and a bubble discharge electromagnetic valve 86b to the 84a inside and outside of the space was replaced off whether or not to communicate with each other. The lower end portion of the pipe 86a and the portion communicating with the storage portion 84a occupies a position higher than the lower end position of the ink amount detection sensor 85a. The opening and closing of the bubble discharge electromagnetic valve 86 b is controlled by the control unit 70. Specifically, the bubble discharge electromagnetic valve 86b is opened when the control unit 70 drives the pump and the ink flows into the storage portion 84a, so that the air in the storage portion 84a is exposed from the top of the ceiling surface 84b to the outside. Are exhausted, exhausted, and degassed. In this respect, the control unit 70 functions as an exhaust control unit, and also functions as a deaeration control unit when the exhaust unit 86 functions as a deaeration unit as described later. Since the position where the pipe 86a and the storage portion 84a communicate with each other is higher than the lower end position of the ink amount detection sensor 85, even the ink in the storage portion 84a is not discharged to the outside.

The pipe 87 corresponds to the portion indicated by the one-dot chain line arrow in FIG. 1, and the ink flows in the direction indicated by the arrow.
The pipe 88 corresponds to the portion indicated by the dashed arrow in FIG. 1, and the ink flows in the direction indicated by the arrow. The pipe 88 is actually provided merely for coupling the distributor tank 84 and each head 61, and is provided substantially in the distributor tank 84 and / or each head 61.

The first filter 89 has impurities as a relatively small small particle size foreign matter such as dust already contained in the ink and ink agglomerated foreign matter that is a liquid agglomerate at the stage of being accommodated in the ink cartridge 81, and other ink. Impurities as relatively large foreign particles such as dust and burrs mixed with ink in the ink cartridge 81, the sub tank 82, the pump 83, and the pipe 87 from the cartridge 81 to the first filter 89 due to the above. By filtering and filtering, the impurities are provided to prevent the image quality from deteriorating, the impurities from clogging the head 61, and the image quality from deteriorating.
Therefore, the first filter 89 has a high filtration accuracy by stacking a plurality of lattice-shaped meshes (not shown) in order to capture impurities including such small particle foreign matter, and the supplemental particle size is relatively high. It is small.
However, if the supplemental particle diameter of the first filter 89, that is, the so-called eye size is reduced in this way, bubbles may be generated when the ink passes through the first filter 89, and these bubbles reach the head 61. And may cause a reduction in image quality.
The distributor tank 84 and the exhaust means 86 are provided to prevent such bubbles from entering the head 61, and the bubbles that have entered the distributor tank 84 are accommodated in the distributor tank 84 and are also contained in the distributor tank 84. While flowing, it reaches the ceiling surface 84 b, rises along the ceiling surface 84, gathers until the pipe 86 a is arranged or at such an arrangement position, and is discharged out of the distributor tank 84 by the exhaust means 86.
Therefore, the exhaust means 86 and / or the distributor tank 84 deaerate and exhaust the ink that has passed through the first filter 89 until the ink passes through the second filter 90 and enters the head 61. Functions as a means.

  The second filter 90 serves as a relatively large large particle size foreign matter such as dust and burrs mixed in the ink in the distributor tank 84 and the pipe 88 from the distributor tank 84 to the head 61 due to these. By filtering and filtering the impurities, the impurities are provided to prevent the image quality from deteriorating, the impurities causing the head 61 to be clogged, and the image quality from deteriorating. Since the second filter 90 is not intended to filter out foreign substances having a small particle size, the second filter 90 has a simple structure including a single plate (not shown) in which a large number of holes are formed. It is larger than the supplemental particle size of the first filter 89. As described above, since the supplementary particle diameter of the second filter 90, that is, the so-called eye size is large, in other words, coarse, the bubbles that may be generated when the ink passes through the first filter 89 are It does not occur when the ink passes through 90, or even if it occurs, the ink is ejected from the head 61 stably and does not affect the image quality. The film 90 is directly connected to the upper end of each head 61 at the lower end of each pipe 88, and is substantially provided in the distributor tank 84 and / or each head 61.

  Each joint 91 includes an attaching / detaching portion 91a located on the first filter 89 side, and an attached / detaching portion 91b to which the attaching / detaching portion 91a is fitted in an airtight manner and the attaching / detaching portion 91a is attached / detached. As a result, the first filter 89, the attaching / detaching portion 91a, and the pipe 87 located between the first filter 89 and the attaching / detaching portion 91a are connected to the main body of the ink supply device 80 and the main body of the ink discharge device 60. The filter cartridge 92 is attached to and detached from the printer. As described above, since the first filter 89 has a small eye size, the first filter 89 is likely to be clogged by trapping impurities over time. If clogging occurs, resistance to the passage of ink increases and ink does not flow easily. Become. However, the first filter 89 can be replaced with a new one as shown by the white arrow in the figure when deterioration due to clogging or the like occurs or in response to periodic replacement. In order to facilitate maintenance, the filter cartridge 92 can be attached to and detached from the main body of the ink supply device 80 and the main body of the ink ejection device 60, thereby facilitating replacement work and maintenance work. ing.

  In the ink ejection device 60 and the ink supply device 80 configured as described above, when ink is ejected from the head 61 in the above-described image forming operation, the first filter 89 and the second filter 90 cause various types of ink from the ink. When impurities are removed and bubbles are included in the ink that has passed through the first filter 89, these bubbles are removed from the ink by the exhausting means 86 and the like, and when the ink passes through the second filter 90, the bubbles are removed. The ink that has passed through the second filter contains no bubbles, and even if it is contained, the amount of the ink is excellent. And good image formation is performed. In addition, even if the first filter 89 has a problem such as clogging, the replacement is easily performed, so that the maintainability is excellent.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  That is, the present invention can be applied to any liquid ejecting apparatus or image forming apparatus that uses a liquid ejecting head. For example, the pipe 88 can be omitted, and the liquid supply unit, the second filter, and the head can be directly connected to each other, so that the influence of impurities in the liquid flow path from the liquid supply unit to the head is minimized. Limited to the limit.

  The image forming apparatus to which the present invention is applied is not limited to the above-described type of image forming apparatus as long as it is an image forming apparatus that uses a liquid ejecting head. Or a multi-function machine such as a multi-function machine or a monochrome machine related to these.

The liquid ejecting apparatus has been described as a part of the image forming apparatus in the above example, but the image forming apparatus itself may be a liquid ejecting apparatus.
The liquid discharge device can be referred to as a droplet discharge device when the head discharges liquid in a droplet state as in the above-described example.

  In addition to the above-described image forming apparatuses, such as copying machines, printers, facsimiles, etc., the liquid ejecting apparatus is used for an electronic circuit forming apparatus that forms a conductive path by the liquid ejected from the head using a liquid mixed with a conductive material. The electronic circuit forming apparatus itself may be used.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

1 is a schematic front view of an image forming apparatus to which the present invention is applied. FIG. 2 is a schematic front view of a liquid discharge apparatus to which the present invention is applied, which is provided in the image forming apparatus shown in FIG. 1.

Explanation of symbols

60 Liquid discharge device 61, 61Y, 61M, 61C, 61BK Head 80 Liquid supply device 81, 81Y, 81M, 81C, 81BK Main tank 82, 82Y, 82M, 82C, 82BK Sub tank 84 Liquid supply unit, exhaust means, deaeration means Distributor 84b Ceiling surface 86 Exhaust means, deaeration means 89 First filter 90 Second filter 100 Image forming apparatus

Claims (4)

A plurality of heads for discharging liquid;
A liquid supply unit that supplies liquid supplied from the main tank side containing the liquid to the head;
A first filter for liquid flowing into the liquid supply unit from the main tank side;
A second filter for liquid flowing into the head from the liquid supply unit side;
An exhaust means for exhausting the liquid that has passed through the first filter before the liquid passes through the second filter;
The second filter is provided to remove impurities resulting from the said liquid feed unit, the supplemental particle diameter rather larger than supplements particle diameter of the first filter,
The liquid supply unit is a distributor that distributes the liquid supplied from the main tank side to the head,
This distributor has an accommodating portion for accommodating the liquid that has flowed through the first filter from below and that has received the liquid.
This accommodating portion has a ceiling surface that is inclined so that the position where the liquid that has passed through the first filter flows in occupies the upper position,
The exhaust means is connected to the top of the ceiling surface at a position facing the position above the position where the liquid that has passed through the first filter flows into the storage section of the storage section. The liquid in the container is exhausted from
The position where the liquid that has passed through the first filter flows into the container and the top of the container are more than the position of the container where the liquid is supplied from the distributor toward the head. A liquid ejection device located upstream in the direction in which the liquid flows in the container . The liquid ejection apparatus according to claim 1, wherein
The liquid ejection apparatus, wherein the first filter is detachable so as to be replaceable. The liquid ejection apparatus according to claim 1 or 2,
A sub tank for supplying the liquid supplied from the main tank side to the liquid supply unit;
The liquid ejecting apparatus according to claim 1, wherein the liquid level in the sub tank has a water head difference in height with which the liquid in the sub tank is naturally supplied to the head with respect to the height of the nozzle surface of the head .   An image forming apparatus that uses ink as the liquid and forms an image with the ink ejected from the head using the liquid ejecting apparatus according to claim 1.

Images