JP2011235470A - Image forming apparatus and liquid filling method in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation in air bubble dischargeability due to the wetting of a filter occurring when a tank having the filter is filled with a liquid.SOLUTION: The ink storage part 22 of a head tank 4 is divided into an upstream chamber 35 and a downstream chamber 36 by a filter member 207 disposed in a direction along a droplet ejection direction, the head tank 4 includes a supply path 203 for supplying an ink from the downstream chamber 36 of the ink storage part 22 to the supply port 14 of a head 2 and a discharge path 25 for discharging the ink discharged from the discharge port 15 of the head 2 to the outside, and the downstream chamber 36 and the discharge path 25 are communicated with each other by a communication path 26. When the head tank 4 is filled with the ink, in such a state that the head tank 4 is empty, air taken in through an air filter 63 and three-way valves 62 and 61 is sent through an ink supply path 51 by an ink supply pump 52, to obtain such a state that the filter 207 is dried and then, the head tank 4 is filled with the ink.

Description

  The present invention relates to an image forming apparatus that discharges droplets to form an image and a liquid filling method 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 sub tank (also synonymous with a buffer tank, a head tank, etc.) is disposed on the recording head side, and a main tank is disposed on the apparatus main body side. A system is known in which ink is replenished and supplied from the main tank to the sub tank, and ink is supplied from the sub tank to the recording head.

  In such an ink supply system, there is one in which ink is supplied from a main tank to a sub tank via a supply tube, and a filter for filtering impurities in the ink is further provided in the sub tank (Patent Document 1).

  When the filter is arranged in the tank in this way, when the filter is wet with ink, a meniscus of ink is formed in the gap between particles and fibers constituting the filter, and it is difficult for gas (bubbles) to pass through. Become. Therefore, when ink is filled from an empty tank, when the filter in the tank becomes wet with a liquid such as ink or filling liquid, it is difficult for bubbles to pass through the filter and remain in the tank. Will do. When air bubbles remain in the tank, if the air bubbles enter the head, droplet discharge from the nozzles becomes impossible or the ejection direction is bent, resulting in a reduction in image quality.

  Therefore, for example, when the filter is separated into two upper and lower filters and a partition is provided between them, and the ink is filled into the tank, the ink is gradually filled from the bottom and the partition is placed above the filter. There is an ink that prevents the ink from spreading and spreading (Patent Document 2).

JP 2009-126044 A JP 2007-276166 A

  As described above, as disclosed in Patent Document 2, the structure in which the filter is separated into two upper and lower parts is effective at the time of initial ink filling when the filter is dry, but is the same during use. When it is necessary to clean the flow path, such as when it is necessary to replace the head with a different color ink, the problem is that the ink once gets wet and spreads in the upper filter during the cleaning process, and bubbles cannot be discharged from the tank. There is.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce residual bubbles in the tank when the liquid storage tank is filled with liquid.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A head for discharging droplets;
A liquid storage tank having a filter for filtering the liquid in a storage section for storing the liquid to be supplied to the head;
Means for sending air into the liquid storage tank,
When the liquid is filled in the liquid storage tank that is not filled with liquid, the filter is dried by sending air into the liquid storage tank prior to filling.

  Here, before the filter is dried, a cleaning liquid for cleaning the flow paths in the head and the liquid storage tank can be supplied.

  Further, the nozzle surface of the head can be sealed with a cap member when air is blown.

The liquid filling method in the image forming apparatus according to the present invention includes:
In a liquid filling method in an image forming apparatus including a liquid storage tank having a filter for filtering the liquid in a storage portion that stores liquid supplied to a head that discharges liquid droplets.
When the liquid is filled in the liquid storage tank that is not filled with liquid, the filter is dried by sending air into the liquid storage tank prior to filling.

  According to the image forming apparatus and the liquid filling method in the image forming apparatus according to the present invention, when the liquid is filled into the liquid storage tank that is not filled with the liquid, the filter is dried by sending air before filling. Since it is configured, it is possible to fill the liquid by drying the filter so that bubbles can easily pass through, reducing the residual bubbles in the tank, and performing stable droplet ejection to produce high-quality images. It becomes possible to form.

It is explanatory drawing of the ink supply system containing the liquid discharge head unit which shows 1st Embodiment of this invention. It is typical cross-sectional explanatory drawing which follows the AA line of FIG. It is a flowchart with which it uses for description of the ink filling process in the ink supply system. It is a flowchart with which it uses for description of the washing | cleaning process of this invention. It is explanatory drawing of the ink supply system with which it uses for description of 2nd Embodiment of this invention. It is a flowchart with which it uses for description of the washing | cleaning process of the embodiment. 1 is a schematic explanatory diagram for explaining an example of an overall configuration of an image forming apparatus according to the present invention.

Embodiments of the present invention will be described below with reference to the accompanying drawings. An image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of an ink supply system of the image forming apparatus according to the embodiment, and FIG. 2 is an explanatory sectional view of a sub tank along the line AA in FIG.
A liquid discharge head unit (hereinafter also simply referred to as “head unit”) 1 includes a head 2 that discharges droplets and a liquid storage tank that stores ink to be supplied to the head 2 (hereinafter referred to as “head tank”). 4 is provided.

  The head 2 is supplied with ink to a plurality of nozzles 11 that discharge droplets, a liquid chamber 12 that communicates with each nozzle 11, a common liquid chamber 13 that supplies ink to each liquid chamber 12, and a common liquid chamber 13. A supply port (ink supply port) 14 and a discharge port (ink discharge port) 15 for discharging ink from the common liquid chamber 13.

  The head tank 4 includes an ink storage portion 22 that stores ink to be supplied to the head 2 in a tank case 21, a supply port 24 that supplies ink from the ink storage portion 22 to the supply port 14 of the head 2, and a discharge port of the head 2. A discharge passage 25 for discharging the ink discharged from the outlet 15 to the discharge flow path 39, and the ink container 22 has a filter upstream chamber 35 by a filter 207 for filtering impurities in the ink arranged in the vertical direction. And the filter downstream chamber 36.

  Further, the filter downstream chamber 36 is provided with a partition wall 202 extending from the filter downstream chamber bottom surface 36 c to the top surface 36 a so that ink does not flow directly from the filter downstream chamber 36 into the supply flow path 203. As a result, the ink supplied from the ink supply flow path port 27 flows into the filter upstream chamber 35, passes through the filter 207, flows through the filter downstream chamber 36, flows into the supply flow path 203, and is supplied from the supply port 24 to the head 2. It is configured to supply ink.

  In addition, the top surface 36a of the filter downstream chamber 36 of the ink storage unit 22 is an inclined surface that inclines toward the center, a bubble reservoir 38 is provided at the highest part 36b of the center of the top surface 36a, and a bubble retention unit is further provided. A communication path 26 that communicates the filter downstream chamber 36 and the discharge flow path 39 from 38 is provided.

  The tank case 21 of the head tank 4 is a member that is open on one side, and a film member 23 (shown with shading in FIG. 1) as a flexible elastically deformable member in the opening. Is attached to absorb pressure fluctuations. The tank case 21 can obtain a damper effect that absorbs the pressure due to the vibration of the ink at the respective portions in the ink containing portion 22 and the supply flow path 203 partitioned by the partition wall 202.

  On the other hand, a replaceable main tank (ink cartridge) 5 is disposed on the apparatus main body side to supply and replenish ink to the head tank 4. The ink tank 5 is provided with a joint 56 with a valve at the tip, and is detachable from the ink supply path 51 and the ink return path 53, and the main tank 5 can be easily replaced from the joint 56. It is like that.

  Then, the ink is supplied from the main tank 5 to the head tank 4 by the ink supply pump 52 through the ink supply path 51. The discharge path 25 of the head tank 4 is connected to the main tank 5 via an ink return path 53, and an open / close valve (valve) 54 is interposed in the ink return path 53.

  Further, the main tank 5 is provided with an air release pipe 55 for preventing the ink in the tank 5 from being exposed to the outside air for a long time and drying or solidifying. The flow path of the atmosphere opening pipe 55 has an elongated tubular shape, and the humidity in the pipe changes along its length, so that it is possible to prevent the ink in the main tank 5 from coming into direct contact with the outside air. It is possible to prevent the ink from drying or thickening or coagulating.

  In this ink supply system, the ink stored in the head tank 4 is supplied from one end of the common liquid chamber 13 from the ink supply port 14 at one end of the head 2 through the supply port 24 and is supplied to the common liquid chamber 13. The ink that has not been used for droplet ejection passes through the ink discharge port 15 at the other end of the head 2 and forms a circulation path that returns from the ink discharge path 26 of the head tank 4 to the main tank 5 via the ink return path 53. To do. The ink flow path between the ink return path 53 of the circulation path and the main tank 5 can be stopped by an open / close valve 54 that can be opened and closed.

  Then, the remaining one flow path of the three-way valve 61 is connected to the outside air via the three-way valve 62 and the air filter 63, and the ink supply pump 52 is driven to supply air (air) to the flow path of the ink supply system. It can be sent in. A cleaning liquid tank 64 containing cleaning liquid is connected to the three-way valve 62, and the ink supply pump 52 is driven so that the cleaning liquid can be fed into the flow path of the ink supply system.

Next, in the ink supply system including such a circulation path, the operation of filling the head 2 with ink will be described with reference to the flowchart shown in FIG.
First, the three-way valve 61 is in a state where the ink supply path 51 communicates with the main tank 5 side, the valve 54 is opened, and the ink is supplied from the main tank 5 to the head tank 4 through the ink supply path 51. This ink flows into the filter upstream chamber 35 from the ink supply flow path port 27 of the head tank 4. At this time, the air in the filter upstream chamber 35 passes through the filter 207 and is discharged through the communication path 26 connecting the filter downstream chamber 36 and the discharge flow path 39, so that ink can flow into the filter upstream chamber 35. . In this case, the filter 207 needs to be dry, and when the filter 207 is wet with a liquid such as ink, a liquid meniscus is formed in the gap between particles and fibers constituting the filter 207. As a result, it becomes difficult for gas (bubbles) to pass through the filter 207, and the filter upstream chamber 35 cannot be filled with ink without bubbles.

  When the filter upstream chamber 35 is filled with ink, the ink passes through the filter 207 and flows into the filter downstream chamber 36. In the filter downstream chamber 36, ink begins to accumulate from the bottom surface 36 c to the top surface 36 a by the partition wall 202, and starts flowing to the supply flow path 203 when it exceeds the partition wall 202. Further, the ink is filled from the highest portion (position portion) 36 b of the top surface 36 a of the filter downstream chamber 36 to the bubble reservoir 38, flows through the communication path 26, and flows into the discharge flow path 39. Ink can be filled without bubbles. Next, the ink that has flowed into the supply flow path 203 is sent to the head 2 through the supply port 24.

  A bubble reservoir 38 is provided at the highest portion (position portion) 36b of the top surface 36a of the filter downstream chamber so that the air (bubbles) in the filter downstream chamber 36 can be efficiently discharged to the discharge passage 39. The air bubbles are easily collected in this portion, so that the air bubbles can be efficiently discharged to the discharge flow path 39 in a short time.

  Next, the ink sent to the head 2 is sent to the common liquid chamber 13 through the ink supply port 14. Part of the ink that has flowed into the common liquid chamber 13 is discharged from each nozzle 11. Further, the ink in the common liquid chamber 13 is discharged from the ink discharge path 25 to the discharge flow path 39 through the ink discharge port 15, merges with the ink flowing out from the communication path 26, and sent to the ink return path 53. Return to main tank 5.

  When ink passes through the valve 54 and ink is fed into the ink return path 53, the valve 54 is closed. Thereafter, the pressure of the ink supply pump 52 is adjusted, ink is discharged from the nozzle 11 of the head 2 to the outside, and bubbles in the nozzle 11 are discharged. Further, the ink supply pump 52 is opened to stop the ink flow, and a negative pressure necessary for ink discharge generated by the water head difference between the main tank 5 and the nozzle 11 of the head 2 is created.

  Thereafter, the nozzle surface is wiped with an elastic body (not shown), preferably a wiper member such as silicon rubber, and the ink dripping on the nozzle surface 11a is wiped to form a meniscus of the nozzle 11 to complete the ink filling.

  In this way, it is possible to fill the head 2 with ink and always supply ink from the main tank 5 to the head 2 through the head tank 4 so that ink can be ejected.

  In this way, when an image forming apparatus using an ink supply system filled with ink is being used, if the use of different color ink or ink of a different component occurs, the ink supply It is necessary to replace the ink in the system.

  In this case, there is a method in which the main tank 5 is removed from the joint 56, the main tank 5 containing the target ink is attached, and the ink supply pump 52 is operated to replace the ink while discharging the ink from the nozzle 11. However, this method requires a large amount of ink for replacement and requires ink that is not used for actual printing, resulting in an increase in cost. Therefore, there is a method in which the ink in the ink supply system is replaced with a liquid that is less expensive than the ink, and then the target ink is replaced. However, since the ink is gradually replaced, there are many methods until the ink is completely replaced. Need time.

Therefore, in the present invention, the ink in the ink supply system is once discharged, and the ink supply system is cleaned using a cleaning liquid that is less expensive than the ink. The procedure will be described with reference to the flowchart shown in FIG.
First, the joint 56b on the ink return path 53 side shown in FIG. 1 is connected to the joint 56c of the waste liquid bottle 65 that contains the waste liquid accompanying the replacement of the ink. Thereafter, when the ink supply pump 52 is operated, the valve 54 is opened at that time, the three-way valve 61 is switched to the side where the ink supply path 51 and the cleaning liquid bottle 64 containing the cleaning liquid communicate with each other, and the three-way valve 62 is further switched to the ink supply path. 51 and the air filter 63 for removing dust in the air sent to the ink supply system are switched to the side where the air filter 63 communicates. Then, the air that has passed through the air filter 63 is sent into the flow path, and the ink in the ink supply system is pressure-fed to the waste liquid bottle 65.

  Then, after the ink in the flow path of the ink supply system is discharged to the waste liquid bottle 65, when the three-way valve 62 is switched to the side where the ink supply path 51 and the cleaning liquid bottle 64 communicate with each other, the cleaning liquid in the cleaning liquid bottle 64 is discharged. Liquid is fed into the ink supply system. After the cleaning liquid is sent, the three-way valve 62 is switched again to the side where the ink supply path 51 and the air filter 63 communicate with each other, air is sent, and the cleaning liquid is discharged to the waste liquid bottle 65.

  Further, the three-way valve 62 is switched to the side where the ink supply path 51 and the cleaning bottle 64 communicate with each other, and the cleaning liquid is fed into the ink supply system.

  This is repeated to clean the inside of the ink supply system. By alternately feeding the air and the cleaning liquid, the liquid in the ink supply system is vigorously stirred, so that the ink supply system can be cleaned in a smaller amount and in a shorter time than when the liquid is kept flowing.

  In this way, when the cleaning of the flow path of the ink supply system is completed, the three-way valve 62 is switched to the side where the ink supply path 51 and the air filter 63 communicate with each other, and the filter 207 is dried in the ink supply system. Continue to send air until. By sending air with the pump 52, the filter 207 can be dried in a short time.

  When the filter 207 is dried, the ink supply pump 52 is stopped, the valve 54 is closed, and the three-way valve 61 is switched to the side where the ink supply path 51 and the main tank 5 communicate with each other, thereby completing the cleaning in the ink supply system. To do.

Thereafter, the main tank 5 containing the ink to be replaced is attached, and the ink replacement process can be performed by performing the ink filling step shown in FIG.

  Here, the filter 207 is dried during the cleaning process in the ink supply system, and as a result, the filter upstream chamber 35 can be filled with ink without bubbles. Although the time, number of times, and pressure value for sending air and cleaning liquid are set as appropriate, this ink supply system cleaning sequence can be automated by demonstrating the optimum number of times, time, and pressure value in advance. it can.

  Further, when the filter 207 is dried, it is necessary to sufficiently clean the inside of the ink supply system. If the cleaning is insufficient, the remaining ink components are deposited while the air is fed and dried, which may cause clogging of the pores of the filter 207 and the nozzles 11 that narrow the flow path in the ink supply system. For this reason, it is important to dry the filter 207 after the inside of the ink supply system has been sufficiently cleaned.

  Further, when the filter 207 is dried, it is preferable to seal the surface of the nozzle 11 with an elastic cap and send air. Accordingly, even if the filter 207 is dried in a state where the inside of the ink supply system is not sufficiently washed, air does not pass through the nozzle 11, so that the nozzle 11 is not dried. It is possible to prevent nozzle clogging due to the deposition of slag.

  On the other hand, when the main tank 5 is replaced to replenish the ink used for printing or for some reason, air bubbles are mixed into the filter upstream chamber 35 and the ink droplet ejection from the nozzle 11 is disturbed. Even when the bubble discharge operation is performed to eliminate the air bubble, it is possible to create a state where there is no air by discharging the ink and drying the filter 207 and then refilling the same ink in this work. Thus, it is possible to deal with a problem of ink droplet ejection from No. 11.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram of the ink supply system in the same embodiment using the cleaning unit 66 dedicated to cleaning the ink supply system.
The cleaning unit 66 stores therein a cleaning liquid bottle 64 containing a cleaning liquid, a waste liquid bottle 65 that stores the waste liquid, and an air bottle 68. The outer shape of the cleaning unit 66 is the same as that of the main tank 5 of the first embodiment, and can be replaced in the same manner as the main tank 65 through the joints 56a and 56b.

The cleaning process of the ink supply system for ink replacement in the present embodiment will be described with reference to the flowchart shown in FIG.
First, the main tank 5 is removed from the joints 56a and 56b, and the cleaning unit 66 is attached. Next, simultaneously with the operation of the ink supply pump 52, the valve 54 is opened, the three-way valve 67 is switched to the side where the ink supply path 51 and the cleaning liquid bottle 64 are communicated, and the three-way valve 67 is further switched to the ink supply path 51 and the air filter 63. Switch to the side that communicates. As a result, the air that has passed through the air filter 63 is sent into the flow path, and the ink in the ink supply system is pumped to the waste liquid bottle 65. After the ink in the flow path is discharged to the waste liquid bottle 65, when the three-way valve C67 is switched to the side where the ink supply path 51 and the cleaning bottle 64 communicate with each other, the cleaning liquid in the cleaning liquid bottle 64 is fed into the ink supply system. Is done. After the cleaning liquid is fed, the three-way valve 67 is switched again to the side where the ink supply path 51 and the air filter 63 communicate with each other, air is sent, and the cleaning liquid is discharged to the waste liquid bottle 65. Further, the three-way valve 67 is switched to the side where the ink supply path 51 and the cleaning bottle 64 communicate with each other, and the cleaning liquid is fed into the ink supply system. This is repeated to clean the inside of the ink supply system.

  When the cleaning in the ink supply system is completed in this way, the three-way valve 67 is switched to the side where the ink supply path 51 and the air filter 63 communicate with each other, and air is continuously sent into the ink supply system until the filter 207 is dried. . After the drying of the filter 207 is completed, the ink supply pump 52 is stopped, the valve 54 is closed, the three-way valve 67 is switched to the side where the ink supply path 51 and the main tank 5 communicate with each other, and the cleaning process in the ink supply system is completed. To do.

  The main tank 5 containing the ink to be replaced is attached, and the ink replacement process shown in FIG. 3 described above can be performed to perform the ink replacement operation.

  As in the first embodiment, when the filter 207 is dried, it is necessary to sufficiently clean the inside of the ink supply system. Further, the surface of the nozzle 11 is sealed with an elastic cap and air is sent. preferable.

  As described above, by using the cleaning unit 66 dedicated to cleaning the ink supply system, a cleaning unit can be assembled in the same manner as the main tank replacement method, and the ink supply system can be easily cleaned. Furthermore, since only the ink in the ink supply system before replacement and the cleaning liquid stored in the cleaning bottle 64 are discharged to the waste liquid tank 65, the waste liquid bottle having the corresponding capacity can be removed from the waste liquid bottle. The possibility of overflowing ink can be avoided.

Next, an example of an image forming apparatus including the ink supply system described in the above embodiments will be described with reference to FIG.
In this image forming apparatus, a recording head 101 composed of the liquid discharge head unit 1 is mounted on a carriage 103, and is slid by a main guide rod 104 and a sub guide member (not shown) that are horizontally mounted between the left and right side plates 100A and 100B. Supports freely. The recording head 101 is moved and scanned in the main scanning direction by the main scanning motor 106 via the timing belt 105. On the other hand, the recording medium 107 is opposed to the nozzle surface 11a of the recording head 101, and is conveyed by the conveying roller 109 in a direction orthogonal to the moving direction of the recording head 101, and ink droplets ejected from the recording head 101 according to the image. An image is formed by adhesion.

  Ink is supplied to the recording head 101 from the main tank unit 102 in which the main tank 5 and the atmosphere release pipe 55 are accommodated via the ink supply pump 52 through the flexible ink supply path 51. Ink that has not been ejected or discharged from the nozzles is returned to the main tank unit 102 through the ink return path 53.

  The cap member 111 provided outside the recording area is made of an elastic body, preferably silicon rubber, for capping the nozzle surface 108 having the plurality of nozzles 11. At the time of non-recording, the recording head 101 moves to above the cap member 111, and the cap member 111 moves by a cap moving mechanism (not shown) to cap the nozzle surface 108. In the cap member 111, an ink absorbing sheet 112 is provided for facilitating suction during ink suction, moistening the atmosphere in the cap, and the like.

  Two tubes 113, 114 are connected to the cap member 111 on the bottom surface, and the tube 113 communicates with the atmosphere via the atmosphere release valve 115. The tube 114 is connected to the suction pump 116, and the nozzle surface 108 is capped by the cap member 111, and the suction pump 116 is driven to generate a negative pressure in the cap member 111 with the atmosphere release valve 115 closed. Then, ink is sucked from the nozzles of the recording head 101 and the air release valve 115 is opened to discharge the ink accumulated in the space 117 in the cap member 111 to the waste liquid tank 118. Further, the cap member 111 prevents the nozzles of the recording head 101 from drying by contacting and holding the nozzle surface 108 with the atmosphere release valve 115 closed.

  Further, a wiper blade (wiper member) 119 is moved to a height at which it contacts the nozzle surface 108 of the recording head 101 by a wiper moving mechanism (not shown), and the recording head 101 is moved in the main scanning direction. The ink and dust adhering to 108 can be wiped off, and the meniscus on the nozzle surface 108 can be generated and cleaned.

  In the above embodiment, the present invention has been described with reference to an example in which the present invention is applied to an image forming apparatus having a printer configuration. However, the present invention is not limited to this, and as described above, for example, an image forming apparatus such as a printer / fax / copier multifunction machine. In addition, the present invention can also be applied to an image forming apparatus using a liquid other than the narrowly defined ink or a fixing processing liquid.

DESCRIPTION OF SYMBOLS 1 Liquid discharge head unit 2 Head 4 Head tank 5 Main tank 11 Nozzle 13 Common liquid chamber 14 Supply port 15 Discharge port 21 Tank case 22 Ink storage part 23 Damper member (film member)
24 supply port 25 discharge path 35 filter upstream chamber 36 filter downstream chamber 39 discharge flow path 40 exhaust flow path 51 ink supply path 52 ink supply pump 53 ink return flow path 54 on-off valve (valve),
56 Joint 61, 62 Three-way valve,
63 Air filter,
64 Cleaning liquid bottle,
66 washing unit,
67 Three-way valve 101 Recording head (liquid discharge head unit)
202 Partition part 203 Supply flow path 207 Filter member

Claims (4)

A head for discharging droplets;
A liquid storage tank having a filter for filtering the liquid in a storage section for storing the liquid to be supplied to the head;
Means for sending air into the liquid storage tank,
2. An image forming apparatus according to claim 1, wherein when the liquid is filled in the liquid storage tank that is not filled with liquid, air is sent into the liquid storage tank to dry the filter prior to filling.   The image forming apparatus according to claim 1, wherein a cleaning liquid for cleaning the flow path in the head and the liquid storage tank is supplied before the filter is dried.   The image forming apparatus according to claim 1, wherein the nozzle surface of the head is sealed with a cap member when air is blown. In a liquid filling method in an image forming apparatus including a liquid storage tank having a filter for filtering the liquid in a storage portion that stores liquid supplied to a head that discharges liquid droplets.
The liquid in the image forming apparatus is characterized in that, when the liquid is filled in the liquid storage tank that is not filled with liquid, the filter is dried by sending air into the liquid storage tank prior to filling. Filling method.

Images