Liquid supply mechanism and inkjet recording device including the same

Abstract

To provide a liquid supply mechanism capable of equalizing water pressure of liquid discharged from a discharge member, and an inkjet recording device including the same.SOLUTION: A liquid supply mechanism includes: a tank that stores liquid; a supply path that has one end connected to the tank and in which the liquid flows; and a discharge member that is arranged on the supply path and discharges the liquid. The discharge member has a filter, a check valve, and a discharge path. The filter has a predetermined flow path resistance with respect to the liquid passing through the filter. The check valve is opened at a predetermined open pressure with respect to the liquid passing through the check valve. In the discharge path, the liquid flows when the check valve is opened and the liquid is discharged from a discharge port formed in a distal end portion of the discharge path. A reduction value due to the flow path resistance of the filter is larger than the open pressure of the check valve.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a liquid supply mechanism and an inkjet recording apparatus equipped with the same. [Background technology]

[0002] A conventional liquid supply mechanism includes a tank for storing liquid, a supply path (tube) through which the liquid flows, one end of which is connected to the tank, a discharge member (head) for discharging the liquid supplied from the supply path, and a check valve. The check valve opens at a predetermined release pressure against air bubbles accumulated in the supply path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 60-90768 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the liquid supply mechanism disclosed in Patent Document 1, when the supply path is branched into multiple paths, the water pressure of the liquid flowing through each of the branched supply paths changes. Therefore, when a discharge member is provided for each of the branched supply paths, there is a problem in that the water pressure of the liquid discharged from the discharge member varies.

[0005] An object of the present invention is to provide a liquid supply mechanism capable of equalizing the water pressure of the liquid discharged from a discharge member, and an inkjet recording apparatus equipped with the same. [Means for solving the problem]

[0006] In order to achieve the above object, a first configuration of the present invention is a liquid supply mechanism including a tank for storing liquid, a supply path having one end connected to the tank and through which the liquid flows, and a discharge member disposed on the supply path for discharging the liquid. The discharge member has a filter, a check valve, and a discharge path. The filter has a predetermined flow path resistance for the liquid passing through it. The check valve opens at a predetermined opening pressure for the liquid passing through it. When the check valve is opened, the liquid flows through the discharge path, and the discharge path discharges the liquid from a discharge port formed at the tip. The reduced pressure value due to the flow path resistance of the filter is greater than the opening pressure of the check valve. Effect of the Invention

[0007] According to the first aspect of the present invention, it is possible to provide a liquid supply mechanism capable of equalizing the water pressure of the liquid discharged from the discharge member, and an inkjet recording apparatus including the same. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of a printer as an inkjet recording apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a plan view of a recording unit included in the printer according to the embodiment; [Diagram 3] A side view of a recording head constituting a line head of a recording unit. [Figure 4] A plan view of the recording head as seen from the ink ejection surface side. [Diagram 5] FIG. 1 is an explanatory diagram illustrating a liquid supply mechanism. [Figure 6] FIG. 1 is a vertical cross-sectional view showing the vicinity of a discharge member of a liquid supply mechanism. [Figure 7] FIG. 2 is a perspective view of the cleaning liquid supplying member as viewed obliquely from below; [Figure 8] FIG. 11 is a side view showing a state in which the wiper is disposed below the recording head. [Figure 9] FIG. 9 is a side view showing a state in which the wiper is raised from the state shown in FIG. 8 and pressed against the cleaning liquid supplying member; [Figure 10]FIG. 10 is a side view showing a state in which the wiper is moved in the direction of the arrow A while being pressed against the cleaning liquid supplying member from the state shown in FIG. [Figure 11] FIG. 11 is a side view showing a state in which the wiper has been further moved in the direction of the arrow A from the state shown in FIG. [Figure 12] 12 is a side view showing a state in which the wiper is further moved in the direction of arrow A from the state shown in FIG. 11 and then lowered and separated from the ink ejection surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] 1. Configuration of the Inkjet Recording Apparatus Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing the general configuration of a printer 100 as an inkjet recording device according to one embodiment of the present invention. The printer 100 is equipped with a paper feed cassette 2 which is a paper storage section. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Inside the paper feed cassette 2, paper P, which is an example of a recording medium, is stored.

[0010] A paper feeder 3 is disposed downstream of the paper feed cassette 2 in the paper transport direction, i.e., above the right side of the paper feed cassette 2 in Fig. 1. The paper feeder 3 separates and sends out the paper P one by one toward the upper right of the paper feed cassette 2 in Fig. 1.

[0011] The printer 100 has a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner, which is the paper feed direction, of the paper feed cassette 2. The paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0012] A pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first transport unit 5 and a recording unit 9 are arranged immediately downstream of the pair of registration rollers 13 in the paper transport direction. The paper P sent out from the paper feed cassette 2 reaches the pair of registration rollers 13 through the first paper transport path 4a. The pair of registration rollers 13 corrects skewed feed of the paper P and sends the paper P toward the first transport unit 5 (particularly the transport belt 8 described later) in time with the ink ejection operation performed by the recording unit 9.

[0013] The paper P sent to the first transport unit 5 by the pair of registration rollers 13 is transported by the transport belt 8 to a position facing the recording unit 9 (particularly recording heads 17a to 17c described below). An image is recorded on the paper P by ejecting ink from the recording unit 9 onto the paper P. At this time, the ejection of ink in the recording unit 9 is controlled by a control device 110 inside the printer 100.

[0014] In the paper transport direction, a second transport unit 12 is disposed downstream of the first transport unit 5 (on the left side in FIG. 1). The paper P on which an image has been recorded by the recording unit 9 is sent to the second transport unit 12. The ink ejected onto the surface of the paper P is dried while passing through the second transport unit 12.

[0015] In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side surface of the printer body 1. The paper P from which the ink has been dried by the second transport unit 12 is sent to the decurler unit 14, where any curls in the paper P are straightened out.

[0016] In the paper transport direction, a second paper transport path 4b is provided downstream (upper in FIG. 1) of the decurler unit 14. When double-sided recording is not performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged to a paper discharge tray 15 provided outside the left side of the printer 100.

[0017] A reversing transport path 16 for double-sided recording is provided at the top of the printer body 1, above the recording unit 9 and the second transport unit 12. When double-sided recording is performed, after recording on one side (first side) of the paper P is completed and the paper P passes through the second transport unit 12 and the decurler unit 14, it is sent to the reversing transport path 16 via the second paper transport path 4b.

[0018] The paper P sent to the reversing transport path 16 has its transport direction switched so that recording can be performed on the other side (second side) of the paper P. The paper P then passes over the top of the printer body 1 and is transported to the right side, passes through the pair of registration rollers 13, and is sent again to the first transport unit 5 with its second side facing up. In the first transport unit 5, the paper P is transported to a position facing the recording section 9, and an image is recorded on the second side by ink ejection from the recording section 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler section 14, and the second paper transport path 4b in that order, and is discharged to the paper discharge tray 15.

[0019] In addition, a maintenance unit 19 and a cap unit 20 are disposed below the second transport unit 12. When performing purging, the maintenance unit 19 moves horizontally below the recording section 9, wipes off ink extruded from the nozzles 18a (see FIG. 2) of the recording heads 17a to 17c, and collects the wiped ink. Purging refers to the operation of forcibly extruding ink from the nozzles 18a of the recording heads 17a to 17c in order to expel thickened ink, foreign matter, air bubbles, and the like from the nozzles 18a.

[0020] When capping the ink ejection surfaces of the recording heads 17a to 17c, the cap unit 20 moves horizontally below the recording section 9, and then moves upward to be attached to the lower surfaces of the recording heads 17a to 17c.

[0021] 2 is a diagram showing the recording unit 9 of the printer 100 as seen from above. The recording unit 9 includes a head housing 10 and line heads 11C, 11M, 11Y, and 11K held by the head housing 10. These line heads 11C to 11K are supported at a height such that a predetermined interval (for example, 1 mm) is formed with respect to the conveying surface of the conveyor belt 8, and as shown in FIG. 1, a plurality of (three in this case) recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (the up-down direction in FIG. 1) perpendicular to the paper conveying direction (the direction of the arrow X). Note that the three recording heads 17a to 17c of each color have the same shape and configuration, and therefore the identification symbols (a, b, c) will be omitted in the following description.

[0022] FIG. 3 is a side view of the recording head 17 constituting the line heads 11C to 11K of the recording unit 9, and FIG. 4 is a plan view of the recording head 17 as viewed from the ink ejection surface F1 side.

[0023] 3 and 4, the ink ejection surface (nozzle surface) F1 of the head section 18 of the recording head 17 is provided with a plurality of nozzle regions Ra to Rd (four blocks in this example) in which a large number of nozzles 18a (see FIG. 2) are arranged. At least the ink ejection surface F1 of the head section 18 is made of, for example, SUS (stainless steel). The ink ejection surface F1 is treated to be water-repellent by applying a fluorine-based or silicone-based water-repellent agent.

[0024] Ink of four colors (cyan, magenta, yellow, and black) stored in ink tanks (not shown) is supplied to the recording heads 17 constituting each of the line heads 11C to 11K for each color of the line heads 11C to 11K.

[0025] Each recording head 17 ejects ink from nozzles 18a toward paper P, which is adsorbed and held on the conveying surface of conveyor belt 8 and conveyed, in accordance with image data received from an external computer by a control signal from control unit 110 (see FIG. 1). As a result, a color image is formed on paper P on conveyor belt 8 by superimposing four colors of ink: cyan, magenta, yellow, and black. In addition, recording head 17 is provided with a cleaning liquid supplying member 60 that supplies a cleaning liquid for inkjet recording heads (hereinafter simply referred to as cleaning liquid).

[0026] 5 is an explanatory diagram showing the liquid supply mechanism 200. The liquid supply mechanism 200 includes a tank 98 that contains a cleaning liquid (liquid), a supply path 90 consisting of a tube having one end connected to the tank 98 and through which the cleaning liquid flows, discharge members 71a to 71c that are disposed on the supply path 90 and discharge the cleaning liquid, and a pump (not shown). The discharge members 71a to 71c are connected to a cleaning liquid supply member 60.

[0027] In this embodiment, the supply path 90 has a supply connection 97 at one end and a discharge connection 96 at the other end. The supply connection 97 is connected to the output side of a pump (not shown). The input side of the pump is connected to a tank 98. The pump provides power to move the cleaning liquid in the supply path 90 and push the cleaning liquid out of the cleaning liquid supply port 60a. That is, both ends of the supply path 90 are connected via the tank 98 to a pump that circulates the cleaning liquid (liquid). In this embodiment, one pump is provided for each liquid flow path, that is, one for each color. The pump is an example of a drive unit in the claims.

[0028] In this embodiment, the flow path lengths from the supply connection portion 97 to the discharge members 71a to 71c in the three recording heads 17a, 17b, and 17c of the same color are different. Specifically, the supply path 90 extending from the supply connection portion 97 branches at a branch portion 92a. One of the supply paths 90 branched at the branch portion 92a is connected to the discharge member 71a. The other of the supply paths 90 branched at the branch portion 92a branches again at a branch portion 92b. One of the supply paths 90 branched at the branch portion 92b is connected to the discharge member 71b. The other of the supply paths 90 branched at the branch portion 92b is connected to the discharge member 71c.

[0029] The supply paths 90 that pass through the discharge members 71a to 71c join at a branching portion 92c and are connected to a discharge connection portion 96. In this embodiment, the discharge connection portion 96 is connected to an on-off valve (not shown) and can stop or allow the cleaning liquid flowing through the supply paths 90 to flow. That is, an on-off valve capable of opening and closing the liquid flow path 90 is further provided downstream of the discharge members 71a to 71c. In this embodiment, the supply paths 90 that branch out in a plurality of directions join at a branching portion (junction portion) 92c downstream of the discharge members, and an on-off valve (not shown) is disposed downstream of the branching portion (junction portion) 92c of the supply paths 90. By disposing an on-off valve downstream of the branching portion (junction portion) 92c of the supply paths 90, the water pressure of the cleaning liquid discharged from the discharge members 71a to 71c can be made uniform by controlling a single on-off valve, and therefore the manufacturing cost of the printer 100 can be reduced. The on-off valves may be provided downstream of the discharge members 71a to 71c and upstream of the branching portion (junction portion) 92c.

[0030] In this embodiment, the supply path 90 branches multiple times, and the lengths of the flow paths from the pump (not shown) to the discharge members 71a to 71c are different, so the water pressure of the cleaning liquid in each of the discharge members 71a to 71c is different. This may cause variations in the water pressure of the cleaning liquid discharged from the discharge members 71a to 71c. In response to this, the discharge members 71a to 71c are configured as follows to make the amount of cleaning liquid pushed out from each of the discharge members 71a to 71c uniform.

[0031] 6 is a side cross-sectional view showing the periphery of discharge member 71a. In the following description, discharge member 71a is illustrated, but the configurations of discharge members 71b and 71c are basically the same, so description thereof will be omitted.

[0032] Discharge member 71a includes cap 80, filter 99, cylindrical portion 72, biasing spring 74, and check valve 73. The inner diameter of the upper portion of cylindrical portion 72 is larger than the inner diameter of the lower portion of cylindrical portion 72. Biasing spring 74 and check valve 73 are disposed in the upper portion of cylindrical portion 72. Check valve 73 is a spherical member having a diameter smaller than the inner diameter of the upper portion of cylindrical portion 72.

[0033] The biasing spring 74 is smaller than the inner diameter of the upper part of the cylindrical portion 72 and larger than the inner diameter of the lower part of the cylindrical portion 72. In addition, the biasing spring 74 is disposed between the step portion 72a formed on the inner circumferential surface of the cylindrical portion 72 and the check valve 73.

[0034] The cap 80 is attached to the outside of the cylindrical portion 72. The cap 80 has a large diameter cylindrical portion 81 arranged coaxially with the cylindrical portion 72, a small diameter cylindrical portion 82, and a connecting portion 83. The cylindrical portion 72 is arranged on the inner peripheral surface of the large diameter cylindrical portion 81 via an O-ring 76. The upper end surface of the small diameter cylindrical portion 82 is closed, and the upper portion of the small diameter cylindrical portion 82 communicates with the supply passage 90. The connecting portion 83 is formed in an annular shape by connecting the upper end of the large diameter cylindrical portion 81 and the lower end of the small diameter cylindrical portion 82. The inner diameter of the connecting portion 83 decreases toward the upper side. An O-ring 75 is arranged on the inner peripheral surface of the connecting portion 83.

[0035] The cap 80 is covered with a plate-shaped holding member 78 , and both sides of the holding member 78 are fixed to the cleaning liquid supplying member 60 via screws 79 .

[0036] The small diameter cylindrical portion 82 of the cap 80 and the inside of the cylindrical portion 72 communicate with the supply path 90 to form a discharge path 95. The cleaning liquid flowing through the supply path 90 is supplied to the discharge port 72b formed at the lower end of the cylindrical portion 72 through the discharge path 95.

[0037] The filter 99 is disposed in the discharge passage 95 between the supply passage 90 and the check valve 73, and has a predetermined flow resistance with respect to the cleaning liquid. As a result, the water pressure of the cleaning liquid that has flowed into the discharge passage 95 via the supply passage 90 is reduced when passing through the filter 99, and the cleaning liquid flows again downstream of the discharge member 71.

[0038] The check valve 73 is biased by the biasing spring 74 in a direction approaching the supply path 90, and abuts against the connecting portion 83 via the O-ring 75. As a result, the discharge path 95 on the supply path 90 side is closed by the check valve 73. At this time, when the water pressure of the cleaning liquid reduced by the filter 99 exceeds a predetermined opening pressure, the check valve 73 moves away from the O-ring 75 against the pressing force of the biasing spring 74. As a result, the check valve 73 is opened and the cleaning liquid is discharged from the discharge port 72b through the discharge path 95.

[0039] At this time, the reduced pressure value due to the flow path resistance of the filter 99 is greater than the opening pressure of the check valve 73. The water pressure of the cleaning liquid (liquid) passing through each of the discharge members 71a to 71c is reduced to a predetermined value or less by the filter 99. As a result, even if the water pressure of the cleaning liquid flowing through each of the branched supply paths 90 is different for each of the discharge members 71a to 71c, the water pressure is reduced by the filter 99 and the check valve 73 is not opened. On the other hand, when the opening / closing valve (not shown) is closed, the water pressure of the cleaning liquid flowing through each of the branched supply paths 90 increases. When the water pressure of the cleaning liquid reaches a predetermined value, the check valve 73 is opened and the cleaning liquid is discharged from each discharge port 72b.

[0040] As a result, the water pressure of the cleaning liquid passing through each of the discharge members 71a to 71c is made uniform until the water pressure of each of the discharge members 71a to 71c rises to a predetermined value or higher. Therefore, the check valve 73 is opened to make the water pressure of the cleaning liquid discharged from each of the discharge members 71a to 71c uniform. As a result, the amount of cleaning liquid pushed out from each of the discharge members 71a to 71c can be made uniform. Furthermore, by providing each of the discharge members 71a to 71c with the check valve 73, it is possible to prevent the cleaning liquid from flowing out from each of the discharge members 71a to 71c due to a difference in water head. It is also possible to prevent air bubbles from being trapped in the supply path 90 from the discharge port 72b.

[0041] It is more preferable that the reduced pressure value due to the flow path resistance of the filter 99 is three or more times larger than the opening pressure of the check valve 73. As a result, the water pressure of the cleaning liquid (liquid) passing through each of the discharge members 71a to 71c is reduced to a predetermined value or less by the filter 99. This makes it possible to make the amount of cleaning liquid pushed out by each of the discharge members 71a to 71c more uniform.

[0042] In addition, it is preferable to set the opening pressure of the check valve 73 of the discharge member 71a higher than the reduced pressure caused by the flow path resistance in the supply path 90 from the downstream of the discharge member 71a to the tank 98. In addition, it is preferable to set the sum of the flow path resistance in the discharge path 95 up to the discharge port 72b, including the reduced pressure caused by the flow path resistance of the filter 99 and the opening pressure of the check valve 73, to be at least twice as high as the flow path resistance in each supply path 90 from the downstream of the discharge member 71a to the tank 98. This makes it possible to more uniform the pressure of the water discharged from the discharge member 71a when the check valve 73 is opened.

[0043] Similarly, the opening pressure of the check valve 73 of the discharge member 71b is set to be greater than the reduced pressure caused by the flow path resistance in the supply path 90 from the downstream of the discharge member 71b to the tank 98, and the sum of the flow path resistance in the discharge path 95 up to the discharge port 72b, including the reduced pressure caused by the flow path resistance of the filter 99 and the opening pressure of the check valve 73, is more than twice as great as the flow path resistance in each supply path 90 from the downstream of the discharge member 71b to the tank 98.

[0044] In addition, the opening pressure of the check valve 73 of the discharge member 71c is set to be greater than the reduced pressure caused by the flow path resistance in the supply path 90 from the downstream of the discharge member 71c to the tank 98, and the sum of the flow path resistance in the discharge path 95 up to the discharge port 72b, including the reduced pressure caused by the flow path resistance of the filter 99 and the opening pressure of the check valve 73, is more than twice as great as the flow path resistance in each supply path 90 from the downstream of the discharge member 71c to the tank 98.

[0045] 7, an inclined surface 62 is formed on the upstream side (right side in FIG. 7) in the wiping direction (direction of arrow A) of the cleaning liquid supplying member 60 relative to the cleaning liquid supplying surface F2. The downstream side (left side in FIG. 7) of the cleaning liquid supplying surface F2 in the wiping direction is formed in a thin plate shape and is disposed so as to overlap with the end of the ink ejection surface F1 of the head portion 18.

[0046] A cleaning liquid supply port 60a is disposed on the cleaning liquid supply surface F2 of the cleaning liquid supply member 60. The cleaning liquid supply port 60a is in communication with the discharge port 72b. The cleaning liquid supply ports 60a may be disposed in a staggered pattern at a predetermined pitch in the wiping direction (arrow A direction) and the head width direction (arrow BB' direction) perpendicular to the wiping direction. By arranging them in this manner, the cleaning liquid can be supplied across the head width direction.

[0047] 2. Recovery operation of the recording head Next, a description will be given of the recovery operation of the recording heads 17 in the printer 100. In the printer 100, in order to clean the ink ejection surfaces F1 of the recording heads 17, a recovery operation is performed on all recording heads 17 when printing starts after a long period of stoppage and between printing operations, in order to prepare for the next printing operation.

[0048] When performing a recovery operation for the recording head 17, the first belt transport unit 5 arranged opposite to the lower surface of the recording unit 9 is lowered. Then, the maintenance unit 19 is moved from the waiting position (see FIG. 1) to below the recording unit 9 by a unit moving mechanism (not shown).

[0049] (Ink extrusion operation) Prior to a wiping operation (a wiping operation described below), ink is supplied to the recording head 17 in response to a control signal from the control unit 110 (see FIG. 1). As shown in FIG. 8, the supplied ink is forcibly extruded (purged) from the nozzles 18a as purged ink 22. This purging operation expels thickened ink, foreign matter, and air bubbles from within the nozzles 18a, allowing the recording head 17 to be restored.

[0050] (Cleaning liquid supply operation) Prior to the wiping operation, cleaning liquid is supplied to the recording head 17 in response to a control signal from the control unit 110. As shown in Fig. 8, a predetermined amount of the supplied cleaning liquid 23 is supplied from the cleaning liquid supply port 60a to the cleaning liquid supply surface F2.

[0051] (wiping action) As shown in FIG. 9, the maintenance unit 19 is raised by a unit lifting mechanism (not shown), thereby bringing the wiper 35 into contact with the inclined surface 62 of the cleaning liquid supplying member 60 of the recording head 17 at a predetermined pressure.

[0052] The wiper 35 is an elastic member (e.g., a rubber member made of EPDM) for wiping off the purged ink 22 extruded from the nozzles 18a of each recording head 17 and the cleaning liquid 23 supplied from the cleaning liquid supply port 60a. The wiper 35 is pressed against a portion (here, the inclined surface 62) on the upstream side in the wiping direction of the cleaning liquid supply member 60, and wipes the cleaning liquid supply surface F2 and the ink ejection surface F1 in a predetermined direction (the direction of the arrow A) by the movement of a carriage (not shown).

[0053] From a state in which the tip of the wiper 35 is in pressure contact with the inclined surface 62 of the cleaning liquid supplying member 60, the wiper 35 is moved along the cleaning liquid supplying surface F2 toward the nozzle region R1 (in the direction of arrow A). As a result, the wiper 35 wipes away the cleaning liquid 23 as shown in FIG. 10, and then moves toward the nozzle regions Ra to Rd while retaining the cleaning liquid 23.

[0054] 11, the wiper 35 moves leftward (in the direction of arrow A) on the ink ejection surface F1 while maintaining the cleaning liquid 23 and purged ink 22. At this time, the ink droplets that have adhered to and solidified on the ink ejection surface F1 swell and dissolve due to the cleaning liquid 23 and purged ink 22, and are wiped away by the wiper 35. The wiper 35 then moves further leftward (in the direction of arrow A), and when it reaches the end of the nozzle region R1 on the opposite side to the cleaning liquid supply member 60, its movement leftward is stopped. The cleaning liquid 23 and purged ink 22 wiped away by the wiper 35 are collected in a waste ink collection tray (not shown) provided in the maintenance unit 19.

[0055] (separation action) After the wiping operation is performed, the wiper 35 is lowered and separated from the ink ejection surface F1, as shown in Fig. 12. Thereafter, the maintenance unit 19 disposed between the recording section 9 and the first transport unit 5 is moved horizontally to a retracted position below the second transport unit 12, and the first transport unit 5 is raised to a predetermined position. In this manner, the recovery operation for the recording head 17 is completed.

[0056] As described above, after the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a, the wiper 35 is moved along the ink ejection surface F1 from the upstream side of the cleaning liquid supply port 60a in the wiping direction, whereby the wiper 35 can wipe the ink ejection surface F1 while holding the cleaning liquid 23.

[0057] This allows ink droplets that have adhered to and solidified on the ink ejection surface F1 to be swelled and wiped off by the cleaning liquid 23, making it possible to easily and reliably clean the ink ejection surface F1. In addition, the cleaning liquid 23 improves the lubricity between the ink ejection surface F1 and the wiper 35, making it possible to effectively prevent the water-repellent film on the ink ejection surface F1 from peeling off due to friction with the wiper 35.

[0058] Furthermore, by wiping off the cleaning liquid 23 together with the purged ink 22 with the wiper 35, the cleaning liquid can be left on the ink ejection surface F1 after wiping. This makes it possible to maintain image quality by suppressing the deterioration of ink straightness (curved flight) and ejection failures over a long period of time, and also to suppress the drying of ink droplets and mist attached to the ink ejection surface F1.

[0059] (Cleaning fluid application operation) The above-mentioned recovery operation of the recording head may include an application operation of the cleaning liquid 23 to the ink ejection surface F1. Specifically, after the wiping operation, a predetermined amount of the cleaning liquid 23 is again supplied from the cleaning liquid supply port 60a to the cleaning liquid supply surface F2. Then, the wiper 35 is moved upstream in the wiping direction to be pressed against the inclined surface 62, and is moved in the direction of arrow A along the cleaning liquid supply surface F2 to hold the cleaning liquid 23 on the wiper 35. In this state, the wiper 35 is moved in the direction of arrow A along the ink ejection surface F1. As a result, the cleaning liquid 23 is applied uniformly to the ink ejection surface F1. After the application operation of the cleaning liquid 23 is completed, the wiper 35 is lowered to separate from the ink ejection surface F1.

[0060] If the purged ink 22 is simply wiped off together with the cleaning liquid 23, the cleaning liquid 23 containing ink components will remain on the ink ejection surface F1. Therefore, by performing an application operation of the cleaning liquid 23, it is possible to apply only the cleaning liquid 23 to the ink ejection surface F1. This makes it possible to prevent the ink ejection surface F1 from drying, and further to effectively prevent the ink droplets and mist adhering to the ink ejection surface F1 after the application of the cleaning liquid 23 from drying and solidifying.

[0061] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible without departing from the spirit of the present invention. The effects of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. [Industrial Applicability]

[0062] The present invention can be used in an inkjet recording device having nozzles that eject water-based ink onto a recording medium. By using the present invention, it is possible to provide an inkjet recording device and a method for cleaning a recording head that improves ink ejection defects by peeling off and dissolving ink that has adhered to and solidified on the nozzle surface of the recording head. [Explanation of symbols]

[0063] 1 Printer body 2 Paper Cassette 3 Paper feeder 4a First paper transport path 4b Second paper transport path 8 Conveyor belt 9. Recording Section 10 Head housing 11C~11K Line Head 12 Second transport unit 13 Registration roller pair 14 Decaler section 15 Paper output tray 16 Reversing conveyor path 17 Recording head 17a~17c Recording head 18 Head section 18a Nozzle 19 Maintenance Unit 20 Cap Units 22 Purge Ink 23 Cleaning Fluid 35 Wiper 60 Cleaning liquid supply member 60a Cleaning fluid supply port 62 Slope 71a to 71c Discharge member 72 Cylindrical part 72a Step 72b Discharge port 73 Check valve 74 Spring 75 O-ring 76 O-ring 78 Retaining member 79 Screw 80 Cap 81 Large diameter cylindrical section 82 Small diameter cylindrical section 83 Continuous section 90 Supply route 92a~92c Branching section 95 Discharge path 96 Discharge Connection 97 Supply Connection 98 Tank 99 Filters 100 Printers 110 Control device 110 Control section 200 Liquid supply mechanism A Arrow BB Arrow F1 Ink ejection surface F2 Cleaning fluid supply surface P Paper R1 Nozzle Area Ra~Rd Nozzle area X Arrow

Claims

1. A tank for containing a liquid; a supply passage having one end connected to the tank and through which liquid flows; a discharge member disposed on the supply path and configured to discharge a liquid, The discharge member is a filter having a predetermined flow resistance to a liquid passing therethrough; a check valve that opens at a predetermined opening pressure to the liquid passing through; a discharge passage through which liquid flows when the check valve is opened and through which the liquid is discharged from a discharge port formed at a tip portion of the discharge passage, A liquid supply mechanism, wherein a pressure reduction value due to the flow resistance of the filter is greater than an opening pressure of the check valve.

2. 2. The liquid supply mechanism according to claim 1, wherein a pressure reduction value due to the flow resistance of the filter is three times or more greater than an opening pressure of the check valve.

3. an opening pressure of the check valve is greater than a reduced pressure caused by a flow resistance in the supply path from the downstream of the discharge member to the tank, 3. The liquid supply mechanism according to claim 1, wherein a sum of flow path resistances in the discharge path up to the discharge port, including a reduced pressure value due to the flow path resistance of the filter and an opening pressure of the check valve, is greater than or equal to two times the flow path resistance in the supply path from downstream of the discharge member to the tank.

4. The supply path is branched into a plurality of branches, The liquid supply mechanism according to claim 1 , wherein the discharge members are disposed on the respective branched supply paths.

5. The liquid supply mechanism according to claim 4 , further comprising an on-off valve capable of opening and closing the flow path of the liquid on a downstream side of the discharge member.

6. The supply passages branch into a plurality of branches and join together at a joining portion downstream of the discharge member, The liquid supply mechanism according to claim 5 , wherein the on-off valve is disposed downstream of the junction of the supply paths.

7. The liquid supply mechanism according to claim 6 , wherein both ends of the supply path are connected to a pump that circulates the liquid.

8. An inkjet recording apparatus comprising the liquid supply mechanism according to claim 1 , a recording head having an ink ejection surface having ink ejection ports through which ink is ejected; a wiper member that comes into contact with the ink ejection surface and moves in a predetermined wiping direction to wipe the ink ejection surface; a cleaning liquid supply unit including a cleaning liquid supply surface having the discharge port for supplying cleaning liquid used for wiping the ink discharge surface by the wiper member, the cleaning liquid supply unit being provided upstream of the ink discharge surface in the wiping direction; The tank containing the cleaning liquid; the supply path for guiding the cleaning liquid from the tank to the cleaning liquid supply unit; a drive unit that applies power to move the cleaning liquid in the supply path and push the cleaning liquid out of the discharge port; a control unit that controls a cleaning operation in which the wiper member wipes the ink ejection surface with the cleaning liquid, The supply path is branched to form a plurality of branch supply paths, The ejection members are disposed on the branched supply paths, respectively.

Images