Liquid supply device and inkjet recording device

Abstract

The present invention provides a liquid supply device capable of pressurizing a liquid with a pump and uniformly discharging it from multiple nozzles. [Solution] The liquid supply device 8 includes a discharge section 82 located in each of the multiple distribution channels 84B. The discharge section 82 comprises a nozzle 821, a check valve 822, and a flow resistance body 823. The check valve 822 is located upstream of the nozzle 821 in the discharge direction and prevents the flow of cleaning liquid in the reverse direction of the discharge direction, allowing the cleaning liquid to flow toward the nozzle 821 when the cleaning liquid in the distribution channel 84B reaches a pressure of 1 or higher. The flow resistance body 823 is located between the check valve 822 and the nozzle 821 and creates resistance to the flow of cleaning liquid, allowing the cleaning liquid to flow toward the nozzle 821 when the cleaning liquid that has passed through the check valve 822 reaches a pressure of 2 or higher, which is higher than the 1 pressure.

Description

Technical Field

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[0001] The present invention relates to a liquid supply device and an inkjet recording device.

Background Art

[0002] As a recording device such as a printer or a copier, an inkjet recording device that ejects ink onto a sheet-like recording medium such as paper to record an image is widely used because it can record high-definition images. In such an inkjet recording device, a liquid (ink, cleaning liquid) is transported by a pump from a container containing a liquid such as ink or a cleaning liquid to a recording head that ejects ink onto the recording medium.

[0003] For example, a conventional inkjet printer disclosed in Patent Document 1 includes an ink head having a plurality of nozzles and an ink supply mechanism for the nozzles. The ink supply mechanism includes an ink container, an ink flow path, and a liquid feed pump. The ink supply mechanism is configured to supply ink from the ink container toward the nozzles through the ink flow path by driving the liquid feed pump.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of a configuration provided with a plurality of ink heads, if there is a difference in the flow path resistance of the liquid at the nozzle portion, there is a problem that the liquid can only be discharged (ejected) from the nozzles with a low flow path resistance. There is a concern that the uniformity of the liquid discharge (ejection) may be impaired, and the reliability of the ink ejection and the supply of the cleaning liquid may be reduced.

[0006] The present invention has been made in view of the above points, and aims to provide a liquid supply device and an inkjet recording device that can pressurize a liquid with a pump and uniformly discharge it from multiple nozzles. [Means for solving the problem]

[0007] To solve the above problems, the liquid supply device of the present invention comprises a flow path and a pump. Liquid flows through the flow path. The pump is connected to the flow path and moves the liquid within the flow path. The flow path includes a plurality of distribution flow paths and a discharge section. The plurality of distribution flow paths are arranged in parallel so as to branch into a plurality at branching points and merge into a single flow path at confluence points. The discharge section is located in each of the plurality of distribution flow paths and discharges the liquid in the distribution flow path to the outside. The discharge section comprises a nozzle, a check valve, and a flow path resistor. The nozzle discharges the liquid to the outside. The check valve is located upstream of the nozzle with respect to the liquid discharge direction and prevents the flow of the liquid in the opposite direction to the liquid discharge direction, and when the liquid in the distribution flow path reaches a first pressure or higher, it allows the liquid to flow toward the nozzle in the liquid discharge direction. The flow resistance element is positioned between the check valve and the nozzle with respect to the liquid discharge direction, and creates resistance to the flow of the liquid. When the liquid that has passed through the check valve reaches a pressure higher than the first pressure (a second pressure or higher), it causes the liquid to flow toward the nozzle in the liquid discharge direction. [Effects of the Invention]

[0008] According to the configuration of the present invention, even if there are differences in performance among multiple check valves, the liquid will remain upstream of the flow resistance until the pressure upstream of the flow resistance reaches the second pressure or higher. When the pressure upstream of the flow resistance reaches the second pressure or higher, the liquid is discharged simultaneously from the nozzles at each of the multiple discharge points. Therefore, when the liquid is pressurized by a pump and discharged from multiple nozzles, uniform discharge becomes possible. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional front view of an image forming system including an inkjet recording device according to one embodiment of the present invention. [Figure 2] Figure 1 is a plan view of the area around the recording unit of an inkjet recording device. [Figure 3] Figure 2 is a side view of the recording head of the recording unit. [Figure 4] Figure 2 is a bottom view of the recording head of the recording unit. [Figure 5] Figure 1 is a front view of the head unit and maintenance unit of the inkjet recording device. [Figure 6] Figure 5 is a front view of the head unit and maintenance unit, showing the head unit and liquid supply device in a raised position. [Figure 7] Figure 5 is a front view of the head unit and maintenance unit, showing the wipe unit in a position below the head unit. [Figure 8] Figure 5 is a front view of the head unit and maintenance unit, showing the head unit in close proximity to the wipe unit. [Figure 9] Figure 5 is a perspective view of the wipe unit and liquid supply device. [Figure 10] Figure 9 is a perspective view of the wipe unit, showing the blade portion in a retracted position. [Figure 11] Figure 5 is a perspective view of the blade portion of the wipe unit. [Figure 12] Figure 5 is a perspective view of the cleaning fluid supply section of the wipe unit. [Figure 13] Figure 5 is a side view of the blade and cleaning fluid supply section of the wipe unit. [Figure 14] Figure 5 is a perspective view of the cleaning fluid supply section of the wipe unit, seen from below. [Figure 15] Figure 9 is a partial cross-sectional perspective view of the wipe unit and liquid supply device, seen from below. [Figure 16] FIG. 15 is a partial cross-sectional perspective view of the wiper unit and the liquid supply device, showing the state where the liquid supply device is close to the wiper unit. [Figure 17] FIG. 16 is an enlarged cross-sectional perspective view of the wiper unit and the liquid supply device. [Figure 18] FIG. 8 is a side view showing the state where the wiper unit of FIG. 7 is moved below the head unit. [Figure 19] FIG. 11 is a side view showing the state where the head unit of FIG. 8 is close to the wiper unit. [Figure 20] FIG. 19 is a side view showing the state where the wiper unit performs a wiping operation on the head unit. [Figure 21] FIG. 9 is a piping system diagram of the liquid supply device. [Figure 22] FIG. 21 is a schematic plan view showing a part of the piping of the liquid supply device. [Figure 23] FIG. 21 is an end view of a vertically cut portion of the discharge portion of the liquid supply device. [Figure 24] FIG. 23 is a partially enlarged end view of a cut portion of the discharge portion. BEST MODE FOR CARRYING OUT THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described based on the drawings. Note that the present invention is not limited to the following content.

[0011] FIG. 1 is a schematic cross-sectional front view of an image forming system 100 including an inkjet recording apparatus 1 according to an embodiment. FIG. 2 is a plan view around a recording unit 4 of the inkjet recording apparatus 1 in FIG. 1. In the following drawings including FIGS. 1 and 2, arrow lines indicating the left-right horizontal direction Dx, the front-back direction Dy, and the up-down direction Dz of the apparatus, as well as arrow lines indicating the sheet conveyance direction Dc and the sheet width direction Dw, are appropriately drawn. The sheet conveyance direction Dc is parallel to the left-right horizontal direction Dx of the apparatus, and the sheet width direction Dw is a direction orthogonal to the sheet conveyance direction Dc and parallel to the front-back direction Dy of the apparatus.

[0012] The image forming system 100 includes a sheet supply device 110, an inkjet recording device 1, a drying device 120, and a sheet discharge device 130. These devices are connected in the image forming system 100 from the upstream end of the sheet transport direction Dc in the order of sheet supply device 110, inkjet recording device 1, drying device 120, and sheet discharge device 130.

[0013] The sheet supply device 110 holds multiple sheets (recording media) S and separates the sheets S one by one and supplies them to the inkjet recording device 1. The inkjet recording device 1 records (forms) an image on the sheets S transported from the sheet supply device 110 using an inkjet method. The drying device 120 heats the sheets S on which the ink image has been recorded by the inkjet recording device 1 to dry the ink. The sheet discharge device 130 discharges the sheets S on which the ink has been dried by the drying device 120 and the image recording (printing) is complete into a tray or the like that can be removed from the outside. The sheet discharge device 130 may include a post-processing device that performs post-processing such as perforation, stapling, and folding on the recorded sheets S.

[0014] The inkjet recording apparatus 1 is, for example, an inkjet recording type image forming apparatus. As shown in Figures 1 and 2, the inkjet recording apparatus 1 includes a transport unit 3, a recording unit 4, and a control unit 5 within its apparatus body 2.

[0015] The transport unit 3 is positioned below the recording unit 4 and opposite to the recording unit 4. The transport unit 3 transports the sheets S received from the sheet supply device 110, passing them below the recording unit 4, toward the drying device 120. The transport unit 3 has an endlessly formed transport belt 31 and a suction unit 32.

[0016] The conveyor belt 31 has multiple through holes (not shown) that penetrate both sides. The suction unit 32 is located inside the endless conveyor belt 31 and is positioned adjacent to the inner circumferential surface of the upper part of the conveyor belt 31. Multiple suction holes (not shown) that draw air downward are formed on the upper surface of the suction unit 32. The conveying unit 3 conveys the sheet S by adsorbing and holding it on the upper surface of the conveyor belt 31 using the suction unit 32.

[0017] The recording unit 4 is positioned above the transport unit 3, facing the transport unit 3. The recording unit 4 is positioned above the transport belt 31, at a predetermined distance, facing the sheet S that is held and transported by suction on the upper surface of the transport belt 31.

[0018] As shown in Figure 2, the recording unit 4 holds head units 41B, 41C, 41M, and 41Y, each corresponding to one of the four colors: black, cyan, magenta, and yellow. The head units 41B, 41C, 41M, and 41Y are arranged side by side along the sheet transport direction Dc, with their longitudinal directions parallel to the sheet width direction Dw. The recording unit 4 is located below the recording unit 4 and is connected to the ink container 6, which contains the black, cyan, magenta, and yellow inks supplied to the recording unit 4. Since the four head units 41B, 41C, 41M, and 41Y have the same basic configuration, the identification symbols "B," "C," "M," and "Y" representing each color may be omitted in the following description unless specifically required.

[0019] Each color head unit 41 has a line-type inkjet recording head 42. Multiple recording heads 42 (for example, three (42a, 42b, 42c)) are arranged in a staggered pattern along the sheet width direction Dw in each color head unit 41.

[0020] The recording head 42 has a plurality of ink ejection nozzles 421 at its bottom. The plurality of ink ejection nozzles 421 are arranged in a line along the sheet width direction Dw, and are able to eject ink over the entire recording area on the sheet S. The recording unit 4 sequentially ejects ink from the recording heads 42 of the four color head units 41B, 41C, 41M, and 41Y toward the sheet S which is being transported by the transport belt 31, and records a full-color image or a monochrome image on the sheet S.

[0021] The control unit 5 includes a CPU, a memory unit, and other electronic circuits and electronic components (none of which are shown). The CPU controls the operation of each component provided in the inkjet recording device 1 based on control programs and data stored in the memory unit, and performs processing related to the functions of the inkjet recording device 1. The transport unit 3 and the recording unit 4 each receive individual commands from the control unit 5 and perform recording on the sheet S in conjunction. Alternatively, the control unit 5 may send individual commands to the sheet supply device 110, the drying device 120, and the sheet discharge device 130 as a whole image forming system 100, and perform recording on the sheet S in conjunction. The memory unit consists of a combination of a non-volatile storage device such as a program ROM (Read Only Memory) or data ROM, and a volatile storage device such as RAM (Random Access Memory).

[0022] Next, the configuration of the recording head 42 of the recording unit 4 will be described. Figures 3 and 4 are side and bottom views of the recording head 42 of the recording unit 4 shown in Figure 2. Note that the three recording heads 42a, 42b, and 42c of each color have the same shape and configuration, so the identification symbols (a, b, c) will be omitted in the following description.

[0023] The recording head 42 has an ink ejection surface 42F on its lower surface. The ink ejection surface 42F faces the surface (upper surface) of the sheet S being transported on the conveyor belt 31. As shown in Figure 4, the ink ejection surface 42F has a nozzle area 42R in which a large number of ink ejection nozzles 421 are arranged. That is, the ink ejection surface 42F has a large number of ink ejection nozzles 421 that open and eject ink onto the sheet S. A water-repellent film (not shown) is formed on the ink ejection surface 42F. Each of the four color (black, cyan, magenta, yellow) recording heads 42 is individually supplied with four colors of ink contained in an ink container 6 (see Figure 1).

[0024] Based on a control signal from the control unit 5, the recording head 42 ejects ink from the ink ejection nozzle 421 toward the sheet S that is being transported by being held and adsorbed to the transport surface of the transport belt 31, according to the image data received from the external computer. More specifically, the control unit 5 inputs an ejection drive signal with a predetermined drive voltage and pulse width to the recording head 42 to drive the recording head 42 and eject ink from the ink ejection nozzle 421. As a result, a color image or a monochrome image is formed on the sheet S on the transport belt 31 by superimposing four colors of ink: black, cyan, magenta, and yellow.

[0025] Furthermore, as shown in Figure 1, the inkjet recording device 1 is equipped with maintenance units 7. Each of the four color (black, cyan, magenta, and yellow) head units 41 is individually positioned upstream of the sheet transport direction Dc, and the maintenance units 7 are arranged side-by-side. Since the four maintenance units 7 have the same basic configuration, only one representative unit will be described below.

[0026] Figure 5 is a front view of the head unit 41 and maintenance unit 7 of the inkjet recording device 1 shown in Figure 1. The maintenance unit 7 comprises a cap unit 71, a wipe unit 72, and a liquid supply device 8. As shown in Figure 5, when maintenance processing of the recording head 42 is not being performed, these devices are arranged in the order of cap unit 71, wipe unit 72, and liquid supply device 8 from bottom to top in the vertical direction Dz.

[0027] The cap unit 71 includes a frame 711 and a cap portion 712. The frame 711 is formed in a rectangular, flat shape in plan view, extending horizontally in the sheet transport direction Dc (left-right lateral direction Dx) and the sheet width direction Dw (front-back direction Dy). The cap portion 712 is formed in a concave shape that is recessed downwards and is positioned on the upper surface of the frame 711. Multiple cap portions 712 (e.g., three) are arranged in a staggered pattern along the sheet width direction Dw, similar to the multiple recording heads 42 that are placed side by side.

[0028] The cap portion 712 is detachable from the ink ejection surface 42F and covers the ink ejection surface 42F. When the cap unit 71 is positioned in a maintenance position that covers the ink ejection surface 42F during maintenance of the recording head 42, the bottom of the recording head 42 moves inside the cap portion 712. This creates a closed space between the ink ejection surface 42F and the cap portion 712.

[0029] The wipe unit 72 includes a waste liquid tray 721, a blade section 722, and a cleaning liquid supply section 723. The waste liquid tray 721 is formed in a rectangular parallelepiped shape in plan view, extending horizontally in the sheet transport direction Dc (left-right lateral direction Dx) and the sheet width direction Dw (front-back direction Dy). The waste liquid tray 721 has a recess 721D formed on its upper surface that is recessed downwards. Multiple recesses 721D are arranged in a staggered pattern along the sheet width direction Dw, similar to the multiple juxtaposed recording heads 42 (for example, three).

[0030] The blade section 722 and the cleaning fluid supply section 723 are provided in each of the three recesses 721D. During maintenance of the recording head 42, the wipe unit 72 is positioned below the ink ejection surface 42F. The blade section 722 carries the cleaning fluid supplied from the liquid supply device 8 to the cleaning fluid supply section 723 to the ink ejection surface 42F. The blade section 722 then wipes away the ink ejected onto the ink ejection surface 42F along with the cleaning fluid it has carried to the ink ejection surface 42F (wiping operation).

[0031] The liquid supply device 8 includes a support plate 81 and a discharge section 82. The support plate 81 is formed in a rectangular shape in plan view, extending horizontally in the sheet transport direction Dc (left-right lateral direction Dx) and the sheet width direction Dw (front-back direction Dy). The discharge section 82 is supported by the support plate 81 so as to penetrate the support plate 81 in the vertical direction Dz (thickness direction). Multiple discharge sections 82 (e.g., three) are arranged in a staggered pattern along the sheet width direction Dw, similar to the multiple juxtaposed recording heads 42.

[0032] More specifically, the discharge unit 82 is positioned above the cleaning fluid supply unit 723 of the wipe unit 72. During maintenance of the recording head 42, the support plate 81 approaches the wipe unit 72 in the vertical direction Dz and supplies cleaning fluid from the discharge unit 82 towards the cleaning fluid supply unit 723.

[0033] Furthermore, the recording unit 4 includes a lifting mechanism and a sliding mechanism (neither of which are shown). The lifting mechanism and the sliding mechanism consist of a motor, guide rails, gear group, wire (belt), and pulleys, etc. The head unit 41 and the liquid supply device 8 are supported by the lifting mechanism and are movable in the vertical direction Dz. The cap unit 71 is supported by the sliding mechanism and is movable in the sheet transport direction Dc (left and right lateral direction Dx). The wipe unit 72 is supported by the lifting mechanism and the sliding mechanism and is movable in the vertical direction Dz and in the sheet transport direction Dc (left and right lateral direction Dx).

[0034] Figure 5 shows the state in which the head unit 41 (recording head 42) is positioned at the recording position relative to the sheet S on the conveyor belt 31 by the lifting mechanism and the sliding mechanism, and the maintenance unit 7 is positioned in a retracted position separated from the head unit 41 in the sheet conveying direction Dc (left and right lateral direction Dx). The head unit 41 (recording head 42) moves downward and approaches the conveyor belt 31. The liquid supply device 8 moves downward and approaches the wipe unit 72 and is positioned to supply cleaning fluid to the wipe unit 72.

[0035] In the inkjet recording device 1, maintenance processing for the recording head 42 is performed at predetermined timings. This maintenance processing for the recording head 42 is performed, for example, when recording starts after a long period of inactivity, or in between recording operations. When performing maintenance processing for the recording head 42, the control unit 5 moves the components of the maintenance unit 7 below the head unit 41 using a lifting mechanism and a sliding mechanism.

[0036] Figure 6 is a front view of the head unit 41 and maintenance unit 7 shown in Figure 5, and depicts the head unit 41 and liquid supply device 8 in a raised position. When performing maintenance on the recording head 42, the liquid supply device 8 rises from its supply position and is positioned in a retracted position spaced apart from the wipe unit 72. Also, when performing maintenance on the recording head 42, the head unit 41 is temporarily raised from its recording position and positioned in a retracted position spaced apart from the conveyor belt 31.

[0037] Figure 7 is a front view of the head unit 41 and maintenance unit 7 shown in Figure 5, with the wipe unit 72 moved below the head unit 41. When performing maintenance on the recording head 42, after the head unit 41 is placed in the retracted position, the wipe unit 72 and cap unit 71 are placed in a maintenance position closer to the head unit 41 on the downstream side in the sheet transport direction Dc. The wipe unit 72 and cap unit 71 are positioned in the space below the head unit 41 when it is in the retracted position.

[0038] Figure 8 is a front view of the head unit 41 and maintenance unit 7 shown in Figure 5, and depicts the head unit 41 in a position close to the wipe unit 72. When performing maintenance on the recording head 42, after placing the wipe unit 72 and cap unit 71 in the maintenance position, the head unit 41 (see Figures 6 and 7), which was temporarily placed in the retracted position, is lowered and placed in the maintenance position close to the wipe unit 72. In the maintenance position, the wipe unit 72 is positioned opposite the ink ejection surface 42F of the head unit 41 (recording head 42).

[0039] Furthermore, although not shown in the figures, when performing maintenance on the recording head 42, it is also possible to place the wipe unit 72 in a retracted position (see Figures 5 and 6), place only the cap unit 71 in a maintenance position (see Figures 7 and 8), and then temporarily move the head unit 41 from the retracted position downwards to a maintenance position closer to the cap unit 71. In the maintenance position, the cap unit 71 is attached to the ink ejection surface 42F of the head unit 41 (recording head 42), and the bottom of the recording head 42 is recessed into the cap portion 712.

[0040] Next, the configuration of the wipe unit 72 will be described. Figure 9 is a perspective view of the wipe unit 72 and liquid supply device 8 shown in Figure 5. Figure 10 is a perspective view of the wipe unit 72 shown in Figure 9, showing the state in which the blade portion 722 has been moved. Figure 11 is a perspective view of the blade portion 722 of the wipe unit 72 shown in Figure 5. Figure 12 is a perspective view of the cleaning liquid supply portion 723 of the wipe unit 72 shown in Figure 5. Figure 13 is a side view of the blade portion 722 and cleaning liquid supply portion 723 of the wipe unit 72 shown in Figure 5. Figure 14 is a perspective view of the cleaning liquid supply portion 723 of the wipe unit 72 shown in Figure 5, viewed from below. As shown in Figures 9 and 10, the wipe unit 72 includes a waste liquid tray 721, a blade portion 722, and a cleaning liquid supply portion 723.

[0041] Each of the recesses 721D arranged in a staggered pattern along the sheet width direction Dw of the waste liquid tray 721 is provided with a blade section 722 and a cleaning liquid supply section 723. The recesses 721D are formed in a rectangular shape in plan view, extending long in the sheet width direction Dw. The length of the recess 721D in the sheet transport direction Dc and the length in the sheet width direction Dw are longer than the ink discharge surface 42F. Ink and cleaning liquid wiped from the ink discharge surface 42F fall into the recesses 721D.

[0042] Furthermore, a liquid receiving section 721C is provided in the recess 721D. The liquid receiving section 721C is located at one end of the recess 721D in the sheet width direction Dw (the front side in the front-rear direction Dy) and is positioned at the end of the wiping operation of the blade section 722 (see Figures 9 and 10). The liquid receiving section 721C is formed as a box with a top surface, front and left and right sides, and an open back and bottom. In other words, the liquid receiving section 721C is a box with an open bottom and the side where the wiping operation of the blade section 722 begins. The liquid receiving section 721C receives the ink and cleaning liquid wiped from the ink discharge surface 42F.

[0043] A support plate 81 of the liquid supply device 8 is positioned above the waste liquid tray 721 (see Figure 9). The discharge sections 82 provided on the support plate 81 are arranged in a staggered pattern along the sheet width direction Dw and are located above the cleaning liquid supply section 723.

[0044] As shown in Figure 11, the blade section 722 includes a holder 722H and a blade 722B. The holder 722H is supported by a sliding mechanism (not shown) extending in the sheet width direction Dw, which is provided on the upper part of the waste liquid tray 721, and is movable in the sheet width direction Dw within the recess 721D (see Figures 9 and 10). Regarding the wiping operation of the blade section 722 on the ink ejection surface 42F, Figure 9 shows the blade section 722 in the starting position, and Figure 10 shows the blade section 722 in the ending position.

[0045] The blade 722B is held in the holder 722H, with its cutting edge protruding upward. The blade 722B is made of rubber, such as EPDM (ethylene propylene diene rubber), and is an elastic member with a cutting edge at its upper end that extends approximately in the sheet transport direction Dc. When the head unit 41 descends in the maintenance position and approaches the wipe unit 72, the blade 722B contacts the ink discharge surface 42F from below with a predetermined pressure. The blade 722B then moves along the sheet width direction Dw as the holder 722H that holds the blade 722B moves.

[0046] The cleaning fluid supply unit 723 is located at the other end of the recess 721D in the sheet width direction Dw (the rear side in the front-rear direction Dy), and is positioned at the starting position of the wiping operation of the blade unit 722 (see Figures 9 and 10). As shown in Figure 12, when the blade unit 722 is positioned at the starting position of the wiping operation, the cleaning fluid supply unit 723 is positioned above the blade unit 722. As shown in Figures 12, 13, and 14, the cleaning fluid supply unit 723 includes a supply member 723S and a transfer member 723D.

[0047] The supply member 723S is formed in a rectangular parallelepiped shape in plan view, extending in the sheet transport direction Dc and the sheet width direction Dw. The upper surface of the supply member 723S is flat. The supply member 723S has a housing portion 723C. The housing portion 723C is located at the end of the supply member 723S on the side of the end position of the wiping operation of the blade portion 722 (the front side in the front-rear direction Dy).

[0048] The containment section 723C is a hollow structure having an internal space for containing cleaning fluid. The containment section 723C has an inlet 723A that opens upward and an outlet 723B that opens downward.

[0049] The inlet 723A is positioned opposite the discharge section 82 of the liquid supply device 8, which is located at the position where cleaning fluid is supplied to the wipe unit 72, in the vertical direction Dz (see Figure 9). As shown in Figure 13, when the blade section 722 is positioned at the starting position of the wiping operation, the outlet 723B is located on the side of the blade section 722 that is at the end position of the wiping operation (in front of it in the front-rear direction Dy). The cleaning fluid supplied from the liquid supply device 8 to the cleaning fluid supply section 723 is contained inside the containment section 723C via the inlet 723A and discharged outside the containment section 723C via the outlet 723B.

[0050] The transfer member 723D is joined to the lower surface of the receiving portion 723C of the supply member 723S. The transfer member 723D is a sheet member with a rectangular shape in plan view, formed of, for example, synthetic resin, and is flexible. The leading edge of the transfer member 723D in the sheet width direction Dw (the front end in the front-rear direction Dy) protrudes forward from the front end of the supply member 723S (receiving portion 723C), as shown in Figures 12 and 13.

[0051] As shown in Figure 14, the transfer member 723D has a through hole 723P that penetrates in the vertical direction Dz. The through hole 723P is positioned opposite the outlet 723B of the receiving section 723C in the vertical direction Dz (see Figure 13).

[0052] Figure 15 is a partial cross-sectional perspective view of the wipe unit 72 and liquid supply device 8 from below, as shown in Figure 9. When cleaning liquid is not supplied to the wipe unit 72, the liquid supply device 8 rises from its supply position and is positioned in a retracted position, spaced apart from the wipe unit 72, as shown in Figure 15.

[0053] Figure 16 is a partial cross-sectional perspective view of the wipe unit 72 and liquid supply device 8 of Figure 15, showing the liquid supply device 8 in a position close to the wipe unit 72. Figure 17 is an enlarged cross-sectional perspective view of the wipe unit 72 and liquid supply device 8 of Figure 16. When supplying cleaning liquid to the wipe unit 72, as shown in Figures 16 and 17, the liquid supply device 8 is positioned at the cleaning liquid supply position, having descended from its retracted position and approaching the wipe unit 72. The inlet 723A of the cleaning liquid supply section 723 of the wipe unit 72 is positioned opposite the discharge section 82 of the liquid supply device 8 in the vertical direction Dz, and the cleaning liquid flows in from the liquid supply device 8.

[0054] Next, the wiping operation of the wipe unit 72 on the ink ejection surface 42F will be described. Figure 18 is a side view showing the wipe unit 72 in Figure 7 moved below the head unit 41. When a wiping operation is performed on the ink ejection surface 42F during the maintenance process of the recording head 42, the wipe unit 72 is moved to the maintenance position and positioned opposite the ink ejection surface 42F of the head unit 41 (recording head 42).

[0055] Prior to this stage, the wipe unit 72 has completed the supply of cleaning fluid from the liquid supply device 8. Cleaning fluid Fc flows out from the through hole 723P of the transfer member 723D onto the underside of the cleaning fluid supply section 723. Due to surface tension, the cleaning fluid Fc is held on the underside of the cleaning fluid supply section 723, spreading out over the entire underside of the cleaning fluid supply section 723 in the sheet width direction Dw and in the sheet transport direction Dc.

[0056] Furthermore, ink Fi is ejected from the ink ejection nozzle 421 onto the ink ejection surface 42F. The ink Fi contains, for example, ink with increased viscosity within the ink ejection nozzle 421, foreign matter, air bubbles, etc., and is forcibly pushed out from the ink ejection nozzle 421. Due to surface tension, the ink Fi is held on the underside of the ink ejection surface 42F, spread out over a predetermined length in the sheet width direction Dw and across the entire surface of the ink ejection surface 42F in the sheet transport direction Dc.

[0057] Next, the head unit 41 descends and approaches the wipe unit 72. Figure 19 is a side view showing the head unit 41 in Figure 8 in the state of approaching the wipe unit 72. As shown in Figure 19, the blade 722B of the wipe unit 72 contacts the lower surface of the cleaning fluid supply unit 723 from below with a predetermined pressure. The blade 722B then wipes the cleaning fluid Fc from the lower surface of the cleaning fluid supply unit 723 and further carries the cleaning fluid Fc to the ink ejection surface 42F. When the cleaning fluid Fc is carried to the ink ejection surface 42F by the blade 722B, it mixes with the ink Fi held at the ink ejection surface 42F and is wiped away.

[0058] Figure 20 is a side view showing the state in which the wipe unit 72 performs a wiping operation on the head unit 41 of Figure 19. As shown in Figure 20, when the blade 722B (blade portion 722) reaches the downstream end (front side in the front-rear direction Dy) in the direction of movement of the blade 722B relative to the ink ejection surface 42F, its movement stops. After that, the blade 722B (blade portion 722) descends and moves away from the ink ejection surface 42F. The ink Fi and cleaning fluid Fc wiped from the ink ejection surface 42F by the blade 722B are received by the fluid receiving portion 721C and fall into the recess 721D for collection.

[0059] Next, the configuration of the liquid supply device 8 will be described. Figure 21 is a piping diagram of the liquid supply device 8 shown in Figure 9. Figure 22 is a schematic plan view showing a part of the piping of the liquid supply device 8 shown in Figure 21. In addition to the support plate 81 and the discharge section 82, the liquid supply device 8 includes a tank 83, a flow path 84, and a pump 85.

[0060] Tank 83 stores the cleaning fluid. A flow path 84 is connected to Tank 83. By driving the pump 85, the cleaning fluid is supplied from Tank 83 to Flow 84, circulates through Flow 84, and is collected back into Tank 83.

[0061] The flow path 84 is attached to the support plate 81. Cleaning fluid (liquid) flows through the flow path 84. The flow path 84 is formed in an annular shape as a whole, from the outlet to the inlet of the tank 83. The flow path 84 is composed of three sections, in order from upstream to downstream with respect to the direction of flow of the cleaning fluid: the supply flow path 84A, multiple distribution flow paths 84B, and the recovery flow path 84C.

[0062] The supply channel 84A is connected to the downstream side of the tank 83, and cleaning fluid flows in from the tank 83. The recovery channel 84C is connected to the upstream side of the tank 83, and cleaning fluid flows out toward the tank 83. Multiple distribution channels 84B are arranged in parallel so that they branch off from the supply channel 84A at the branching section 84D and merge into a single recovery channel 84C at the confluence section 84E. The number of distribution channels 84B is equal to the number of cleaning fluid supply units 723 provided in the wipe unit 72 (for example, three).

[0063] Pump 85 is connected to flow path 84. Pump 85 is located downstream of the tank 83 in the direction of cleaning fluid flow and is positioned on the supply flow path 84A. Pump 85 applies pressure to the cleaning fluid in flow path 84 and moves the cleaning fluid within flow path 84.

[0064] Furthermore, a discharge unit 82 is provided in each of the three distribution channels 84B. As described above, the discharge unit 82 is supported by the support plate 81 so as to penetrate the support plate 81 in the vertical direction Dz (thickness direction). The discharge unit 82 discharges the cleaning fluid in the distribution channels 84B to the outside. In other words, the discharge unit 82 supplies the cleaning fluid in the distribution channels 84B to the cleaning fluid supply unit 723 of the wipe unit 72.

[0065] Next, the detailed configuration of the discharge section 82 will be described. Figure 23 is a vertical cross-sectional end view of the discharge section 82 of the liquid supply device 8 shown in Figure 21. The discharge section 82 is formed in a cylindrical shape that extends in the vertical direction. The discharge section 82 comprises a nozzle 821, a check valve 822, and a flow resistance body 823.

[0066] The nozzle 821 is positioned at the lower end of the discharge section 82. The nozzle 821 is formed in a cylindrical shape extending vertically, connected to a check valve 822 at its upper end, and opening as a discharge port 821D at its lower end. The nozzle 821 discharges the cleaning fluid to the outside from the discharge port 821D at its lower end.

[0067] The check valve 822 is connected to the distribution channel 84B via a communication section 822C. The check valve 822 is positioned upstream of the nozzle 821 with respect to the cleaning fluid discharge direction (downward in Figure 23). The check valve 822 is a ball-type check valve whose valve member is a ball 822V. The check valve 822 includes a biasing member 822B that biases the ball 822V toward the communication section 822C on the upstream side in the discharge direction.

[0068] The check valve 822 prevents the flow of cleaning fluid in the opposite direction to the discharge direction (upward in Figure 23) by the valve member ball 822V in the communication section 822C. On the other hand, when the cleaning fluid in the distribution channel 84B reaches a pressure equal to or greater than the first pressure, the ball 822V moves away from the communication section 822C against the biasing force of the biasing member 822B. In other words, when the cleaning fluid in the distribution channel 84B reaches a pressure equal to or greater than the first pressure, the check valve 822 allows the cleaning fluid to flow toward the nozzle 821 in the discharge direction.

[0069] The flow resistance element 823 is positioned between the check valve 822 and the nozzle 821 with respect to the cleaning fluid discharge direction (downward in Figure 23). The flow resistance element 823 has the same cross-sectional shape as the cylindrical discharge section 82 in the direction intersecting the cleaning fluid discharge direction, and is formed in a circular shape when viewed from that discharge direction. The flow resistance element 823 covers the cleaning fluid flow cross-section of the discharge section 82.

[0070] The flow resistance element 823 creates resistance to the flow of the cleaning fluid. When the cleaning fluid that has passed through the check valve 822 reaches a pressure higher than the first pressure (a second pressure or higher), the flow resistance element 823 causes the cleaning fluid to flow toward the nozzle 821 in the discharge direction.

[0071] According to the above configuration, even if there are differences in performance among the multiple check valves 822, the cleaning fluid will remain upstream of the flow resistance 823 until the pressure upstream of the flow resistance 823 reaches the second pressure or higher. When the pressure upstream of the flow resistance 823 reaches the second pressure or higher, the cleaning fluid is discharged simultaneously from the nozzles 821 at each of the multiple discharge sections 82. Therefore, when the cleaning fluid is pressurized by the pump 85 and discharged from multiple nozzles 821, uniform discharge becomes possible.

[0072] Furthermore, the flow path 84 is equipped with an on-off valve 84V. The on-off valve 84V is located in the recovery flow path 84C downstream of the confluence section 84E with respect to the flow direction of the cleaning fluid. The on-off valve 84V opens and closes the flow path 84. That is, when the on-off valve 84V is opened, the cleaning fluid flows through the flow path 84, and when the on-off valve 84V is closed, the flow of the cleaning fluid through the flow path 84 is blocked.

[0073] With the above configuration, by closing the on-off valve 84V, the pressure of the cleaning fluid in the distribution channel 84B and the discharge section 82 can be easily increased to the first or second pressure. Therefore, by controlling the opening and closing of the on-off valve 84V, it becomes possible to supply a uniform amount of cleaning fluid to each of the three cleaning fluid supply sections 723 of the wipe unit 72 at the appropriate timing.

[0074] Furthermore, if we define the pressure of the cleaning fluid flowing through the distribution channel 84B when the on-off valve 84V is open as the third pressure, then this third pressure is lower than the second pressure. In other words, the pressure of the cleaning fluid flowing through the distribution channel 84B when the on-off valve 84V is open is lower than the pressure of the cleaning fluid that can pass through the flow resistance element 823.

[0075] Furthermore, if we define the pressure of the cleaning fluid flowing through the distribution channel 84B when the on-off valve 84V is open as the third pressure, then this third pressure is lower than the first pressure. In other words, the pressure of the cleaning fluid flowing through the distribution channel 84B when the on-off valve 84V is open is lower than the pressure of the cleaning fluid that can pass through the check valve 822.

[0076] With the above configuration, when the on-off valve 84V is open, cleaning fluid can be prevented from being discharged from the discharge section 82. Then, by switching the on-off valve 84V open or closed as needed, it becomes possible to discharge the cleaning fluid from the discharge section 82 at the appropriate timing.

[0077] Furthermore, the flow resistor 823 acts as a filter for the cleaning fluid. This filter is made of, for example, a metal mesh. This configuration allows for the removal of impurities from the cleaning fluid and the adjustment of the pressure of the cleaning fluid discharged from the discharge section 82.

[0078] Next, the detailed configuration of the check valve 822 will be described. Figure 24 is a partially enlarged cross-sectional end view of the discharge section 82 of Figure 23. In addition to the ball 822V and the biasing member 822B, the check valve 822 includes a cylindrical section 822P and a sealing member 822S.

[0079] The cylindrical section 822P extends in the direction of cleaning fluid discharge (up and down in Figures 23 and 24). The cylindrical section 822P is connected to the distribution channel 84B at the communication section 822C located at the upstream end in the cleaning fluid discharge direction. The downstream end of the cylindrical section 822P in the discharge direction is connected to the nozzle 821.

[0080] The cylindrical section 822P houses the ball 822V, the biasing member 822B, and the flow resistance member 823. Inside the cylindrical section 822P, the ball 822V, the biasing member 822B, and the flow resistance member 823 are arranged in that order from the upstream side in the cleaning fluid discharge direction. The biasing member 822B biases the ball 822V toward the communication section 822C on the upstream side in the discharge direction. The flow resistance member 823 is positioned directly above the nozzle 821.

[0081] The sealing member 822S is positioned within the cylindrical portion 822P. More specifically, the sealing member 822S is positioned upstream of the ball 822V with respect to the cleaning fluid discharge direction, between the wall portion 822W at the upstream end of the cylindrical portion 822P and the ball 822V. The sealing member 822S is an annular member, such as an O-ring made of an elastic material like rubber, with its outer circumference in close contact with the wall portion 822W of the cylindrical portion 822P. The outer diameter of the sealing member 822S is larger than the inner diameter of the circular communication portion 822C in plan view. The inner diameter of the sealing member 822S is smaller than the outer diameter of the ball 822V.

[0082] The ball 822V is movable within the cylindrical portion 822P in the direction of cleaning fluid discharge (up and down direction in Figures 23 and 24). When the ball 822V moves upstream in the discharge direction, it comes into contact with the inner circumference of the sealing member 822S and closes the check valve 822. As a result, the check valve 822 allows the cleaning fluid to flow only in the direction of discharge from the nozzle 821, preventing backflow of the cleaning fluid.

[0083] The biasing member 822B is positioned downstream of the ball 822V in the discharge direction (towards the nozzle 821). The biasing member 822B is composed of, for example, a compression coil spring, with the axis of the coil portion extending along the central axis of the cylindrical portion 822P.

[0084] The upstream end of the biasing member 822B in the discharge direction contacts the valve member, the ball 822V. The downstream end of the biasing member 822B in the discharge direction contacts the flow resistance member 823. As a result, the biasing member 822B biases the ball 822V toward the upstream direction in the cleaning fluid discharge direction, so that it contacts the annular sealing member 822S. The check valve 822 prevents backflow of the cleaning fluid by causing the ball 822V to contact the inner circumference of the tubular sealing member 822S using the biasing member 822B, thereby allowing the cleaning fluid to flow only in the direction of discharge from the nozzle 821.

[0085] As shown in Figure 24, the outer diameter ds of the sealing member 822S is smaller than the inner diameter dp of the cylindrical portion 822P. However, if, for example, the outer diameter ds of the sealing member 822S were the same as or larger than the inner diameter dp of the cylindrical portion 822P, when the sealing member 822S adheres to the ball 822V due to ink drying or the like, even if the cleaning fluid in the distribution channel 84B reaches a pressure equal to or greater than the first pressure, the flow of the cleaning fluid in the check valve 822 in the discharge direction may be blocked by the sealing member 822S.

[0086] However, according to the configuration of the above embodiment, since the outer diameter ds of the sealing member 822S is smaller than the inner diameter dp of the cylindrical portion 822P, even if the sealing member 822S becomes stuck to the ball 822V due to the drying of the ink or the like, a gap is created between the outer circumference of the sealing member 822S and the inner circumference of the cylindrical portion 822P. Therefore, the check valve 822 can circulate the cleaning liquid in the distribution channel 84B in the discharge direction toward the nozzle 821 when the cleaning liquid in the distribution channel 84B reaches a pressure equal to or greater than the first pressure.

[0087] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications can be made to implement the invention without departing from the spirit of the invention.

[0088] For example, in the above embodiment, the liquid that the liquid supply device 8 discharges from the discharge section 82 and supplies to other components is a cleaning liquid, but this liquid is not limited to a cleaning liquid. The liquid supplied by the liquid supply device 8 may be other liquids such as ink. [Industrial applicability]

[0089] The present invention can be used in liquid supply devices and inkjet recording devices. [Explanation of Symbols]

[0090] 1. Inkjet recording device 2. Main unit of the device 3. Conveyor Unit 4 Recording Unit 5. Control Unit 7 Maintenance Unit 8 Liquid supply device 41 Head Unit 42 Recording heads 42F Ink ejection surface 71 Cap Unit 72 wipe units 81 Support plate 82 Discharge section 83 tanks 84 channels 84B Distribution channel 84D Branch 84E Junction 84V shut-off valve 85 pumps 100 Image Forming Systems 721 Waste liquid tray 722 Blade section 723 Cleaning fluid supply unit 821 Nozzle 821D outlet 822 Check valve 822B Biasing member 822C Communication part 822P Cylindrical section 822S Sealing member 822V Ball 823 Flow Resistor

Claims

1. A channel through which liquid flows, A pump connected to the aforementioned flow path and for moving the liquid within the aforementioned flow path, Equipped with, The aforementioned flow path is Multiple distribution channels are arranged in parallel so that they branch into multiple channels at the branching point and merge into one channel at the confluence point, Discharge units are provided in each of the multiple distribution channels for discharging the liquid in the distribution channel to the outside, Includes, The aforementioned discharge section is A nozzle for discharging the aforementioned liquid to the outside, A check valve is positioned upstream of the nozzle with respect to the liquid discharge direction, which prevents the flow of the liquid in the opposite direction to the liquid discharge direction, and when the liquid in the distribution channel reaches a first pressure or higher, it allows the liquid to flow toward the nozzle in the liquid discharge direction. A flow path resistor is positioned between the check valve and the nozzle in the direction of liquid discharge, which creates resistance to the flow of the liquid, and when the liquid that has passed through the check valve reaches a second pressure or higher, which is higher than the first pressure, it causes the liquid to flow toward the nozzle in the direction of liquid discharge. A liquid supply device characterized by being equipped with the following features.

2. The liquid supply device according to claim 1, characterized in that the flow path is arranged downstream of the confluence with respect to the liquid flow direction and is equipped with an on / off valve for opening and closing the flow path.

3. The liquid supply device according to claim 2, characterized in that the third pressure, which is the pressure of the liquid flowing through the distribution channel when the on-off valve is in an open state, is lower than the second pressure.

4. The liquid supply device according to claim 2, characterized in that the third pressure, which is the pressure of the liquid flowing through the distribution channel when the on-off valve is in an open state, is lower than the first pressure.

5. The liquid supply device according to claim 1, characterized in that the flow path resistor is a filter for the liquid.

6. The aforementioned check valve is, A ball as a valve component, A cylindrical portion extending in the direction of liquid discharge and housing the ball, A biasing member is disposed within the cylindrical portion and biases the ball toward the upstream side in the liquid discharge direction, An annular sealing member having an inner diameter smaller than the ball is positioned between the wall portion of the upstream end of the cylindrical portion and the ball, on the upstream side of the ball with respect to the liquid discharge direction, It is a ball-type check valve equipped with, The liquid supply device according to claim 1, characterized in that the outer diameter of the sealing member is smaller than the inner diameter of the cylindrical portion.

7. A recording head having an ink ejection surface from which nozzles for ejecting ink onto a recording medium open, A liquid supply device according to any one of claims 1 to 6, which supplies cleaning liquid to the ink ejection surface, An inkjet recording device characterized by comprising the following features.

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