Maintenance device and inkjet recording device

Abstract

To reduce a replacement frequency of a belt-shaped member when cleaning liquid is supplied to a nozzle surface by using the belt-shaped member.SOLUTION: A maintenance device includes: a frame body 41 storing cleaning liquid; a press roller 42 exposed upward from the frame body 41 and pressed against a nozzle surface 14F of an inkjet head 12; an opposite roller 43 provided in a lower part of the press roller 42 and immersed in the cleaning liquid; an endless belt-shaped member 50 wound around the press roller 42 and the opposite roller 43; and a drive part (drive roller 44) around which the belt-shaped member 50 circulates.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a maintenance device and an inkjet recording apparatus. [Background technology]

[0002] In inkjet recording devices, ink may remain on or adhere to the nozzle surface of an inkjet head, causing ejection problems. Therefore, technologies for cleaning the nozzle surface have been studied. For example, Patent Document 1 discloses a configuration in which a wiper scrapes off cleaning liquid from a cleaning liquid supply port adjacent to the nozzle surface, and the wiper holding the cleaning liquid slides along the nozzle surface. Patent Document 2 discloses a configuration including a container containing cleaning liquid and a blade that moves around a path immersed in the cleaning liquid and wipes the nozzle surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-108711 [Patent Document 2] Japanese Patent Application Publication No. 2017-148971 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the configurations disclosed in Patent Documents 1 and 2 have a problem in that the wiper or blade has a low ability to retain cleaning liquid, resulting in a small amount of cleaning liquid being supplied to the nozzle surface. One possible configuration that can increase the amount of cleaning liquid supplied is one in which a belt-shaped member holding cleaning liquid is unwound using a roll-to-roll method and pressed against the nozzle surface. However, with the roll-to-roll method, the belt-shaped member is disposable, which causes problems such as high running costs, the effort required to replace the belt-shaped member, and increased waste.

[0005] SUMMARY OF THE INVENTION In consideration of the above circumstances, an object of the present invention is to reduce the frequency of replacing a belt-shaped member when a cleaning liquid is supplied to a nozzle surface using the belt-shaped member. [Means for solving the problem]

[0006] In order to solve the above problems, the maintenance device of the present invention includes a frame body that stores cleaning liquid, a pressure roller that is exposed upward from the frame body and is pressed against the nozzle surface of the inkjet head, an opposing roller that is provided below the pressure roller and immersed in cleaning liquid, an endless belt-like member that is wound around the pressure roller and the opposing roller, and a drive unit that rotates the belt-like member.

[0007] The maintenance device may include a slide device that slides the pressure roller and the inkjet head relatively in parallel with the nozzle surface.

[0008] The maintenance device may include an exchange means for exchanging the cleaning liquid.

[0009] The maintenance device may include a cleaner that holds the belt-shaped member between itself and the opposing roller.

[0010] The pressure roller may be disposed behind the opposing roller with respect to the direction of travel of the belt-shaped member below the opposing roller.

[0011] An inkjet recording apparatus according to the present invention includes the inkjet head and the maintenance device. [Effects of the Invention]

[0012] According to the present invention, when a cleaning liquid is supplied to the nozzle surface using a belt-shaped member, the frequency of replacing the belt-shaped member can be reduced. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view showing the appearance of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 2] 1 is a side view schematically illustrating the internal configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 3] 1 is a perspective view schematically illustrating the internal configuration of an inkjet recording apparatus according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing an inkjet head according to an embodiment of the present invention; [Figure 5] 1 is a perspective view showing an inkjet head according to an embodiment of the present invention; [Figure 6] FIG. 2 is a right side view showing an inkjet head according to an embodiment of the present invention. [Figure 7] FIG. 2 is a bottom view showing an inkjet head according to an embodiment of the present invention. [Figure 8] FIG. 2 is a rear view showing the inkjet head according to the embodiment of the present invention. [Figure 9] FIG. 2 is a plan view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 10] FIG. 2 is a right side view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 11] FIG. 2 is a rear view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 12] FIG. 2 is a cross-sectional view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 13] FIG. 2 is a cross-sectional view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 14] FIG. 2 is a cross-sectional view showing a cleaning liquid supply unit and an inkjet head according to an embodiment of the present invention. [Figure 15] FIG. 10 is a cross-sectional view showing a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] An inkjet recording apparatus 1 according to one embodiment of the present invention will be described below with reference to the drawings.

[0015] FIG. 1 is a perspective view showing the appearance of inkjet recording apparatus 1. FIG. 2 is a side view schematically showing the internal configuration of inkjet recording apparatus 1. FIG. 3 is a perspective view schematically showing the internal configuration of inkjet recording apparatus 1. FIGS. 4 and 5 are perspective views showing inkjet head 12. FIG. 6 is a right side view showing inkjet head 12. FIG. 7 is a bottom view showing inkjet head 12. FIG. 8 is a rear view showing inkjet head 12. In the following description, the left side of the paper in FIG. 2 is the front side (front side) of inkjet recording apparatus 1, and the left and right directions are described based on the direction when inkjet recording apparatus 1 is viewed from the front. In each drawing, U, Lo, L, R, Fr, and Rr represent up, down, left, right, front, and rear, respectively.

[0016] The inkjet recording apparatus 1 (see FIGS. 1 and 2) includes a lower housing 3A and an upper housing 3B disposed above the lower housing 3A. Inside the lower housing 3A, there are a payout roll 4, a take-up roll 9 disposed in front of the payout roll 4, a transport unit 7 disposed above the payout roll 4 and the take-up roll 9, and a transport path 10 extending from the payout roll 4 to the take-up roll 9 via the transport unit 7. One end of the sheet S is wound around the payout roll 4, and the other end of the sheet S is wound around the take-up roll 9. The sheet S may be paper, a resin film, cloth, or the like. The transport unit 7 includes a drive roller 25, a driven roller 22 disposed parallel to and behind the drive roller 25, and an endless belt 21 wound around the drive roller 25 and the driven roller 22.

[0017] The upper housing 3B houses an imaging unit 6 and a maintenance device 30. The imaging unit 6 includes a plurality of inkjet heads 12 (four in this embodiment) facing the transport unit 7. The imaging unit 6 ejects ink onto the sheet S on the transport unit 7 while being reciprocated in the left-right direction by a drive device (not shown). The maintenance device 30 will be described later.

[0018] The inkjet head 12 (see FIG. 6) includes a rectangular parallelepiped housing 12H whose longitudinal direction is the front-to-rear direction, a nozzle plate 14 whose longitudinal direction is the front-to-rear direction and provided on the bottom of the housing 12H, and a socket 12S to which a pipe for supplying ink is connected. The nozzle plate 14 includes a number of nozzles 14N arranged in the front-to-rear direction. The nozzles 14N include branch flow paths 14B branching off from the downstream side of the socket 12S and a number of ejection orifices 14A provided in a nozzle surface 14F, which is the lower surface of the nozzle plate 14. The ejection orifices 14A are provided in a rectangular region (referred to as an ejectable region 14R) of the nozzle surface 14F excluding both front and rear ends and both left and right ends. A vibration plate 14V also serves as part of the inner wall of the branch flow path 14B. A pressure element 14Z is provided on the vibration plate 14V. The pressure element 14Z may be a piezoelectric element, an electrostatic actuator, a heater, or the like. The pressure element 14Z is connected to a drive circuit 12D that drives the pressure element 14Z.

[0019] The control unit 2 (see FIG. 2) includes a calculation unit and a storage unit (not shown). The calculation unit is, for example, a CPU (Central Processing Unit). The storage unit includes storage media such as a ROM (Read Only Memory), a RAM (Random Access Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The calculation unit performs various processes by reading and executing control programs stored in the storage unit. Note that the control unit 2 may be realized by an integrated circuit that does not use software.

[0020] The basic image formation operation of the inkjet recording device 1 is as follows: When an image formation job is input to the inkjet recording device 1 from an external computer or the like, the control unit 2 drives the payout roll 4, the transport unit 7, and the take-up roll 9 in the counterclockwise direction in FIG. 2, and the sheet S is transported in the Y direction along the transport path 10. When the control unit 2 supplies a drive signal corresponding to the image data to the drive circuit 12D in synchronization with the transport of the sheet S, the drive circuit 12D supplies an ejection signal corresponding to the gradation of the image data to the pressure element 14Z, and ink is ejected from the nozzle 14N.

[0021] [Maintenance equipment] The maintenance device 30 (see FIG. 3) includes a cap unit 31, a wiping unit 32, and a cleaning liquid supply unit 13. The maintenance device 30 is provided at the right end of the upper housing 3B. Although only one wiping unit 32 is shown in FIG. 3, in reality, the same number of wiping units 32 as the inkjet heads 12 are arranged at the same intervals as the inkjet heads 12. Furthermore, although only one cleaning liquid supply unit 13 is shown in FIG. 3, in reality, the same number of cleaning liquid supply units 13 as the inkjet heads 12 are arranged at the same intervals as the inkjet heads 12.

[0022] [Wipe unit] The wiping unit 32 includes a frame 81 and a blade 82 provided on the upper surface of the frame 81. The maintenance device 30 is provided with a slide device 83 that slides the wiping unit 32 in the front-to-rear direction (the longitudinal direction of the nozzle surface 14F).

[0023] [Cap Unit] The cap unit 31 has a rectangular parallelepiped frame 71. The portion of the frame 71 that corresponds to the upper surface of the rectangular parallelepiped is open. The frame 71 is provided with the same number of caps 72 as the inkjet heads 12, in the same arrangement as the inkjet heads 12 in the imaging unit 6. The maintenance device 30 is provided with an elevator device 77 that raises and lowers the cap unit 31. After the imaging unit 6 moves above the cap unit 31, the cap unit 31 is raised, and the caps 72 are attached to the nozzle surface 14F. The elevator device 77 may be provided in the imaging unit 6.

[0024] [Cleaning liquid supply unit] Fig. 9 is a plan view showing the cleaning liquid supply unit 13 and the inkjet head 12. Fig. 10 is a right side view showing the cleaning liquid supply unit 13 and the inkjet head 12. Fig. 11 is a rear view showing the cleaning liquid supply unit 13 and the inkjet head 12. Figs. 12 to 14 are cross-sectional views showing the cleaning liquid supply unit 13 and the inkjet head 12.

[0025] The cleaning liquid supply unit 13 includes a rectangular parallelepiped frame 41 whose longitudinal direction is the front-to-rear direction. The portion of the frame 41 that corresponds to the top surface of the rectangular parallelepiped is open. The frame 41 is provided with a pressure roller 42, an opposing roller 43, a drive roller 44 (an example of a drive unit), a tension roller 45, and a cleaner 46. The pressure roller 42, the opposing roller 43, the drive roller 44, and the tension roller 45 are supported by the frame 41 via shafts 42A, 43A, 44A, and 45A whose axial directions are in the left-to-right direction, respectively, and are rotatable around the shafts 42A, 43A, 44A, and 45A. The cleaner 46 is provided at the center of the bottom of the frame 41 in the front-to-rear direction. The cleaner 46 may be brush-like, sponge-like, or block-like with a rough surface.

[0026] A part or all of the pressure roller 42 is exposed upward from the upper edge of the frame 41. The pressure roller 42 is disposed rearward of the cleaner 46. The drive roller 44 is disposed forward of the cleaner 46, and the tension roller 45 is disposed rearward of the pressure roller 42. The drive roller 44 and the tension roller 45 are disposed above the cleaner 46 and below the pressure roller 42.

[0027] The belt-shaped member 50 is an endless belt made of a liquid-absorbent material such as nonwoven fabric, woven fabric, or porous resin. The belt-shaped member 50 is wound around a pressure roller 42, a tension roller 45, an opposing roller 43, and a drive roller 44 in the clockwise direction, in that order. The drive roller 44 is driven clockwise by a motor or the like (not shown), causing the belt-shaped member 50 to rotate clockwise. The opposing roller 43 is pressed against a cleaner 46, and the belt-shaped member 50 is sandwiched between the opposing roller 43 and the cleaner 46.

[0028] The frame 41 is provided with a replacement unit for replacing the cleaning liquid. Specifically, a supply hole 41K and a discharge hole 41H are provided at the bottom of the frame 41. A tank 13T for storing the cleaning liquid and a pump 13P for discharging the cleaning liquid are connected to the supply hole 41K via a supply pipe 47K. A pump 15P for sucking the waste liquid and a tank 15T for storing the waste liquid are connected to the discharge hole 41H via a discharge pipe 47H. The cleaning liquid is supplied to the frame 41 through the supply hole 41K. The level of the cleaning liquid is controlled to a height sufficient to immerse the lower part of the opposing roller 43. The cleaning liquid is discharged through the discharge hole 41H at a predetermined timing and replaced with unused cleaning liquid. The predetermined timing may be, for example, after a predetermined amount of image formation has been performed or periodically.

[0029] The cleaning liquid supply unit 13 is provided with a slide device 48 that slides the cleaning liquid supply unit 13 in the front-to-rear direction (the longitudinal direction of the nozzle surface 14F). The slide device 48 may be a belt drive, a feed screw, a rack and pinion, or the like. The slide device 48 may also be provided in the imaging unit 6.

[0030] [Maintenance device operation] Next, the operation of the maintenance device 30 will be described. Maintenance of the inkjet head 12 is performed at a predetermined timing. The predetermined timing may be, for example, after an image forming job is completed, after a predetermined amount of image formation has been performed, or periodically. Before maintenance begins, the cap unit 31 is retracted downward, and the cleaning liquid supply unit 13 and the wiping unit 32 are retracted rearward.

[0031] First, the control unit 2 positions the imaging unit 6 so that all of the inkjet heads 12 are located in front of the cleaning liquid supply units 13, and then causes the sliding device 48 to slide the frame 41 while rotating the belt-shaped member 50 clockwise (see FIGS. 12 to 14 ). Cleaning liquid is supplied to the nozzle surface 14F by the belt-shaped member 50, the highly viscous ink remaining on the nozzle surface 14F is diluted with the cleaning liquid, and waste liquid containing the ink and cleaning liquid is wiped away by the belt-shaped member 50. The belt-shaped member 50 containing the waste liquid is sandwiched between the opposing roller 43 and the cleaner 46, and the waste liquid is removed from the belt-shaped member 50 by friction with the cleaner 46. In this way, the belt-shaped member 50 can be repeatedly used in a state almost like new, thereby reducing the frequency with which the belt-shaped member 50 needs to be replaced.

[0032] Next, the control unit 2 retracts the cleaning liquid supply unit 13 to the rear, then positions the imaging unit 6 so that all of the inkjet heads 12 are positioned in front of the wiping unit 32, and slides the wiping unit 32 using the sliding device 83 to wipe away waste liquid containing ink and cleaning liquid from the nozzle surface 14F.

[0033] Next, the control unit 2 retracts the wiping unit 32 rearward, then moves the imaging unit 6 above the cap unit 31, raises the cap unit 31, and waits until a new image formation job is input. Because the cap 72 is attached to the nozzle surface 14F, the nozzle surface 14F is moisturized, and an increase in the viscosity of the ink in the nozzles 14N is suppressed.

[0034] The maintenance device 30 according to the present embodiment described above includes a frame 41 that stores cleaning liquid, a pressure roller 42 that is exposed upward from the frame 41 and presses against the nozzle surface 14F of the inkjet head 12, an opposing roller 43 that is provided below the pressure roller 42 and immersed in cleaning liquid, an endless belt-like member 50 that is wound around the pressure roller 42 and the opposing roller 43, and a drive unit (drive roller 44) that rotates the belt-like member 50. According to the present embodiment, when cleaning liquid is supplied to the nozzle surface 14F using the belt-like member 50, the frequency with which the belt-like member 50 needs to be replaced can be reduced.

[0035] Furthermore, the maintenance device 30 according to this embodiment is provided with a slide device 48 that relatively slides the pressure roller 42 and the inkjet head 12 parallel to the nozzle surface 14F. According to this embodiment, cleaning liquid can be supplied to the entire nozzle surface 14F.

[0036] Furthermore, the maintenance device 30 according to this embodiment is provided with an exchange means for exchanging the cleaning liquid (pump 13P, tank 13T, pump 15P, tank 15T, discharge hole 41H, supply hole 41K, discharge pipe 47H, and supply pipe 47K). According to this embodiment, a cleaning liquid that is less likely to be contaminated by waste liquid can be used.

[0037] Furthermore, the maintenance device 30 according to this embodiment is provided with the cleaner 46 that holds the belt-shaped member 50 between itself and the opposing roller 43. According to this embodiment, removal of dirt from the belt-shaped member 50 can be facilitated.

[0038] Furthermore, according to the maintenance device 30 of this embodiment, the pressure roller 42 is disposed behind the opposing roller 43, with reference to the traveling direction of the belt-shaped member 50 below the opposing roller 43. Waste liquid is squeezed out and drops from the belt-shaped member 50 pressed by the pressure roller 42. However, if the pressure roller 42 were disposed in front of the opposing roller 43 or directly above the opposing roller 43, the belt-shaped member 50 from which the waste liquid has been removed by the cleaner 46 would be contaminated again with the waste liquid. According to this embodiment, because the pressure roller 42 is disposed behind the opposing roller 43, the waste liquid that has dropped onto the belt-shaped member 50 is removed by the cleaner 46. Therefore, according to this embodiment, contamination of the belt-shaped member 50 can be suppressed.

[0039] Furthermore, the inkjet recording apparatus 1 according to this embodiment includes the inkjet head 12 and the maintenance device 30. According to this embodiment, ink ejection defects are suppressed, and therefore deterioration in image quality can be suppressed.

[0040] The above embodiment may be modified as follows.

[0041] 15 is a cross-sectional view showing a modified example. In this modified example, a roller-shaped cleaner 49 is provided instead of the cleaner 46 of the above embodiment. The opposing roller 43 is pressed against the cleaner 49, and a belt-shaped member 50 is sandwiched between the opposing roller 43 and the cleaner 49. The opposing roller 43 is driven in the clockwise direction, and the cleaner 49 is driven in the clockwise direction by a motor or the like (not shown). The cleaner 49 rubs against the belt-shaped member 50, removing waste liquid.

[0042] In the above embodiment, an example has been shown in which the belt-like member 50 is wound around the pressure roller 42, the tension roller 45, the opposing roller 43, and the drive roller 44, but the belt-like member 50 may be wound around a plurality of rollers including at least the pressure roller 42 and the opposing roller 43. In this case, one of the plurality of rollers is driven.

[0043] In the above embodiment, an example has been shown in which the sliding device 48 slides the frame 41 in the front-rear direction, but the sliding device 48 may be provided in the imaging unit 6. The sliding device 48 may also be configured to slide the pressure roller 42 in the front-rear direction. In short, it is sufficient that the pressure roller 42 and the inkjet head 12 are configured to slide relatively in parallel to the nozzle surface 14F. [Explanation of symbols]

[0044] 1. Inkjet recording device 12 Inkjet head 13P Pump (replacement means) 13T Tank (replacement means) 14F nozzle surface 15P Pump (replacement means) 15T Tank (replacement means) 30 Maintenance Equipment 41 Frame 41H Discharge hole (exchange means) 41K supply hole (exchange means) 42 Pressure roller 43 Opposing Roller 44 Drive roller (drive unit) 46, 49 Cleaner 47H Discharge pipe (exchange means) 47K supply pipe (exchange means) 48 Slide device 50 Belt-shaped member

Claims

1. a frame for storing a cleaning liquid; a pressure roller exposed upward from the frame and pressed against a nozzle surface of the inkjet head; an opposing roller provided below the pressure roller and immersed in a cleaning solution; an endless belt-like member wound around the pressure roller and the opposing roller; a drive unit that rotates the belt-like member.

2. The maintenance device according to claim 1 , further comprising a slide device that slides the pressure roller and the inkjet head relatively in parallel with the nozzle surface.

3. 3. The maintenance device according to claim 1, further comprising an exchange means for exchanging the cleaning liquid.

4. The maintenance device according to claim 1 , further comprising a cleaner that holds the belt-like member between the opposing roller and the cleaner.

5. 2. The maintenance device according to claim 1, wherein the pressure roller is disposed rearward of the opposing roller with respect to the direction of travel of the belt-like member below the opposing roller.

6. the inkjet head; An inkjet recording apparatus comprising: the maintenance device according to claim 1 .

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