Inkjet recording apparatus

Abstract

The invention relates to an ink jet recording apparatus. An ink jet recording apparatus includes a recording head in which a nozzle surface is disposed obliquely, a transport unit, a cover, a suction unit, and a control unit. The cover has a bottom surface portion facing the nozzle surface, and side wall portions erected along four sides of the bottom surface portion. The suction unit performs a suction cleaning process, that is, sucks a sealed space between the cover and the nozzle surface. When the cap is removed from the nozzle surface, the control unit sequentially performs: a first separation operation of separating the other side wall portions from the nozzle surface in a state in which the lower side wall portion is brought into contact with the nozzle surface, and a second separation operation of separating the other side wall portions from the nozzle surface in a state in which the lower side wall portion is brought into contact with the nozzle surface; a wiping operation in which the cover is moved upward along the nozzle surface while the side wall portion located on the lower side is brought into contact with the nozzle surface; and a second separation operation of separating all side wall parts of the cover from the nozzle surface.

Description

Technical Field

[0001] The present invention relates to an inkjet recording device. Background Art

[0002] It is known that in inkjet recording devices such as inkjet printers, when printing is not performed for a long time, the ink in the nozzle of the recording head will dry, which becomes the main reason for ink failure. Therefore, a capping operation in which a flat box-shaped component such as a cap is installed on the nozzle surface is performed to seal the nozzle periphery, so that the sealed space is kept at a high humidity, thereby suppressing the drying of the ink.

[0003] However, due to repeated printing operations, ink ejection failure may occur due to foreign matter attached to the nozzle. In this case, a technique called suction cleaning is known: a suction unit connected to the inside of the cap when the cap is sealed on the nozzle surface is used to suck the sealed space between the cap and the nozzle surface, thereby forcibly discharging the ink and foreign matter from the nozzle.

[0004] On the other hand, in the case of an inkjet recording device that is particularly required to be small and space-saving, the recording head is sometimes arranged to be tilted relative to the horizontal plane, depending on the layout relationship with the recording medium to be transported, so that the ink is ejected at an angle from the vertical direction to the horizontal direction. When the recording head installed in such a tilted state is suction-cleaned, the ink discharged into the cap that is not completely sucked out by the suction unit will accumulate at the lower end of the cap.

[0005] As a result, when the cap is removed during printing, ink remains in the part where the cap contacts the nozzle surface, and falls due to gravity, adhering to the side of the recording head. When the ink adhering to the side of the recording head continues to accumulate, the ink will fall and contaminate the paper conveying path. In addition, when the ink dries and fixes on the side of the recording head, it will not be possible to seal the nozzle surface using the shape of the cap, and the recording head must be cleaned and replaced. Summary of the invention 1. Technical issues to be resolved

[0006] An object of the present invention is to provide an inkjet recording apparatus capable of suppressing adhesion of ink to the side surfaces of a recording head when suction cleaning is performed in a state where a cap is attached to a recording head disposed obliquely. (II) Technical solution

[0007] The inkjet recording device of the first structure of the present invention is characterized in that it comprises: a recording head having a nozzle surface, on which a plurality of nozzles for ejecting ink are formed; a cap which is removable relative to the nozzle surface of the recording head; a suction unit which performs a suction cleaning process, that is, suctions the closed space between the cap installed on the nozzle surface and the nozzle surface, thereby sucking out the ink in the nozzle; and a control unit which controls the loading and unloading action of the cap relative to the nozzle surface, wherein the nozzle surface of the recording head is arranged tilted relative to a horizontal plane, and the cap has: a bottom portion which is rectangular and spaced apart from the nozzle surface The cover comprises a plurality of side walls, each of which is opposite to the nozzle surface and is disposed at a specified interval; and a side wall portion, which is erected along the four sides of the bottom surface and the front end is in contact with the nozzle surface. When the cover is removed from the nozzle surface, the control unit sequentially performs the following actions: a first separation action, in which the other side wall portions of the cover are separated from the nozzle surface while the side wall portion located on the lower side of the cover is in contact with the nozzle surface; a wiping action, in which the cover is moved upward along the nozzle surface by a specified amount while the side wall portion located on the lower side of the cover is in contact with the nozzle surface; and a second separation action, in which all the side wall portions of the cover are separated from the nozzle surface. (III) Beneficial effects

[0008] According to the first structure of the present invention, when the suction cleaning process is performed on the recording head arranged obliquely, the ink attached to the periphery of the contact portion between the nozzle surface and the side wall portion of the cap can be moved to the vicinity of the center of the nozzle surface, and the ink can be efficiently recovered into the cap. Thus, it is possible to effectively prevent the ink from entering the side of the recording head and attaching to it, thereby contaminating the inside of the printer. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a side cross-sectional view showing a schematic structure of a printer 100 as an inkjet recording apparatus according to one embodiment of the present invention. Figure 2 It means in Figure 1 1 is a side cross-sectional view showing a state where the cap 20 is mounted on the recording head 9 in the printer 100. Figure 3 It means in Figure 2 1 is a side cross-sectional view showing a state in which the cap 20 is removed from the recording head 9 in the printer 100. Figure 4 It is a side cross-sectional view of the cover 20 used in the printer 100 according to the first embodiment of the present invention. Figure 5 It is a side cross-sectional view showing a state where the cap 20 is attached to the recording head 9 of the printer 100 according to the first embodiment. Figure 6 It means from Figure 5It is a side cross-sectional view of a state in which the side wall portion 21b located on the lower side of the cap 20 is kept in contact with the nozzle surface 9a and the other side wall portion 21b is separated from the nozzle surface 9a. Figure 7 It means from Figure 6 It is a side cross-sectional view of a state in which the side wall portion 21b located on the lower side of the cap 20 is kept in contact with the nozzle surface 9a and the cap 20 is moved upward along the nozzle surface 9a. Figure 8 It means from Figure 7 20 is a side sectional view showing a state in which the cap 20 is completely separated from the nozzle surface 9a. Fig. 9 It is a side cross-sectional view of the cover 20 used in the printer 100 according to the second embodiment of the present invention. Fig.10 This is a side sectional view showing a state in which the cap 20 is installed on the recording head 9 of the printer 100 in the second embodiment, the lower side wall portion 21b of the cap 20 is kept in contact with the nozzle surface 9a and the other side wall portion 21b is separated from the nozzle surface 9a. Fig.11 It is a side cross-sectional view of the cover 20 used in the printer 100 according to the third embodiment of the present invention. Fig.12 This is a side sectional view showing a state in which the cap 20 is installed on the recording head 9 of the printer 100 in the third embodiment, the side wall portion 21b located on the lower side of the cap 20 is kept in contact with the nozzle surface 9a and the other side wall portion 21b is separated from the nozzle surface 9a. DETAILED DESCRIPTION

[0010] (1. Structure of inkjet recording device) Embodiments of the present invention will be described below with reference to the accompanying drawings. Figure 1 1 is an explanatory diagram showing a schematic configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. The printer 100 includes a paper feed cassette 2 as a paper storage portion. The paper feed cassette 2 is disposed below the printer body 1. Paper P as an example of recording media is stored inside the paper feed cassette 2.

[0011] In the paper conveying direction (hereinafter referred to as the conveying direction), on the downstream side of the paper feeding cassette 2 ( Figure 1 A paper feed unit 3 is arranged at the upper right side of the paper feed cassette 2 in the drawing. The paper feed unit 3 is composed of, for example, a paper feed roller pair, which is composed of a feed roller and a retard roller. The paper P stored in the paper feed cassette 2 is separated and output one by one toward the downstream side in the conveying direction by the paper feed unit 3.

[0012] The first paper conveying path 4a is provided inside the printer 100. The first paper conveying path 4a is located downstream in the conveying direction, that is, above and to the right of the paper cassette 2. The paper P fed from the paper cassette 2 is conveyed vertically upward along the side of the printer body 1 through the first paper conveying path 4a.

[0013] A conveying unit 5 and a recording head 9 are disposed at the downstream end of the first paper conveying path 4a in the conveying direction. The paper P output from the paper cassette 2 reaches the conveying unit 5 after passing through the first paper conveying path 4a.

[0014] The recording head 9 is arranged to be inclined at a predetermined angle relative to a horizontal plane. Figure 5 ) are arranged opposite to each other at a predetermined interval, and the paper P is conveyed along the nozzle surface 9a. A plurality of nozzles for inkjet are formed on the nozzle surface 9a. The recording head 9 ejects ink onto the paper P according to the control signal from the control unit 90 and the image data received from the external computer, thereby recording (printing) an image on the paper P. Figure 1 Although one recording head 9 is described in the figure, one or more recording heads 9 are provided for each color of yellow, magenta, cyan, and black.

[0015] The ink containers 11Y to 11K store yellow (Y), magenta (M), cyan (C), and black (K) inks, respectively. The ink supply system 6 is composed of an ink supply path, a pump, an opening and closing valve, a check valve (none of which are shown), etc. The ink supply system 6 supplies the inks of the four colors (yellow, cyan, magenta, and black) stored in the ink containers 11Y to 11K to the recording heads 9 of the respective colors according to a control signal from the control unit 90.

[0016] In the paper conveying direction (arrow A direction), on the downstream side of the conveying unit 5 ( Figure 1 A second paper conveying path 4b is provided above the printer 100. After the paper P on which the image is recorded by the recording head 9 passes through the second paper conveying path 4b, it is discharged to a discharge tray 15 through a discharge unit 12 composed of a discharge roller pair. The discharge tray 15 is provided on the upper surface of the printer 100.

[0017] A cover 20 is disposed below the recording head 9. Figure 1 Although one cap 20 is described, the same number of caps 20 as the number of recording heads 9 arranged corresponding to four colors of ink are prepared.

[0018] In order to remove dry, viscous ink, foreign matter, etc. in the nozzles of the recording head 9, the printer 100 performs a suction cleaning process at the start of printing after a long stop and during idle time during the printing operation. That is, when the cap 20 is mounted on the nozzle surface 9a, the space (enclosed space) between the nozzle surface 9a and the cap 20 is sucked by the suction pump 7 to forcibly suck out the ink from all the nozzles of the recording head 9 to prepare for the subsequent printing operation. The ink (cleaning ink) sucked out from the nozzle into the cap 20 is discharged to the outside of the cap 20 by the suction pump 7, and then recovered into the waste ink tank 8 through the waste ink recovery flow path (not shown).

[0019] Figure 2 It means in Figure 1 1 is a side cross-sectional view of a state where the cap 20 is mounted on the recording head 9 in the printer 100. When the printing operation is not performed for a long time, the control unit 90 moves the recording head 9 in a direction orthogonal to the conveying direction (the direction of arrow B) by a driving source such as a motor (not shown) to separate it from the conveying unit 5. Then, the control unit 90 moves the cap 20 from the retracted position ( Figure 1 The cap 20 is moved upward (in the position of the recording head 9) and arranged between the recording head 9 and the conveying unit 5. Then, the cap 20 is moved in a direction close to the recording head 9 (in the direction of arrow B) and mounted on the nozzle surface 9a of the recording head 9.

[0020] Figure 3 It means in Figure 2 A side cross-sectional view of the printer 100 with the cover 20 removed from the recording head 9. Figure 2 When printing is performed from the state of being closed, the control unit 90 moves the cap 20 in the direction of separation from the recording head 9 (the direction opposite to the arrow B) and removes it from the nozzle surface 9a of the recording head 9. Thereafter, the control unit 90 moves the cap 20 to the retracted position again and moves the recording head 9 in the direction of approaching the transport unit 5 (the direction opposite to the arrow B) to restore the printing operation. Figure 1 status.

[0021] (2. Cover structure) Next, the structure of the cover 20 will be described. Figure 4 FIG. 2 is a side cross-sectional view of the cap 20 used in the printer 100 according to the first embodiment of the present invention. The cap 20 includes a main body 21 and an ink absorber 22. The main body 21 includes: Figure 5 ) The main body 21 is formed of a rectangular bottom portion 21a which is opposed to each other at a predetermined interval, and a side wall portion 21b which is erected along the four sides of the bottom portion 21a, and is in a flat rectangular parallelepiped shape with an open top surface. The main body 21 is integrally formed of an elastic material such as rubber.

[0022] The ink absorber 22 is arranged along the bottom surface 21a on the inner side of the main body 21. The ink absorber 22 is formed of a porous material such as sponge. In addition, although not shown here, the cover 20 is provided with: a suction port connected to the suction pump 7, and an atmospheric release valve (both not shown), which connects or blocks the inside of the cover 20 with the outside, thereby switching the inside of the cover 20 to a sealed state and an atmospheric release state.

[0023] Figure 5 1 is a side cross-sectional view showing a state where the cap 20 is mounted on the recording head 9 of the printer 100 according to the first embodiment. Figure 5 As shown in FIG. 1 , when the recording head 9 is provided with the cap 20, the front ends of the side wall portions 21b formed on the four sides of the main body 21 are in close contact with the nozzle face 9a. Thus, a closed space is formed between the nozzle face 9a and the cap 20, and the viscosity of the ink in the nozzle formed on the nozzle face 9a is suppressed.

[0024] In addition, since the recording head 9 is inclined, the cap 20 is also installed inclined along the inclined nozzle surface 9 a . Therefore, the ink In that is not completely absorbed by the ink absorber 22 is accumulated on the lower end side of the cap 20 .

[0025] (3. Action of removing the cap from the recording head) Next, the operation of removing the cap 20 from the recording head 9 will be described in detail. Figure 6 It means from Figure 5 It is a side cross-sectional view of a state in which the side wall portion 21b located on the lower side of the cap 20 is kept in contact with the nozzle surface 9a and the other side wall portion 21b is separated from the nozzle surface 9a.

[0026] First, if Figure 6 As shown, when the cover 20 is located at the lower side ( Figure 6 In the state where the side wall portion 21b of the cover 20 (lower left side) is in contact (close contact) with the nozzle surface 9a, the other side wall portion 21b of the cover 20 is separated from the nozzle surface 9a (first separation action). At this time, even if there is ink In that has not been completely absorbed by the ink absorber 22 (refer to Figure 5 ) is accumulated on the lower end side of the cap 20, the inclination of the cap 20 is changed (slowed down) so that the ink In can easily flow to the ink absorber 22. As a result, the ink In accumulated on the lower end side of the cap 20 can be absorbed by the ink absorber 22. In addition, some ink In remains in the close contact portion between the side wall portion 21b located on the lower side of the cap 20 and the nozzle surface 9a.

[0027] Figure 7 It means from Figure 6 The side cross-sectional view of the state in which the side wall portion 21b of the cover 20 located at the lower side is kept in contact with the nozzle surface 9a and the cover 20 is moved upward along the nozzle surface 9a. After the first separation action is performed, as shown in FIG. Figure 7 As shown in FIG. 1 , the cap 20 is moved upward along the nozzle surface 9a by a predetermined amount (e.g., about 1 cm) while the side wall portion 21b of the cap 20 is brought into contact (close contact) with the nozzle surface 9a (wiping action). By performing this action, the ink attached to the portion where the nozzle surface 9a and the side wall portion 21b are in contact is wiped off by the side wall portion 21b, and the ink flows down to the inner side of the cap 20 along the side wall portion 21b together with the ink In remaining in the close contact portion.

[0028] Figure 8 It means from Figure 7 The side cross-sectional view of the state in which the cover 20 is completely separated from the nozzle surface 9a. Figure 8 As shown, the entire side wall portion 21b of the cap 20 is separated from the nozzle surface 9a (second separation operation). Here, a water-repellent film (not shown) made of fluororesin or the like is formed on the nozzle surface 9a, so that the ink is more easily attached to the rubber cap 20 than to the nozzle surface 9a.

[0029] Therefore, even if some ink In remains in the close contact portion between the side wall portion 21b located at the lower side of the cap 20 and the nozzle surface 9a, most of the ink will adhere to the cap 20 side, and only a small amount of ink will remain on the nozzle surface 9a. If such a small amount of ink does not fall along the inclination of the nozzle surface 9a, it will not contaminate the side surface of the recording head 9.

[0030] By removing the cap 20 from the nozzle surface 9a of the recording head 9 according to the above process, the suction cleaning process is performed on the recording head 9 arranged obliquely. At this time, the ink In attached to the periphery of the contact portion between the nozzle surface 9a and the side wall portion 21b of the cap 20 can be moved to the vicinity of the center of the nozzle surface 9a, and the ink In can be efficiently recovered into the cap 20. In this way, it is possible to effectively prevent the inside of the printer 100 from being contaminated by the ink entering the side of the recording head 9 and attaching.

[0031] (4. Other structures of the cover) Fig. 9 2 is a side sectional view of the cover 20 used in the printer 100 according to the second embodiment of the present invention. In this embodiment, when the cover 20 is mounted on the recording head 9, the side wall portion 21b ( Fig. 9 The front end of the left side wall portion 21b is formed with an inclined surface 23 in which the outer corner is chamfered (cut) downward.

[0032] Fig.101 is a side cross-sectional view showing a state in which the side wall portion 21b of the cap 20 is kept in contact with the nozzle surface 9a and the other side wall portion 21b is separated from the nozzle surface 9a in the state in which the cap 20 is installed on the recording head 9 of the printer 100 according to the second embodiment. Fig. 9 ) and from the state where the cover 20 is installed ( Figure 5 For example, if the cover 20 is rotated 20° from the mounted state when the first separation action is performed, the angle θ1 of the inclined surface 23 is set to 20°.

[0033] Therefore, if Fig.10 As shown in the figure, after the first separation action is performed, the nozzle surface 9a and the inclined surface 23 can be reliably brought into surface contact. Therefore, the ink In remaining in the close contact portion between the side wall portion 21b located at the lower side of the cap 20 and the nozzle surface 9a is not easy to pass through the close contact portion, and the ink can be more effectively suppressed from falling to the side of the recording head 9.

[0034] Fig.11 1 is a side sectional view of the cover 20 used in the printer 100 according to the third embodiment of the present invention. In this embodiment, when the cover 20 is mounted on the recording head 9, the side wall portion 21b ( Fig.11 A curved surface portion 24 is formed at the front end of the side wall portion 21b on the left side so that the inner corner portion has an arc shape (R surface) in a cross-sectional view.

[0035] Fig.12 This is a side cross-sectional view showing a state in which the side wall portion 21b of the cap 20 is kept in contact with the nozzle face 9a and the other side wall portions 21b are separated from the nozzle face 9a, from the state in which the cap 20 is mounted on the recording head 9. According to the structure of this embodiment, when the wiping operation is performed, the ink In remaining in the close contact portion between the side wall portion 21b of the cap 20 and the nozzle face 9a is easily flowed down along the curved surface portion 24. As a result, the ink In is easily recovered to the ink absorber 22, and the ink In can be suppressed from contaminating the side of the recording head 9 through the close contact portion.

[0036] (5. Others) The present invention is not limited to the above-mentioned embodiments, and various changes can be made without departing from the scope of the present invention. For example, the inclination angle of the nozzle surface 9a of the recording head 9 can be appropriately set according to the layout and structure inside the printer 100. In addition, the rotation angle of the cap 20 when performing the first separation action of the cap 20 and the movement amount of the cap 20 when performing the wiping action of the cap 20 can also be appropriately set within the range that can suppress the adhesion of ink to the side of the recording head 9.

[0037] In the above embodiment, a color printer that records color images using four-color inks is described as the inkjet recording apparatus, but the present invention is also applicable to a monochrome printer that records monochrome images using black ink.

[0038] The present invention can be used in inkjet recording devices such as inkjet printers.

Claims

1. An inkjet recording device, characterized in that have: A recording head having a nozzle face formed with a plurality of nozzles for ejecting ink; a cap that is removable relative to the nozzle surface of the recording head; a suction portion that performs a suction cleaning process, that is, suctions a closed space between the cap installed on the nozzle surface and the nozzle surface, thereby sucking out the ink in the nozzle; and a control unit for controlling the attachment and detachment of the cap relative to the nozzle surface, The nozzle surface of the recording head is arranged to be inclined relative to a horizontal plane. The cover has: a bottom portion which is rectangular and faces the nozzle surface at a predetermined interval; as well as a side wall portion which is erected along four sides of the bottom portion and has a front end portion in contact with the nozzle surface, When the cap is removed from the nozzle surface, the control unit performs the following actions in sequence: a first separation action of separating the other side wall portions of the cover from the nozzle surface while the side wall portion of the cover located on the lower side is in contact with the nozzle surface; a wiping action, wherein the side wall portion of the cover located on the lower side is brought into contact with the nozzle surface, while the cover is moved upward along the nozzle surface by a predetermined amount; as well as The second separation operation separates the entire side wall portion of the cap from the nozzle surface.

2. The inkjet recording device according to claim 1, wherein An inclined surface having an outer corner chamfered downward is formed at a front end of the side wall portion that is located on a lower side of the cap when the cap is mounted on the recording head.

3. The inkjet recording device according to claim 2, wherein: The angle of the inclined surface relative to the horizontal plane is the same as the rotation angle of the cover in the first separation action.

4. The inkjet recording device according to claim 1, wherein: A curved surface portion having an inner corner in an arc shape in a cross-sectional view is formed at a front end of the side wall portion that is located on the lower side of the cap when the cap is mounted on the recording head.

5. The inkjet recording device according to any one of claims 1 to 4, characterized in that: An ink absorber formed of a porous material is arranged inside the cover along the bottom surface portion.

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