Maintenance apparatus and inkjet recording apparatus

Abstract

The present invention provides a maintenance device and an ink jet recording apparatus, the maintenance device including: a cover attached to a nozzle surface of an ink jet head; an air supply port provided in the cover; and an air vent which is provided in the cover and which is open to the atmosphere.

Description

Technical Field

[0001] The present invention relates to a maintenance device for maintaining an inkjet head and an inkjet recording device. Background Art

[0002] In an inkjet recording device using water-based ink, when printing is not performed, the ink in the nozzle evaporates and the viscosity increases, which poses a risk of poor ejection and clogging. Therefore, in the past, a technology for suppressing the evaporation of water from the ink in the nozzle has been studied. As a related technology, a device for supplying humidified air into a cap covering the ejection surface (nozzle surface) of the head has been studied.

[0003] However, in the structure of the above-mentioned related art, since the cap is sealed, the cap is adsorbed to the nozzle surface when negative pressure is generated inside the cap. When forming an image, the cap needs to be detached, but it is difficult to detach the cap due to the negative pressure. If the cap is forcibly detached, there is a risk of damaging the cap and the head. Summary of the invention

[0004] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to suppress the difference in air pressure between the inside and outside of the cover.

[0005] In order to solve the above-mentioned problems, the maintenance device of the present invention includes: a cap mounted on a nozzle surface of an inkjet head; an air supply port provided in the cap; and a vent provided in the cap and open to the atmosphere.

[0006] Preferably, the cover includes an exhaust port, and the vent port is provided on a downstream side of the exhaust port in a direction from the air supply port side toward the exhaust port side.

[0007] Preferably, the maintenance device includes a suppressing member provided at least between the air supply port and the nozzle surface, having a first gap between the suppressing member and the air supply port, and having a second gap between the suppressing member and the nozzle surface.

[0008] Preferably, the suppressing member is formed of resin.

[0009] Furthermore, an inkjet recording apparatus according to the present invention includes the inkjet head and any one of the maintenance devices described above.

[0010] According to the present invention, the difference in air pressure between the inside and outside of the cover can be suppressed.

[0011] This specification is presented in a simplified form, with appropriate reference to the accompanying drawings, to summarize the concepts described in the following detailed description. This specification is not intended to limit the important features and essential features of the subject matter described in the claims, nor is it intended to limit the scope of the subject matter described in the claims. In addition, the subject matter described in the claims is not limited to implementations that solve some or all of the disadvantages described in any part of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view showing the appearance of the image forming system according to the first embodiment of the present invention.

[0013] Figure 2 It is a front view schematically showing the internal structure of the inkjet recording apparatus according to the first embodiment of the present invention.

[0014] Figure 3 It is a front view schematically showing the head unit and the maintenance device according to the first embodiment of the present invention.

[0015] Figure 4 It is a plan view schematically showing the head unit and the wiping unit according to the first embodiment of the present invention.

[0016] Figure 5 It is a plan view schematically showing the cover unit according to the first embodiment of the present invention.

[0017] Figure 6 It is a cross-sectional view showing an ink jet head according to a first embodiment of the present invention.

[0018] Figure 7 It is a front view showing the operation of the maintenance device according to the first embodiment of the present invention.

[0019] Figure 8 It is a perspective view showing a cover unit according to the first embodiment of the present invention.

[0020] Fig. 9 It is a plan view showing the cover unit according to the first embodiment of the present invention.

[0021] Fig.10 Yes means Fig. 9 Cross-sectional view of section II.

[0022] Fig.11 It is an exploded view showing the cover unit according to the first embodiment of the present invention.

[0023] Fig.12 It is a diagram showing the flow of air and humidified air in the cover unit according to the first embodiment of the present invention.

[0024] Fig.13It is a plan view showing the positions of the humidification container and the recovery container according to the first embodiment of the present invention.

[0025] Fig.14 This is a cross-sectional view showing the flow of humidified air in the cover according to the first embodiment of the present invention.

[0026] Fig.15 It is a cross-sectional view showing a cover unit according to a first embodiment of the present invention.

[0027] Fig.16 It is a top view showing the cover according to the first embodiment of the present invention.

[0028] Fig.17 It is a cross-sectional view showing a cover unit according to a second embodiment of the present invention.

[0029] Fig.18 It is a top view showing a cover according to a second embodiment of the present invention.

[0030] Fig.19 It is a plan view showing a cover according to a third embodiment of the present invention.

[0031] Fig. 20 It is a plan view showing a cover according to a fourth embodiment of the present invention.

[0032] Fig.21 It is a plan view showing a cover according to a fifth embodiment of the present invention.

[0033] Fig. 22 It is a plan view showing a cover according to a sixth embodiment of the present invention.

[0034] Fig.23 It is a plan view showing a cover according to a seventh embodiment of the present invention.

[0035] Fig.24 Yes means Fig. 22 Cross-sectional view of section IV-IV.

[0036] Fig.25 It is a cross-sectional view showing a cover according to a first modified example of the sixth embodiment of the present invention.

[0037] Fig.26 It is a cross-sectional view showing a cover according to a second modified example of the sixth embodiment of the present invention.

[0038] Fig. 27 It is a cross-sectional view showing a cover unit according to an eighth embodiment of the present invention.

[0039] Fig.28 It is a plan view showing a cover according to an eighth embodiment of the present invention.

[0040] Fig.29It is a cross-sectional view showing a cover unit according to a ninth embodiment of the present invention.

[0041] Fig.30 It is a top view showing a cover according to a ninth embodiment of the present invention. DETAILED DESCRIPTION

[0042] [First embodiment] Hereinafter, an inkjet recording apparatus 1 according to a first embodiment of the present invention will be described with reference to the drawings.

[0043] Figure 1 It is a perspective view showing the appearance of the image forming system 100 . Figure 2 It is a front view schematically showing the internal structure of the inkjet recording device 1 . Figure 3 It is a front view schematically showing the head unit 11 and the maintenance device 30 . Figure 4 It is a plan view schematically showing the head unit 11 and the wiping unit 32 . Figure 5 It is a plan view schematically showing the cover unit 31 . Figure 6 It is a cross-sectional view showing the inkjet head 12. Figure 7 30 is a front view showing the operation of the maintenance device 30. Figure 2 The front side of the paper in the figure is regarded as the front side (front side) of the inkjet recording device 1, and the left and right directions are described based on the direction when the inkjet recording device 1 is viewed from the front. In each figure, U, Lo, L, R, Fr, and Rr represent up, down, left, right, front, and back, respectively.

[0044] Image forming system 100 (see Figure 1 ) includes a paper feeding device 110, an inkjet recording device 1, a drying device 120, and a post-processing device 130. The paper feeding device 110 stores thousands of sheets and supplies the sheets to the inkjet recording device 1. The inkjet recording device 1 forms an image on the sheet by inkjet method. The drying device 120 heats the sheet conveyed from the inkjet recording device 1 to dry the ink. The post-processing device 130 performs post-processing such as punching, stapling, and folding on the sheet conveyed from the drying device 120.

[0045] Inkjet recording device 1 (refer to Figure 2) is provided with a main body shell 3 in the shape of a rectangular parallelepiped. A conveying unit 7 for sucking a sheet and conveying it in the Y direction is provided in the central part of the main body shell 3. An imaging unit 6 for ejecting ink to form an image is provided above the conveying unit 7. A paper feed port 8 for introducing a sheet from a paper feed device 110 is provided on the right side of the main body shell 3. A discharge port 9 for discharging the sheet with an image formed thereon to a drying device 120 is provided on the left side of the main body shell 3. A conveying passage 10 is provided inside the main body shell 3, which extends from the paper feed port 8 through the gap between the conveying unit 7 and the imaging unit 6 to the discharge port 9. A registration roller 18 is provided on the upstream side of the conveying unit 7 in the conveying direction Y.

[0046] The conveying unit 7 includes an endless conveyor belt 21 and a suction unit 24. The conveyor belt 21 has a plurality of vents (not shown) and is wound around a driving roller 25 and a driven roller 22. The upper surface of the suction unit 24 has a plurality of vents (not shown) and is in contact with the inner surface of the conveyor belt 21. The suction unit 24 sucks air through the vents of the conveyor belt 21 and the vents of the suction unit 24, thereby adsorbing the sheet to the conveyor belt 21. The driving roller 25 is driven counterclockwise by a driving unit (not shown) including a motor and a reduction gear, so that the conveyor belt 21 rotates counterclockwise, and the sheet adsorbed to the conveyor belt 21 is conveyed in the Y direction.

[0047] The imaging unit 6 includes a plurality of (four in this embodiment) head units 11. The head unit 11 (see Figure 3 , 4 ) is provided with one or more (three in this embodiment) inkjet heads 12. Each head unit 11 is connected to an ink tank 20, and the ink tank 20 is filled with black, cyan, magenta and yellow inks, respectively.

[0048] Inkjet head 12 (see Figure 6 ) is provided with a rectangular parallelepiped housing 12H with the front-to-back direction as the long side direction, a nozzle plate 14 provided at the bottom of the housing 12H, and a socket 12S connected to a pipe for supplying ink. The nozzle plate 14 is provided with a plurality of nozzles 14N arranged in the front-to-back direction. The nozzle 14N includes a branch flow channel 14B branched from the downstream side of the socket 12S, and a discharge port 14A provided on a nozzle surface 14F as the lower surface of the nozzle plate 14. The vibration plate 14V also serves as a part of the inner wall of the branch flow channel 14B. A pressure element 14Z is provided on the vibration plate 14V. As the pressure element 14Z, a piezoelectric element, an electrostatic actuator, a heater, etc. are used. A driving circuit 12D for driving the pressure element 14Z is connected to the pressure element 14Z.

[0049] Control unit 2 (refer to Figure 2) has a computing unit and a storage unit (not shown). The computing unit is, for example, a CPU (Central Processing Unit). The storage unit includes storage media such as ROM (Read Only Memory), RAM (Random Access Memory), and EEPROM (Electrically Erasable Programmable Read Only Memory). The computing unit performs various processes by reading and executing the control program stored in the storage unit. In addition, the control unit 2 can also be implemented by an integrated circuit that does not use software.

[0050] A display operation unit 19 (see Figure 1 , 2 The display operation unit 19 includes a display panel, a touch panel stacked on the display panel, and a keyboard (not shown). The control unit 2 displays a screen showing an operation menu, status, etc. of the inkjet recording device 1 on the display panel, and controls various parts of the inkjet recording device 1 according to operations detected by the touch panel and the keyboard.

[0051] The basic image forming operation of the inkjet recording device 1 is as follows. When an image forming job is input to the inkjet recording device 1 from the display operation unit 19, an external computer, etc., the paper feed device 110 feeds the sheet to the conveying path 10 through the paper feed port 8, and the registration roller 18, which has stopped rotating, corrects the skew of the sheet. When the registration roller 18 feeds the sheet to the conveying unit 7 at a predetermined timing, the conveying unit 7 adsorbs the sheet to the conveying belt 21 and conveys it in the Y direction. Ink is ejected from the inkjet head 12 onto the sheet to form an image. The sheet with the image formed thereon is discharged to the drying device 120 through the discharge port 9.

[0052] [Maintenance device] Next, the maintenance device 30 will be described. In addition, since the four head units 11 have the same structure and the four maintenance devices 30 have the same structure, one head unit 11 and one maintenance device 30 provided on the right thereof will be described below.

[0053] The head unit 11 includes a head base 11B (see Figure 3 , 4 ) Three inkjet heads 12 are arranged alternately on the head base 11B.

[0054] Maintenance device 30 (see Figure 3 ) is provided on the side (right side in this embodiment) of the head unit 11. The maintenance device 30 includes a cap unit 31 and a wiping unit 32.

[0055] [Cover unit] Cover unit 31 (see Figure 3 , 5 ) is provided with the same number of caps 72 as the inkjet heads 12 provided in the head unit 11 (three in this embodiment). The three caps 72 are arranged alternately like the inkjet heads 12 and supported by the frame 71. Two caps 72 are arranged front and back on the right side of the center in the left-right direction of the frame 71, and one cap 72 is arranged on the left side of the center in the left-right direction of the frame 71. The left cap 72 is arranged in the middle of the two right caps 72 in the front-back direction.

[0056] [Wipe unit] Wiping unit 32 (see Figure 3 , 4 ) is provided with a waste liquid tray 81 and a cleaning member 82. The waste liquid tray 81 is provided with the same number of recesses 81U as the inkjet heads 12 provided in the head unit 11. The plurality of recesses 81U are arranged alternately in the same manner as the inkjet heads 12. The cleaning member 82 is provided in each recess 81U. The cleaning member 82 is, for example, a scraper. The waste liquid tray 81 is provided with a driving portion (not shown) for causing the cleaning member 82 to slide along the nozzle surface 14F. The waste liquid tray 81 is carried by a plurality of covers 72. In other words, the wiping unit 32 is carried by the cover unit 31. A cleaning liquid supply device 13 (refer to Figure 6 ).

[0057] [Head lifting device] Head lifting device 11L (refer to Figure 4 ) are provided in front and behind the head base 11B. The head lifting device 11L is composed of, for example, a ball screw, a belt drive device, etc. The head lifting device 11L raises and lowers the head unit 11 between the image forming position and the retreat position. Image forming position (refer to Figure 7 (A) is a position where the distance between the conveying path 10 (the upper surface of the conveying belt 21) for conveying sheets and the nozzle surface 14F is a predetermined distance suitable for image formation. The image forming position is the lower limit position of the lifting range of the head unit 11 by the head lifting device 11L. The retreat position (refer to Figure 7 (B)) is a position where the head unit 11 does not interfere with the wiping unit 32 when the cover unit 31 and the wiping unit 32 are slid using the cover sliding device 34 described later. The retracted position is the upper limit position of the lifting range of the head unit 11.

[0058] [Cover sliding device] Cover sliding device 34 (see Figure 5) are provided at the front and rear of the frame 71 of the cover unit 31. The cover slide device 34 is composed of, for example, a ball screw, a belt drive device, etc. The cover slide device 34 slides the cover unit 31 between the home position and the maintenance position. The home position (refer to Figure 7 (A)) is located to the right of the head unit 11 at the image forming position. Figure 7 (F)) is a position below the head unit 11 located at the retracted position.

[0059] [Wipe lift device] Wiping lifting device 35 (refer to Figure 4 ) are provided in front and behind the waste liquid tray 81 of the wiping unit 32. The wiping lifting device 35 is composed of, for example, a ball screw, a belt drive device, etc. The wiping lifting device 35 enables the wiping unit 32 to be in a contact position (refer to Figure 7 (B)) and the separation position where the waste liquid tray 81 is separated from the cover 72 by a predetermined distance (refer to Figure 7 (E)) rises and falls.

[0060] Next, the structure of the cover unit 31 will be described in detail. Figure 8 It is a perspective view showing the cover unit 31 . Fig. 9 It is a plan view showing the cover unit 31 . Fig.10 Yes means Fig. 9 Cross-sectional view of section II. Fig.11 It is an exploded view showing the cover unit 31 . Fig.12 1 and 2 are diagrams showing the flows of the air A and the humidified air WA in the cover unit 31 . Fig.13 It is a plan view showing the positions of the humidification container 92 and the recovery container 94 . Fig.14 It is a cross-sectional view showing the flow of the humidified air WA in the cover 72 .

[0061] [build] Cover 72 (see Figures 8 to 10 ) is formed into a box shape that opens upward. The cover 72 has a bottom 72B that is roughly rectangular with the front-to-back direction as the long side direction, and a side wall portion 72W that stands upright from the edge of the bottom 72B to the top. The side wall portion 72W is formed of a flexible raw material such as rubber. An air supply port 72NA and an exhaust port 72EA are provided in the bottom 72B. In the covers 72 on the right rear side and the left side, an air supply port 72NA is provided on the rear side, and an exhaust port 72EA is provided on the front side. In the cover 72 on the right front side, an air supply port 72NA is provided on the front side, and an exhaust port 72EA is provided on the rear side.

[0062] [Humidification container, recovery container] Below the frame 71 (see Figure 8 , 1113) There are provided humidifying containers 92 of the same number as the covers 72 (three in this embodiment) and one recovery container 94. The humidifying containers 92 and the recovery container 94 are supported by the frame 91. Each humidifying container 92 is respectively arranged below the air supply port 72NA of each cover 72. The recovery container 94 has a shape that includes all the exhaust ports 72EA when viewed from above, and is arranged below all the exhaust ports 72EA.

[0063] An air supply pipe 72N (see FIG. 72N ) is connected to the air supply port 72NA of each cover 72 so as to communicate the cover 72 with the humidification container 92 therebelow. Fig.10 An exhaust pipe 72E that allows the cover 72 to communicate with the recovery container 94 is connected to the exhaust port 72EA of each cover 72. That is, the three exhaust pipes 72E communicate with the recovery container 94.

[0064] The air pump 95 passes through the recovery flow channel 95E (see Figure 8 , 9 , 11) is connected to the recovery container 94, and is connected to all the humidification containers 92 through the supply flow path 95N. The air pump 95 recovers air A from the recovery container 94 through the recovery flow path 95E, and supplies the recovered air A to all the humidification containers 92 through the supply flow path 95N (refer to Fig.12 ).

[0065] All humidification containers 92 are connected through a connecting pipe 92C (see Fig.10 , 11 , 12) is connected to the humidification auxiliary container 93. The humidification auxiliary container 93 is connected to a humidification medium container 93T and a humidification medium pump 93P. The humidification medium container 93T stores a humidification medium WM (see Fig.14 The humidifying medium WM is, for example, water. The humidifying medium pump 93P supplies the humidifying medium WM from the humidifying medium container 93T to the humidifying auxiliary container 93. The humidifying auxiliary container 93 is provided with a liquid level sensor 93S (see Figure 8 , 9 , 11). The humidification container 92 is provided with a heater 92H for heating the humidification medium WM (see Fig.10 ).

[0066] Next, the basic operation of the maintenance device 30 will be described. Figure 7 In (A), the head unit 11 is located at the image forming position, and the cover unit 31 is located at the starting position. The wiping unit 32 is carried by the cover unit 31. That is, the waste liquid tray 81 is in contact with the cover 72. The control unit 2 performs the following processing at a predetermined timing. The predetermined timing is, for example, a timing when the viscosity of the ink in the nozzle 14N is expected to increase, specifically, when the period during which the image forming operation is not performed continues for a predetermined period.

[0067] First, the control unit 2 operates the head lifting device 11L to raise the head unit 11 to the retracted position (see Figure 7 Next, the control unit 2 operates the cover sliding device 34 to slide the cover unit 31 to the maintenance position (see Figure 7 (C)). At this time, since the wiper unit 32 is supported by the cover unit 31, the wiper unit 32 also slides to the maintenance position together with the cover unit 31. Next, the control unit 2 operates the head lifting device 11L to lower the head unit 11 to a height where the nozzle surface 14F contacts the cleaning member 82 (see Figure 7 (D)).

[0068] Next, after forcibly causing the inkjet head 12 to eject a predetermined amount of ink, the control unit 2 supplies cleaning liquid to the nozzle surface 14F and causes the cleaning member 82 to slide along the nozzle surface 14F. Thus, the ink remaining on the nozzle surface 14F is diluted by the cleaning liquid, and waste liquid containing the ink and the cleaning liquid is scraped off by the cleaning member 82 and falls into the waste liquid tray 81.

[0069] Next, the control unit 2 operates the head lifting device 11L to raise the head unit 11 to the retracted position (see Figure 7 Then, the control unit 2 operates the cover sliding device 34 to slide the cover unit 31 and the wiping unit 32 to the starting position (see Figure 7 (B)).

[0070] Next, the control unit 2 operates the wiping lifting device 35 to raise the wiping unit 32 to the separation position (see Figure 7 Next, the control unit 2 operates the cover sliding device 34 to slide the cover unit 31 to the maintenance position (see Figure 7 At this time, since the wiping unit 32 is separated from the cover unit 31, the wiping unit 32 remains at the starting position, and only the cover unit 31 slides to the maintenance position.

[0071] Next, the control unit 2 operates the head lifting device 11L to lower the head unit 11 to a height where the nozzle surface 14F contacts the cap 72 (see FIG. 14 ). Figure 7 In this way, the cap 72 is mounted on the nozzle face 14F.

[0072] Next, the control unit 2 humidifies the inside of the cover 72. The control unit 2 monitors the measured value of the liquid level sensor 93S and maintains the height of the liquid level in the humidification auxiliary container 93 within a predetermined range. Specifically, when the measured value of the liquid level is lower than the predetermined range, the humidification medium WM is replenished from the humidification medium container 93T to the humidification auxiliary container 93 by a predetermined amount using the humidification medium pump 93P. Since the humidification auxiliary container 93 is connected to the humidification container 92 through the connecting pipe 92C, the height of the liquid level of the humidification medium WM becomes the same in the humidification auxiliary container 93 and all the humidification containers 92.

[0073] Air pump 95 (refer to Fig.12 ) The air A is recovered from the recovery container 94 through the recovery flow path 95E, and the recovered air A is supplied to all the humidification containers 92 through the supply flow path 95N. The end of the humidification container 92 side of the supply flow path 95N is arranged below the liquid level of the humidification medium WM (refer to Fig.14 ). Therefore, in the humidification container 92, air A is blown into the humidification medium WM to generate bubbles B. The water vapor pressure of the bubbles B rises until the bubbles B float to the liquid surface. In addition, the humidification medium WM in the humidification container 92 is heated by the heater 92H, so it becomes easy to generate water vapor. Therefore, the humidified air WA with increased water vapor pressure fills the space above the liquid surface of the humidification container 92, and the humidified air WA flows into the cover 72 through the air supply pipe 72N.

[0074] On the other hand, in the recovery container 94, the air A is sucked by the air pump 95, so that negative pressure is generated. Therefore, in the cover 72, an airflow of the humidified air WA is generated from the air supply port 72NA toward the exhaust port 72EA. In addition, since the humidified air WA heated by the heater 92H is supplied to the cover 72, convection is generated in the cover 72, and the high-temperature humidified air WA is supplied to the nozzle surface 14F. In this way, the humidified air WA contacts the ink in the nozzle 14N and suppresses the increase in the viscosity of the ink.

[0075] When an image forming job is to be executed, the control unit 2 operates the head lifting device 11L to raise the head unit 11 to the retracted position (see Figure 7 (F)), the cover sliding device 34 is operated to slide the cover unit 31 to the starting position (refer to Figure 7 (E)), the wiping lifting device 35 is operated to lower the wiping unit 32 to the contact position (refer to Figure 7 (B)). Then, the control unit 2 operates the head lifting device 11L to lower the head unit 11 to the image forming position to perform the image forming operation.

[0076] However, since the humidified air WA flowing into the cap 72 through the air supply pipe 72N rises toward the nozzle surface 14F, there is a risk that the ink in the nozzle 14N above the air supply port 72NA will vibrate and fall. There is a risk that the fallen ink will accumulate in the cap 72 and hinder the flow of the humidified air WA or clog the air supply pipe 72N.

[0077] Therefore, the maintenance device 30 of the present embodiment includes the suppression member 73 . Fig.15 It is a cross-sectional view showing the cover unit 31 . Fig.16 72 is a top view showing the cover 72. Fig.15 express Fig.16 Section II-II.

[0078] The maintenance device 30 of this embodiment includes: a cap 72 mounted on the nozzle surface 14F of the inkjet head 12; an air supply port 72NA provided on the cap 72; and a suppressing member 73 provided at least between the air supply port 72NA and the nozzle surface 14F, having a first gap G1 between the air supply port 72NA and the nozzle surface 14F, and having a second gap G2 between the air supply port 72NA and the nozzle surface 14F. The details are as follows.

[0079] The suppressing member 73 is disposed above the air supply port 72NA. The suppressing member 73 is a plate-shaped member whose thickness direction is the up-down direction, and is formed of resin. The suppressing member 73 is supported by a support 72P disposed at the bottom 72B of the cover 72. The dimensions of the suppressing member 73 in the front-to-back direction and the left-to-right direction are larger than the dimensions of the air supply port 72NA in the front-to-back direction and the left-to-right direction. The suppressing member 73 is disposed in a manner that at least covers the entire air supply port 72NA when viewed from above. A first gap G1 is provided between the air supply port 72NA and the lower surface of the suppressing member 73. A second gap G2 is provided between the nozzle surface 14F and the upper surface of the suppressing member 73.

[0080] A portion WA1 (see FIG. 1 ) of the humidified air that flows into the cover 72 from the air supply port 72NA Fig.15 ) flows forward from the first gap G1 and is sucked into the exhaust port 72EA. Another portion WA2 of the humidified air flows from the first gap G1 through the rear of the suppression member 73 into the second gap G2, flows forward from the second gap G2 and is sucked into the exhaust port 72EA. Another portion WA3 of the humidified air (see Fig.16 ) flows forward from the spaces on the left and right of the suppressing member 73 and is sucked into the exhaust port 72EA. That is, above the air supply port 72NA, the humidified air WA flows along the lower surface and the upper surface of the suppressing member 73, so that the vibration of the ink in the nozzle 14N above the air supply port 72NA is reduced, thereby suppressing the ink from falling.

[0081] The reason why the suppressing member 73 is formed of resin is as follows. Since the suppressing member 73 takes heat from the humidified air WA, there is a risk of condensation forming on the suppressing member 73. In particular, in the present embodiment, a heater 92H is provided in the humidifying container 92 in order to increase the amount of water vapor in the humidified air WA, so condensation is easily generated. If condensation occurs, the water vapor pressure of the humidified air WA decreases, and thus the humidification effect on the ink in the nozzle 14N decreases. In order to suppress condensation, the suppressing member 73 is preferably formed of a raw material with low thermal conductivity. Generally speaking, resin has a lower thermal conductivity than metal, and is therefore suitable as a raw material for the suppressing member 73.

[0082] According to the maintenance device 30 of the present embodiment described above, it comprises: a cap 72 mounted on the nozzle surface 14F of the inkjet head 12; an air supply port 72NA provided in the cap 72; and a suppressing member 73 provided at least between the air supply port 72NA and the nozzle surface 14F, having a first gap G1 between the air supply port 72NA and the nozzle surface 14F, and having a second gap G2 between the air supply port 72NA and the nozzle surface 14F. According to the present embodiment, it is possible to suppress the ink from falling due to the humidified air WA.

[0083] Moreover, according to the maintenance device 30 of this embodiment, the suppression member 73 is formed of resin. According to this embodiment, condensation of the humidified air WA can be suppressed.

[0084] Furthermore, according to the inkjet recording apparatus 1 of the present embodiment, the inkjet head 12 and the maintenance device 30 are provided. The viscosity increase of the ink in the nozzles 14N of the inkjet head 12 can be suppressed.

[0085] [Second embodiment] Fig.17 It is a cross-sectional view showing a cover unit 31 according to the second embodiment. Fig.18 2 is a top view showing a cover 72 according to the second embodiment. Fig.17 express Fig.18 Section III-III.

[0086] The suppressing member 74 is provided along the direction from the air supply port 72NA side toward the exhaust port 72EA side. Specifically, the suppressing member 74 is a rectangular plate-shaped member with the direction from the air supply port 72NA side toward the exhaust port 72EA side as the long side direction. The suppressing member 74 is supported by a support 72P provided at the bottom 72B of the cover 72. The rear end portion of the suppressing member 74 is arranged above the air supply port 72NA. The front end portion of the suppressing member 74 is located further behind than the exhaust port 72EA. A first gap G1 is provided between the air supply port 72NA and the lower surface of the suppressing member 74. A second gap G2 is provided between the nozzle surface 14F and the upper surface of the suppressing member 74.

[0087] The suppression member 74 includes a through hole 74H extending from the air supply port 72NA side to the nozzle surface 14F side at a position not facing the air supply port 72NA. The through hole 74H is provided at a plurality of locations (three locations in this embodiment) along the direction from the air supply port 72NA side to the exhaust port 72EA side.

[0088] A portion WA1 (see FIG. 1 ) of the humidified air that flows into the cover 72 from the air supply port 72NA Fig.17 ) flows forward in the first gap G1 and is sucked into the exhaust port 72EA. Another portion WA2 of the humidified air flows from the first gap G1 through the rear of the suppression member 74 into the second gap G2, flows forward in the second gap G2 and is sucked into the exhaust port 72EA. Another portion WA3 of the humidified air (see Fig.18 ) flows forward in the space on the left and right of the suppressing member 74 and is sucked into the exhaust port 72EA. That is, the humidified air WA flows along the lower surface and the upper surface of the suppressing member 74 in a wider range than that in the above-mentioned embodiment, so the vibration of the ink in the nozzle 14N above the air supply port 72NA is reduced, and the falling of the ink is suppressed.

[0089] In addition, a portion WA4 of the humidified air flowing toward the exhaust port 72EA in the first gap G1 flows from the first gap G1 to the second gap G2 through the through hole 74H, thereby compensating for the insufficient supply of humidified air WA caused by the suppression member 74 and supplying a large amount of humidified air WA to the nozzle surface 14F away from the air supply port 72NA, thereby improving the uniformity of humidification.

[0090] According to the maintenance device 30 of the present embodiment described above, the cover 72 has the exhaust port 72EA, and the suppression member 74 is provided along the direction from the air supply port 72NA side toward the exhaust port 72EA side. According to the present embodiment, it is possible to suppress the ink from falling due to the humidified air WA in a wide range along the direction from the air supply port 72NA side toward the exhaust port 72EA side.

[0091] According to the maintenance device 30 of this embodiment, the suppressing member 74 includes the through hole 74H extending from the air supply port 72NA side to the nozzle surface 14F side at a position not facing the air supply port 72NA. According to this embodiment, the insufficient supply of the humidified air WA caused by the suppressing member 74 can be compensated.

[0092] In addition, according to the maintenance device 30 of the present embodiment, the cover 72 has the exhaust port 72EA, and the through holes 74H are provided at a plurality of locations along the direction from the air supply port 72NA side toward the exhaust port 72EA side. According to the present embodiment, it is possible to compensate for the insufficient supply of the humidified air WA caused by the suppression member 74. In addition, according to the present embodiment, it is possible to improve the uniformity of humidification.

[0093] [Third Embodiment] Fig.19 1 is a top view of the cover 72 of the third embodiment. The maintenance device 30 of the present embodiment comprises: a cover 72 mounted on the nozzle surface 14F of the inkjet head 12; an air supply port 72NA and an exhaust port 72EA provided on the cover 72; and a suppressing member 75 provided at least between the air supply port 72NA and the nozzle surface 14F, having a first gap G1 between the air supply port 72NA and the nozzle surface 14F, and having a second gap G2 between the air supply port 72NA and the nozzle surface 14F, wherein the suppressing member 75 has a plurality of through holes 75H extending from the air supply port 72NA side to the nozzle surface 14F side at a position not opposite to the air supply port 72NA, wherein the diameters of the plurality of through holes 75H are equal, and the density of the through holes 75H increases as the position is closer to the exhaust port 72EA.

[0094] Specifically, the through hole group 75Hs including a plurality of through holes 75H is provided at a plurality of locations along the direction from the air supply port 72NA side toward the exhaust port 72EA side, and the closer to the exhaust port 72EA, the shorter the distance between adjacent through hole groups 75Hs. In addition, in the example shown in the figure, the number of through holes 75H included in the through hole group 75Hs is five, but the number of through holes 75H included in the through hole group 75Hs may be any number.

[0095] According to this embodiment, the uniformity of humidification can be improved compared to a case where the density of the through holes 75H is uniform. In addition, according to this embodiment, the uniformity of humidification can be improved compared to a case where the plurality of through hole groups 75Hs are arranged at equal intervals in the direction from the air supply port 72NA side toward the exhaust port 72EA side.

[0096] [Fourth Embodiment] Fig. 20 1 is a top view showing the cover 72 of the fourth embodiment. In the maintenance device 30 of the present embodiment, through hole groups 76Hs1 to 76Hs4 including a plurality of through holes 76H are provided at a plurality of locations along a direction from the air supply port 72NA side toward the exhaust port 72EA side, and the closer to the exhaust port 72EA, the greater the number of through holes 76H in each of the through hole groups 76Hs1 to 76Hs4.

[0097] In the example shown in the figure, the through hole groups 76Hs1 to 76Hs4 include five, nine, fourteen, and eighteen through holes 76H, respectively. In the example shown in the figure, when the number of through holes 76H included in the through hole groups 76Hs1 to 76Hs4 exceeds five, the through holes 76H are arranged in a staggered manner, but in the through hole groups 76Hs1 to 76Hs4, the plurality of through holes 76H may be arranged in any manner. In addition, in the example shown in the figure, the closer to the exhaust port 72EA, the shorter the distance between adjacent through hole groups 76Hs1 to 76Hs4, but the distance between adjacent through hole groups 76Hs1 to 76Hs4 may also be fixed. According to the present embodiment, the uniformity of humidification can be improved compared to the case where the number of through holes 76H included in the plurality of through hole groups 76Hs1 to 76Hs4 is the same.

[0098] [Fifth Embodiment] Fig.21 72 is a top view showing the cover 72 of the fifth embodiment. The arrangement of the through holes 77H is different from that of the third and fourth embodiments. The diameters of the plurality of through holes 77H of this embodiment are equal, and the density of the through holes 77H increases as it is closer to the exhaust port 72EA. According to this embodiment, the uniformity of humidification can also be improved compared to the case where the density of the through holes 77H is uniform.

[0099] [Sixth Embodiment] Fig. 22 7 is a top view showing the cover 72 of the sixth embodiment. The maintenance device 30 of the present embodiment comprises: a cover 72 mounted on the nozzle surface 14F of the inkjet head 12; an air supply port 72NA and an exhaust port 72EA provided on the cover 72; and a suppressing member 78 provided at least between the air supply port 72NA and the nozzle surface 14F, having a first gap G1 between the air supply port 72NA and the nozzle surface 14F, and having a second gap G2 between the air supply port 72NA and the nozzle surface 14F, and the suppressing member 78 has a plurality of through holes 78H1 to 78H3 extending from the air supply port 72NA side to the nozzle surface 14F side at a position not opposite to the air supply port 72NA, and the diameters of the through holes 78H1 to 78H3 are larger as they are closer to the exhaust port 72EA.

[0100] Specifically, the through hole groups 78H1s, 78H2s, and 78H3s including the plurality of through holes 78H1, 78H2, and 78H3 are provided at a plurality of locations along the direction from the air supply port 72NA side toward the exhaust port 72EA side, and the diameters of the through holes 78H1, 78H2, and 78H3 of the through hole groups 78H1s, 78H2s, and 78H3s are larger as they are closer to the exhaust port 72EA. According to this embodiment, the uniformity of humidification can be improved compared to the case where the diameters of the through holes 78H1, 78H2, and 78H3 of the through hole groups 78H1s, 78H2s, and 78H3s are equal.

[0101] Fig.24 Yes means Fig. 22 The suppression member 78 is provided along the direction from the air supply port 72NA side toward the exhaust port 72EA side, and a plurality of through holes 78H1 to 78H3 are provided at both end sides of the suppression member 78 in the width direction, and the width direction intersects with the direction from the air supply port 72NA side toward the exhaust port 72EA side. The plurality of through holes 78H1 to 78H3 penetrate from the bottom surface of the suppression member 78 to the upper surface. According to this embodiment, compared with the case where the through holes 78H1 to 78H3 are provided in the center in the width direction, the uniformity of humidification in the width direction can be improved.

[0102] Fig.25 2 is a cross-sectional view showing a cover 72 according to a first modified example of the sixth embodiment. A plurality of through holes 78H1 to 78H3 penetrate from the bottom surface to the side surface of the suppression member 78. According to this embodiment, the uniformity of humidification in the width direction can also be improved.

[0103] Fig.26 This is a cross-sectional view of a cover 72 showing a second modified example of the sixth embodiment. A plurality of through holes 78H1 to 78H3 penetrate from the bottom surface to the ridge line formed by the intersection of the upper surface and the side surface of the suppression member 78. According to this embodiment, the uniformity of humidification in the width direction can also be improved.

[0104] [Seventh Embodiment] Fig.23 7 is a plan view showing a cover 72 according to the seventh embodiment. In the present embodiment, the diameters of the through holes 79H1, 79H2, ..., 79H9 gradually increase as they approach the exhaust port 72EA. According to the present embodiment, the uniformity of humidification can also be improved.

[0105] [Eighth Embodiment] Fig. 27 It is a cross-sectional view showing a cover unit 31 according to the eighth embodiment. Fig.28 : is a top view showing a cover 72 according to the eighth embodiment. Fig. 27 express Fig.28 In the second embodiment (refer to Fig.17 ), since the end of the suppression member 74 on the exhaust port 72EA side is located further rearward than the exhaust port 72EA, there is a problem in that it is difficult to supply the humidified air WA to the area R which is further forward than the end of the suppression member 74 on the exhaust port 72EA side in the nozzle surface 14F.

[0106] Therefore, in the present embodiment, the end of the suppressing member 74 on the exhaust port 72EA side faces the exhaust port 72EA. According to the present embodiment, the humidified air WA flowing forward in the second gap G2 goes around the first gap G1 from the front of the suppressing member 74 and is sucked into the exhaust port 72EA, so the humidified air WA can also be supplied to the nozzle surface 14F on the exhaust port 72EA side. Therefore, according to the present embodiment, the uniformity of humidification can be improved.

[0107] [Ninth Embodiment] Fig.29 It is a cross-sectional view showing a cover unit 31 according to a ninth embodiment. Fig.30 : is a top view showing a cover 72 according to the ninth embodiment. Fig.29 express Fig.30 Section VI-VI of the graph.

[0108] After the cap 72 is attached to the nozzle surface 14F, the temperature, humidity, air pressure, etc. may change inside and outside the cap 72, and negative pressure may be generated inside the cap 72. In order to form an image, the cap 72 needs to be separated from the nozzle surface 14F. If negative pressure is generated inside the cap 72, a greater force than usual is required to separate the cap 72. However, if the cap 72 is forcibly separated, there is a risk of damaging the cap 72 and the inkjet head 12.

[0109] Therefore, the cover 72 of this embodiment has a vent 72V open to the atmosphere. Fig.29 , 30 , an example in which the cover 72 of the first embodiment is provided with a vent 72V is shown. The vent 72V penetrates the bottom 72B of the cover 72. According to this structure, the humidified air WA can freely enter and exit through the vent 72V, so that the air pressure difference inside and outside the cover 72 can be suppressed. In addition, even if an air pressure difference occurs, it will be eliminated in a short time. Since a large force is not required to detach the cover 72, there is no risk of damaging the cover 72 and the inkjet head 12 when the cover 72 is detached.

[0110] Next, the position of the vent 72V is described. Assuming that the vent 72V is provided between the air supply port 72NA and the exhaust port 72EA, there is a risk that a portion of the air flow of the humidified air WA from the air supply port 72NA toward the exhaust port 72EA escapes from the vent 72V to the outside of the cover 72 before reaching the exhaust port 72EA, thereby reducing the humidification performance.

[0111] Therefore, the vent 72V of the present embodiment is formed on the side from the air supply port 72NA (at Fig.29 , 30The vent 72V is disposed on the downstream side (right side) of the exhaust port 72EA in the direction from the air supply port 72NA to the exhaust port 72EA (right side). According to this structure, the humidified air WA does not escape before the airflow of the humidified air WA from the air supply port 72NA toward the exhaust port 72EA reaches the exhaust port 72EA, thereby suppressing the decrease in humidification performance caused by the escape of the humidified air WA. In addition, the vent 72V may also be disposed on the side wall portion 72W of the cover 72.

[0112] In this embodiment, it is also preferable that the suppression member 73 is formed of resin. Generally speaking, resin has lower thermal conductivity than metal, and therefore it is difficult for resin to take away heat from the humidified air WA, and it is difficult for negative pressure to be generated in the cover 72.

[0113] In addition, Fig.29 , 30 , an example in which the cover 72 of the first embodiment is provided with the vent 72V is shown, but the vent 72V may be provided in any of the covers 72 of the second to eighth embodiments. In this case, it is also preferred that the vent 72V is provided on the downstream side of the exhaust port 72EA in the direction from the air supply port 72NA side toward the exhaust port 72EA side.

[0114] In addition, the cover 72 (see Fig.14 ) The vent 72V is provided. In this case, it is also preferable that the vent 72V is provided on the downstream side of the exhaust port 72EA in the direction from the air supply port 72NA side toward the exhaust port 72EA side.

[0115] The scope of the present invention is not limited to the above content, but is defined by the description of the claims, so it can be considered that the embodiments described in this specification are only illustrative, not limiting. Therefore, all changes that do not depart from the scope and limits of the claims, as well as contents that are equivalent to the scope and limits of the claims, are included in the scope of the claims.

Claims

1. A maintenance device, characterized in that: have: A cover mounted on the nozzle surface of the inkjet head; an air supply port, disposed on the cover; and a vent, which is provided on the cover and is open to the atmosphere.

2. The maintenance device according to claim 1, characterized in that: The cover has an exhaust port, The vent port is provided on the downstream side of the exhaust port in the direction from the air supply port side toward the exhaust port side.

3. The maintenance device according to claim 1 or 2, characterized in that: A suppressing member is provided at least between the air supply port and the nozzle surface, and has a first gap between the suppressing member and the air supply port, and has a second gap between the suppressing member and the nozzle surface.

4. The maintenance device according to claim 3, characterized in that: The check member is formed of resin.

5. An inkjet recording device, characterized in that: have: The maintenance device according to claim 1; and The inkjet head.

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