Inkjet type image forming apparatus

Abstract

To provide an inkjet type image forming apparatus capable of reducing the adhesion of ink to a cap after purging an inkjet head in which a nozzle surface is arranged obliquely.SOLUTION: There is provided an inkjet type image forming apparatus which has an inkjet head 5 in which a plane including a nozzle surface and a nozzle non-forming surface is provided obliquely, a cap 7 for capping the inkjet head 5 and a suction device 69 which sucks air in a capping space during capping to discharge ink in the nozzle. The cap 7 has a bottom wall 31, a peripheral wall 33 in close contact with the plane and a partition wall 35 for dividing the capping space into a first chamber R1 including the nozzle surface and a second chamber R2 including the nozzle non-forming surface. The second chamber R2 is disposed below the first chamber R1 in a direction of gravity and the first chamber R1 and the second chamber R2 communicate with each other through a communication port 37 provided on the partition wall 35.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an inkjet image forming apparatus having a cap for capping a nozzle surface of an inkjet head. [Background technology]

[0002] Inkjet image forming devices form images on recording media by ejecting ink from the nozzles of an inkjet head. When the inkjet head is not in use (when no image is being formed), the ink in the nozzles dries out, which can cause ink not to be ejected, so a capping operation is performed to seal the space including the surface on which the nozzles are formed (nozzle surface) with a cap. By sealing the space, the humidity in the space is kept high, preventing the ink from drying out.

[0003] However, repeated image forming operations may cause foreign matter to adhere to the nozzles, resulting in poor ink ejection.

[0004] In such a case, an operation called purging is performed in which, while the nozzles are capped, the sealed space is suctioned using suction means connected to the cap, and the ink is expelled from the nozzles together with any foreign matter, thereby recovering from the ejection failure.

[0005] Inkjet image forming technology is used for a variety of purposes. For example, when it is necessary to install the device in a small space, the inkjet head may be placed at an angle to the horizontal depending on the design relationship with the layout of the recording medium. In this case, ink is ejected from the inkjet head at an angle from the vertical to the horizontal.

[0006] When a purge operation is performed on an inkjet head that is tilted in this way, the discharged ink accumulates inside the cap, below the direction of gravity. As a result, when the cap is separated from the inkjet head, ink adheres to the outer edge of the cap (the lip, the part that comes into contact with the nozzle face). If the ink that has adhered to the lip dries and hardens, the space including the nozzle face cannot be completely sealed when capping is performed, and the ejection failure cannot be reliably resolved. In such a case, the cap must be replaced.

[0007] There are several methods for preventing ink from adhering to the lip. Patent Document 1 discloses a technique for removing ink adhering to the lip by supplying a cleaning liquid to the lip and the nozzle forming surface facing the lip. Patent Document 2 discloses a technique for forming a cap with a double structure including a first chamber surrounding the nozzle outlet and a second chamber not including the nozzle outlet, and for preventing ink from remaining on the lip by pressurizing the second chamber. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2022-164913 A [Patent Document 2] JP 2012-179815 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, the technology disclosed in Patent Document 1 requires the provision of a space for storing cleaning liquid and a mechanism for supplying cleaning liquid, which increases the size of the device. Furthermore, it is necessary to manage the amount of cleaning liquid. Also, in the technology described in Patent Document 2, the second chamber cannot be kept at a high humidity, so ink (ink mist generated during ejection) that adheres to the nozzle surface corresponding to the second chamber dries and adheres to the nozzle surface. Then, when wiping the nozzle surface with a blade, excessive pressure is applied to the blade, causing the blade to break, and wiping cannot be performed reliably.

[0010] In view of the above circumstances, the present invention aims to provide an inkjet image forming device that can reduce ink adhesion to the lip portion of the cap when purging is performed on an inkjet head whose nozzle surface is arranged at an angle. [Means for solving the problem]

[0011] In order to solve the above problems, an inkjet type image forming apparatus of the present invention includes an inkjet head in which a plane including a nozzle surface in which ink ejection ports of a plurality of nozzles are opened and a non-nozzle surface in which the ink ejection ports are not provided is inclined with respect to a horizontal plane; a cap that performs capping to seal a space including the nozzle surface and the non-nozzle surface of the inkjet head; a suction device that sucks air in a capping space formed between the nozzle surface and the non-nozzle surface and the cap during the capping to discharge ink in the nozzles to the outside of the nozzles; and and an atmospheric release means for sucking the air in the capping space and then returning the capping space to atmospheric pressure, wherein the cap comprises a bottom wall covered with an absorbing member that absorbs ink discharged outside the nozzles by the suction device, a peripheral wall that is provided along the periphery of the bottom wall and comes into close contact with the plane during capping, and a partition wall that divides the capping space into a first chamber including the nozzle surface and a second chamber including the non-nozzle surface, wherein the second chamber is positioned below the first chamber in the direction of gravity, and the first chamber and the second chamber are connected via a communication port provided in the partition wall.

[0012] In the present invention, the second chamber may have a suction port communicating with the suction device.

[0013] In the present invention, the suction ports may be arranged in multiple numbers in the longitudinal direction of the cap along the horizontal direction, the communication ports may be arranged in multiple numbers in the longitudinal direction, and the multiple suction ports and the multiple communication ports may overlap when viewed in the short direction of the cap.

[0014] In the present invention, the suction port may be provided in a bottom plate of the second chamber, a cylinder may be connected to the suction port, and an upper portion of the cylinder may be inclined downward.

[0015] In the present invention, the atmosphere opening means may be in communication with an atmosphere opening port formed in an upper portion of the first chamber.

[0016] In the present invention, the atmosphere open port may not face the ink ejection port in the ink ejection direction. Effect of the Invention

[0017] According to the present invention, since no discharged ink remains on the lip portion of the peripheral wall of the cap after the purging operation is performed, the purging operation can be performed reliably. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating a schematic diagram of an ink jet type image forming apparatus according to an embodiment of the present invention (during a printing operation). [Diagram 2] FIG. 2 is a diagram illustrating a schematic diagram of an ink jet type image forming apparatus according to one embodiment of the present invention (at the time of transition to a capping operation). [Diagram 3] FIG. 1 is a diagram illustrating an ink jet image forming apparatus according to an embodiment of the present invention (during a capping operation). [Figure 4A] FIG. 2 is a plan view showing a cap of the ink jet image forming apparatus according to the embodiment of the present invention. [Figure 4B] FIG. 2 is a cross-sectional view showing a cap of the ink jet image forming apparatus according to one embodiment of the present invention. [Diagram 5] 2 is a block diagram showing a control unit of the inkjet image forming apparatus according to the embodiment of the present invention. FIG. [Figure 6] 5 is a flowchart showing a purge operation of the ink jet image forming apparatus according to one embodiment of the present invention. [Figure 7A] 5 is a flowchart showing a purge operation (capping operation) of the ink jet image forming apparatus according to one embodiment of the present invention. [Figure 7B] 5 is a flowchart showing a purge operation (discharge operation) of the ink jet type image forming apparatus according to one embodiment of the present invention. [Figure 8A]5 is a flowchart showing a purge operation (idle suction operation) of the ink jet type image forming apparatus according to one embodiment of the present invention. [Figure 8B] 5 is a flowchart showing a purge operation (decapping operation) of the ink jet image forming apparatus according to one embodiment of the present invention. [Figure 9] FIG. 1 is a diagram illustrating a purge operation of a conventional ink jet image forming apparatus. [Figure 10] 5A to 5C are diagrams illustrating a purge operation of the inkjet recording apparatus according to one embodiment of the present invention. [Figure 11] FIG. 11 is a plan view showing a cap according to a first modified example in an ink jet image forming apparatus according to an embodiment of the present invention. [Figure 12A] FIG. 13 is a plan view showing a cap according to a second modified example in an ink jet image forming apparatus according to an embodiment of the present invention. [Figure 12B] FIG. 11 is a cross-sectional view showing a cap according to a second modified example in an ink jet image forming apparatus according to an embodiment of the present invention. [Figure 13] FIG. 13 is a plan view showing a cap according to a third modified example in an ink jet image forming apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ink jet type image forming apparatus according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0020] First, the overall configuration of an inkjet type image forming apparatus 1 will be described with reference to Figures 1 to 3. Figures 1 to 3 are diagrams that diagrammatically show the image forming apparatus 1. In each diagram, U and Lo indicate the upper side and the lower side of the image forming apparatus 1, respectively.

[0021] The inkjet type image forming apparatus 1 includes a transport unit 3 that transports a recording medium, an inkjet head 5 that forms an image by ejecting ink onto the recording medium transported by the transport unit 3, and a cap 7 that performs capping to seal a space including the ink ejection ports of the inkjet head 5. Note that the image forming apparatus 1 may also include a wiping unit that wipes the ink ejection ports, but in this embodiment, a description of the wiping unit will be omitted.

[0022] First, the transport unit 3 will be described. The transport unit 3 includes a driving roller 11 that is driven and rotated by a motor (not shown), a driven roller 13 that is driven and rotated by the driving roller 11, and a transport belt 15 that is wound around the driving roller 11 and the driven roller 13. The driving roller 11 and the driven roller 13 are arranged to be spaced apart in the vertical and horizontal directions. In this embodiment, both rollers 11 and 13 are spaced apart in the diagonally right direction in the figure. When the driving roller 11 rotates in the clockwise direction in the figure, the transport belt 15 circulates and runs in the clockwise direction in the figure. The outer surface of the transport belt that is transported along the upper running track becomes the transport surface on which the recording medium is supported and transported. As shown in the figure, the transport surface is a surface that is inclined along the diagonally right direction with respect to the horizontal plane. The recording medium is supported on the transport surface and transported along the transport direction that faces diagonally upward to the right.

[0023] Next, the inkjet head 5 will be described. The inkjet head 5 has four nozzle rows (not shown) each consisting of a plurality of nozzles. The four nozzle rows are arranged in a line in the transport direction corresponding to yellow, magenta, cyan, and black inks. Each nozzle row is formed by arranging a row of nozzles in a staggered manner in the width direction intersecting with the transport direction. The nozzle outlets are opened on one side surface (lower surface) of the inkjet head 5. Each nozzle is provided with a piezoelectric element (not shown). By driving the piezoelectric element, the ink in the nozzle is ejected from the outlet. The lower surface on which the nozzle outlets of the plurality of nozzles are opened is defined as a nozzle surface 21. The lower surface other than the nozzle surface 21 is defined as a non-nozzle surface 23. In general, the non-nozzle surface 23 is formed around the nozzle surface 21.

[0024] The inkjet head 5 is disposed so that the lower surface on which the nozzle surface 21 and the non-nozzle surface 23 are formed is parallel to the transport surface of the transport belt 15 of the transport unit 3. In other words, the nozzle surface 21 and the non-nozzle surface 23 are inclined diagonally to the right with respect to the horizontal plane. Ink is ejected from the ejection openings of each nozzle in a direction perpendicular to the nozzle surface 21.

[0025] The inkjet head 5 is supported by a lifting mechanism 25 (not shown in Figs. 1 to 3, see Fig. 5) at a plurality of positions including a printing position and a retracted position so as to be movable in a direction perpendicular to the conveyance surface. The printing position is a position (home position, see Fig. 1) where the nozzle surface 21 and the non-nozzle surface 23 of the inkjet head 5 face the conveyance surface of the conveyor belt 15 with a predetermined gap therebetween. The retracted position is a position (see Fig. 2) where the inkjet head 5 is farther away from the conveyance surface than the printing position. The lifting mechanism 25 is electrically connected to the control unit 101 (see Fig. 5).

[0026] Next, the cap 7 will be described with reference to Figs. 4A and 4B. Fig. 4A is a plan view of the cap 7, and Fig. 4B is a cross-sectional view of the cap 7. The cap 7 is a box-shaped member with one open side, and has a size that allows it to surround the nozzle surface 21 of the inkjet head 5 and a part of the non-nozzle surface 23. The cap 7 has a rectangular bottom wall 31 that is long in the width direction W, and a peripheral wall 33 that stands along the periphery of the bottom wall 31. The cap 7 is made of an elastic material such as rubber.

[0027] The space surrounded by the bottom wall 31 and the peripheral wall 33 is divided into a first chamber R1 and a second chamber R2 by a partition wall 35 along the width direction W. The height of the partition wall 35 is equal to the height of the peripheral wall 33. The area of ​​the bottom wall 31 of the first chamber R1 is larger than the area of ​​the bottom wall 31 of the second chamber R2. The partition wall 35 is formed with a plurality of communication openings 37 that communicate between the first chamber R1 and the second chamber R2. The communication openings 37 are formed at equal intervals with a predetermined gap in the width direction W. The bottom walls 31 of the first chamber R1 and the second chamber R2 are covered with an absorbing member 39 capable of absorbing liquid (ink). The communication openings 37 are formed at a position lower than the height of the absorbing member 39.

[0028] An atmosphere open port 41 is provided in the bottom wall 31 of the first chamber R1. The atmosphere open port 41 is disposed in the center in the width direction W and at the upper part in the direction of gravity. The atmosphere open port 41 penetrates the absorbing member 39 and communicates with the first chamber R1 above the absorbing member 39. A suction port 43 is provided in the bottom wall 31 of the second chamber R2. The suction port 43 is disposed in the center in the width direction W.

[0029] As shown in Figs. 1 to 3, the cap 7 is disposed below the inkjet head 5 in an inclined position parallel to the transport surface with its open surface facing upward, the first chamber R1 on the upper side, and the second chamber R2 on the lower side (see Fig. 1). This position is defined as the retracted position. After the inkjet head 5 moves to the retracted position (see Fig. 2), the cap 7 can be moved to the capping position by a movement mechanism 45 (not shown in Figs. 1 to 3, see Fig. 5). The capping position is a position (see Fig. 3) where the open surface of the cap 7 faces the nozzle surface 21 and the non-nozzle surface 23 of the inkjet head 5 that has moved to the retracted position. The movement mechanism 45 is electrically connected to the control unit 101 (see Fig. 5).

[0030] After the inkjet head 5 moves to the retracted position, the cap 7 moves to the capping position (see FIG. 2), and then the inkjet head 5 moves to the capping position, so that the peripheral wall 33 of the cap 7 and the tip end portion (referred to as lip portions 33a and 35a) of the partition wall 35 are brought into close contact with the lower surface (surface including the nozzle surface 21 and the non-nozzle surface 23) of the inkjet head 5, as shown in FIG. 3 and FIG. 4B. This forms a sealed capping space between the nozzle surface 21, the non-nozzle surface 23, and the cap 7. In detail, the peripheral wall 33 of the first chamber R1 and the lip portions 33a and 35a of the partition wall 35 are brought into close contact with the periphery of the nozzle surface 21, sealing the first chamber R1. In addition, the peripheral wall 33 of the second chamber R2 and the lip portions 33a and 35b of the partition wall 35 are brought into close contact with the periphery of the non-nozzle surface 23, sealing the second chamber R2.

[0031] As shown in Figs. 1 to 3, the atmosphere opening port 41 of the cap 7 is connected to a first tube 51. The tip of the first tube 51 is open to the atmosphere. A first valve 53 is provided in the first tube 51. The first tube 51 is an example of an atmosphere opening means in the present invention that returns the capping space to atmospheric pressure. The first valve 53 is electrically connected to the control unit 101 (see Fig. 5).

[0032] The suction port 43 of the cap 7 is connected to a pressure chamber 63 by a second tube 61. A second valve 65 is provided in the second tube 61. The pressure chamber 63 is connected to a pump 69 by a third tube 67. A third valve 71 is provided in the third tube 67. The second valve 65, the pump 69, and the third valve 71 are electrically connected to a control unit 101 (see FIG. 5).

[0033] The first tube 51 and the second tube 61 are connected to the atmosphere opening port 41 and the suction port 43 via an L-shaped or U-shaped coupling.

[0034] Next, the control unit 101 of the image forming apparatus 1 will be described with reference to the block diagram shown in FIG. The control unit 101 is electrically connected to a lifting mechanism 25 of the inkjet head 5. The control unit 101 controls the lifting mechanism 25 to move the inkjet head 5 to the printing position and the retracted position, or to an arbitrary position (capping position) between the two positions. The control unit 101 is electrically connected to a moving mechanism 45 of the cap 7. The control unit 101 controls the moving mechanism 45 to move the cap 7 to the retracted position and the capping position.

[0035] The control unit 101 is electrically connected to the first to third valves 53, 65, and 71, and opens and closes the first to third valves 53, 65, and 71. The control unit 101 is electrically connected to the pump 69, and drives or stops the pump 69.

[0036] The purge operation of the image forming apparatus 1 having the above configuration will be described with reference to Figures 1 to 3, 6, 7A to 7B, and 8A to 8B. Figures 6, 7A to 8B are flow charts showing each operation.

[0037] As shown in FIG. 6, the purging operation is performed in the order of a capping operation (step S1), a discharging operation (step S2), an empty suction operation (step S3), and a decapping operation (step S4).

[0038] First, the capping operation (S1) will be described with reference to FIG. 7A. In step S11, the control unit 101 controls the lifting mechanism 25 to lift the inkjet head 5 from the printing position to the retracted position (see FIG. 2). Then, in step S12, the control unit 101 controls the moving mechanism 45 to move the cap 7 from the retracted position to the capping position. Then, in step S13, the control unit 101 controls the lifting mechanism 25 to lower the inkjet head 5 to the capping position. As a result, as described above, the peripheral wall 33 of the cap 7 and the lip portions 33a and 35a of the partition wall 35 are brought into close contact with the nozzle surface 21 and the non-nozzle surface 23 of the inkjet head 5, thereby sealing the first chamber R1 and the second chamber R2 (see FIG. 3). This ends the capping operation.

[0039] Next, the discharge operation (S2) will be described with reference to FIG. 7B. First, in step S21, the control unit 101 opens the third valve 71 to communicate between the pressure chamber 63 and the pump 69. Furthermore, the control unit 101 closes the first valve 53 and the second valve 65. Thereafter, in step S22, the control unit 101 drives the pump 69 to suck air from the pressure chamber 63. In step S23, the control unit 101 determines whether the pressure in the pressure chamber 63 has been reduced to a predetermined pressure. When the pressure in the pressure chamber 63 has been reduced to the predetermined pressure, the process proceeds to step S24, where the control unit 101 closes the third valve 71, and then proceeds to step S25, where the control unit 101 stops driving the pump 69.

[0040] Next, the process proceeds to step S26, where the control unit 101 opens the second valve 65. Then, the depressurized pressure chamber 63 communicates with the second chamber R2 via the second tube 61, and the second chamber R2 is depressurized. Furthermore, the first chamber R1, which communicates with the second chamber R2 via the communication port 37, is also depressurized. As a result, the inside of the nozzle that opens to the nozzle surface 21 in the first chamber R1 is also depressurized, and ink remaining in the nozzle, ink adhering to the nozzle, and foreign matter are discharged from the nozzle to the first chamber R1. By applying such a steep negative pressure to the nozzle, the recovery of the nozzle against non-ejection can be improved. In the present invention, the pump 69 is an example of a suction device that discharges ink in the nozzle to the outside of the nozzle by sucking air in the capping space.

[0041] The discharged ink is absorbed by the absorbing member 39 of the first chamber R1, or is stored in the corner between the partition 35 and the bottom wall 31. Because the cap 7 is in an inclined position as described above, the ink absorbed by the absorbing member 39 of the first chamber R1 moves downward in the direction of gravity and passes through the communication port 37 of the partition 35 to the absorbing member 39 of the second chamber R2.

[0042] After a predetermined time has elapsed, the process proceeds to step S27, where the control unit 101 opens the first valve 53. This causes the first chamber R1 and the second chamber R2 to return to atmospheric pressure, and the discharge operation ends.

[0043] Next, the dry suction operation (S3) will be described with reference to Fig. 8A. First, in step S31, the control unit 101 opens the third valve 71 to communicate between the pressure chamber 63 and the pump 69, and then proceeds to step S32 to drive the pump 69. After a predetermined time has elapsed, the control unit 101 proceeds to step S33 to stop driving the pump 69. As a result, the ink absorbed in the absorbing member 39 of the second chamber R2 is sucked into the pressure chamber 63 through the first tube 51. This ends the dry suction operation.

[0044] Next, the decapping operation (S4) will be described with reference to Fig. 8B. First, in step S41, the control unit 101 controls the lifting mechanism 25 to move the inkjet head 5 to the retracted position. Then, in step S42, the control unit 101 controls the moving mechanism 45 to move the cap 7 to the retracted position. Then, in step S43, the control unit 101 lowers the inkjet head 5 to the printing position (home position). This completes the decapping operation.

[0045] Next, the difference in effect between the cap 7 of the present invention and the conventional cap 7' will be described with reference to Figures 9 and 10. Figures 9 and 10 are diagrams showing the above-mentioned purging operation in a simplified manner. The conventional cap 7' is a cap that does not have the partition wall 35 of the cap 7 of the present invention.

[0046] First, a conventional cap 7' will be described with reference to Fig. 9. After the discharge operation shown in the top diagram of Fig. 9 is performed, the discharged ink L gathers at the lower end of the absorbing member 39, as shown in the second diagram from the top, or is stored in the corner between the peripheral wall 33 and the bottom wall 31 of the cap 7', or in the space surrounded by the peripheral wall 33, the bottom wall 31, and the lower surface of the inkjet head 5. Thereafter, when the empty suction operation shown in the third diagram from the top is performed and then the decapping operation shown in the bottom diagram is performed, the discharged ink L remains on the lip portion 33a of the peripheral wall 33 on the lower side of the cap 7. This ink L may dry and adhere to the lip portion 33a.

[0047] Next, the cap 7 of the present invention will be described with reference to Fig. 10. After the discharge operation shown in the top diagram of Fig. 10 is performed, the discharged ink L is stored in the corner between the partition wall 35 and the peripheral wall 33 of the first chamber R1 as shown in the second diagram from the top, and a part of the ink L passes through the communication port 37 and is absorbed by the absorbing member 39 of the second chamber R2. Thereafter, when the empty suction operation shown in the third diagram from the top is performed and then the decapping operation shown in the bottom diagram is performed, the discharged ink L remains in the lip portion 35a of the partition wall 35 of the cap 7 but does not remain in the lip portion 33a of the peripheral wall 33 of the cap 7.

[0048] As described above, according to the present invention, after the purge operation is performed, no discharged ink remains on the lip portion 33a of the peripheral wall 33 of the cap 7. Therefore, it is possible to prevent capping failure caused by ink adhering to the lip portion 33a of the cap 7, and it is possible to perform the purge operation reliably.

[0049] In addition, a suction port 43 is formed in the bottom wall 31 of the second chamber R2. Since the ink discharged during the discharge operation remains downward in the direction of gravity, by providing the suction port 43 in the bottom wall 31 of the second chamber R2 disposed downward in the direction of gravity, it is possible to reliably discharge ink during dry suction.

[0050] Furthermore, the atmosphere open port 41 is formed above the bottom wall 31 of the first chamber R1 in the direction of gravity. When the first chamber R1 is opened to the atmosphere during dry suction, air flows into the first chamber R1. At this time, if ink adheres to the atmosphere open port 41, the ink may scatter and contaminate the nozzle surface 21. For this reason, by locating the atmosphere open port 41 above the absorbing member 39 and above in the direction of gravity, it is possible to prevent ink from adhering to the atmosphere open port 41.

[0051] Next, first to third modified examples of the cap 7 will be described with reference to FIGS.

[0052] First, a first modified example will be described with reference to the plan view of Fig. 11. In the first modified example, a plurality of suction ports 43 are formed in the bottom wall 31 of the second chamber R2. The plurality of suction ports 43 are arranged at positions corresponding to the communication ports 37 of the partition wall 35 in the short-side direction of the cap 7. Second tubes 61 (see Fig. 1, etc.) communicating with the pressure chambers 63 are connected to the plurality of suction ports 43. The second tubes 61 have the same length.

[0053] In the first modified example, multiple suction ports 43 are provided along the width direction W, so the distances between the suction ports 43 and the nozzle surface 21 are approximately equal. Furthermore, the lengths of the second tubes 61 connected to the multiple suction ports 43 are also equal, so the suction forces of the pumps 69 are equal. For this reason, during idle suction, ink can be sucked with equal suction forces in the width direction W. Therefore, ink can be reliably discharged from the second chamber R2.

[0054] Next, a second modified example will be described with reference to Figures 12A and 12B. In the second modified example, as shown in the cross-sectional view of Figure 12B, a cylinder 81 is connected to the suction port 43. The upper part of the cylinder 81 is inclined downward. This allows the ink collected in the cap 7 to be reliably sucked into the second tube 61 via the cylinder 81.

[0055] Next, a third modified example will be described with reference to the plan view of Fig. 13. In the third modified example, the atmosphere open port 41 is formed at a position on the nozzle surface 21 corresponding to a portion where the nozzle row N is not formed. As described above, if ink adheres to the atmosphere open port 41 when the nozzle surface 21 is opened to the atmosphere during dry suction, the ink may scatter. Therefore, by locating the atmosphere open port 41 at a position that avoids the nozzle ejection ports of the nozzle row N, it becomes difficult for ink to adhere to the atmosphere.

[0056] Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and those skilled in the art may modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of symbols]

[0057] 1. Inkjet image forming device 5 Inkjet head 7 Cap 21 Nozzle surface 23 Nozzle non-forming surface 31 Bottom wall 33 Peripheral wall 35 Bulkhead 37 Connecting port 39 Absorbing material 41 Atmospheric vent 43 Suction port 51 First tube (atmospheric release means) 69 Pump (suction device) 81 Cylinder

Claims

1. an inkjet head in which a plane including a nozzle surface in which ink ejection ports of a plurality of nozzles are formed and a non-nozzle surface in which the ink ejection ports are not formed is inclined with respect to a horizontal plane; a cap that seals a space including the nozzle surface and the non-nozzle surface of the inkjet head; and a suction device that sucks air from within a capping space formed between the nozzle surface and the cap and between the non-nozzle surface and the cap during the capping process to discharge ink from within the nozzles to the outside of the nozzles; and an air release means for returning the capping space to atmospheric pressure after the air in the capping space is sucked by the suction device, The cap is a bottom wall on which an absorbing member is laid to absorb the ink discharged from the nozzles by the suction device; a peripheral wall provided along the periphery of the bottom wall and in close contact with the flat surface when the capping is performed; a partition wall that divides the capping space into a first chamber including the nozzle surface and a second chamber including the nozzle non-forming surface, an ink jet type image forming apparatus, characterized in that the second chamber is disposed below the first chamber in the direction of gravity, and the first chamber and the second chamber are connected to each other via a communication port provided in the partition wall.

2. 2. The ink-jet image forming apparatus according to claim 1, wherein the second chamber has a suction port communicating with the suction device.

3. The suction port is arranged in a plurality of portions in a longitudinal direction of the cap along a horizontal direction, The communication port is arranged in a plurality of portions in the longitudinal direction, 2. The ink-jet image forming apparatus according to claim 1, wherein the plurality of suction ports and the plurality of communication ports overlap each other when viewed in a lateral direction of the cap.

4. The suction port is provided in a bottom plate of the second chamber, 2. The ink-jet image forming apparatus according to claim 1, wherein a cylinder is connected to the suction port, and an upper portion of the cylinder is inclined downward.

5. 2. The ink-jet image forming apparatus according to claim 1, wherein the atmosphere opening means is in communication with an atmosphere opening port formed in an upper portion of the first chamber.

6. 6. The ink-jet image forming apparatus according to claim 5, wherein the air opening does not face the ink ejection orifices in the ink ejection direction.

Images