Discharge unit and image forming apparatus

Abstract

To provide an inkjet type image forming apparatus which enables reduction of accumulation of ink on a side surface of a recording head during wiping.SOLUTION: An image forming apparatus includes: a recording head 31 provided with a nozzle area N in which multiple ink discharge ports are open downward; and a wiper 67 which contacts with the nozzle area N and moves in a predetermined wiping direction to wipe the ink discharge ports. A head attachment member 41 along the wiping direction is provided on a side surface of the recording head 31 along the wiping direction. A surface of the head attachment member 41 has higher water repellency than that of the side surface. Concave portions 45 and convex portions 43 are alternately formed at a lower end of the head attachment member 41.SELECTED DRAWING: Figure 4A

Description

Technical Field

[0001] The present invention relates to an inkjet type image forming apparatus including a discharge unit having a recording head and a wiper for wiping an ink ejection opening of the recording head.

Background Art

[0002] An inkjet type image forming apparatus includes a wiper for wiping an ink ejection opening of a nozzle of a recording head. The wiper moves in one direction from a wiping start position to a wiping end position while contacting a nozzle region where the ink ejection opening opens, and wipes the ink ejection opening.

[0003] During such a wiping operation (wipering), the wiped ink may overflow from the wiper, flow around to the side surface of the recording head, rise along the side surface, adhere, and accumulate. When wiping is repeated, the amount of accumulated ink increases, and there is a problem that the accumulated ink may fall onto the sheet, causing image defects or contaminating the inside of the machine.

[0004] Therefore, Patent Document 1 discloses an inkjet type image forming apparatus including a head cover that covers a side surface portion of a recording head. The side surface portion and the surface portion of the head cover are subjected to a water repellent treatment. Thereby, even when ink flows around to the side surface portion of the recording head, the ink is repelled by the head cover, so that the adhesion of ink to the side surface portion of the recording head can be reduced.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the inkjet recording device described in Patent Document 1 above, a considerable gap is formed between the head cover and the recording head, and wiped ink can enter this gap. If a large amount of ink enters, it may fall out and cause the aforementioned image defects and contamination inside the machine.

[0007] Therefore, in view of the above circumstances, the present invention aims to provide an inkjet image forming apparatus that can reduce ink deposition on the side surface of the recording head during wiping. [Means for solving the problem]

[0008] To solve the above problems, the image forming apparatus of the present invention comprises a recording head provided with a nozzle region in which a plurality of ink ejection ports open downward, and a wiper that contacts the nozzle region and moves in a predetermined wiping direction to wipe the ink ejection ports, wherein a head mounting member is provided on the side surface of the recording head in the direction of the wiping direction, the surface of the head mounting member has higher water repellency than the side surface, and the lower end of the head mounting member is characterized in that recesses and protrusions are alternately formed.

[0009] In the image forming apparatus of the present invention, the convex portion may be formed such that its width narrows downwards, and the concave portion may be formed such that its width widens downwards.

[0010] In the image forming apparatus of the present invention, the lower end of the head mounting member may be characterized by being wavy, sawtooth-shaped, or rectangular wavy.

[0011] The image forming apparatus of the present invention may be characterized in that the angle formed between the lower side surface of the head mounting member and the side surface of the recording head is acute.

[0012] The discharge unit of the present invention comprises a recording head that is elongated in one direction and has a nozzle region in which a plurality of ink discharge ports open downward, a head mounting member is provided on the side surface of the recording head in the nozzle region, the surface of the head mounting member has higher water repellency than the side surface, and the lower end of the head mounting member has alternating recesses and protrusions.

[0013] In the discharge unit of the present invention, the convex portion may be formed so as to narrow in width toward downward, and the concave portion may be formed so as to widen in width toward downward.

[0014] In the discharge unit of the present invention, the lower end of the head mounting member may be characterized by being wavy, sawtooth-shaped, or rectangularly wavy.

[0015] The ejection unit of the present invention may be characterized in that the angle formed between the lower side surface of the head mounting member and the side surface of the recording head is acute.

[0016] In the ejection unit of the present invention, the recording head may be characterized by having an ejection section provided with an ink ejection port, and a reservoir positioned above the ejection section to supply liquid to the ejection section, wherein a downward step is formed on the side surface of the reservoir along the longitudinal direction of the recording head, and the head mounting member abuts against the step.

[0017] In the discharge unit of the present invention, the upper end of the head mounting member may be characterized by being straight.

[0018] In the discharge unit of the present invention, the side surface of the head mounting member may be located inward from the step of the reservoir.

[0019] In the ejection unit of the present invention, the lower end of the head attachment member may be located above the nozzle region of the recording head.

[0020] The image forming apparatus of the present invention includes the ejection unit and a wiper that wipes the ink ejection port by moving in a predetermined wiping direction in contact with the nozzle region.

Advantages of the Invention

[0021] According to the present invention, the ink that rises up the side surface of the recording head and enters the recess during wiping moves downward along the convex portion and is likely to fall by its own weight from the lower end of the convex portion. Therefore, accumulation of ink on the side surface of the recording head can be prevented, and image defects and internal contamination of the apparatus can be prevented.

Brief Description of the Drawings

[0022] [Figure 1] It is a front view schematically showing the internal structure of an image forming apparatus according to an embodiment of the present invention. [Figure 2] In an image forming apparatus according to an embodiment of the present invention, it is a perspective view showing an ejection unit. [Figure 3] In an image forming apparatus according to an embodiment of the present invention, it is a plan view showing a cleaning unit. [Figure 4A] In an image forming apparatus according to an embodiment of the present invention, it is a side view showing a recording head. [Figure 4B] In an image forming apparatus according to an embodiment of the present invention, it is a front view showing a recording head. [Figure 5A] In an image forming apparatus according to an embodiment of the present invention, it is a side view showing a recording head according to a first modification. [Figure 5B] In an image forming apparatus according to an embodiment of the present invention, it is a side view showing a recording head according to a second modification. [Figure 5C] In an image forming apparatus according to an embodiment of the present invention, it is a side view showing a recording head according to a third modification. [Figure 6] This is a front view showing a recording head according to a fourth modified example in an image forming apparatus according to one embodiment of the present invention. [Figure 7A] This is a side view showing a recording head according to a fifth modified example in an image forming apparatus according to one embodiment of the present invention. [Figure 7B] This is a front view showing a recording head according to a fifth modified example in an image forming apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0023] The following describes an image forming apparatus according to one embodiment of the present invention, with reference to the attached drawings.

[0024] The image forming apparatus 1 will be described with reference to Figure 1. Figure 1 is a schematic front view showing the internal configuration of the image forming apparatus 1 (during image formation). Fr, Rr, L, and R shown in each figure indicate the front, rear, left, and right directions of the image forming apparatus 1.

[0025] The image forming apparatus 1 comprises a paper feeding unit 3, an inkjet-type image forming unit 5, and a transport path 7 through which sheets S fed by the paper feeding unit 3 are transported through the image forming unit 5 to an outlet (not shown). The paper feeding unit 3 comprises a paper feeding cassette 9 for storing sheets S and a paper feeding device 11 for feeding sheets S from the paper feeding cassette 9 to the transport path 7. The image forming unit 5 comprises a head unit 13, a transport unit 15, and a maintenance unit 17.

[0026] First, let's describe the head unit 13. The head unit 13 has four ejection units 21 that correspond to four colors (yellow, magenta, cyan, and black) of ink. The four ejection units 21 are arranged in parallel along the transport direction (leftward) of the sheet S along the transport path 7.

[0027] Next, each discharge unit 21 will be described with reference to Figure 2. Figure 2 is a perspective view showing the discharge unit 21.

[0028] Each ejection unit 21 has three recording heads 31 and a head base 33 that supports the three recording heads 31.

[0029] Each recording head 31 has a rectangular parallelepiped shape that is elongated in the front-to-back direction and is equipped with a number of nozzles arranged in the front-to-back and left-to-right directions. The front-to-back direction is an example of one direction in this invention. The ink ejection port of each nozzle opens on the lower surface of the recording head 31. Each nozzle ejects ink downward from the ink ejection port by an ink ejection method such as a piezo or thermal type. The area on the lower surface of the recording head 31 where the ink ejection port opens is called the nozzle area N.

[0030] The head base 33 is a flat, plate-shaped member that is long in the front-to-back direction. Three recording heads 31 are supported on the head base 33, arranged in a staggered pattern along the front-to-back direction. Each recording head 31 is supported such that its nozzle region N protrudes downward from the lower surface of the head base 33. The recording heads 31 are made of a metal such as SUS. The configuration of the recording heads 31 will be described later.

[0031] Referring again to Figure 1, the head unit 13 is supported so as to be able to move up and down between a printing position where image formation takes place (see solid line in Figure 1) and a retracted position above the printing position where maintenance and protection of the head unit 13 are performed (see dashed line in Figure 1).

[0032] Next, the transport unit 15 will be described with reference to Figure 1. The transport unit 15 is equipped with a transport belt 51 that is wrapped between rollers that are spaced apart in the left-right direction and travels in a counterclockwise direction as shown in Figure 1. The upper running surface of the transport belt 51 forms part of the transport path 7 that passes through the image forming unit 5. When the head unit 13 descends to the printing position, the nozzle area N of each recording head 31 of the four ejection units 21 comes into close proximity to the upper running surface of the transport belt 51.

[0033] During image formation, the head unit 13 descends to the printing position. The sheet S fed by the paper feeding unit 3 is transported along the transport path 7 to the image forming unit 5. In the image forming unit 5, ink is ejected from the recording head 31 of each ejection unit 21 based on image data onto the sheet S transported by the transport belt 51, and an image is formed on the sheet S.

[0034] Next, the maintenance unit 17 will be described with reference to Figure 1. The maintenance unit 17 comprises a cap unit 61 and a wipe unit 63.

[0035] The cap unit 61 is equipped with caps corresponding to each recording head 31 of each ejection unit 21 of the head unit 13. The cap unit 61 is supported so as to be movable in the left-right direction between a retracted position on the left side of the head unit 13 and a capping position below the head unit 13 when it is raised to the retracted position. After moving the cap unit 61 to the capping position, the head unit 13 is lowered so that each cap is pressed against the head base 33 and covers the nozzle area N of each recording head 31.

[0036] The wipe unit 63 will be described with reference to Figures 1 and 3. Figure 3 is a plan view showing the wipe unit 63. The wipe unit 63 comprises four wiper carriages 65 corresponding to the four ejection units 21 of the head unit 13. The wiper carriages 65 are supported so as to be movable in the front-rear direction. Each wiper carriage 65 is equipped with three wipers 67 corresponding to the three recording heads 31 of the ejection unit 21, and a tray 69 from which the ink wiped by each wiper 67 is collected. The wipers 67 can be, for example, blades formed of an elastic material, or blades or rollers formed of an elastic material with cloth attached around them. The wipe unit 63 is supported so as to be movable in the left-right direction between a retracted position on the left side of the head unit 13 and a wiping position below the head unit 13 when it has risen to the retracted position.

[0037] After moving the wipe unit 63 to the wiping position, the head unit 13 is lowered to bring the wiper 67 into contact with the nozzle area N, and each wiper carriage 65 is moved from the front wiping start position (see solid line in Figure 3) to the rear wiping end position (see dashed line in Figure 3), so that the nozzle area N of each recording head 31 (see Figure 2) of each ejection unit 21 is wiped by the wiper 67 of the wiper carriage 65. The ink wiped by the wiper 67 falls into the tray 69 and is collected through the collection port (not shown). The direction of movement of the wiper carriage 65 is called the wiping direction X. In this embodiment, the wiping direction X is from front to back.

[0038] Next, the recording head 31 will be described with reference to Figures 4A and 4B. Figure 4A is a view of the recording head 31 from the left side, and Figure 4B is a view of the recording head 31 from the front side.

[0039] A head mounting member 41 is formed on the side surface 31a of the recording head 31 along the wiping direction X (front-to-back direction). More specifically, in the wiping direction X, the head mounting member 41 is formed on both sides of the nozzle region N along the longitudinal direction of the recording head 31 (front-to-back direction, i.e., wiping direction X). As shown in Figure 4B, the head mounting member 41 has a vertically elongated rectangular cross-sectional shape when viewed from the front-to-back direction and is formed at a position higher than the nozzle region N. For example, the distance of the head mounting member 41 from the nozzle region N is 0.1 mm. In this case, the side surface 31a of the recording head 31 is the surface adjacent to the lower surface where the nozzle region N exists and is generally an upward-extending surface.

[0040] As shown in Figure 4A, the lower end of the head mounting member 41 has a wave-like uneven surface in which, when viewed from the left and right directions, downwardly convex portions 43 and upwardly concave portions 45 are alternately formed. In detail, the convex portions 43 are formed so as to narrow in width toward the bottom, and the concave portions 45 are formed so as to widen in width toward the bottom. The head mounting member 41 is made of a material (for example, silicone resin or fluororesin) that has higher water repellency than the side surface 31a of the recording head 31. In other words, the contact angle of the ink with respect to the surface of the head mounting member 41 is greater than the contact angle of the ink with respect to the side surface 31a of the recording head 31. Alternatively, the head mounting member 41 may be coated only on its surface with a material that has high water repellency. As an example, the thickness of the head mounting member 41 is 0.2 to 0.3 mm.

[0041] The head mounting member 41 is fixed to the side surface 31a of the recording head 31 by methods such as double-sided tape, adhesive, or heat fusion, so as to protrude from it. More specifically, the head mounting member 41 is fixed to the side surface 31a without any gaps.

[0042] Wiping in the image forming apparatus 1 having the above configuration will be explained with reference to Figures 4A and 4B. Wiping is performed, for example, after purging the ink in the nozzle of the recording head 31. During wiping, as described above, the wiper carriage 65 (see Figure 3) of the wipe unit 63 moves in the wiping direction X, and the wiper 67 wipes the nozzle area N. The wiper 67 is pressed against the nozzle area N with a predetermined pressure, so as shown in Figure 4A, it curves downstream in the wiping direction X. Also, since the width of the wiper 67 is slightly wider than the width of the nozzle area N, when pressed against the nozzle area N, both ends of the wiper 67 protrude above the nozzle area N, as shown in Figure 4B.

[0043] The ink L wiped away by the wiper 67 is pushed up (rises) from both ends of the wiper 67 onto the side 31a of the recording head 31. The rising ink eventually reaches the head mounting member 41 and enters the recess 45.

[0044] However, the head mounting member 41 has higher water repellency than the side surface 31a of the recording head 31 and is less likely to absorb ink, so the ink is repelled from the recess 45. The ink repelled from the recess 45 moves downward along both sides of the recess 45, that is, along the sides of the two protrusions 43 adjacent to the recess 45. As a result, the ink that has entered the two adjacent recesses 45 gathers at the tip (lower end) of one of the protrusions 43 between the two recesses 45. Then, the amount of collected ink increases, and it becomes easier for it to fall from the lower end of the protrusion 43 due to its own weight. In this way, the ink falls from the recess 45 and is less likely to accumulate on the side surface 31a of the recording head 31.

[0045] As is clear from the above description, according to the present invention, ink that rises up on the side surface 31a of the recording head 31 and enters the recess 45 during wiping moves downward along the protrusion 43 and easily falls from the lower end of the protrusion 43 due to its own weight. Therefore, at the end of wiping, it is possible to prevent ink from adhering to or accumulating on the side surface 31a of the recording head 31, or to reduce the amount of ink that adheres to or accumulates on the side surface 31a of the recording head 31. Consequently, it is possible to prevent or reduce ink from falling from the side surface 31a of the recording head 31 during image formation, thereby preventing image defects and in-machine contamination.

[0046] Furthermore, since the recess 45 is formed to widen towards the bottom, the contact area between the side of the recess 45 and the ink is relatively small, making it difficult for the ink that has entered to be retained in the recess 45. Also, since the convex portion 43 is formed to narrow towards the bottom, ink tends to collect from the recesses 45 on both sides to the lower end of the convex portion 43. Therefore, the ink that has entered the recess 45 can be made to fall out. Moreover, since the rising ink does not get into the space between the head mounting member 41 and the side surface 31a of the recording head 31, ink accumulation can be prevented more reliably.

[0047] Next, with reference to Figures 5A to 5C, the first to third modified examples of the recording head 31 will be described. Figures 5A to 5C are side views of the recording head 31 as seen from the left side.

[0048] First, a first modified example will be described with reference to Figure 5A. In the first modified example, the lower end of the head mounting member 41 has a triangular wave-shaped uneven surface in which downward-convex convex portions 43 and upward-concave recessed portions 45 are alternately formed when viewed from the left-right direction. In detail, the convex portions 43 are formed so as to narrow in width toward the bottom, and the recessed portions 45 are formed so as to widen in width toward the bottom.

[0049] In the first modified example, as in the embodiment described above, the ink L that has entered the two adjacent recesses 45 moves downward along the protrusion 43 between the two recesses 45 and collects at the lower end of the protrusion 43. As the amount of collected ink increases, it falls from the protrusion 43 due to its own weight, making it less likely for the ink to accumulate on the side surface 31a of the recording head 31.

[0050] Next, a second modified example will be described with reference to Figure 5B. In the second modified example, the lower end of the head mounting member 41 is formed in a sawtooth shape when viewed from the left and right directions. That is, a right-angled triangular shape with a convex portion 43 that is convex downwards and a concave portion 45 that is concave upwards is formed alternately. The convex portion 43 is formed so as to narrow in width toward downwards, and the concave portion 45 is formed so as to widen in width toward downwards. In addition, the concave portion 45 is formed so that the downstream side in the wiping direction X is vertical and the upstream side is inclined.

[0051] In the second modified example, the ink that has risen to the side surface 31a of the recording head 31 is pushed downstream in the wiping direction X as the wiper 67 moves in the wiping direction X, and is pressed against the inclined side surface of the recess 45, making it easier for the ink to collect at the tip of the protrusion 43 along the inclined side surface. By making it easier for the ink to collect at the tip of the protrusion 43 in this way, the dripping of the ink from the tip of the protrusion 43 can be promoted.

[0052] Next, a third modification will be described with reference to Figure 5C. In the third modification, the lower end of the head mounting member 41 has rectangular protrusions 43 formed at predetermined intervals along the wiping direction X when viewed from the left-right direction. As a result, rectangular recesses 45 are formed between adjacent protrusions 43 when viewed from the left-right direction. The width of the protrusions 43 along the wiping direction X is narrower than the width of the recesses 45.

[0053] In the third modification, the ink L that rises up on the side surface 31a of the recording head 31 and enters the recess 45 is pushed downstream in the wiping direction X as the wiper 67 moves in the wiping direction X, and is blocked by the protrusion 43. The blocked ink L gathers at the lower end of the protrusion 43 and becomes more likely to fall from the protrusion 43 due to its own weight.

[0054] Next, a fourth modified example will be described with reference to Figure 6. Figure 6 is a front view of the recording head 31.

[0055] In the fourth modification, the angle α formed between the lower side surface of the head mounting member 41 and the side surface 31a of the recording head 31 is formed as an acute angle. The head mounting member 41 is fixed to the side surface 31a of the recording head 31 by, for example, adhesive 47. The adhesive 47 is applied to the upper part of the head mounting member 41. In the fourth modification, the contact area between the ink that has risen along the side surface 31a of the recording head 31 and the head mounting member 41 is reduced, so that ink L is less likely to be retained in the corner between the head mounting member 41 and the side surface 31a of the recording head 31, thereby promoting ink removal.

[0056] Next, a fifth modified example of the recording head 31 will be described with reference to Figures 7A and 7B. Figure 7A is a side view of the recording head 31, and Figure 7B is a front view of the recording head 31.

[0057] The fifth modified recording head 31 includes a discharge unit 91 and a reservoir 93. An ink discharge port of the nozzle opens on the lower surface of the discharge unit 91. The area on the lower surface of the discharge unit 91 where the ink discharge port opens is called the nozzle area N. The reservoir 93 is stacked above the discharge unit 91 with a piezoelectric element for discharging ink in between, and supplies ink to the discharge unit 91.

[0058] The reservoir 93 is rectangular in shape and has an upper part and a lower part that communicates with the discharge part 91. The lower part is wider than the upper part in the left-right direction. As a result, a downward-facing flat stepped surface 93x is formed on the side surface of the reservoir 93.

[0059] Head mounting members 41 are formed on both sides 93a of the lower part of the reservoir 93 and on both sides 91a of the discharge section 91, along the wiping direction X. The head mounting members 41 have higher water repellency than the sides of the recording head 31, more specifically, the sides 91a of the discharge section 91. The cross-sectional shape of the head mounting member 41, when viewed from the front-to-back direction, is a vertically elongated rectangular cuboid. The upper end surface of the head mounting member 41 is a straight, flat surface, and the lower end is formed in a wave-like shape with alternating convex portions 43 and concave portions 45. In addition, the thickness (length along the left-to-right direction) of the head mounting member 41 is greater than the height (length along the left-to-right direction) of the stepped surface 93x. Furthermore, the height (length along the vertical direction) of the head mounting member 41 is shorter than the height (length along the vertical direction) of the lower part of the reservoir 93 and the discharge part 91. That is, both sides 93a of the lower part of the reservoir 93 are covered by the head mounting member 41. It is preferable, but not necessarily, for the head mounting member 41 to cover the entire lower sides 93a of the reservoir 93. If the lower sides 93a of the reservoir 93 are exposed below the head mounting member 41, it is preferable, but not necessarily, for the head mounting member 41 to have higher water repellency than the lower sides 93a of the reservoir 93.

[0060] The upper end surface of the head mounting member 41 abuts against the stepped surface 93x and is fixed to the stepped surface 93x using adhesive or double-sided tape. Furthermore, the side surface of the head mounting member 41 is located inward from the upper side surface of the reservoir 93. Additionally, the lower end surface of the head mounting member 41 is located above the nozzle region N of the discharge section 91.

[0061] In the recording head 31 having the above configuration, the ink L wiped off by the wiper 67 is pushed up (rises) from both ends of the wiper 67 to the side surface 91a of the discharge section 91 of the recording head 31. As described above, the risen ink enters the recess 45, is repelled from the recess 45, moves downward along the side surfaces of the two protrusions 43 adjacent to the recess 45, and easily falls from the lower end of the protrusions 43 due to its own weight. In this way, the ink falls out of the recess 45 and is less likely to accumulate on the side surface of the recording head 31.

[0062] As described above, with the recording head 31 of the present invention, since the upper end surface of the head mounting member 41 abuts against the stepped surface 93x, the head mounting member 41 can be easily aligned with the recording head 31. Furthermore, since the upper end surface of the head mounting member 41 is formed in a flat, straight shape, the contact area between the upper end surface and the stepped surface 93x can be increased, and the head mounting member 41 and the recording head 31 can be firmly fixed. Moreover, since both sides of the head mounting member 41 are located inward from both sides of the recording head 31, contact between the head mounting member 41 and surrounding parts is prevented, making it difficult for the head mounting member 41 to peel off. Furthermore, since the lower end of the head mounting member 41 is located above the nozzle region N, the possibility of the head mounting member 41 coming into contact with a recording medium such as a sheet can be reduced, and damage to the head mounting member 41 can be suppressed.

[0063] The head mounting member 41 is integrally provided with the recording head 31, and its surface may be processed to have higher water repellency than the side surface 31a of the recording head 31.

[0064] Although the present invention has been described in terms of specific embodiments, the present invention is not limited to the above embodiments. Those skilled in the art can modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of Symbols]

[0065] 1. Image forming apparatus 21 Discharge Unit 31 Recording head 41 Head mounting component 43 Convex part 45 recess 67 Wiper 91 Discharge part 93 Reservoir

Claims

1. A recording head is provided with a nozzle area in which multiple ink ejection ports open downwards, The device comprises a wiper that contacts the nozzle area and moves in a predetermined wiping direction to wipe the ink outlet, A head mounting member is provided on the side surface of the recording head in the direction of the wiping, The image forming apparatus is characterized in that the surface of the head mounting member has higher water repellency than the side surface, and the lower end of the head mounting member has alternating recesses and protrusions.

2. The image forming apparatus according to claim 1, characterized in that the convex portion is formed to narrow in width toward the downward direction, and the concave portion is formed to widen in width toward the downward direction.

3. The image forming apparatus according to claim 1, characterized in that the lower end of the head mounting member is wavy, sawtooth-shaped, or rectangular wavy.

4. The image forming apparatus according to claim 1, characterized in that the angle formed by the lower side surface of the head mounting member and the side surface of the recording head is an acute angle.

5. The recording head is provided with a nozzle area that is elongated in one direction and has multiple ink ejection ports that open downwards. A head mounting member is provided on the side surface of the recording head in the nozzle region, along the longitudinal direction of the recording head. The discharge unit is characterized in that the surface of the head mounting member has higher water repellency than the side surface, and the lower end of the head mounting member has alternating recesses and protrusions.

6. The discharge unit according to claim 5, characterized in that the convex portion is formed to narrow in width toward the downward direction, and the concave portion is formed to widen in width toward the downward direction.

7. The discharge unit according to claim 5, characterized in that the lower end of the head mounting member is wavy, sawtooth-shaped, or rectangularly wavy.

8. The ejection unit according to claim 5, characterized in that the angle formed by the lower side surface of the head mounting member and the side surface of the recording head is an acute angle.

9. The recording head includes an ejection section provided with the ink ejection port, and a reservoir positioned above the ejection section to supply liquid to the ejection section. A downward step is formed on the side of the reservoir, along the longitudinal direction of the recording head. The discharge unit according to claim 5, characterized in that the head mounting member is abutted against the step.

10. The discharge unit according to claim 9, characterized in that the upper end of the head mounting member is straight.

11. The reservoir has an upper part above the step and a lower part below the step, The head mounting member is attached to the lower side surface. The discharge unit according to claim 9, characterized in that the side surface of the head mounting member is located inward from the upper side surface of the reservoir.

12. The discharge unit according to claim 9, characterized in that the lower end of the head mounting member is located above the nozzle area of ​​the recording head.

13. A discharge unit according to any one of claims 5 to 12, An image forming apparatus characterized by comprising a wiper that contacts the nozzle area and moves in a predetermined wiping direction to wipe the ink discharge port.

Images