JP2018108711A - Recording head and inkjet recording device comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording head that can supply evenly cleaning liquid to an entire area in a width direction of an ink discharge surface and an inkjet recording device comprising the same.SOLUTION: The recording head comprises an ink discharge surface and a cleaning liquid supply surface. The ink discharge surface includes a nozzle area where a plurality of ink discharge nozzles for discharging ink onto a recording medium open. The cleaning liquid supply surface F2 is provided at an upstream side in a wiping direction, the direction in which a wiper wipes the ink discharge surface, with respect to the nozzle area, where a plurality of cleaning liquid supply ports 60a for supplying cleaning liquid open. In the cleaning liquid supply surface, in an area including at least the cleaning liquid supply ports, a hydrophilic area F3 having higher wettability to water than the ink discharge surface is formed substantially uniformly across an entire area in a width direction orthogonal to the wiping direction.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a recording head having an ink discharge nozzle for discharging ink onto a recording medium such as paper, and an ink jet recording apparatus including the recording head.

  2. Description of the Related Art As a recording apparatus such as a facsimile, a copying machine, and a printer, an ink jet recording apparatus that forms an image by ejecting ink is widely used because it can form a high-definition image.

  In such an ink jet recording apparatus, a micro ink droplet (hereinafter referred to as a mist) ejected together with an ink droplet for image recording, or a bounce mist generated when the ink droplet adheres to a recording medium, The ink adheres to the ink ejection surface and solidifies. When the mist on the ink ejection surface gradually increases and overlaps the ink ejection nozzle, the straightness of the ink (flying curve), non-ejection, etc. occur and the printing performance of the recording head decreases.

  In many cases, a water repellent film is formed on the ink ejection surface in order to reduce ink adhesion. However, when water-based pigment ink is used, when the wiping operation with a rubber wiper is repeated, the pigment particles act as an abrasive and the water repellent film is gradually scraped. For this reason, mist tends to adhere to the ink discharge surface, and the ink discharge surface cannot be kept clean.

  Accordingly, various methods for cleaning the mist adhering to the ink ejection surface have been devised. For example, Patent Document 1 discloses a method for cleaning a plurality of ink ejection surfaces among the ink ejection surfaces in order to clean the ink ejection surface of the recording head. An ink jet recording apparatus is disclosed in which a plurality of cleaning liquid supply ports are provided outside the nozzle area where the nozzles are open (upstream in the wiping direction of the wiper). In this ink jet recording apparatus, after supplying the cleaning liquid from the cleaning liquid supply port, the wiper is moved along the ink discharge surface from the outside of the cleaning liquid supply port, so that the ink discharge surface is held while the wiper holds the cleaning liquid. Can be wiped. In this way, the recording head recovery process can be performed.

JP 2007-83396 A

  When supplying the cleaning liquid to the ink discharge surface as in Patent Document 1, if there is a portion where the cleaning liquid is not supplied in the width direction of the ink discharge surface, the cleaning liquid exists between the ink discharge surface and the blade (wiper). An area that does not occur. When the wiping operation is performed in this state, the friction between the ink discharge surface and the blade is increased, causing a problem that the blade and the ink discharge surface are damaged.

  In view of the above problems, an object of the present invention is to provide a recording head capable of uniformly supplying a cleaning liquid to the entire width direction of an ink discharge surface and an ink jet recording apparatus including the recording head.

  In order to achieve the above object, a first configuration of the present invention is a recording head including an ink discharge surface and a cleaning liquid supply surface. The ink ejection surface includes a nozzle region in which a plurality of ink ejection nozzles that eject ink onto the recording medium are opened. The cleaning liquid supply surface is provided on the upstream side of the wiping direction, which is the direction in which the wiper wipes the ink discharge surface with respect to the nozzle region, and a plurality of cleaning liquid supply ports for supplying the cleaning liquid are opened. On the cleaning liquid supply surface, a hydrophilic region having high wettability with respect to water as compared with the ink ejection surface is formed substantially uniformly over the entire width direction orthogonal to the wiping direction, at least in the region including the cleaning liquid supply port. Yes.

  According to the first configuration of the present invention, the cleaning liquid supplied from the cleaning liquid supply port is held in a state of spreading over the hydrophilic region, and the cleaning liquid is uniformly supplied over the entire width direction of the cleaning liquid supply surface. . Thereby, the cleaning liquid is brought into contact with the entire width direction of the wiper, and the entire width direction area of the ink discharge surface continuous with the cleaning liquid supply surface can be easily and uniformly cleaned. Therefore, it is possible to maintain the image quality by suppressing the deterioration of the straightness of the ink (flying curve), non-ejection, and the like over a long period of time. In addition, peeling of the water-repellent film on the ink discharge surface and loss of the wiper due to friction between the ink discharge surface and the wiper can be suppressed. Further, since the cleaning liquid spreads and is held along the hydrophilic region, it is possible to prevent the cleaning liquids from being united to form a large liquid droplet, which is caused by the cleaning liquid falling from the cleaning liquid supply surface. The loss of the cleaning liquid can be reduced.

Schematic showing the structure of an ink jet recording apparatus provided with the recording head of the present invention The top view which looked at the 1st conveyance unit and recording part of the ink-jet recording device shown in Drawing 1 from the upper part Diagram of the recording head that constitutes the line head of the recording unit FIG. 3 is a diagram of the recording head according to the first embodiment of the present invention viewed from the ink ejection surface side. The perspective view which looked at the recording head periphery of 1st Embodiment from diagonally downward The perspective view which looked at the cleaning-liquid supply member of the recording head of 1st Embodiment from diagonally downward The top view which looked at the cleaning liquid supply member of the recording head of a 1st embodiment from the lower part Side view showing how cleaning liquid is held near the boundary between the ink ejection surface and the hydrophilic region The perspective view which looked at the recording head periphery of 1st Embodiment from diagonally upward. Side view showing a state in which the maintenance unit is arranged below the recording unit Side view showing a state in which the wiper is disposed below the recording head Side surface sectional view of the cleaning liquid being held on the cleaning liquid supply surface as viewed from the downstream side in the wiper wiping direction The side view which shows the state which raised the wiper from the state of FIG. 11, and was made to press-contact with the cleaning liquid supply member The side view which shows the state which moved to the arrow A direction in the state which pressed the wiper to the cleaning liquid supply member from the state of FIG. The side view which shows the state which moved the wiper further to the arrow A direction from the state of FIG. FIG. 15 is a side view showing a state where the wiper is further moved in the direction of arrow A from the state of FIG. 15 and then the wiper is lowered and separated from the ink discharge surface. The top view which looked at the cleaning liquid supply member of the recording head concerning a 2nd embodiment of the present invention from the lower part The top view which looked at the cleaning liquid supply member of the recording head concerning 3rd Embodiment of this invention from the downward direction The top view which looked at the cleaning liquid supply member of the recording head concerning 4th Embodiment of this invention from the downward direction The top view which looked at the cleaning liquid supply member of the recording head concerning 5th Embodiment of this invention from the downward direction Side surface sectional drawing which looked at the state where cleaning liquid was hold | maintained at the cleaning liquid supply surface in the recording head of 5th Embodiment from the wiping direction downstream of the wiper The side view which looked at the cleaning liquid supply member of the recording head concerning a 6th embodiment of the present invention from the lower part

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view showing the structure of an ink jet recording apparatus 100 having recording heads 17a to 17c of the present invention, and FIG. 2 is a diagram illustrating a first transport unit 5 and a recording unit 9 of the ink jet recording apparatus 100 shown in FIG. It is the figure which looked at from the upper part. As shown in FIG. 1, a paper feed tray 2 that accommodates paper S (recording medium) is provided on the left side of the inkjet recording apparatus 100, and the paper S that is accommodated at one end of the paper feed tray 2. Are fed one by one from the uppermost sheet S to a first transport unit 5 (to be described later), and a driven roller 4 that is in pressure contact with the feed roller 3 and is driven to rotate. Is provided.

  A first transport unit 5 and a recording unit 9 are arranged on the downstream side (right side in FIG. 1) of the paper feed roller 3 and the driven roller 4 with respect to the paper transport direction (arrow X direction). The first transport unit 5 includes a first drive roller 6, a first driven roller 7, and a first transport belt 6 that is stretched over the first drive roller 6 and the first driven roller 7. When the first drive roller 6 is driven to rotate in the clockwise direction by a control signal from the control unit 110 of the recording apparatus 100, the paper S held on the first transport belt 8 is transported in the arrow X direction.

  The recording unit 9 includes a head housing 10 and line heads 11C, 11M, 11Y, and 11K held by the head housing 10. These line heads 11C to 11K are supported at such a height that a predetermined interval (for example, 1 mm) is formed with respect to the conveying surface of the first conveying belt 8, and as shown in FIG. A plurality (three in this case) of recording heads 17a to 17c are arranged in a zigzag pattern along the orthogonal paper width direction (vertical direction in FIG. 2).

  3 is a side view of the recording heads 17a to 17c constituting the line heads 11C to 11K of the recording unit 9, and FIG. 4 is a plan view of the recording heads 17a to 17c as viewed from the ink ejection surface F1 side. FIG. 5 is a perspective view of the periphery of the recording head 17a as viewed obliquely from below. Since the recording heads 17a to 17c have the same shape and configuration, the recording heads 17a to 17c are shown in one drawing in FIGS. As shown in FIGS. 3 and 4, the ink discharge surface F1 of the head portion 18 of the recording heads 17a to 17c is provided with a nozzle region R1 in which a large number of ink discharge nozzles 18a (see FIG. 2) are arranged. At least the ink discharge surface F1 of the head unit 18 is formed of, for example, SUS (stainless steel). The ink discharge surface F1 is water-repellent by applying a fluorine-based or silicon-based water repellent, and here has a contact angle with water of 113 °.

  In the recording heads 17a to 17c constituting the line heads 11C to 11K, inks of four colors (cyan, magenta, yellow, and black) respectively stored in ink tanks (not shown) are stored in the line heads 11C to 11K. Supplied for each color.

  Each of the recording heads 17a to 17c is transported while being sucked and held on the transport surface of the first transport belt 8 in accordance with image data received from an external computer by a control signal from the control unit 110 (see FIG. 1). Ink is ejected from the ink ejection nozzle 18a. As a result, a color image in which four colors of cyan, magenta, yellow, and black are superimposed is formed on the sheet S on the first conveying belt 8. The recording heads 17a to 17c are provided with a cleaning liquid supply member 60 for supplying a cleaning liquid.

  Returning to FIG. 1, the second transport unit 12 is arranged on the downstream side (right side in FIG. 1) of the first transport unit 5 with respect to the paper transport direction. The second transport unit 12 includes a second drive roller 13, a second driven roller 14, and a second transport belt 15 stretched over the second drive roller 13 and the second driven roller 14. When the two drive rollers 13 are rotationally driven in the clockwise direction, the paper S held on the second transport belt 15 is transported in the arrow X direction.

  The paper S on which the ink image is recorded by the recording unit 9 is sent to the second transport unit 12, and the ink ejected on the surface of the paper S while passing through the second transport unit 12 is dried. A maintenance unit 19 and a cap unit 90 are disposed below the second transport unit 12. The maintenance unit 19 moves below the recording unit 9 when performing a wiping operation by a wiper 35 described later. Then, the cleaning liquid is supplied from the cleaning liquid supply port 60a of the recording heads 17a to 17c, and the ink discharge surface F1 (see FIG. 3) is wiped off while spreading the cleaning liquid using the wiper 35, and the wiped cleaning liquid is removed. to recover. The cap unit 90 horizontally moves below the recording unit 9 when capping the ink ejection surfaces F1 of the recording heads 17a to 17c, and further moves upward to be attached to the head unit 18 of the recording heads 17a to 17c.

  Further, on the downstream side of the second transport unit 12 with respect to the paper transport direction, a discharge roller pair 16 that discharges the paper S on which an image has been recorded to the outside of the inkjet recording apparatus 100 is provided. On the downstream side, a discharge tray (not shown) on which the sheets S discharged to the outside of the ink jet recording apparatus 100 are stacked is provided.

  The maintenance unit 19 supports a plurality of wipers 35 (see FIG. 11) that can move along the ink ejection surface F1, a substantially rectangular carriage (not shown) to which the plurality of wipers 35 are fixed, and the carriage. And a support frame (not shown). A carriage (not shown) is supported to be slidable in the direction of arrow AA ′ with respect to a support frame (not shown).

  The wiper 35 is an elastic member (for example, a rubber member made of EPDM) for wiping off the cleaning liquid supplied from the cleaning liquid supply ports 60a (see FIG. 7) of the recording heads 17a to 17c. The wiper 35 is in pressure contact with the upstream portion (in this case, the inclined surface 62) of the cleaning liquid supply member 60 in the wiping direction, and moves the cleaning liquid supply surface F2 and the ink discharge surface F1 in a predetermined direction by movement of a carriage (not shown). Wiping is performed in the direction of arrow A.

  FIG. 6 is a perspective view of the cleaning liquid supply member 60 of the recording heads 17a to 17c of the first embodiment as viewed obliquely from below, and FIG. 7 is a plan view of the cleaning liquid supply member 60 as viewed from below. The cleaning liquid supply member 60 is formed of resin or SUS, and is disposed adjacent to the upstream side (right side in FIG. 3) of the wiper 35 described later with respect to the head unit 18. The cleaning liquid supply member 60 has a cleaning liquid supply surface F2 on which cleaning liquid supply ports 60a for supplying the cleaning liquid are arranged. The cleaning liquid supply member 60 is subjected to a water repellent process that is weaker than the ink discharge surface F1, and the contact angle of the cleaning liquid supply member 60 with respect to water is 95 ° or less.

  As shown in FIGS. 3, 5, and 6, an inclined surface 62 is formed at a portion upstream of the cleaning liquid supply surface F <b> 2 of the cleaning liquid supply member 60 in the wiping direction (right side in FIG. 3). . A portion of the cleaning liquid supply surface F2 on the downstream side in the wiping direction (left side in FIG. 3) is formed in a thin plate shape, and is disposed so as to overlap the end portion of the ink discharge surface F1 of the head portion 18. Note that in FIG. 5 and FIG. 11 described later, only a part of the recording heads 17a to 17c is illustrated for easy understanding.

  As shown in FIGS. 6 and 7, the cleaning liquid supply ports 60a are arranged in a staggered manner at a predetermined pitch in the wiping direction (arrow A direction) and the head width direction (arrow BB ′ direction) orthogonal to the wiping direction. Yes.

  Further, the hydrophilic region F3 (FIG. 6, FIG. 6) has a high wettability with respect to water over the entire area of the cleaning liquid supply surface F2 compared to the ink discharge surface F1 and other portions of the cleaning liquid supply member 60 (for example, the inclined surface 62). 7 hatching regions) are formed. As a method of forming the hydrophilic region F3, a method of not applying a water repellent to the cleaning liquid supply surface F2, a method of roughening the cleaning liquid supply surface F2, or a cleaning liquid supply surface F2 instead of the water repellent is used. Examples thereof include a method of applying a hydrophilic coating agent. Examples of hydrophilic coating agents include titanium oxide-based and polysilicate-based coating agents.

  6 and 7, a plurality of independent cleaning liquid supply ports 60a are arranged at a predetermined pitch. However, instead of the independent cleaning liquid supply ports 60a, a plurality of cleaning liquid supply ports 60a are gathered. A plurality of nozzle groups may be arranged at a predetermined pitch.

  FIG. 8 is a side cross-sectional view showing a state in which the cleaning liquid 23 is held near the boundary between the ink ejection surface F1 and the hydrophilic region F3. When the contact angle of the hydrophilic region F3 with respect to water is 90 ° or more, the aqueous cleaning liquid 23 protrudes from the hydrophilic region F3 to the ink ejection surface F1 side by surface tension (indicated by a broken line in FIG. 8). Therefore, the cleaning liquid 23 is likely to flow to the ink ejection surface F1 side due to vibration and impact. If the cleaning liquid 23 flows to the ink ejection surface F1 side when the recovery operation of the recording heads 17a to 17c, which will be described later, is not performed, there is a possibility of adversely affecting the flying property of the ink from the ink ejection nozzle 18a.

  On the other hand, when the water contact angle of the hydrophilic region F3 is less than 90 °, the aqueous cleaning liquid 23 does not protrude from the hydrophilic region F3 to the ink ejection surface F1 side (indicated by a solid line in FIG. 8). Accordingly, the contact angle of the hydrophilic region F3 with respect to water is preferably less than 90 °. Since most liquids have a smaller surface tension than water, the contact angle of the hydrophilic region F3 with respect to water is less than 90 °, so that the cleaning liquid 23 based on other liquids can be used. There is no possibility that the cleaning liquid 23 flows from the hydrophilic region F3 to the ink ejection surface F1.

  As shown in FIGS. 5 and 9, the cleaning liquid supply member 60 is connected to the downstream end of a supply path 70 formed of a tube through which the cleaning liquid 23 passes. The upstream end of the supply path 70 is connected to a cleaning liquid supply mechanism (not shown). The cleaning liquid supply mechanism includes a tank (not shown) that stores the cleaning liquid 23 and a pump (not shown) that pumps the cleaning liquid 23 from the tank to the supply path 70.

  The supply path 70 is configured by one path at the upstream end, but repeats branching toward the downstream side and branches into 12 paths. The twelve paths are respectively connected to the cleaning liquid supply members 60 of the recording heads 17a to 17c.

  In the ink jet recording apparatus 100, in order to clean the ink discharge surfaces F1 of the recording heads 17a to 17c, the cleaning liquid for all the recording heads 17a to 17c is used at the start of printing after being stopped for a long time and between printing operations. The cleaning liquid 23 is supplied to the cleaning supply surface F2 from the supply port 60a (see FIG. 11), and the recovery operation of the recording heads 17a to 17c for wiping the ink discharge surface F1 with a wiper 35 described later is executed to prepare for the next printing operation. .

  Next, the recovery operation of the recording heads 17a to 17c using the maintenance unit 19 in the inkjet recording apparatus 100 of the present embodiment will be described. The recovery operation of the recording heads 17a to 17c described below is executed by controlling the operations of the recording heads 17a to 17c, the maintenance unit 19 and the like based on a control signal from the control unit 110 (see FIG. 1). The

  When the recovery operation of the recording heads 17a to 17c is performed, first, the first transport unit 5 located below the recording unit 9 is lowered as shown in FIG. Then, the maintenance unit 19 disposed below the second transport unit 12 is moved horizontally and disposed between the recording unit 9 and the first transport unit 5. In this state, the wiper 35 (see FIG. 11) of the maintenance unit 19 is disposed below the ink discharge surface F1 and the cleaning liquid supply surface F2 (see FIG. 11) of the recording heads 17a to 17c.

(Cleaning liquid supply operation)
Prior to the wiping operation (wiping operation described later), as shown in FIG. 11, the cleaning liquid 23 is supplied to the recording heads 17a to 17c by a control signal from the control unit 110 (see FIG. 1). The supplied cleaning liquid 23 is discharged from the cleaning liquid supply port 60a (see FIG. 7) to the cleaning liquid supply surface F2 by a predetermined amount.

  Here, as shown in FIG. 7, since the hydrophilic region F3 is formed over the entire area of the cleaning liquid supply surface F2, as shown in FIG. 12, the cleaning liquid 23 becomes hydrophilic region F3 (cleaning liquid supply). The surface F2) is held in a state of spreading over the entire region in the width direction (arrow BB ′ direction).

(Ink extrusion operation)
Prior to the wiping operation (wiping operation described later), the ink 22 is supplied to the recording head 17 by the control unit 110 (see FIG. 1) as shown in FIG. The supplied ink 22 is forcibly extruded (purged) from the ink discharge nozzle 18a. By this purging operation, thickened ink, foreign matter and bubbles in the ink discharge nozzle 18a are discharged from the ink discharge nozzle 18a. At this time, the purge ink 22 is pushed out to the ink discharge surface F1 along the shape of the nozzle region R1 where the ink discharge nozzle 18a exists. In the figure, the ink (purge ink) 22 is hatched for easy understanding.

(Wiping operation)
As shown in FIG. 13, the wiper 35 is raised by a control signal from the control unit 110 and brought into contact with the inclined surface 62 of the cleaning liquid supply member 60 of the recording heads 17a to 17c with a predetermined pressure.

  From the state in which the tip of the wiper 35 is in pressure contact with the inclined surface 62 of the cleaning liquid supply member 60, the wiper 35 is moved along the cleaning liquid supply surface F2 in the direction of the nozzle region R1 (arrow A direction). As a result, the wiper 35 wipes the cleaning liquid 23 as shown in FIG. 14, and then moves in the direction of the nozzle region R1 while holding the cleaning liquid 23.

  As shown in FIG. 15, the wiper 35 moves to the left (in the direction of arrow A) on the ink ejection surface F <b> 1 while maintaining the state where the cleaning liquid 23 and the purge ink 22 are held. At this time, the ink droplets (waste ink) adhered and solidified on the ink ejection surface F 1 are dissolved by the cleaning liquid 23 and the purge ink 22 and are wiped off by the wiper 35. The wiper 35 further moves leftward (in the direction of arrow A) and stops moving leftward when it reaches the end of the nozzle region R1 opposite to the cleaning liquid supply member 60. The cleaning liquid 23 and waste ink wiped off by the wiper 35 are collected in a cleaning liquid collection tray (not shown) provided in the maintenance unit 19.

(Separation operation)
After executing the wiping operation, as shown in FIG. 16, the wiper 35 is lowered and separated from the ink ejection surface F1.

  Finally, the maintenance unit 19 disposed between the recording unit 9 and the first transport unit 5 is horizontally moved and disposed below the second transport unit 12 to raise the first transport unit 5 to a predetermined position. . In this way, the recovery operation of the recording heads 17a to 17c is completed.

  In the present embodiment, as described above, the plurality of cleaning liquid supply ports 60a for supplying the cleaning liquid 23 are provided on the upstream side in the wiping direction (arrow A direction) with respect to the nozzle region R1. Thus, after supplying the cleaning liquid 23 from the cleaning liquid supply port 60a, the wiper 35 is moved along the ink discharge surface F1 from the upstream side of the cleaning liquid supply port 60a in the wiping direction. The ink discharge surface F1 can be wiped while holding the ink. For this reason, the ink discharge surface F1 can be cleaned.

  Further, a hydrophilic region F3 is formed over the entire area of the cleaning liquid supply surface F2, and the cleaning liquid 23 supplied from the cleaning liquid supply port 60a is held in a state of spreading over the hydrophilic region F3. As a result, the cleaning liquid is uniformly supplied over the entire width direction (arrow BB ′ direction) of the cleaning liquid supply surface F2, so that the cleaning liquid can be brought into contact with the entire width direction of the wiper 35. Accordingly, the entire width direction of the ink discharge surface F1 continuous to the cleaning liquid supply surface F2 can be easily and uniformly cleaned, and the straightness of the ink is deteriorated (flying bending), non-discharge, etc. over a long period of time. Generation can be suppressed and image quality can be maintained. In addition, peeling of the water-repellent film on the ink discharge surface F1 due to friction between the ink discharge surface F1 and the wiper 35 and loss of the wiper 35 can be suppressed.

  Further, since the cleaning liquid 23 is spread and held along the hydrophilic region F3, it is possible to prevent the cleaning liquids 23 from uniting and forming a large droplet. For this reason, since it can suppress that the cleaning liquid 23 falls from the cleaning liquid supply surface F2, the loss of the cleaning liquid 23 can be reduced.

  As described above, since the cleaning liquid supply member 60 is subjected to water repellency that is weaker than that of the ink discharge surface F1, the hydrophilicity of the cleaning liquid supply surface F2 is slightly higher than that of the ink discharge surface F1. . In the present embodiment, hydrophilic processing such as applying no water repellent to the cleaning liquid supply surface F2, roughening the cleaning liquid supply surface F2, or applying a hydrophilic coating agent to the cleaning liquid supply surface F2 is performed. Thus, a hydrophilic region F3 in which the hydrophilicity of the cleaning liquid supply surface F2 is further increased is formed. That is, when the contact angle of water on the ink discharge surface F1 is θ1, the contact angle of water on the cleaning liquid supply surface F2 (cleaning liquid supply member 60) is θ2, and the contact angle of water on the hydrophilic region F3 is θ3, θ1> The relationship θ2> θ3 is established.

  FIG. 17 is a view of the cleaning liquid supply member 60 of the recording heads 17a to 17c according to the second embodiment of the present invention as viewed from below. In the present embodiment, as shown in FIG. 17, the hydrophilic region F3 extends across the entire width direction in a region including the cleaning liquid supply port 60a of the cleaning liquid supply surface F2 in the movement direction (arrow AA ′ direction) of the wiper 35. It is formed in a continuous band shape. The configuration of other parts of the cleaning liquid supply member 60 is the same as that of the first embodiment shown in FIGS. 6 and 7.

  According to the configuration of the present embodiment, since the hydrophilic region F3 is formed only on a part of the cleaning liquid supply surface F2, the cleaning liquid supply member 60 can be easily processed. Further, since the cleaning liquid 23 is collected and held in the moving direction of the wiper 35 (arrow AA ′ direction), the cleaning liquid 23 is spread over the entire width direction of the cleaning liquid supply surface F2 even if the supply amount of the cleaning liquid 23 is reduced. Becomes easier to spread. Furthermore, since the cleaning liquid supply surface F2 is interposed between the hydrophilic region F3 and the ink ejection surface F1, the leakage of the cleaning liquid 23 from the hydrophilic region F3 to the ink ejection surface F1 can be prevented more reliably.

  FIG. 18 is a view of the cleaning liquid supply member 60 of the recording heads 17a to 17c according to the third embodiment of the present invention as viewed from below. In the present embodiment, as shown in FIG. 18, hydrophilic regions F3 are formed long in the moving direction (arrow AA ′ direction) of the wiper 35 at both ends in the width direction (arrow BB ′ direction) of the cleaning liquid supply surface F2. Yes. The configuration of the other parts of the cleaning liquid supply member 60 is the same as in the first and second embodiments.

  In the first and second embodiments, the cleaning liquid 23 supplied from the cleaning liquid supply port 60a becomes a large droplet as shown in FIG. Gather in the center. According to the configuration of the present embodiment, since the hydrophilic region F3 has a large area at both ends in the width direction of the cleaning liquid supply surface F2, the cleaning liquid 23 is also provided at both ends in the width direction of the cleaning liquid supply surface F2. Becomes easier to spread. Therefore, the cleaning liquid 23 can be supplied more uniformly over the entire width direction of the cleaning liquid supply surface F2 than in the first and second embodiments.

  FIG. 19 is a view of the cleaning liquid supply member 60 of the recording heads 17a to 17c according to the fourth embodiment of the present invention as viewed from below. In the present embodiment, as shown in FIG. 19, the hydrophilic region F3 is formed in a trapezoidal shape that becomes wider from the upstream side to the downstream side in the wiping direction (arrow A direction). The configuration of other parts of the cleaning liquid supply member 60 is the same as in the first to third embodiments.

  According to the configuration of the present embodiment, the cleaning liquid 23 supplied from the cleaning liquid supply port 60a is held on the upstream side (right side) of the hydrophilic region F3 immediately before the wiping operation, and is on the cleaning liquid supply surface F2. It does not spread to both ends in the width direction. Then, the cleaning liquid 23 is spread from the upstream side toward the downstream side along the shape of the hydrophilic region F <b> 3 by the wiping operation by the wiper 35. As a result, the cleaning liquid 23 can be prevented from being pushed out by the wiper 35 to the outside in the width direction of the cleaning liquid supply surface F2 immediately after the start of the wiping operation, and the cleaning liquid 23 can be used for cleaning the ink discharge surface F1 without waste. can do.

  FIG. 20 is a view of the cleaning liquid supply member 60 of the recording heads 17a to 17c according to the fifth embodiment of the present invention as viewed from below, and FIG. 21 shows the cleaning in the recording heads 17a to 17c of the fifth embodiment. It is the figure which looked at a mode that the liquid 23 was hold | maintained by the cleaning liquid supply surface F2 from the wiping direction downstream of the wiper 35. FIG. In the present embodiment, as shown in FIG. 20, three independent hydrophilic regions F31, F32, and F33 are formed along the width direction (arrow BB ′ direction) of the cleaning liquid supply surface F2. The configuration of other parts of the cleaning liquid supply member 60 is the same as in the first to fourth embodiments.

  According to the configuration of the present embodiment, the three hydrophilic regions F31 to F33 are independently formed in the width direction of the cleaning liquid supply surface F2, thereby being supplied from the cleaning liquid supply port 60a as shown in FIG. The cleaning liquid 23 is divided and held in hydrophilic regions F31 to F33. Thereby, as shown in FIG. 12, the cleaning liquid 23 is not biased and held in the center in the width direction, and the cleaning liquid 23 can be supplied substantially uniformly throughout the entire width direction.

  FIG. 22 is a view of the cleaning liquid supply member 60 of the recording heads 17a to 17c according to the sixth embodiment of the present invention as viewed from below. In the present embodiment, as in the fifth embodiment, three independent hydrophilic regions F31, F32, and F33 are formed along the width direction (arrow BB ′ direction) of the cleaning liquid supply surface F2. Further, the hydrophilic region F32 at the center in the width direction is formed to be shifted to the upstream side (right side in FIG. 22) in the wiping direction, and the hydrophilic regions F31 and F33 at both ends in the width direction are located downstream in the wiping direction (see FIG. 22 on the left side). The configuration of other parts of the cleaning liquid supply member 60 is the same as in the first to fifth embodiments.

  According to the configuration of the present embodiment, since the cleaning liquid 23 is divided and held in the hydrophilic regions F31 to F33 as in the fifth embodiment, the cleaning liquid 23 is supplied substantially uniformly throughout the entire width direction. Can do. Further, since the hydrophilic region F32 at the center in the width direction is shifted to the upstream side in the wiping direction and the hydrophilic regions F31 and F33 at both ends in the width direction are shifted to the downstream side in the wiping direction, the wiping operation by the wiper 35 causes the cleaning liquid. 23 is expanded from the hydrophilic region F32 toward the hydrophilic regions F31 and F33. As a result, as in the fourth embodiment, the cleaning liquid 23 can be prevented from being pushed out by the wiper 35 to the outside in the width direction of the cleaning liquid supply surface F2 immediately after the start of the wiping operation. It can be used without waste for cleaning F1.

  In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the cleaning liquid supply member 60 having the cleaning liquid supply port 60a is provided as an example separate from the head unit 18, but the present invention is not limited thereto. The cleaning liquid supply member 60 may be provided in the head unit 18 without providing the cleaning liquid supply member 60. Further, the arrangement and pitch of the cleaning liquid supply ports 60a can be arbitrarily set.

  In the fifth and sixth embodiments, the three hydrophilic regions F31 to F33 are formed along the width direction of the cleaning liquid supply surface F2. However, two or four or more hydrophilic regions are independently provided. May be formed.

  Further, in each of the above embodiments, the cleaning liquid supply operation is illustrated as an example performed before the wiping operation. However, if the wiper 35 is before entering the hydrophilic region F3, the cleaning liquid supply operation may be performed simultaneously with the wiping operation. Good.

17a to 17c Recording head 18a Ink discharge nozzle 23 Cleaning liquid 35 Wiper 60 Cleaning liquid supply member 60a Cleaning liquid supply port 100 Inkjet recording apparatus F1 Ink discharge surface F2 Cleaning liquid supply surface F3, F31, F32, F33 Hydrophilic region R1 Nozzle region S paper (recording medium)

Claims (10)

A recording head having an ink ejection surface including a nozzle region in which a plurality of ink ejection nozzles that eject ink onto a recording medium are opened,
On the upstream side of the wiping direction, which is the direction in which the wiper wipes the ink ejection surface with respect to the nozzle region, a cleaning liquid supply surface is provided in which a plurality of cleaning liquid supply ports for supplying the cleaning liquid are opened.
On the cleaning liquid supply surface, in a region including at least the cleaning liquid supply port, a hydrophilic region having high wettability to water compared to the ink discharge surface is substantially uniform over the entire width direction perpendicular to the wiping direction. A recording head characterized in that the recording head is formed.   The said hydrophilic area | region is formed in the area | region including the said cleaning liquid supply port of the said cleaning liquid supply surface in the said wiping direction in the strip | belt shape continuous over the said width direction whole region. Recording head.   The recording head according to claim 2, wherein the hydrophilic region is formed at a predetermined interval from the ink ejection surface.   4. The recording head according to claim 2, wherein the hydrophilic region is formed long in the wiping direction at both end portions in the width direction of the cleaning liquid supply surface. 5.   The recording head according to claim 2, wherein the hydrophilic region is formed in a trapezoidal shape that becomes wider from the upstream side to the downstream side in the wiping direction.   The recording head according to claim 1, wherein a plurality of independent hydrophilic regions are formed on the cleaning liquid supply surface along a width direction of the cleaning liquid supply surface.   Among the plurality of hydrophilic regions, the hydrophilic region located at the center in the width direction of the cleaning liquid supply surface is formed to be shifted to the upstream side in the wiping direction, and both ends in the width direction of the cleaning liquid supply surface The recording head according to claim 6, wherein the hydrophilic region located in the portion is formed to be shifted downstream in the wiping direction.   The recording head according to claim 1, wherein a contact angle of the hydrophilic region with respect to water is less than 90 °.   The cleaning liquid supply surface is formed on a cleaning liquid supply member disposed adjacent to the ink discharge surface, the contact angle of the ink discharge surface with respect to water is θ1, and the contact angle of the cleaning liquid supply member with respect to water. The recording head according to claim 1, wherein θ1> θ2> θ3, where θ2 is θ2 and a contact angle of the hydrophilic region with respect to water is θ3.   An ink jet recording apparatus comprising the recording head according to claim 1.