JP2018153956A - Head cleaning mechanism and ink-jet recording device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head cleaning mechanism capable of cleaning an ink discharge surface while suppressing a wiper from being damaged, and suppressing ink or cleaning liquid adhering to a recording head from adhering or dropping to a recording medium by coming contact with the recording medium.SOLUTION: A head cleaning mechanism includes a recording head including an ink discharge surface, and a wiper wiping the ink discharge surface. The recording head includes an inclined plane 62 arranged at an upstream side in the wiping direction to the ink discharge surface. The inclined plane 62 has a cleaning liquid supply port 60a which is arranged at an upstream side in the wiping direction than a pressure-welding start position Ps in which pressure-welding with the wiper is started in wiping operation, and supplies cleaning liquid, and a water-repellent region R10 which is provided from a position P1 at an upstream side in the wiping direction than the pressure-welding start position Ps to a position P2 at a downstream side.SELECTED DRAWING: Figure 5

Description

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

  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 port, the straightness of the ink (flying curve), non-ejection, etc. occur and the print performance of the recording head decreases.

  Therefore, in order to clean the ink discharge surface of the recording head, a cleaning liquid supply port is provided outside the ink discharge region (upstream in the wiping direction of the wiper) where a plurality of ink discharge ports of the ink discharge surface open. An ink jet recording apparatus provided with a plurality of ink jets is known. 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.

  An ink jet recording apparatus in which a plurality of cleaning liquid supply ports are provided on the ink discharge surface of the recording head is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-151867.

JP 2007-83396 A

  However, the above-described conventional ink jet recording apparatus has a problem in that the wiper passes over the cleaning liquid supply port every time the recovery process of the recording head is performed, and the edge of the cleaning liquid supply port causes a scratch on the tip of the wiper. . In addition, when the damage | wound of the tip of a wiper becomes large and a chip | tip arises in the tip of a wiper, the wiping performance of a wiper will fall remarkably and wiping will arise.

  In the conventional ink jet recording apparatus, the wiper is pressed against the ink discharge surface so that the amount of wiper biting (overlap amount) with respect to the ink discharge surface is about 1 mm. For this reason, when the wiper is brought into pressure contact with the ink ejection surface perpendicularly, a load when the wiper is brought into pressure contact with the ink ejection surface becomes large.

  Therefore, a method is conceivable in which the wiper is raised at a position upstream of the ink discharge surface in the wiping direction, and the wiper is moved in the horizontal direction (wiping direction) from that position. As a result, the tip of the wiper is pressed against the ink discharge surface while being bent in the direction opposite to the wiping direction, and it is possible to suppress an increase in load when the wiper is pressed against the ink discharge surface.

  However, in this method, when the wiper comes in contact with the side surface of the recording head by moving the wiper in the wiping direction, the ink or cleaning liquid adhering to the tip of the wiper is removed from the corner portion (side surface and ink) of the recording head. The ink and the cleaning liquid adhere to the corners of the recording head. In the next wiping operation, ink and cleaning liquid further adhere. When this is repeated and the ink and cleaning liquid gradually increase, there is a problem that the ink or cleaning liquid contacts the recording medium and adheres to the recording medium or falls to the recording medium or the recording medium transport unit. .

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to clean the ink ejection surface while adhering to the recording head while suppressing damage to the wiper. It is an object of the present invention to provide a head cleaning mechanism capable of suppressing ink or cleaning liquid from adhering to or dropping from a recording medium due to contact with the recording medium, and an ink jet recording apparatus including the head cleaning mechanism.

  In order to achieve the above object, a head cleaning mechanism according to a first aspect of the present invention includes a recording medium including an ink discharge surface provided with an ink discharge region in which a plurality of ink discharge ports for discharging ink are opened on a recording medium. A head and a wiper for wiping the ink discharge surface in a predetermined direction. The recording head is disposed on the upstream side in the wiping direction, which is the direction in which the wiper wipes the ink ejection surface with respect to the ink ejection surface, and is inclined downward toward the downstream side in the wiping direction. It includes an inclined surface to be pressed. The inclined surface is arranged on the upstream side in the wiping direction from the press-contact start position where the press-contact by the wiper is started during the wiping operation, and has a plurality of cleaning liquid supply ports for supplying the cleaning liquid and the upstream in the wiping direction from the press-start position. And a water repellent region having a contact angle with respect to water of 90 ° or more.

  According to the head cleaning mechanism of the first aspect of the present invention, the recording head is disposed on the upstream side in the wiping direction with respect to the ink ejection surface, and includes an inclined surface that is inclined downward toward the downstream side in the wiping direction. The inclined surface has a plurality of cleaning liquid supply ports for supplying the cleaning liquid. Accordingly, when the cleaning liquid is supplied from the cleaning liquid supply port, the cleaning liquid flows on the inclined surface toward the downstream side in the wiping direction. After the cleaning liquid reaches the downstream end of the inclined surface, the ink discharge surface can be wiped while holding the cleaning liquid by the wiper by moving the wiper along the ink discharge surface from the pressure contact start position of the inclined surface. For this reason, the ink discharge surface can be cleaned.

  In addition, a cleaning liquid supply port is provided on the upstream side in the wiping direction from the pressure contact start position of the inclined surface. Thus, when performing the recovery operation of the recording head, the wiper does not contact the edge of the cleaning liquid supply port. For this reason, since the tip of the wiper does not rub against the edge of the cleaning liquid supply port, damage to the tip of the wiper can be suppressed.

  Further, by providing the water repellent region on the inclined surface, it is possible to suppress the cleaning liquid supplied from the cleaning liquid supply port and flowing through the inclined surface toward the downstream end from staying in the inclined surface.

  In addition, by raising the wiper below the inclined surface and moving the wiper in the wiping direction from that position, the tip of the wiper is pressed against the ink ejection surface in a state of bending in the direction opposite to the wiping direction. Unlike the case where the wiper is pressed against the ink discharge surface perpendicularly, it is possible to suppress an increase in load when the wiper is pressed against the ink discharge surface.

  Further, the inclined surface is provided from the upstream position in the wiping direction to the downstream position with respect to the pressing start position, and has a water repellent region having a contact angle with water of 90 ° or more. As a result, the ink or cleaning liquid adhered (moved) from the wiper to the inclined surface during the wiping operation flows on the inclined surface to a position downstream in the wiping direction from the press contact start position. The ink or cleaning liquid that has flowed on the inclined surface is wiped off by the wiper during the next wiping operation. For this reason, since it can suppress that the ink and cleaning liquid on the surface of a recording head increase gradually, it adheres to a recording medium when an ink or cleaning liquid contacts a recording medium, or a recording medium or a recording medium It can suppress falling to a conveyance part.

The figure which shows the structure of the inkjet recording device provided with the recording head of one Embodiment of this invention. The figure 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 View of the recording head viewed from the ink ejection surface View of the cleaning liquid supply member of the recording head as seen from diagonally below View of the cleaning liquid supply member of the recording head viewed from below The figure which shows a mode that a cleaning liquid is hold | maintained in a hydrophilic region in the vicinity of the boundary of the lower surface of a cleaning liquid supply member, and a hydrophilic region. The figure which shows the structure of a cleaning liquid supply member The figure which shows the state which is moving to the arrow A direction in the state in which the wiper was press-contacted to the ink discharge surface The figure which shows the state which the wiper is moving to the arrow A direction in the state pressed against the inclined surface of the cleaning liquid supply member The figure which shows the state which has arrange | positioned the wipe unit under the recording part The figure which shows the state in which the cleaning liquid supplied from the cleaning liquid supply port is flowing toward the downstream of the wiping direction on the inclined surface The figure which shows the state by which the cleaning liquid supplied from the cleaning liquid supply port is hold | maintained in the hydrophilic region The figure which shows the state which has arrange | positioned the wiper under the recording head The figure which shows the state which lifted the wiper from the state of FIG. 14, and was press-contacted to the cleaning liquid supply member The figure 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 figure which shows the state which pressed the wiper to the inclined surface, when the ink and cleaning liquid which adhered to the front-end | tip part of the wiper at the time of the last wiping operation | movement remain. The figure 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. 18 is a view showing a state where the wiper is further moved in the direction of arrow A in a state where the wiper is pressed against the cleaning liquid supply member from the state of FIG. The figure which shows the state which moved the wiper to the arrow A direction further from the state of FIG. 20 is a diagram illustrating a state where the wiper is further moved in the direction of arrow A from the state of FIG. 20 and then the wiper is lowered and separated from the ink discharge surface. The figure which looked at the cleaning liquid supply member of the recording head of the 1st modification of this invention from diagonally downward. FIG. 7 is a diagram of a recording liquid cleaning member for a recording head according to a second modification of the present invention as viewed obliquely from below.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a paper feed tray 2 for storing paper S (recording medium) is provided on the left side of the ink jet recording apparatus 100 according to an embodiment of the present invention. In this case, the accommodated sheets S are conveyed one by one from the uppermost sheet S one by one to a first conveying unit 5 to be described later, and the sheet feeding roller 3 is in pressure contact with the sheet feeding roller 3 and is driven to rotate. A driven roller 4 is provided.

  A first transport unit 5 and a recording unit 9 are disposed 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. The first driving roller 6 is driven to rotate in the clockwise direction by a control signal from the control unit 110 that controls the entire recording apparatus 100, whereby the sheet S held on the first conveying belt 8 is conveyed in the arrow X direction. The

  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. The recording head 17 is composed of one or more (in this case, one) recording heads 17 extending along the orthogonal sheet width direction (vertical direction in FIG. 2).

  As shown in FIGS. 3 and 4, an ink discharge region R1 in which a large number of ink discharge ports 18a (see FIG. 2) are arranged is formed on the ink discharge surface F1 of the head portion (ink discharge head portion) 18 of the recording head 17. Is provided. Note that at least the ink discharge surface F1 of the head portion 18 is formed of, for example, SUS (stainless steel). The ink discharge surface F1 is subjected to water repellent treatment by applying a fluorine-based or silicon-based water repellent, and here has a contact angle with water of 113 °.

  In the recording heads 17 constituting the line heads 11C to 11K, inks of four colors (cyan, magenta, yellow, and black) stored in ink tanks (not shown) are provided for the respective colors of the line heads 11C to 11K. To be supplied.

  Each recording head 17 is directed to the sheet S conveyed by being held by suction on the conveying surface of the first conveying 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 port 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 head 17 is provided with a cleaning liquid supply member (cleaning liquid supply head section) 60 for supplying a cleaning liquid. The cleaning liquid supply member 60 is disposed adjacent to the head portion 18 on the upstream side in the wiping direction of the wiper 35 described later (the right side in FIG. 3). The cleaning liquid supply member 60 has an inclined surface 62 inclined downward toward the downstream side in the wiping direction, and a downstream end 62a (lower end in FIG. 3) of the inclined surface 62 in the wiping direction toward the ink ejection surface F1. And an extending lower surface F2. The lower surface F2 is disposed substantially parallel to the ink ejection surface F1.

  The inclined surface 62 includes a cleaning liquid supply region R2 in which a large number of cleaning liquid supply ports 60a (see FIG. 5) for supplying a cleaning liquid are arranged. The cleaning liquid supply member 60 is made of, for example, resin or SUS. The detailed structure of the cleaning liquid supply member 60 will be described later.

  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 wipe unit 19 and a cap unit 90 are disposed below the second transport unit 12. When performing a wiping operation (wiping operation) by a wiper 35 to be described later, the first transport unit 5 is lowered, and the wipe unit 19 is moved below the recording unit 9 from the ink discharge port 18a of the recording head 17. The ink discharged forcibly and the cleaning liquid supplied from the cleaning liquid supply port 60a are wiped off, and the wiped ink and cleaning liquid are collected. When capping the ink ejection surface F1 (see FIG. 3) of the recording head 17, the first transport unit 5 is lowered, and the cap unit 90 is moved horizontally below the recording unit 9 and further moved upward. Mounted on the lower surface of the recording head 17.

  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 is recorded to the outside of the apparatus main body is provided. Is provided with a discharge tray (not shown) on which the sheets S discharged outside the apparatus main body are stacked.

  The wipe unit 19 supports a plurality of wipers 35 (see FIG. 9) movable 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 by a support frame (not shown) so as to be slidable in the direction of arrow AA ′.

  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 port 60a (see FIG. 5) of each recording head 17. The wiper 35 is pressed against a cleaning liquid supply region R2 (see FIG. 4) on the inclined surface 62 of the cleaning liquid supply member 60 at a predetermined position (pressure contact start position Ps (see FIG. 5)) on the downstream side in the wiping direction. Then, the lower surface F2 and the ink discharge surface F1 are wiped in a predetermined direction (arrow A direction) by moving a carriage (not shown). The wiper unit 19 including the wiper 35 and the recording head 17 constitute a head cleaning mechanism.

  Next, the structure of the cleaning liquid supply member 60 will be described in detail.

  As shown in FIGS. 5 and 6, the cleaning liquid supply port 60 a is provided above the pressure contact start position Ps of the inclined surface 62 where pressure contact by the wiper 35 is started during the wiping operation (upstream in the wiping direction). It has been. In the figure, the press-contact start position Ps is hatched for easy understanding. A plurality of cleaning liquid supply ports 60a are arranged at a predetermined pitch in the head width direction (arrow BB ′ direction) orthogonal to the wiping direction (arrow A direction). In the figure, only one row of a plurality of cleaning liquid supply ports 60a arranged along the head width direction is drawn, but this row is provided adjacent to the wiping direction (arrow A direction). It may be done.

  The inclined surface 62 is provided with a water repellent region R10 from a position P1 on the upstream side (right side in FIG. 6) in the wiping direction to a position P2 on the downstream side of at least the pressure contact start position Ps. In the figure, the water-repellent region R10 is hatched for easy understanding. In the present embodiment, the water repellent region R10 has a downstream end 62a in the wiping direction of the inclined surface 62 from the upstream side position P1 in the wiping direction with respect to the cleaning liquid supply port 60a (a connecting portion between the inclined surface 62 and the lower surface F2, It is formed up to the downstream position P2). The water repellent region R10 is formed over the entire area of the inclined surface 62 in the head width direction (arrow BB ′ direction).

  Examples of the method of forming the water repellent region R10 include a method of applying a fluorine-based or silicon-based water repellent to the region where the water repellent region R10 is formed. The contact angle of the water repellent region R10 with respect to water is 90 ° or more (here 95 °).

  Further, a hydrophilic region R11 is provided in the vicinity of the downstream end 62a in the wiping direction of the inclined surface 62 and on the downstream side in the wiping direction of the water repellent region R10. In the figure, the hydrophilic region R11 is hatched for easy understanding. The hydrophilic region R11 is formed so as to have higher wettability with respect to water than other portions of the cleaning liquid supply member 60 (for example, the water repellent region R10 and the lower surface F2). In the present embodiment, the hydrophilic region R11 is provided on the lower surface F2, and is formed with a predetermined length from the connecting portion (downstream end 62a) between the inclined surface 62 and the lower surface F2 toward the downstream side in the wiping direction. ing. The hydrophilic region R11 may be provided on the inclined surface 62 as long as it is in the vicinity of the downstream end 62a.

  The hydrophilic region R11 is formed so as to extend in the head width direction (arrow BB ′ direction). Further, the hydrophilic region R11 is formed in a strip shape that is continuous over substantially the entire region in the head width direction in the vicinity of the downstream end 62a. Thereby, as will be described later, when the cleaning liquid is supplied from the cleaning liquid supply port 60a to the inclined surface 62, the cleaning liquid flows on the inclined surface 62 downstream in the wiping direction (left side in FIGS. 5 and 6). When it reaches the hydrophilic region R11, it spreads wet in the head width direction.

  Examples of the method of forming the hydrophilic region R11 include a method of applying a hydrophilic coating agent to the region of forming the hydrophilic region R11 or a method of roughening the surface. Examples of hydrophilic coating agents include titanium oxide and polysilicate coating agents. The contact angle with respect to water of the hydrophilic region R11 is less than 90 ° (here, 60 °), the contact angle with respect to water (here, 70 °) of the lower surface F2 (excluding the hydrophilic region R11) and the repellent property. It is smaller than the contact angle (here 95 °) with respect to water of the aqueous region R10.

  As shown in FIG. 7, when the contact angle of the hydrophilic region R11 with respect to water is 90 ° or more, the aqueous cleaning liquid 23 is stretched from the hydrophilic region R11 to the lower surface F2 side (ink ejection surface F1 side) by surface tension. (Displayed with a broken line in FIG. 7). Therefore, the cleaning liquid 23 easily flows to the lower surface F2 side (ink ejection surface F1 side) due to vibration or impact. If the cleaning liquid 23 flows to the ink ejection surface F1 when the recovery operation of the recording head 17 described later is not performed, there is a possibility that the flying property of the ink from the ink ejection nozzle 18a is adversely affected.

  On the other hand, when the contact angle of the hydrophilic region R11 with respect to water is less than 90 °, the aqueous cleaning liquid 23 does not protrude from the hydrophilic region R11 to the lower surface F2 side (ink ejection surface F1 side) (in the solid line in FIG. 7). display). Therefore, the contact angle of the hydrophilic region R11 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 R11 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 R11 to the lower surface F2 side (ink ejection surface F1 side).

  Further, as shown in FIGS. 8 and 9, in the cleaning liquid supply member 60, the inclination angle α1 (see FIG. 8) of the inclined surface 62 with respect to the ink discharge surface F1 and the lower surface F2 is wiped by the wiper 35. In this state, the wiper 35 is formed so as to be smaller than the pressure contact angle α2 (see FIG. 9) with respect to the ink discharge surface F1 of the tip of the wiper 35. Specifically, the pressure contact angle α2 with respect to the ink discharge surface F1 and the lower surface F2 at the tip of the wiper 35 is set to about 45 °. The inclination angle α1 of the inclined surface 62 with respect to the ink ejection surface F1 and the lower surface F2 is preferably set to 15 ° or more and less than 45 °, and more preferably set to 30 ° or more and less than 40 °.

  Since the inclination angle α1 is smaller than the pressure contact angle α2, as shown in FIG. 10, when the wiper 35 is moved in the wiping direction (left direction in FIG. 10), the tip of the wiper 35 is moved in the wiping direction. Only the downstream corner portion 35 a contacts the inclined surface 62. That is, the downstream side surface 35 b of the wiper 35 in the wiping direction does not contact the inclined surface 62.

  The cleaning liquid supply member 60 is connected to a tank (not shown) that stores the cleaning liquid 23 via a cleaning liquid supply path (not shown). The cleaning liquid supply path is provided with a cleaning liquid supply pump (not shown) that draws the cleaning liquid 23 from the tank and sends it to the cleaning liquid supply member 60.

  In the ink jet recording apparatus 100, in order to clean the ink discharge surface F1 of the recording head 17, ink is discharged from the ink discharge ports 18a of all the recording heads 17 at the start of printing after being stopped for a long time and between printing operations. Is forcibly discharged, and in parallel, the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a (see FIG. 5) of all the recording heads 17 to the cleaning liquid supply region R2, and the wiper 35 wipes the ink discharge surface F1. The recovery operation of the head 17 is executed to prepare for the next printing operation.

  Next, the recovery operation of the recording head 17 using the wipe unit 19 in the inkjet recording apparatus 100 of the present embodiment will be described. The recovery operation of the recording head 17 described below is executed by controlling the operations of the recording head 17, the wipe unit 19, the cleaning liquid supply pump, and the like based on a control signal from the control unit 110 (see FIG. 1). Is done.

  When performing the recovery operation of the recording head 17, first, as shown in FIG. 11, the control unit 110 (see FIG. 1) lowers the first transport unit 5 located below the recording unit 9. Then, the control unit 110 horizontally moves the wipe unit 19 disposed below the second transport unit 12 so as to be disposed between the recording unit 9 and the first transport unit 5. In this state, the wiper 35 (see FIG. 14) of the wipe unit 19 is disposed below the ink discharge surface F1 and the lower surface F2 (see FIG. 14) of the recording head 17.

(Cleaning liquid supply operation)
Prior to the wiping operation (wiping operation described later), a cleaning liquid supply pump (not shown) is driven (turned on) by a control signal from the control unit 110 (see FIG. 1), and the cleaning liquid 23 is supplied to the recording head 17. Is done. At this time, as shown in FIG. 12, the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a to the inclined surface 62 by a predetermined amount. The cleaning liquid 23 supplied to the inclined surface 62 flows on the inclined surface 62 toward the downstream side in the wiping direction (arrow A direction). Then, as shown in FIG. 13, when the cleaning liquid 23 reaches the hydrophilic region R11 provided in the vicinity of the downstream end 62a, the hydrophilic region R11 wets and spreads in the head width direction, and the lower surface F2 is substantially in the head width direction. It is held in a state of spreading over the entire area. In the figure, the cleaning liquid 23 is hatched for easy understanding.

(Ink extrusion operation)
Prior to the wiping operation (wiping operation described later), as shown in FIG. 14, the ink is supplied to the recording head 17 by the control unit 110 (see FIG. 1). The supplied ink 22 is forcibly extruded (purged) from the ink discharge port 18a. By this purging operation, thickened ink, foreign matter and bubbles in the ink discharge port 18a are discharged from the ink discharge port 18a. At this time, the purge ink 22 is pushed out to the ink discharge surface F1 along the shape of the ink discharge region R1 where the ink discharge port 18a exists. In the figure, the ink (purge ink) 22 is hatched for easy understanding.

(Wiping operation)
As shown in FIG. 15, the control unit 110 raises the wiper 35 to contact the inclined surface 62 of the cleaning liquid supply member 60 of the recording head 17 with a predetermined pressure. At this time, the wiper 35 is raised so that the upper surface of the wiper 35 is higher than the ink discharge surface F1 and the lower surface F2 and lower than the cleaning liquid supply port 60a. Thereby, the wiper 35 does not contact the cleaning liquid supply port 60a. Note that when the wiper 35 is raised, the wiper 35 may not be in pressure contact with the inclined surface 62. That is, the wiper 35 may be raised at a position on the right side of FIG.

  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 control unit 110 moves the wiper 35 along the lower surface F2 in the direction of the ink discharge region R1 (direction of arrow A) as shown in FIG. Move. As a result, the wiper 35 moves in the direction of the ink ejection region R <b> 1 while holding the cleaning liquid 23.

  At this time, as shown in FIG. 17, if the ink 22a or the cleaning liquid 23a attached to the tip of the wiper 35 remains during the previous wiping operation, the ink 22a or the cleaning liquid attached to the tip of the wiper 35 is left. 23 a adheres (moves) to the press contact start position Ps of the inclined surface 62.

  Here, as shown in FIG. 10, when the wiper 35 moves below the inclined surface 62 in the wiping direction (arrow A direction), only the corner portion 35a at the tip of the wiper 35 contacts the inclined surface 62. As shown in FIG. 5, a part of the ink 22a and the cleaning liquid 23a adhering to the inclined surface 62 (a portion on the downstream side in the wiping direction from the corner portion 35a of the wiper 35) is wiped off by the wiper 35.

  Further, as shown in FIG. 18, the remaining ink 22a and cleaning liquid 23a adhering (moving) from the tip of the wiper 35 to the inclined surface 62 is moved downstream of the water repellent region R10 in the wiping direction (in the direction of arrow A, downward). To the side).

  Thereafter, as shown in FIG. 19, the ink 22a and the cleaning liquid 23a that have flowed through the water-repellent region R10 reach the hydrophilic region R11 and are held wet and spread throughout the entire hydrophilic region R11. The ink 22a and the cleaning liquid 23a held in the hydrophilic region R11 are wiped off by the wiper 35 at the next wiping operation.

  After the state shown in FIG. 16, the wiper 35 moves the ink ejection surface F1 leftward (arrow A direction) while maintaining the state where the cleaning liquid 23 and the purge ink 22 are held, as shown in FIG. 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 a position opposite to the cleaning liquid supply member 60 with respect to the ink ejection region R1. 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 wipe unit 19.

(Separation operation)
After executing the wiping operation, as shown in FIG. 21, the control unit 110 lowers the wiper 35 and separates it from the ink ejection surface F1.

  Finally, the control unit 110 horizontally moves the wipe unit 19 disposed between the recording unit 9 and the first transport unit 5 and disposes the first transport unit 5 below the second transport unit 12. Raise to the position. In this way, the recovery operation of the recording head 17 is completed.

  In the present embodiment, as described above, the recording head 17 includes the inclined surface 62 that is disposed on the upstream side in the wiping direction with respect to the ink ejection surface F1 and is inclined downward toward the downstream side in the wiping direction. The surface 62 has a plurality of cleaning liquid supply ports 60 a for supplying the cleaning liquid 23. Accordingly, when the cleaning liquid 23 is supplied from the cleaning liquid supply port 60a, the cleaning liquid 23 flows on the inclined surface 62 toward the downstream side in the wiping direction. After the cleaning liquid 23 reaches the downstream end 62a of the inclined surface 62, the wiper 35 is moved from the pressure contact start position Ps of the inclined surface 62 along the ink discharge surface F1, thereby holding the cleaning liquid 23 with the wiper 35. The ink discharge surface F1 can be wiped. For this reason, the ink discharge surface F1 can be cleaned.

  Further, a cleaning liquid supply port 60a is provided on the upstream side in the wiping direction from the pressure contact start position Ps of the inclined surface 62. Accordingly, when performing the recovery operation of the recording head 17, the wiper 35 does not contact the edge of the cleaning liquid supply port 60a. For this reason, since the tip of the wiper 35 does not rub against the edge of the cleaning liquid supply port 60a, the tip of the wiper 35 can be prevented from being damaged.

  Further, by providing the water repellent region R10 on the inclined surface 62, the cleaning liquid 23 supplied from the cleaning liquid supply port 60a and flowing through the inclined surface 62 toward the downstream end 62a in the wiping direction stays in the middle of the inclined surface 62. Can be suppressed.

  Further, the wiper 35 is lifted below the inclined surface 62, and the wiper 35 is moved in the wiping direction from that position, whereby the tip of the wiper 35 is bent in the direction opposite to the wiping direction to the ink ejection surface F1. Since the pressure contact is made, unlike the case where the wiper 35 is pressed perpendicularly to the ink discharge surface F1, it is possible to suppress an increase in load when the wiper 35 is pressed against the ink discharge surface F1.

  The inclined surface 62 has a water-repellent region R10 that is provided from the upstream position P1 in the wiping direction to the downstream position P2 with respect to the press contact start position Ps, and has a contact angle with water of 90 ° or more. As a result, the ink 22a and the cleaning liquid 23a adhering (moving) from the wiper 35 to the inclined surface 62 during the wiping operation flow through the inclined surface 62 to a position P2 on the downstream side in the wiping direction from the pressing start position Ps. The ink 22a and the cleaning liquid 23a that have flowed through the inclined surface 62 are wiped off by the wiper 35 during the next wiping operation. For this reason, since the ink 22a and the cleaning liquid 23a on the surface of the recording head 17 can be suppressed from gradually increasing, the ink 22a and the cleaning liquid 23a are attached to the paper S when they contact the paper S, It is possible to suppress the sheet S or the sheet S from being dropped onto the conveyance unit.

  Further, as described above, the water repellent region R10 is provided from the position P1 upstream of the cleaning liquid supply port 60a in the wiping direction to the position P2 downstream of the pressure contact start position Ps in the wiping direction. As a result, the cleaning liquid 23 supplied from the cleaning liquid supply port 60a can easily flow to the position P2 on the downstream side in the wiping direction from the press contact start position Ps.

  As described above, the water repellent region R10 is provided from the upstream position P1 in the wiping direction to the downstream end 62a of the inclined surface 62 from the press contact start position Ps. As a result, the cleaning liquid 23 supplied from the cleaning liquid supply port 60 a and flowing through the inclined surface 62 can easily flow to the downstream end 62 a of the inclined surface 62.

  Further, as described above, the water-repellent region R <b> 10 is provided in substantially the entire region of the inclined surface 62 in the head width direction. Accordingly, the ink 22a and the cleaning liquid 23a attached to both ends of the inclined surface 62 in the head width direction from the wiper 35 during the wiping operation can also flow toward the downstream side in the wiping direction.

  Further, as described above, the hydrophilic region R11 having a contact angle with respect to water of less than 90 ° is located near the downstream end 62a of the inclined surface 62 and downstream of the water repellent region R10 in the wiping direction. It is formed to extend in the width direction. Thereby, the cleaning liquid 23 supplied from the cleaning liquid supply port 60a and flowing to the downstream end 62a of the inclined surface 62 wets and spreads in the hydrophilic region R11 in the head width direction. For this reason, it is possible to shorten the time from the start of wiping the cleaning liquid 23 by the wiper 35 until the cleaning liquid 23 spreads over the entire area of the recording head 17 in the head width direction, and therefore, at both ends of the ink discharge surface F1 in the head width direction. The occurrence of unwiping can be suppressed.

  In addition, since the cleaning liquid 23 supplied from the cleaning liquid supply port 60a is spread and held along the hydrophilic region R11, the cleaning liquid 23 gathers at the center in the head width direction (arrow BB ′ direction) and is a large liquid. It can be suppressed that the liquid drops and drops from the cleaning liquid supply member 60. Thereby, the loss of the cleaning liquid 23 can be reduced.

  Further, the ink 22a and the cleaning liquid 23a that adhere (move) to the inclined surface 62 from the wiper 35 and flow to the downstream end 62a of the inclined surface 62 during the wiping operation spread out in the hydrophilic region R11. It is possible to suppress sagging. For this reason, it is possible to further suppress the ink 22a and the cleaning liquid 23a from adhering to the paper S due to contact with the paper S.

  Further, since the ink 22a and the cleaning liquid 23a attached (moved) from the wiper 35 to the inclined surface 62 during the wiping operation are spread and held along the hydrophilic region R11, the ink 22a and the cleaning liquid 23a are moved in the head width direction (arrows). It can be suppressed that the liquid drops gather from the central portion in the BB ′ direction and become large droplets and fall from the cleaning liquid supply member 60.

  Further, as described above, the hydrophilic region R11 is formed in substantially the entire head width direction in the vicinity of the downstream end 62a. Accordingly, it is possible to easily reduce the time from the start of wiping the cleaning liquid 23 with the wiper 35 until the cleaning liquid 23 spreads over the entire area of the recording head 17 in the head width direction. It is possible to easily suppress the occurrence of unwiping in the part.

  Further, since the hydrophilic region R11 is formed in substantially the entire region in the head width direction in the vicinity of the downstream end 62a, the both ends of the inclined surface 62 in the head width direction are attached (moved) from the wiper 35 to the inclined surface 62 during the wiping operation. The ink 22a and the cleaning liquid 23a that have flowed through the nozzle can reliably reach the hydrophilic region R11.

  Further, as described above, the recording head 17 includes the head portion 18 having the ink discharge surface F1, and the cleaning liquid supply member 60 having the inclined surface 62 and the lower surface F2. Thereby, compared with the case where the inclined surface 62 is formed in the head part 18, the inclined surface 62 can be formed easily.

  Further, since the ink passage path and the cleaning liquid passage path in the recording head 17 can be formed on separate members (the head portion 18 and the cleaning liquid supply member 60), the structure of the recording head 17 is prevented from being complicated. can do.

  Further, as described above, the inclination angle α1 of the inclined surface 62 with respect to the ink ejection surface F1 is greater than the pressure contact angle α2 with respect to the ink ejection surface F1 at the tip of the wiper 35 in the state where the wiper 35 wipes the ink ejection surface F1. Is also small. Accordingly, when the wiper 35 moves in the wiping direction in a state where the wiper 35 is in pressure contact with the inclined surface 62 of the recording head 17, the wiper 35 does not bend more than the pressure contact angle α2 with respect to the ink ejection surface F1, and therefore the wiper 35 is only the corner portion 35a. Moves while contacting the inclined surface 62. That is, the side surface 35 b of the wiper 35 does not contact the side surface (the inclined surface 62) of the recording head 17. For this reason, it is possible to suppress the cleaning liquid 23, the ink 22 a, and the cleaning liquid 23 a from remaining on the inclined surface 62.

  As described above, the inclination angle α1 is not less than 15 ° and less than 45 °. Accordingly, the cleaning liquid 23, the ink 22a, and the cleaning liquid 23a can be easily flowed toward the downstream end 62a of the inclined surface 62, and only the corner portion 35a at the tip of the wiper 35 is easily in contact with the inclined surface 62. Can be made.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the cleaning liquid supply member 60 in which the inclined surface 62 and the cleaning liquid supply port 60a are formed is provided separately from the head portion 18 is shown, but the present invention is not limited to this. The inclined surface 62 and the cleaning liquid supply port 60a may be formed in the head portion 18 without providing the cleaning liquid supply member 60.

  In the above-described embodiment, the example in which the water-repellent region R10 is provided from the upstream position P1 in the wiping direction to the downstream side in the wiping direction from the cleaning liquid supply port 60a has been described. Not exclusively. For example, as in the first modification of the present invention shown in FIG. 22, the water-repellent region R10 is positioned downstream of the cleaning liquid supply port 60a in the wiping direction and upstream of the pressure contact start position Ps in the wiping direction. To the downstream side in the wiping direction. Further, for example, the water repellent region R <b> 10 may be provided over the entire inclined surface 62 as in the second modification of the present invention illustrated in FIG. 23.

  In the above-described embodiment, the hydrophilic region R11 is illustrated as an example in which the hydrophilic region R11 is formed in a continuous belt shape in the vicinity of the downstream end 62a over substantially the entire region in the head width direction, but the present invention is not limited to this. For example, a plurality of hydrophilic regions R11 may be provided independently (divided) in the head width direction. If comprised in this way, it can suppress easily that the cleaning liquid 23, the ink 22a, and the cleaning liquid 23a gather in the center part of a head width direction (arrow BB 'direction). A plurality of hydrophilic regions R11 may be provided adjacent to the wiping direction. Moreover, you may form hydrophilic region R11 in shapes other than rectangular shape (band | belt shape).

  In the above embodiment, an example in which the recovery operation of the recording head 17 is performed using the cleaning liquid 23 and the ink (purge ink) 22 has been described. However, the recovery operation of the recording head 17 is performed using only the cleaning liquid 23. Also good. That is, it is not necessary to perform the ink pushing operation.

  Further, a configuration obtained by appropriately combining the configurations of the above-described embodiment and modification examples is also included in the technical scope of the present invention.

17 Recording Head 18 Head (Ink Ejection Head)
18a Ink discharge port 22, 22a Ink 23, 23a Cleaning liquid 35 Wiper 60 Cleaning liquid supply member (cleaning liquid supply head)
60a Cleaning liquid supply port 62 Inclined surface 62a Downstream end 100 Inkjet recording apparatus F1 Ink discharge surface F2 Lower surface P1 Upstream position P2 Downstream position Ps Pressure start position R1 Ink discharge region R10 Water repellent region R11 Hydrophilic region S Paper ( recoding media)
α1 Inclination angle α2 Pressure contact angle

Claims (10)

A recording head including an ink ejection surface provided with an ink ejection area in which a plurality of ink ejection openings for ejecting ink are opened on a recording medium;
A wiper for wiping the ink ejection surface in a predetermined direction;
With
The recording head is disposed on the upstream side in the wiping direction, which is the direction in which the wiper wipes the ink ejection surface with respect to the ink ejection surface, and is inclined downward toward the downstream side in the wiping direction, and also has a wiping operation. Including an inclined surface to which the tip of the wiper is sometimes pressed,
The inclined surface is
A plurality of cleaning liquid supply ports that are arranged on the upstream side in the wiping direction from a pressing start position at which the pressing by the wiper is started at the time of the wiping operation;
A water-repellent region provided from the upstream position in the wiping direction to the downstream position with respect to the pressure contact start position, and a contact angle with respect to water of 90 ° or more;
A head cleaning mechanism comprising:   The head cleaning mechanism according to claim 1, wherein the water-repellent region is provided at least from the cleaning liquid supply port to a position downstream in the wiping direction.   3. The head cleaning mechanism according to claim 1, wherein the water repellent region is provided from a position on the upstream side to a downstream end of the inclined surface in the wiping direction.   4. The head cleaning mechanism according to claim 1, wherein the water repellent region is provided in a substantially entire region in a head width direction orthogonal to the wiping direction of the inclined surface.   Near the downstream end of the inclined surface in the wiping direction and downstream of the water repellent region in the wiping direction, a hydrophilic region having a water contact angle of less than 90 ° is orthogonal to the wiping direction. The head cleaning mechanism according to claim 1, wherein the head cleaning mechanism is formed so as to extend in a head width direction.   The head cleaning mechanism according to claim 5, wherein the hydrophilic region is formed in substantially the entire region in the head width direction in the vicinity of the downstream end. The recording head is
An ink discharge head portion having the ink discharge surface;
A cleaning liquid supply head section having the inclined surface and a lower surface extending from the downstream end of the inclined surface in the wiping direction toward the ink ejection surface;
The head cleaning mechanism according to claim 1, comprising:   The inclination angle of the inclined surface with respect to the ink discharge surface is smaller than a pressure contact angle with respect to the ink discharge surface of a tip portion of the wiper in a state where the wiper wipes the ink discharge surface. The head cleaning mechanism according to any one of 1 to 7.   The head cleaning mechanism according to claim 8, wherein the inclination angle is 15 ° or more and less than 45 °.   An ink jet recording apparatus comprising the head cleaning mechanism according to claim 1.

Images