JP6308113B2 - RECOVERY SYSTEM OF PRINT HEAD, INKJET RECORDING DEVICE EQUIPPED WITH THE SAME, AND RECOVERY METHOD OF RECORD HEAD - Google Patents

Description

  The present invention relates to an inkjet recording apparatus that performs recording by ejecting ink onto a recording medium such as paper, and in particular, purge ink that adheres to an ink ejection surface after forcibly ejecting ink from ejection nozzles of a recording head. The present invention relates to a recording head recovery system for wiping off a recording head with a wiper, an ink jet recording apparatus including the recording head recovery method, and a recording head recovery method.

  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, there is a case where the straight performance of the ink is deteriorated (flying bending), non-ejection, etc., and the printing performance of the recording head is deteriorated. This may be caused by foreign matters such as paper dust, dust, and dust generated during conveyance of the paper (recording medium), minute ink droplets (hereinafter referred to as mist) ejected together with ink droplets for image recording, The occurrence of meniscus abnormality due to the rebound mist generated when the ink droplets adhere to the recording medium adhere to the ink discharge surface of the recording head can be considered. Further, it is conceivable that the sealing performance is lowered when the cap is attached due to the mist adhering to the place where the cap is attached and drying, and the viscosity of the ink in the nozzle is increased accordingly.

  Therefore, in order to prevent ink from being dried in the discharge nozzles with openings on the ink discharge surface of the recording head and clogging of the nozzles due to thickening of the ink in the discharge nozzles, the ink is forced out of the nozzles. A configuration is used in which, after (purging), the purge ink adhering to the ink ejection surface (nozzle surface) is wiped with a wiper to perform a recovery process of the recording head.

  For example, a method of wiping the ink discharge surface by bringing a wiper into contact with a portion of the ink discharge surface of the recording head without a nozzle at a predetermined contact pressure is known. Specifically, as shown in FIG. 30A, the wiper 103 is pressed substantially perpendicularly onto an area (wiping start position) outside the nozzle area 102 where the ejection nozzles are arranged on the ink ejection surface 101a of the recording head 101. Next, the wiper 103 is moved horizontally in the direction of arrow A along the ink discharge surface 101a as shown in FIGS. 30B and 30C to wipe off the ink 104 in the nozzle region 102, and the wiper 103 is removed from the ink discharge surface as shown in FIG. 30D. After separating from 101a, it is returned to the wiping start position by horizontally moving in the direction of arrow A '.

  However, in the method shown in FIGS. 30A to 30D, as shown in FIG. 31A, the inks 104a and 104b are attached to the side surface and the tip of the wiper 103 at the second wiping. The inks 104a and 104b adhering to the side surface and the tip of the wiper 103 are thickened by contact with air and adhere to the ink ejection surface 101a as shown in FIGS. 31B and 31C.

  By repeating the wiping operation as described above, the ink 104b gradually accumulates in the vicinity of the wiping start position, resulting in a large ink reservoir. There is a disadvantage in that the ink reservoir falls on a recording medium passing under the ink discharge surface 101a or comes into contact with the print surface to be soiled.

  In order to improve this inconvenience, Patent Document 1 has two wipers that can sequentially contact the ink discharge surface of the recording head, wipe the purge ink with the preceding wiper, and remove the preceding wiper with the subsequent wiper. A wiping mechanism of an ink jet recording apparatus is disclosed in which ink remaining in the vicinity of the wiping start position is wiped off.

JP 2013-49205 A

  However, in the structure of Patent Document 1, the ink wiped by the subsequent wiper adheres to the wiping start position of the subsequent wiper at the next wiping. There is a problem that a large ink reservoir is formed by repeating the wiping operation. In addition, this wiping mechanism has a problem that the structure becomes complicated because the number of wipers increases.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to recover a recording head that can suppress the occurrence of ink accumulation on the ink ejection surface with a simple configuration. It is an object to provide a system, an ink jet recording apparatus including the system, and a recording head recovery method.

  In order to achieve the above object, a recording head recovery system of the present invention is a recording head recovery system in which a nozzle region in which an ejection nozzle for ejecting ink is provided on a recording medium is provided. A wiper that wipes out the purged ink that has been pushed out, a drive mechanism that reciprocates the wiper along the ink ejection surface including the nozzle region, and extrusion and ejection of ink from the ejection nozzle, as well as controlling the operation of the drive mechanism. A control unit. The control unit includes a first ink pushing operation for forcibly pushing the ink from the discharge nozzle to attach the purge ink to the nozzle region, and after pressing the wiper to the first position outside the nozzle region on the ink discharge surface, Is moved in the first direction toward the nozzle region along the ink discharge surface in a state where the ink is in pressure contact with the ink discharge surface, thereby wiping the purge ink to remove the second ink on the side opposite to the first position with respect to the nozzle region. After performing the first wiping operation for moving the wiper to the position and the first wiping operation, the second ink forcibly extrudes ink from the discharge nozzle and attaches more purge ink to the nozzle area than the first ink extruding operation. By moving in a second direction opposite to the first direction along the ink ejection surface in a state where the extrusion operation and the wiper are pressed against the ink ejection surface, Operation and the second wiping to wipe off the purge ink is extruded at 2 ink extrusion operation, it is possible to perform the recovery operation of the recording head including a.

  According to the present invention, it is possible to suppress the residual ink from collecting on the ink discharge surface, and thus it is possible to suppress the occurrence of a large ink pool. Further, it is possible to prevent the structure of the recording head recovery system from becoming complicated.

The figure which shows the structure of the inkjet recording device which concerns on 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 View of the recording unit from diagonally above 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 A view of the wiping mechanism mounted on the maintenance unit from above. The figure which looked at the carriage which constitutes the wiping mechanism from diagonally above A view of the support frame constituting the wiping mechanism as seen from above. The figure which shows the state which removed the wiping mechanism from the unit housing | casing of the maintenance unit It is a figure of the raising / lowering mechanism arrange | positioned at a unit housing | casing, and is a figure which shows the state which has a lift member in a horizontal state It is a figure of the raising / lowering mechanism arrange | positioned at a unit housing | casing, and is a figure which shows the state which the lift member stood up from the state of FIG. Diagram of lift members that constitute the lifting mechanism The figure which shows the state which has arrange | positioned the maintenance unit under the recording part The figure which shows the carriage, wiper, support frame, raising / lowering mechanism in the maintenance unit in the state of FIG. 14 is a diagram illustrating a state in which the support frame and the carriage are lifted by the lifting mechanism from the state of FIG. 14 and the wiper is disposed in contact with the ink discharge surface. Diagram of the recording head showing a state in which the wiper is disposed below the first position FIG. 16 is a diagram of the recording head when the ink ejection surface in the state of FIG. 16 is viewed from below. FIG. 7 is a diagram of a recording head showing a state where the wiper is moved in the direction of arrow A while being in pressure contact with the ink ejection surface. FIG. 18 is a diagram of the recording head showing a state where the wiper is moved from the state of FIG. 18 to the second position. 19 is a diagram of the recording head when the nozzle area on the ink ejection surface in the state of FIG. 19 is viewed from below. FIG. 6 is a diagram of the recording head showing a state where the wiper is separated from the ink ejection surface at the second position. FIG. 21 is a diagram of the recording head showing a state where the wiper is further moved in the direction of arrow A from the state of FIG. FIG. 22 is a diagram of a recording head showing a state in which purge ink is pushed out from the state of FIG. 23 is a diagram of the recording head when the nozzle area of the ink ejection surface in the state of FIG. 23 is viewed from below. The figure of the recording head which shows the state which raised the wiper from the state of FIG. FIG. 25 is a diagram of the recording head showing a state where the wiper is moved in the direction of arrow A ′ from the state of FIG. FIG. 26 is a diagram of the recording head showing a state in which the wiper is further moved in the arrow A ′ direction from the state of FIG. 26 and the purge ink is in contact with the residual ink. FIG. 27 is a diagram of the recording head showing a state where the wiper is moved from the state of FIG. 27 to the downstream edge in the arrow A ′ direction. The figure which shows the state which a support frame and a carriage descend | fall by the raising / lowering mechanism, and the wiper was spaced apart from the ink discharge surface. FIG. 7 is a diagram showing a conventional wiping mechanism that wipes the ink discharge surface of the recording head by bringing the wiper into contact with the ink discharge surface from a substantially vertical direction at a predetermined contact pressure, and shows a state in which the wiper is disposed below the wiping start position. Figure FIG. 30A is a diagram of the recording head showing a state where the wiper is moved in the direction of the nozzle region while being in contact with the ink ejection surface from the state of FIG. 30A. FIG. 30B is a diagram of the recording head showing a state where the wiper is further moved from the state of FIG. FIG. 30C is a diagram of the recording head showing a state where the wiper is separated from the ink ejection surface from the state of FIG. 30C. FIG. 30 is a diagram of the recording head showing a state in which the wiper is disposed below the wiping start position in order to perform the second wiping using the conventional wiping mechanism shown in FIG. 30A. FIG. 31A is a diagram of the recording head showing a state where the wiper is brought into contact with the ink ejection surface from the state of FIG. 31A. FIG. 31B is a diagram of the recording head showing a state where the wiper is moved in the direction of the nozzle region while being in contact with the ink ejection surface from the state of FIG. 31B.

  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. Includes a paper feed roller 3 for feeding the stored paper S one by one from the topmost paper S to a first transport unit 5 to be described later, and a follower that is in pressure contact with the paper feed roller 3 and driven to rotate. A 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 disposed on the downstream side in the paper transport direction, a first driven roller 7 disposed on the upstream side, the first drive roller 6 and the first driven roller 7. The first conveying belt 8 is configured to include the first conveying belt 8 that is stretched, and the first driving roller 6 is rotated in the clockwise direction by a control signal from the control unit 110 of the inkjet recording apparatus 100. 8 is transported in the direction of arrow X.

  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 conveyance surface of the first conveyance belt 8, and as shown in FIGS. A plurality (three in this case) of recording heads 17a to 17c are arranged in a staggered manner along the paper width direction (vertical direction in FIG. 2) perpendicular to the transport direction. 3 shows a state in which the recording unit 9 is viewed from the back side in FIG. 1 (upper side in FIG. 2), and the arrangement of the line heads 11C to 11K is opposite to that in FIGS.

  As shown in FIGS. 4 and 5, a nozzle region R in which a large number of ejection nozzles 18 (see FIG. 2) are arranged is provided on the ink ejection surfaces F of the recording heads 17a to 17c. 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.

  In the recording heads 17a to 17c constituting the line heads 11C to 11K, inks of four colors (cyan, magenta, yellow, and black) stored in ink tanks (not shown) are respectively 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 ejection nozzle 18 toward the end. 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.

  Further, in order to prevent ink discharge failure due to drying or clogging of the recording heads 17a to 17c, the printing nozzles of all the recording heads 17a to 17c can be started from the discharge nozzles 18 at the start of printing after being stopped for a long time. Is prepared for the next printing operation by executing a purge that pushes out the ink with increased viscosity in the discharge nozzles 18 from the discharge nozzles 18 of the recording heads 17a to 17c whose ink discharge amount is not more than a specified value.

  Further, a hydrophilic member 60 (see FIG. 16) having a higher hydrophilicity than the nozzle region R is attached to one end of the ink ejection surface F of the recording heads 17a to 17c. The hydrophilic member 60 is formed of, for example, an SUS plate having a thickness of 50 to 100 μm, and the contact angle (about 90 degrees or less) of the hydrophilic member 60 with respect to water is larger than the contact angle (about 110 degrees) of the nozzle region R. Smaller than about 20 degrees. A part of the hydrophilic member 60 protrudes outward from the ink discharge surface F, and the protruding portion is bent upward to form an inclined surface 60a. The inclined surface 60a is bent, for example, about 60 degrees with respect to the ink ejection surface F.

  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 disposed on the downstream side in the paper transport direction, a second driven roller 14 disposed on the upstream side, and the second drive roller 13 and the second driven roller 14. And the second transport belt 15 is stretched, and the second driving roller 13 is driven to rotate in the clockwise direction, whereby the paper S held on the second transport belt 15 is transported in the arrow X direction. Is done.

  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 the purge described above, and wipes off the ink pushed out from the ejection nozzles 18 of the recording heads 17a to 17c and adhering to the ink ejection surface F. Collect the remaining ink. The cap unit 90 horizontally moves below the recording unit 9 when capping the ink ejection surfaces F (see FIG. 4) of the recording heads 17a to 17c, and further moves upward to be attached to the lower surfaces of the recording heads 17a to 17c. Is done. The detailed configuration of the maintenance unit 19 will be described later.

  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.

  A wiping mechanism 30 shown in FIG. 6 is mounted on the maintenance unit 19. The wiping mechanism 30 includes a substantially rectangular carriage 31 to which a plurality of wipers 35 a to 35 c (see FIG. 7) are fixed, and a support frame 40 that supports the carriage 31. Rail portions 41a and 41b are formed at opposing edges of the upper surface of the support frame 40. The sliding rollers 36 provided at the four corners of the carriage 31 abut against the rail portions 41a and 41b. The support frame 40 is slidably supported in the direction of the arrow AA ′.

  As illustrated in FIG. 7, the carriage 31 includes first stays 32 a and 32 b that are slidably engaged with rail portions 41 a and 41 b of the support frame 40 via a slide roller 36, and first stays 32 a and 32 b. The second stays 33a, 33b, and 33c fixed in a bridging manner are formed in a frame shape.

  Rack teeth 38 that mesh with the input gear 43 (see FIG. 6) held by the support frame 40 are formed on the first stay 32a. When the input gear 43 rotates in the forward and reverse directions, the carriage 31 reciprocates in the horizontal direction (the direction of arrow AA ′ in FIG. 6) along the support frame 40. The rack teeth 38 and the input gear 43 constitute the drive mechanism of the present invention.

  The wipers 35a to 35c are members for wiping off the ink pushed out from the ejection nozzles 18 of the recording heads 17a to 17c. The wipers 35a to 35c are pressed from a position substantially perpendicular to a position outside the nozzle region R (see FIG. 5) where the nozzle surface of the discharge nozzle 18 is exposed, and move the carriage 31 to move the ink discharge surface F including the nozzle region R. Wipe in a predetermined direction (arrow AA ′ direction in FIG. 6).

  Four wipers 35a are fixed to the second stay 33a at substantially equal intervals. Similarly, four wipers 35b are substantially fixed to the second stay 33b, and four wipers 35c are substantially omitted to the second stay 33c. Fixed at regular intervals. The wipers 35a and 35c are disposed at positions corresponding to the left and right recording heads 17a and 17c (see FIG. 3) constituting the line heads 11C to 11K, respectively. Further, the wiper 35b is disposed at a position corresponding to the central recording head 17b (see FIG. 3) constituting each of the line heads 11C to 11K, and the movement direction of the carriage 31 (see FIG. 6) with respect to the wipers 35a and 35c. It is fixed by being shifted by a predetermined distance in a direction orthogonal to the direction of arrow AA ′.

  Gap rollers 37 are provided at four locations on the upper surfaces of the second stays 33a and 33c. The gap roller 37 contacts the head housing 10 of the recording unit 9 when the wiping mechanism 30 is raised to the recording unit 9 side in order to perform the wiping operation of the ink discharge surfaces F of the recording heads 17a to 17c by the wipers 35a to 35c. The contact state between the wipers 35a to 35c and the ink discharge surface F is kept constant by contact.

  As shown in FIG. 8, on the upper surface of the support frame 40, an ink collection tray 44 for collecting waste ink wiped off from the ink ejection surface F by the wipers 35a to 35c is arranged. A groove portion 44a is formed in a substantially central portion of the ink collection tray 44 along the extending direction of the second stays 33a to 33c. The tray surfaces 44b and 44c on both sides of the groove portion 44a face the groove portion 44a. The slope is descending. An ink discharge hole 44d is provided in the groove 44a, and the bottom surface of the groove 44a is inclined downward toward the ink discharge hole 44d.

  Waste ink that has been wiped off from the ink discharge surface F by the wipers 35a to 35c and dropped onto the tray surfaces 44b and 44c is collected in the groove 44a and further flows in the groove 44a toward the ink discharge hole 44d. Thereafter, the ink is recovered into a waste ink recovery tank (not shown) through an ink recovery path (not shown) connected to the ink discharge hole 44d.

  Next, the elevating mechanism 50 for elevating the wiping mechanism 30 of this embodiment will be described. The maintenance unit 19 includes a unit casing 45 shown in FIG. 9, a wiping mechanism 30 (see FIG. 6) attached to the unit casing 45, and an elevating mechanism 50 disposed in the unit casing 45. As shown in FIGS. 9 and 10, the lifting mechanism 50 in which two lift members 50 a are fixed to both ends of the shaft 50 b is provided on the bottom surface 45 a of the unit housing 45 in the moving direction of the carriage 31 (arrow AA in FIG. 6). A pair is disposed along the side surfaces 45b and 45c facing each other in the 'direction'. That is, the elevating mechanism 50 is disposed at a position facing both ends in the width direction of the head housing 10 of the recording unit 9 (upper and lower ends in FIG. 2). In FIG. 9, the description of the lifting mechanism 50 on the side surface 45c side is omitted. The side surface 45d adjacent to the side surfaces 45b and 45c of the unit housing 45 is provided with a motor 47 and a drive transmission shaft 48 that transmits the rotational driving force of the motor 47 to the shaft 50b.

  As shown in FIG. 12, the lower end portion of the lift member 50a is fixed to the shaft 50b, and the lift member 50a swings as the shaft 50b rotates. A push-up roller 53 is rotatably attached to the upper end portion of the lift member 50a. The push-up roller 53 is engaged with an engaging portion 41c (see FIG. 6) formed at the lower end portion of the support frame 40, and is rotatable along the engaging portion 41c. Accordingly, since the friction between the support frame 40 and the lift member 50a when operating the lifting mechanism 50 is reduced by the rotation of the push-up roller 53, a smooth lifting operation can be performed. Further, the push-up roller 53 is urged by the coil spring 55 in a direction away from the shaft 50b (upward in FIG. 12).

  10, when the shaft 50b of the right elevating mechanism 50 is rotated in the clockwise direction and the shaft 50b of the left elevating mechanism 50 is rotated in the counterclockwise direction, the lift member 50a that has fallen into the inside of the unit housing 45 is removed. It rises in the outer direction (arrow B direction), and the push-up roller 53 moves to the outer end of the engaging portion 41c. Accordingly, the lift member 50a is switched from the horizontal state to the standing state (the state shown in FIG. 11), and the carriage 31 is raised together with the support frame 40.

  On the other hand, when the shaft 50b of the right elevating mechanism 50 is rotated counterclockwise and the shaft 50b of the left elevating mechanism 50 is rotated clockwise from the state of FIG. It falls down (in the direction of arrow B ′), and the push-up roller 53 moves to the inner end of the engaging portion 41c. Accordingly, the lift member 50a is switched from the standing state to the horizontal state (the state shown in FIG. 10), and the carriage 31 is lowered together with the support frame 40.

  Next, the recovery operation of the recording heads 17a to 17c using the wiping mechanism 30 in the inkjet recording apparatus 100 of the present embodiment will be described. 14, 15, and 29 show a state where the recording unit 9 and the maintenance unit 19 are viewed from the downstream side in the sheet conveyance direction (left side in FIG. 13). Further, the support frame 40 is simplified and described in a plate shape, and the unit housing 45 describes only the bottom surface 45a. Further, the recovery operation and the cap unit mounting operation of the recording heads 17a to 17c described below are performed based on the control signal from the control unit 110 (see FIG. 1), the recording heads 17a to 17c, the wiping mechanism 30, the lifting mechanism 50, and the like. It is executed by controlling the operation of

  When performing the recovery operation of the recording heads 17a to 17c, first, as illustrated in FIG. 13, the control unit 110 lowers the first transport unit 5 located below the recording unit 9. Then, the control unit 110 horizontally moves the maintenance 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, as shown in FIG. 14, the lift member 50a of the elevating mechanism 50 is in a horizontal state, and the wipers 35a to 35c fixed to the carriage 31 are separated from the ink ejection surfaces F of the recording heads 17a to 17c. .

(First ink extrusion operation)
Prior to the wiping operation (first wiping operation described later), the control unit 110 supplies the ink 22 to the recording heads 17a to 17c. As shown in FIG. 16, the supplied ink 22 is forcibly extruded (purged) from the discharge nozzle 18. By this purging operation, the thickened ink, foreign matter and bubbles in the discharge nozzle 18 are discharged from the discharge nozzle 18, and the recording heads 17a to 17c can be recovered. At this time, as shown in FIG. 17, the purge ink 22 b is pushed out to the ink ejection surface F along the shape of the nozzle region R where the ejection nozzle 18 exists. 17, 20, and 24 show the ink shape in a state where the number of ejection nozzles 18 is reduced for simplification of the drawing.

(First wiping operation)
The control unit 110 brings the wipers 35a to 35c into contact with the first position P1 outside the nozzle region R of the ink ejection surfaces F of the recording heads 17a to 17c with a predetermined pressure. Specifically, as shown in FIGS. 15 and 16, the control unit 110 rotates the shaft 50 b of the elevating mechanism 50 to raise the lift member 50 a in the direction of arrow B, thereby moving the support frame 40 and the carriage 31. lift. At this time, since the gap roller 37 provided on the carriage 31 is pressed against the lower surface of the head housing 10 by the biasing force of the coil spring 55 (see FIG. 12) of the lift member 50a, the wipers 35a to 35c are moved against the ink discharge surface F. It is always possible to press contact with a constant pressure.

  From the state in which the tips of the wipers 35a to 35c are in pressure contact with the ink ejection surface F, the control unit 110 rotates the input gear 43 (see FIG. 6) in the forward direction to move the carriage 31 in the direction of arrow A in FIG. As a result, the wipers 35a to 35c supported by the carriage 31 are also in pressure contact with the ink discharge surface F as shown in FIG. 18 in the direction of the nozzle region R along the ink discharge surface F (left direction, first direction). , In the direction of arrow A). Since an upward force is applied to the support frame 40 by the lifting mechanism 50, the carriage 31 moves in the arrow A direction while maintaining the state where the gap roller 37 is pressed against the head housing 10.

  At this time, as shown in FIG. 18, the residual ink 22a remaining at the tip (upper end) of the wipers 35a to 35c during the previous recording head recovery operation and thickened by contact with air for a long period of time becomes the first of the ink discharge surface F. It adheres to the 1 position P1 and is separated from the tips of the wipers 35a to 35c.

  As shown in FIG. 19, the wipers 35 a to 35 c move to the left (in the direction of arrow A) while wiping the purge ink 22 b on the ink ejection surface F, and are opposite to the first position P <b> 1 with respect to the nozzle region R. When reaching the position on the side (the second position P2, the position where the hydrophilic member 60 is provided), the movement in the left direction is stopped. Note that most of the waste ink wiped off by the wipers 35a to 35c is collected in the ink collection tray 44 (see FIG. 8).

  Here, in the first wiping operation, the tips of the wipers 35a to 35c immediately after the start of wiping are not wetted by the ink 22, and thus the thickened portion of the peripheral edge of the purge ink 22b cannot be sufficiently wiped off. On the other hand, when the wipers 35a to 35c move in the direction of arrow A and the tips of the wipers 35a to 35c are wetted by the ink 22, ink adhesion to the ink discharge surface F does not occur. For this reason, as shown in FIGS. 19 and 20, after the first wiping operation is performed, a portion of the peripheral edge of the purge ink 22b close to the first position P1 remains attached to the ink ejection surface F. Hereinafter, the ink remaining on the ink ejection surface F after thickening the periphery of the purge ink 22b is referred to as the thickened purge ink 22c. When the thickening purge ink 22c is repeatedly deposited, the thickening purge ink 22c increases and spreads over the entire ink ejection surface F, and ink ejection failure may occur.

(Separation operation)
After performing the first wiping operation, the control unit 110 separates the wipers 35a to 35c from the ink ejection surface F as shown in FIG. Specifically, the control unit 110 reversely rotates the shaft 50b (see FIG. 15) of the elevating mechanism 50 and swings the lift member 50a in the direction of the arrow B ′ so as to be in a horizontal state, so that the support frame 40 and The carriage 31 is lowered. When the wipers 35a to 35c are separated from the ink ejection surface F, a part of the purge ink 22b remains at the tips of the wipers 35a to 35c as shown in FIG.

(Movement operation)
After performing the separation operation, as shown in FIG. 22, the control unit 110 moves the wipers 35a to 35c horizontally. Specifically, the control unit 110 rotates the input gear 43 (see FIG. 6) from the state shown in FIG. 21 to move the carriage 31 in the direction of arrow A, thereby causing the carriage 31 to move as shown in FIG. The supported wipers 35a to 35c move in the direction (left direction) opposite to the nozzle region R with respect to the second position P2.

(Second ink extrusion operation)
After executing the moving operation, the control unit 110 supplies the ink 22 to the recording heads 17a to 17c. As shown in FIGS. 23 and 24, more ink 22 is forcibly extruded (purged) from the ejection nozzle 18 than in the first ink extrusion operation. As a result, the thickened purge ink 22c remaining after the first wiping operation is covered and re-dissolved by the purge ink 22d extruded by the second ink extrusion operation. By increasing the extrusion pressure or extending the extrusion time, the amount of purge ink 22d by the second ink extrusion operation can be easily increased from the amount of purge ink 22c by the first ink extrusion operation. Can do.

(Second wiping operation)
Thereafter, the control unit 110 performs a wiping operation of wiping the purge inks 22b and 22d and the residual ink 22a on the ink ejection surface F. Specifically, the control unit 110 lifts the support frame 40 and the carriage 31 by rotating the shaft 50b of the elevating mechanism 50 and raising the lift member 50a in the direction of arrow B. Thereby, as shown in FIG. 25, the wipers 35 a to 35 c are raised to a height at which the wipers 35 a to 35 c can come into contact with the ink ejection surface F. Then, the control unit 110 reversely rotates the input gear 43 (see FIG. 6) from the state shown in FIG. 25 to move the carriage 31 in the direction opposite to the arrow A direction (right direction, second direction). As shown, the wipers 35a to 35c move in the direction of the nozzle region R (rightward) along the ink discharge surface F in a state where the wipers 35a to 35c are pressed against the ink discharge surface F. At this time, the ink that has slightly adhered to the tips of the wipers 35 a to 35 c after the separating operation is scraped off to the inclined surface 60 a of the hydrophilic member 60. Even when ink is collected on the inclined surface 60a of the hydrophilic member 60, unlike the case where ink is collected on the ink ejection surface F, the accumulated ink is prevented from coming into contact with the paper surface and being stained. Can do.

  Then, the purge ink 22b at the second position P2, the purge ink 22d in the nozzle region R in which the thickened purge ink 22c is redissolved, and the residual ink 22a at the first position P1 are wiped off. At this time, as shown in FIG. 27, when the purge inks 22b and 22d wiped by the wipers 35a to 35c come into contact with the residual ink 22a, the residual ink 22a is redissolved in the purge inks 22b and 22d and the residual ink 22a. The increase in viscosity is relieved.

  Thereafter, the control unit 110 moves the wipers 35a to 35c to the edge of the ink ejection surface F of the recording heads 17a to 17c (the right edge in FIG. 28), and the waste ink wiped off by the wipers 35a to 35c The ink flows down and is collected in the ink collection tray 44 (see FIG. 8). Then, as shown in FIG. 29, the control unit 110 rotates the shaft 50b of the elevating mechanism 50 to cause the lift member 50a to fall down in the direction of the arrow B ′, thereby causing the wipers 35a to 35c to move to the recording heads 17a to 17c. The maintenance unit 19 is returned to the state shown in FIG. Finally, the control unit 110 horizontally moves the maintenance unit 19 arranged between the recording unit 9 and the first conveyance unit 5 and arranges the maintenance unit 19 below the second conveyance unit 12 to place the first conveyance unit 5 in a predetermined manner. And the recovery operation of the recording heads 17a to 17c is completed.

  When the cap unit 90 is attached to the recording heads 17a to 17c, first, as shown in FIG. 13, the control unit 110 lowers the first belt conveyance unit 5 disposed to face the lower surface of the recording unit 9. Then, the cap unit 90 disposed below the second belt conveyance unit 12 is horizontally moved between the recording unit 9 and the first belt conveyance unit 5 and disposed at a position facing the recording unit 9.

  Next, the control unit 110 raises the first belt conveyance unit 5, thereby pushing up the cap unit 90. Then, the control unit 110 completes the mounting of the cap unit 90 by stopping the rising of the first belt conveying unit 5 when the cap unit 90 comes into close contact with the recording heads 17a to 17c.

  In the present embodiment, as described above, after the first wiping operation is performed, the second wiping operation for moving the wipers 35a to 35c in the direction of the arrow A ′ (rightward) along the ink ejection surface F is performed. The residual ink 22a at the first position P1 can be wiped off by the wipers 35a to 35c. Thereby, since it is possible to suppress the residual ink 22a from being accumulated on the ink ejection surface F, it is possible to suppress the occurrence of a large ink accumulation. Further, unlike the case where two wipers 35a to 35c that are sequentially brought into contact with the ink discharge surface F are provided (the configuration of Patent Document 1 above), it is possible to suppress an increase in the number of wipers 35a to 35c. Complicating the structure of the recovery system of the heads 17a to 17c can be suppressed.

  Further, in the second wiping operation, the wipers 35a to 35c are moved in the direction of the arrow A ′ (right direction) so that the wipers 35a to 35c wipe the purge ink 22d extruded during the second ink extrusion operation. The residual ink 22a at the first position P1 is wiped off. Accordingly, when the wipers 35a to 35c wipe the residual ink 22a, the purge ink 22d that has not been thickened contacts the residual ink 22a that has been thickened by being exposed to the atmosphere for a long time. Re-dissolving in 22d reduces the thickening of the residual ink 22a. For this reason, in the second wiping operation, the residual ink 22a adhering to the ink discharge surface F can be easily wiped off by the wipers 35a to 35c.

  Further, in the second ink push-out operation, the ink 22 is forcibly pushed out from the discharge nozzle 18 so that more purge ink 22d is attached to the nozzle region R than in the first ink push-out operation. As a result, the thickened purge ink 22c remaining in the portion that was the periphery of the purge ink 22b after the first wiping operation can be redissolved by the purge ink 22d extruded during the second ink extrusion operation. For this reason, in the second wiping operation, the thickened purge ink 22c remaining after the first wiping operation can be easily wiped off.

  Further, as described above, in the second wiping operation, the wipers 35a to 35c are moved along the ink discharge surface F from the position opposite to the nozzle region R with respect to the second position P2 to which the purge ink 22b is attached. By moving in the arrow A ′ direction (right direction), the purge ink 22b at the second position P2 and the purge ink 22d pushed during the second ink push-out operation are wiped off. Thereby, it is possible to suppress the occurrence of unwiping from the second position P2 on the arrow A ′ direction (right direction) side in the second wiping operation. If there is a region where the purge ink 22b is insufficient at the second position P2, if the second wiping operation is performed, the remaining ink is left on the ink ejection surface F in the region where the purge ink 22b is insufficient.

  Further, the wipers 35a to 35c wipe the purge ink 22d extruded during the second ink extrusion operation after wiping the purge ink 22b at the second position P2. Thereby, even if the peripheral edge of the purge ink 22d extruded during the second ink extrusion operation is thickened, the thickened purge ink is redissolved and wiped by the purge ink 22b at the second position P2. be able to.

  Further, as described above, the second position P2 is formed so as to have higher hydrophilicity than the nozzle region R. Thereby, in the separation operation, the amount of the ink 22 that adheres to the second position P2 can be increased.

  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, the first ink extrusion operation is performed before the first wiping operation, but if the wipers 35a to 35c are before entering the nozzle region R, the first ink extrusion operation is performed simultaneously with the first wiping operation. Also good.

  In the above embodiment, the second ink extrusion operation is performed after the separation operation. However, the second ink extrusion operation may be performed before the separation operation or before the wipers 35a to 35c enter the nozzle region R. It may be executed simultaneously with the second wiping operation.

  Moreover, in the said embodiment, although the example which formed the hydrophilic member 60 with the SUS board was shown, this invention is not limited to this. The hydrophilic member 60 may be formed of a resin member or a film.

  In the above embodiment, the example in which the hydrophilic member 60 is provided in the predetermined region including the second position P2 of the ink ejection surface F has been described. However, the hydrophilic member 60 may not be provided.

  As the drive mechanism (rack teeth 38, input gear 43) and the lifting mechanism 50, other conventionally known driving mechanisms and lifting mechanisms can be used. The number of ejection nozzles 18 and nozzle intervals of the recording heads 17 a to 17 c can also be appropriately set according to the specifications of the inkjet recording apparatus 100. Further, the number of recording heads is not particularly limited. For example, one, two, or four or more recording heads 17 can be arranged for each of the line heads 11C to 11K.

  Further, the present invention can also be applied to an inkjet recording apparatus for monochrome printing that includes only one of the line heads 11C to 11K. In that case, since the recording heads 17a to 17c are provided one by one, the wipers 35a to 35c corresponding to the recording heads 17a to 17c may be fixed to the carriage 31 one by one.

17a to 17c Recording head 18 Discharge nozzle 22 Ink 22a Residual ink 22b, 22d Purge ink 35a to 35c Wiper 38 Rack teeth (drive mechanism)
43 Input gear (drive mechanism)
60 Hydrophilic member 100 Inkjet recording apparatus 110 Control unit F Ink ejection surface P1 First position P2 Second position R Nozzle area S Paper (recording medium)

Claims (6)

A recording head recovery system provided with a nozzle region in which a discharge nozzle for discharging ink is opened on a recording medium,
A wiper for wiping the purge ink forced out of the discharge nozzle;
A drive mechanism for reciprocating the wiper along an ink ejection surface including the nozzle region;
A controller that controls the ejection and ejection of ink from the ejection nozzle and the operation of the drive mechanism;
With
The controller is
A first ink extruding operation for forcibly extruding ink from the ejection nozzle and attaching the purge ink to the nozzle region;
After the wiper is brought into pressure contact with the first position outside the nozzle region on the ink ejection surface, the wiper is moved toward the nozzle region along the ink ejection surface with the wiper being in pressure contact with the ink ejection surface. A first wiping operation for wiping the purge ink by moving in one direction and moving the wiper to a second position opposite to the first position with respect to the nozzle region;
A second ink extruding operation for forcibly extruding ink from the ejection nozzles and attaching more purge ink to the nozzle area than the first ink extruding operation after performing the first wiping operation;
The purge ink extruded during the second ink extrusion operation by moving the wiper in a second direction opposite to the first direction along the ink ejection surface in a state where the wiper is in pressure contact with the ink ejection surface. And a second wiping operation for wiping off ink adhering to the first position during the first wiping operation ;
A recovery system for a recording head, wherein the recovery operation of the recording head can be executed. The controller is
After performing the first wiping operation, performing a separating operation for separating the wiper from the ink ejection surface,
In the second wiping operation, the wiper is brought into pressure contact with the ink ejection surface at a position opposite to the nozzle region with respect to the second position, and the wiper is brought into pressure contact with the ink ejection surface. The ink adhering to the second position by the separation operation and the purge ink pushed out during the second ink extrusion operation are wiped off by moving in the second direction along the ejection surface. Item 8. The recording head recovery system according to Item 1.   The recording head recovery system according to claim 2, wherein the second position is formed so as to have higher hydrophilicity than the nozzle region.   The recording head recovery system according to claim 3, wherein a hydrophilic member having a higher hydrophilicity than the nozzle region is provided in a predetermined region including the second position of the ink ejection surface. .   An ink jet recording apparatus comprising the recording head recovery system according to claim 1. A method for recovering a recording head including an ink ejection surface provided with a nozzle region in which an ejection nozzle for ejecting ink is opened on a recording medium,
A first ink extruding operation for forcibly extruding ink from the ejection nozzle and attaching purge ink to the nozzle region;
After a wiper is pressed against a first position outside the nozzle region on the ink discharge surface, a first heading toward the nozzle region along the ink discharge surface with the wiper pressed against the ink discharge surface A first wiping operation for wiping the purge ink by moving in a direction and moving the wiper to a second position opposite to the first position with respect to the nozzle region;
A second ink extruding operation for forcibly extruding ink from the ejection nozzles and attaching more purge ink to the nozzle area than the first ink extruding operation after performing the first wiping operation;
The purge ink extruded during the second ink extrusion operation by moving the wiper in a second direction opposite to the first direction along the ink ejection surface in a state where the wiper is in pressure contact with the ink ejection surface. And a second wiping operation for wiping off ink adhering to the first position during the first wiping operation ;
A recording head recovery method comprising:

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