JP5328620B2 - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device capable of preventing ink which is adhered to a wiper member and whose viscosity is increased from adhering to the nozzle surface of a recording head again. <P>SOLUTION: The inkjet recording device 1 includes: the recording head 30 having the nozzle surface 31 in which a plurality of nozzles are formed; the wiper member 41 relatively moved with respect to the recording head 30 in a direction along the nozzle surface 31, to clean the nozzle surface 31; and an ink removal means capable of removing the ink from the wiper member 41, in such a manner that a water-soluble organic solvent whose boiling point is 200&deg;C or more and solubility parameter is 9.5 to 13.7 comes into contact with the wiper member 41 to which the ink is adhered due to cleaning. The ink removal means includes a wiper case 40, a wiper rotation drive mechanism 45 and a porous member 71. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an ink jet recording apparatus that performs recording on a recording medium such as paper by ejecting ink from nozzles.

  A recording head in an ink jet recording apparatus has a nozzle surface on which a plurality of nozzles for discharging ink are formed. The nozzle surface is cleaned in order to prevent ink from being difficult to be ejected due to foreign matters such as ink and dust adhering to the vicinity of the nozzle and the ink ejection direction from being changed.

  Regarding the cleaning of the nozzle surface, a technique is known in which the nozzle surface is cleaned (wiped) with a wiper member to remove ink adhering to the nozzle surface. After the nozzle surface is cleaned, the ink adheres to the wiper member. If the wiper member is left in a state where the ink is attached, the ink thickens (viscosity increases). When the nozzle surface is cleaned again by the wiper member in the state where the thickened ink is adhered, the ink that has adhered to the wiper member and thickened again adheres to the recording head, and ink ejection is likely to be disturbed. In order to prevent the disturbance of ejection caused by such thickening of the ink, it is a common practice to remove the ink adhering to the wiper member.

  Patent Document 1 discloses a technique for removing thickened ink from a recording head by an ink absorber attached to the recording head.

JP 2007-21696A

  However, with the technique described in Patent Document 1, it is difficult to completely remove the ink from the wiper member, and a small amount of ink forms a film and remains on the wiper member, and the remaining small amount of ink further increases. Sticky and dry. When such thickening or drying of the ink repeatedly occurs, a large amount of thickened or dried ink is attached to the wiper member. If the thickened ink is reattached to the nozzle surface of the recording head, it may cause the ink ejection to be disturbed.

  Therefore, the present invention has been made in view of such a point, and an object of the present invention is to perform ink jet recording capable of suppressing reattachment of the ink thickened by adhesion to the wiper member to the nozzle surface of the recording head. To provide an apparatus.

  An inkjet recording apparatus of the present invention includes a recording head having a nozzle surface on which a plurality of nozzles are formed, and a wiper member that moves relative to the recording head in a direction along the nozzle surface to clean the nozzle surface. Ink removing means capable of removing the ink from the wiper member by bringing a water-soluble organic solvent having a boiling point of 200 ° C. or higher and a solubility parameter of 9.5 or higher and 13.7 or lower into contact with the wiper member to which ink has adhered by the cleaning. And.

  In this configuration, the water-soluble organic solvent (resin solubilizer) having the above physical properties is brought into contact with the wiper member to remove the ink attached to the wiper member, so that the ink hardly remains on the wiper member after the removal. The water-soluble organic solvent having the physical properties is excellent in the effect of suppressing the increase in the viscosity of the ink, as shown in Examples described later. In other words, the water-soluble organic solvent is excellent in the effect of reducing the viscosity of the ink. Therefore, when the water-soluble organic solvent comes into contact with the ink attached to the wiper member, the viscosity decreases and the ink is easily removed. Thereby, it can suppress that the ink which remained in the wiper member and was thickened adheres to a nozzle surface again.

Further, the water-soluble organic solvent agents are water-soluble ether solvent or a water-soluble diol solvent, the water-soluble ether solvent is diethylene glycol monoethyl ether, triethylene glycol monoethyl ether or triethylene glycol monobutyl ether is there.

  Further, when the ink contains a pigment as a coloring material, the water-soluble organic solvent is excellent in compatibility with a resin (for example, styrene acrylic resin) contained in the pigment dispersion.

  In addition, the line head type in which the plurality of nozzles are arranged in a line in a direction intersecting the paper transport direction is often left for a long time in a situation where the recording head tends to thicken. The present invention is effective because it tends to thicken.

In addition, the ink removing unit includes a support member that rotatably supports the wiper member, a cleaning position where the cleaning is performed by the wiper member, and a standby position where the wiper member waits when the cleaning is not performed. Driving means for rotating the wiper member between the wiper member, a position where the wiper member can contact during rotation of the wiper member , and a position where the wiper member in the standby position does not contact , a solvent absorber the water-soluble organic solvent is impregnated, that have a.

  In this configuration, the wiper member can be brought into contact with the solvent absorber during rotation of the wiper member by the driving means. Thus, the water-soluble organic solvent can be reliably brought into contact with the wiper member with a simple structure. In addition, when the wiper member is rotated from the cleaning position to the standby position to make the wiper member standby, the wiper member can be brought into contact with the solvent absorber, and can be rotated from the standby position to the cleaning position. When the wiper member is returned, the wiper member can be brought into contact with the solvent absorber.

  Further, the support member is a wiper case having a housing part for housing the wiper member and the solvent absorber, and an opening part capable of projecting at least a part of the wiper member to the outside of the housing part during the cleaning. In this case, the ink jet recording apparatus of the present invention preferably further includes a wiper cap member that closes the opening of the wiper case when the cleaning is not performed.

  In this configuration, the opening of the wiper case that accommodates and supports the wiper member can be closed by the wiper cap member. Therefore, even after the ink on the wiper member is removed by the solvent absorber, even if the ink remains on the wiper member, the wiper member can be accommodated in a sealed space surrounded by the wiper case and the wiper cap member. It is possible to prevent the ink attached to the member from being thickened. Further, when the cleaning is not performed, the solvent absorber can also be accommodated in the sealed space, so that it is possible to suppress the thickening of the ink adhering to the solvent absorber and to suppress the volatilization of the water-soluble organic solvent. be able to.

  In the present invention, it is preferable to further include a cartridge in which the water-soluble organic solvent is stored and the solvent absorber can be replenished with the water-soluble organic solvent.

In this configuration, the water-soluble organic solvent can be replenished from the cartridge to the solvent absorber. When this cartridge becomes empty, the solvent absorber can be continuously replenished with the water-soluble organic solvent simply by replacing it with another cartridge.
Further, in the rotation operation of the wiper member from the cleaning position to the standby position, the wiper member decreases when the wiper member contacts the solvent absorber so that the contact time between the wiper member and the solvent absorber becomes longer. Ru is fast.

  As described above, according to the present invention, it is possible to suppress the ink that has adhered to the wiper member and thickened from reattaching to the nozzle surface of the recording head.

It is a top view which shows typically the outline | summary of the inkjet recording device of 1st Embodiment. FIG. 2 is a right side view schematically showing the outline of the ink jet recording apparatus of the first embodiment. It is a front view which shows typically the outline | summary of the state at the time of the recording by the inkjet recording device of 1st Embodiment. It is a top view which shows the cap unit in 1st Embodiment. It is a right view which shows the cap unit in 1st Embodiment. It is a front view which shows the cap unit in 1st Embodiment. It is a longitudinal cross-sectional view which shows the state which the wiper cap member closed the wiper opening part of the cleaning unit in 1st Embodiment. It is the longitudinal cross-sectional view which looked at the cleaning unit in 1st Embodiment in the 2nd direction Y2. It is the top view which looked at the cleaning unit in a 1st embodiment in the Z direction. It is a longitudinal cross-sectional view which shows the state which the wiper cap member left | separated from the wiper opening part of the cleaning unit in 1st Embodiment. It is a top view which shows the moving range of the cleaning unit in 1st Embodiment. It is a right view which shows the moving range of the cleaning unit in 1st Embodiment. FIG. 7 is a right side view illustrating a process in which the cleaning unit according to the first embodiment moves in the first direction Y1 to clean the nozzle surface of the recording head. FIG. 7 is a right side view illustrating a process in which the cleaning unit according to the first embodiment moves backward in the second direction Y2 to clean the nozzle surface of the recording head. It is a top view which shows the movement range of the cap unit in 1st Embodiment. It is a right view which shows the moving range of the cap unit in 1st Embodiment. FIG. 3 is a front view illustrating a state in which the nozzle cap member according to the first embodiment covers the nozzle surface of the recording head. It is a longitudinal cross-sectional view which shows the state which the wiper cap member closed the wiper opening part of the cleaning unit in 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
As shown in FIGS. 1 to 3, the ink jet recording apparatus 1 of the present embodiment includes a transport unit 2, a nozzle unit 3, a cleaning unit 4, a cap unit 5, and a wiper cap member 6. .

  The transport unit 2 includes a drive roller 20, a driven roller 21, a transport belt 22 that is stretched over the drive roller 20 and the driven roller 21, a tension roller 23 that adjusts the tension of the transport belt 22, and a suction unit 24. doing. The conveyance belt 22 is provided with a number of through holes (not shown) for suction. The upper surface portion of the conveyance belt 22 forms a conveyance surface 22A. The conveying surface 22A of the conveying belt 22 is horizontally moved by the drive roller 20 from one side to the other side in the X direction in the horizontal plane. The X direction is also referred to as “conveying direction X”. The suction unit 24 is disposed on the lower side (opposite side) of the conveyance surface 22 </ b> A of the conveyance belt 22.

  As shown in FIG. 3, at the time of predetermined recording, the recording paper T as a recording medium is introduced onto the conveyance surface 22 </ b> A of the conveyance belt 22 from one side in the conveyance direction X. With the operation of the suction unit 24, a suction force acting on the transport belt 22 is generated on the transport surface 22A through the suction through hole (not shown). The recording paper T introduced onto the transport surface 22A of the transport belt 22 is attracted to the transport surface 22A by the suction force and transported toward the other side in the transport direction X. Ink is ejected from the recording head 30 for ejecting ink of the nozzle unit 3 (described later) toward the recording paper T that is transported while being attracted to the transport surface 22A of the transport belt 22 in this manner, thereby recording. An image or the like is recorded (printed) on the paper T.

  The nozzle unit 3 includes a nozzle unit base member 32 and a recording head 30. The nozzle unit base member 32 is a base member that supports the recording head 30.

  The recording heads 30 are supported by the nozzle unit base member 32, and a plurality (four in the present embodiment) are provided in parallel with each other at regular intervals in the transport direction X. The recording head 30 extends in a direction Y (hereinafter also referred to as “lateral direction”) orthogonal to the transport direction X in a horizontal plane.

  The recording head 30 has a nozzle surface 31 at its lower end. The nozzle surface 31 faces the conveyance surface 22 </ b> A of the conveyance belt 22. On the nozzle surface 31, an ejection port (not shown) of an ink ejection nozzle (not shown) is formed. The ink ejection nozzles are provided over substantially the entire area in the lateral direction Y on the nozzle surface 31. The ink ejection nozzle is not provided at the peripheral edge of the nozzle surface 31.

  The transport unit 2 is configured to be moved up and down (moved) in a direction Z (hereinafter also referred to as “vertical direction Z”) perpendicular to the horizontal plane with respect to the nozzle unit 3 by a first lifting mechanism (not shown). By the movement of the conveyance unit 2 in the vertical direction Z, the conveyance surface 22A of the conveyance belt 22 can be relatively approached or separated from the nozzle surface 31 of the recording head 30 facing the conveyance surface 22A.

  As shown in FIGS. 2 and 4 to 6, the cap unit 5 includes a nozzle cap member 50, a shaft member 51, a nozzle cap base member 52, a stopper 53, and a coil spring 54.

  The nozzle cap base member 52 is a plate-like base member that supports the nozzle cap member 50 via the shaft member 51 and the like. The nozzle cap base member 52 includes a through hole 52 </ b> A at a position corresponding to the shaft member 51. The nozzle cap member 50 is a member that covers the nozzle surface 31 of the recording head 30 in the nozzle unit 3, and is provided in the same number (four in this embodiment) as the recording head 30. The nozzle cap member 50 extends in the lateral direction Y.

  The shaft member 51 is fixedly connected to the lower side of each nozzle cap member 50 in the vicinity of both end portions in the lateral direction Y (two in total). The shaft member 51 is inserted into the through hole 52 </ b> A of the nozzle cap base member 52 and includes a stopper 53. The stopper 53 is connected to the lower end portion (the end portion on the nozzle cap base member 52 side) of the shaft member 51, and has an outer diameter larger than the diameter of the through hole 52A.

  The coil spring 54 is disposed between the nozzle cap member 50 and the nozzle cap base member 52 so as to surround the outer periphery of the shaft member 51. As a result, the nozzle cap member 50 is urged upward in the vertical direction Z via the elastic force of the coil spring 54 with respect to the nozzle cap base member 52 and covers the nozzle surface 31 of the recording head 30. It adheres elastically to.

The cap unit 5 is disposed on one side in the lateral direction Y with respect to the transport unit 2 and the nozzle unit 3 (upper side in FIG. 1 and right side in FIG. 2). The direction from the cap unit 5 in this state toward the transport unit 2 and the nozzle unit 3 is also referred to as “second direction Y2”. The cap unit 5 has a second horizontal movement mechanism (see FIG. 16) in a separated state (see FIG. 16) in which the transport unit 2 moves downward in the vertical direction Z and the transport surface 22A is sufficiently separated from the nozzle surface 31 of the nozzle unit 3. It moves to the 2nd direction Y2, and it is comprised so that arrangement | positioning is possible in the conveyance space A (refer FIG. 16) between the nozzle surface 31 and the conveyance surface 22A. By the operation of the second horizontal movement mechanism, the cap unit 5 moves the retraction position P1 indicated by the solid line in FIGS. 1 and 2 and the virtual line in FIGS. 15 and 16 and the nozzle cap position indicated by the solid line in FIGS. It is configured to be movable between P2.

  Next, the cleaning unit 4 will be described in detail.

  As shown in FIGS. 7 to 10, the cleaning unit 4 includes a wiper case 40, a wiper member 41, a cleaning unit base member 44, a shaft member 46, a wiper rotation drive mechanism (drive means) 45, and a solvent. And a porous member 71 as an absorber. The wiper case 40, the wiper rotation drive mechanism 45, and the porous member 71 constitute ink removing means that can remove ink attached to the wiper member 41.

  The cleaning unit base member 44 is a base member that supports the wiper case 40. The wiper case 40 has a wiper housing part 42 and a wiper opening 43. The wiper case 40 is a support member that supports the wiper member 41. The wiper accommodating portion 42 is a portion that can accommodate the wiper member 41. The wiper opening 43 is an opening located at the top of the wiper case 40. As shown in FIG. 1, the same number of wiper cases 40 as the nozzle surfaces 31 of the recording head 30 (four in this embodiment) are provided. Similar to the nozzle cap member 50, the wiper case 40 is arranged at equal intervals in the transport direction X and is fixed on the cleaning unit base member 44.

  In the bottom wall portion 40A of the wiper case 40, a discharge port 40C that penetrates the cleaning unit base member 44 and opens downward in the vertical direction Z is formed. The discharge port 40 </ b> C discharges the ink cleaned from the nozzle surface 31 by the wiper member 41 to the outside of the wiper housing portion 42.

  Further, a stopper portion 40S is provided inside the side wall portion 40B of the wiper case 40. The stopper portion 40S abuts on a support member 41B of the wiper member 41, which will be described later, and restricts the rotation of the wiper member 41.

  As shown in FIG. 7, the wiper member 41 has a wiping portion 41A and a support member 41B that supports the wiping portion 41A.

  The wiping portion 41A is made of rubber such as urethane rubber or EPDM (ethylene-propylene-diene rubber).

  The shaft member 46 penetrates through the support member 41B and is rotatably supported by the wiper case 40. One end of the shaft member 46 protrudes from the outer surface of the wiper case 40.

  The wiper member 41 is accommodated in the wiper accommodating portion 42 of the wiper case 40 and is rotatably supported by the wiper case 40 via the shaft member 46. Accordingly, the wiper member 41 is configured such that the wiping portion 41 </ b> A can protrude to the outside of the wiper housing portion 42 via the wiper opening 43 when the support member 41 </ b> B rotates about the shaft member 46.

  As shown in FIGS. 7 and 8, the wiper rotation drive mechanism 45 includes a large diameter gear 48 </ b> A, a small diameter gear 48 </ b> B, and a drive motor 49. The large-diameter gear 48A is a gear attached to a portion of the shaft member 46A that protrudes from the outer surface of the wiper case 40. The small diameter gear 48B is a gear that meshes with the large diameter gear 48A. The drive motor 49 is a motor having a small-diameter gear 48B attached to the rotation shaft.

  The wiper rotation drive mechanism 45 can rotate the wiper member 41 in the forward direction or the reverse direction with the shaft member 46 as a fulcrum. As a result, the wiper member 41 is switched between a state in which it is accommodated in the wiper accommodating portion 42 (standby position) and a state in which the wiper member 41 protrudes outside the wiper accommodating portion 42 via the wiper opening 43 (cleaning position). It is configured to be possible (movable). By changing the rotation drive amount of the wiper rotation drive mechanism 45, the rotation angle of the wiper member 41 can be adjusted.

  The cleaning unit 4 is disposed on the other side in the lateral direction Y with respect to the transport unit 2 and the nozzle unit 3 (the lower side in FIG. 1 and the left side in FIG. 2). The direction from the cleaning unit 4 in this state toward the transport unit 2 and the nozzle unit 3 is also referred to as a “first direction Y1”. The cleaning unit 4 includes a first horizontal movement mechanism (see FIG. 12) in a separated state (see FIG. 12) in which the transport unit 2 moves downward in the vertical direction Z and the transport surface 22A is sufficiently separated from the nozzle surface 31 of the nozzle unit 3. It moves to the 1st direction Y1, and it is comprised so that arrangement | positioning is possible in the conveyance space A (refer FIG. 12) between the nozzle surface 31 and the conveyance surface 22A. By the operation of the first horizontal movement mechanism, the cleaning unit 4 has the retracted position P3 indicated by the solid line in FIGS. 1 and 2 and the virtual line in FIGS. 11 and 12, and the folding position P4 indicated by the solid line in FIGS. Between the two.

  As shown in FIGS. 7 and 10, the wiper cap member 6 includes an inner portion 61 and a flange portion 62. The inner part 61 is a part that fits into the wiper housing part 42 of the wiper case 40 and closes the wiper opening 43. The flange portion 62 is a portion that comes into contact with the upper end edge 40 </ b> E of the side wall portion 40 </ b> B of the wiper case 40 when the inner portion 61 is fitted into the wiper housing portion 42.

  The wiper cap member 6 is arranged above the retracted position P3 of the cleaning unit 4 in the vertical direction Z and is configured to be movable up and down (moved) in the vertical direction Z via a second lifting mechanism (not shown). The wiper cap member 6 is configured to be movable between a closed position P5 for closing the wiper opening 43 of the wiper case 40 shown in FIG. 7 and a retracted position P6 shown in FIG. Has been.

  The porous member 71 is for removing the ink from the wiper member 41 by bringing a water-soluble organic solvent described later into contact with the wiper member 41 to which the ink has adhered by cleaning.

  As shown in FIGS. 7 and 9, the porous member 71 is a flat plate in which the base end portion 71b is fixed to the bottom surface of the wiper case 40, is erected in the Z direction (vertical direction), and the thickness in the direction Y is thin. Shaped member. As shown in FIG. 9, the porous member 71 is disposed along the side wall on one side in the direction Y of the wiper case 40.

  As shown in FIG. 7, the side surface of the porous member 71 on the wiper member 41 side is curved in an arc shape. The thickness of the porous member 71 is large, and the thickness decreases as it goes downward. The arc-shaped side surface is an arc-shaped contact portion 71 a that contacts the vicinity of the tip of the wiping portion 41 </ b> A of the wiper member 41 during the rotation of the wiper member 41.

  The arcuate contact portion 71 a has a shape that substantially follows the rotational trajectory of the wiper member 41 with the shaft member 46 as the center. The width of the porous member 71 (length in the direction X) is larger than the width of the wiper member 41 (length in the direction X). Thereby, the entire tip of the wiping portion 41 </ b> A of the wiper member 41 can contact the arcuate contact portion 71 a of the porous member 71. As a result, the foreign matter 91 adhering to the wiper member 41 during cleaning is removed (captured) at the arcuate contact portion 71a as shown in FIG.

  The porous member 71 has a base end (lower end) adjacent to the discharge port 40C. When the viscosity of the foreign material 91 captured by the porous member 71 is lowered by the water-soluble organic solvent and the fluidity is increased, a part or all of the foreign material 91 flows downward along the porous member 71 and is collected through the discharge port 40C. Is done. Therefore, it is possible to suppress the ink from thickening and fixing in the porous member 71.

  As the porous member 71, for example, a porous soft sponge-like member having a large number of fine holes therein can be used. Such a porous member 71 can absorb and hold a water-soluble organic solvent as exemplified below, and can easily release the water-soluble organic solvent by an external force. As a material of the porous member 71, for example, synthetic resin, synthetic rubber, or the like can be used. The porous member 71 can be produced by foam molding of synthetic resin, synthetic rubber or the like.

  As the water-soluble organic solvent, those having a boiling point of 200 ° C. or more and a solubility parameter (SP value) of 9.5 or more and 13.7 or less are used. When the boiling point is in the above range, volatilization of the water-soluble organic solvent is suppressed during use of the recording apparatus 1. Further, when the SP value is in the above range, the solidification of the resin contained in the ink is suppressed, and the thickening of the ink can be suppressed. In other words, since the effect of dissolving the resin contained in the ink is high, the viscosity of the ink can be reduced.

The water-soluble organic solvent, Ru-soluble ether solvent or a water-soluble diol solvents der. Specifically, water-soluble ether solvent is diethylene glycol monoethyl ether, triethylene glycol monomethyl et Chirueteru, or Ru triethylene glycol monobutyl ether Rudea. Examples of the water-soluble diol solvent include 2,5-hexanediol, 1,5-pentadiol, 1,6-hexanediol, 2-ethyl-3-hexanediol, 2-methyl-1,3 -Hexanediol, 2,4-diethyl-1,5-pentanediol and the like.

  When a pigment is used as the coloring material of the aqueous ink, the acid value of the pigment dispersion resin contained in the ink is generally about 150 to 250 in terms of stability and pigment dispersibility.

  Next, the operation of the inkjet recording apparatus 1 of the first embodiment will be described.

  In the state shown in FIGS. 1 to 3, the recording paper T introduced onto the conveyance surface 22 </ b> A of the conveyance belt 22 via the driving roller 20 is caused by the suction force acting on the conveyance belt 22 as the suction unit 24 operates. Adsorbed to the transport surface 22A and transported from one side of the transport direction X to the other. Ink is ejected from the recording head 30 of the nozzle unit 3 toward the recording sheet T conveyed on the conveying surface 22A, whereby a predetermined image or the like is recorded (printed) on the recording sheet T.

  At the time of this recording, as shown in FIGS. 1 and 2, the cap unit 5 stands by at the retracted position P1, and the cleaning unit 4 stands by at the retracted position P3. Further, the wiper cap member 6 is disposed at the closing position P5 and closes the wiper opening 43 of the wiper case 40 in the cleaning unit 4.

  After the recording of a predetermined image or the like is completed, the first elevating mechanism operates. The transport unit 2 moves downward in the vertical direction Z by the operation of the first lifting mechanism. Due to the movement of the transport unit 2, the transport surface 22A of the transport belt 22 is sufficiently separated from the nozzle surface 31 of the recording head 30, as shown in FIGS. A conveyance space A is formed between the transfer space A and 31.

  Next, the second elevating mechanism operates. By the operation of the second lifting mechanism, the wiper cap member 6 moves upward in the vertical direction Z as shown in FIGS. 12 to 14 and is disposed at the retracted position P6. The wiper member 41 in the cleaning unit 4 is rotated by the wiper rotation drive mechanism 45 about the shaft member 46 as a fulcrum. After that, as shown in FIG. 10, when the wiper member 41 stands up to a substantially vertical state, the wiper rotation drive mechanism 45 is stopped, and the wiper member 41 is held in a substantially vertical state.

  Subsequently, the first horizontal movement mechanism operates. By the operation of the first horizontal movement mechanism, the cleaning unit 4 moves in the first direction Y1 and is disposed in the transport space A as shown in FIG. That is, it moves in the first direction Y1 from the retracted position P3 indicated by the solid line in FIGS. 1 and 2 and the phantom line in FIGS. 11 and 12 toward the folding position P4 indicated by the solid line in FIGS. During the forward movement of the cleaning unit 4, the wiper member 41 is held in a substantially upright state by being limited in rotation by the wiper rotation drive mechanism 45, and thus resists the elasticity of the sweep portion 41 </ b> A. The tip of the bending and wiping portion 41 </ b> A elastically contacts the nozzle surface 31 of the recording head 30. In this state, the wiper member 41 moves forward in the first direction Y1, whereby the nozzle surface 31 of the recording head 30 is cleaned (wiped).

  Then, after the cleaning unit 4 moves to the folding position P4 and stops, the first horizontal movement mechanism performs a reverse operation. By the reverse operation of the second horizontal movement mechanism, as shown in FIG. 14, the cleaning unit 4 moves backward in the second direction Y2 from the folding position P4 toward the retracted position P3.

  During the backward movement of the cleaning unit 4, the wiper member 41 is held in a state where the wiper rotation drive mechanism 45 restricts the rotation and stands substantially vertically, and thus resists the elasticity of the sweep portion 41 </ b> A. Then, the tip of the wiping portion 41A elastically contacts the nozzle surface 31 of the recording head 30. In this state, the wiper member 41 moves backward in the second direction Y2, whereby the nozzle surface 31 of the recording head 30 is cleaned.

  As described above, the wiper member 41 of the cleaning unit 4 cleans the nozzle surface 31 of the recording head 30 both when the cleaning unit 4 reciprocates (when the cleaning unit 4 moves in the first direction Y1 and the second direction Y2). Do. Then, the cleaning unit 4 that has been cleaned moves to the retracted position P3.

  Next, the ink adhering to the wiper member 41 is removed at the retracted position P3. That is, the wiper member 41 is rotated by the wiper rotation drive mechanism 45 from the cleaning position where the wiper member 41 shown in FIG. 10 is raised to the standby position where the wiper member 41 shown in FIG. Is done. In this turning process, when the wiper member 41 comes into contact (sliding contact) with the arcuate contact portion 71a of the porous member 71, the ink (foreign matter 91) adhering to the tip wiping of the wiping portion 41A of the wiper member 41 is removed. Then, it is captured by the porous member 71 by friction with the arcuate contact portion 71a (FIG. 7).

  The rotation of the wiper member 41 may be continuously performed from the cleaning position to the standby position. For example, the wiper member 41 stops or decelerates when the wiping portion 41A of the wiper member 41 contacts the arcuate contact portion 71a of the porous member 71. May be. By controlling in this way, the water-soluble organic solvent impregnated in the porous member 71 is sufficiently brought into contact with the wiping portion 41A and the foreign matter 91 adhering thereto, and the water-soluble organic solvent is brought into contact with the interface between the wiping portion 41A and the foreign matter 91. Can penetrate. Thereby, the effect which removes the foreign material 91 from 41 A of wiping parts can be heightened more.

  When the viscosity of the foreign material 91 captured by the porous member 71 is lowered by the water-soluble organic solvent and the fluidity is increased, a part or all of the foreign material 91 flows downward along the porous member 71 and is collected through the discharge port 40C. Is done.

  When cleaning is performed next time, the wiper member 41 is rotated from the standby position to the cleaning position, that is, the operation reverse to the above. Even during this rotation, the wiping portion 41 </ b> A of the wiper member 41 contacts the porous member 71. Therefore, when ink remains on the wiper member 41, part or all of the ink is removed by this contact.

  Next, the second elevating mechanism is reversely operated. By the reverse operation of the second lifting mechanism, the wiper cap member 6 located at the retracted position P6 moves downward in the vertical direction Z and is disposed at the closed position P5 (see FIG. 16). The wiper opening 43 of the wiper case 40 is closed by the wiper cap member 6 disposed at the closing position P5.

  Next, an operation in which the nozzle cap member 50 of the cap unit 5 covers the nozzle surface 31 of the recording head 30 after the cleaning of the nozzle surface 31 of the recording head 30 by the cleaning unit 4 is completed will be described.

  As shown in FIGS. 15 to 17, even when the cleaning by the cleaning unit 4 is completed, the transport unit 2 is held in a state of being arranged below the vertical direction Z. Accordingly, as shown in FIGS. 16 and 17, the conveyance surface 22 </ b> A of the conveyance belt 22 is in a state sufficiently separated from the nozzle surface 31 of the recording head 30, and between the conveyance surface 22 </ b> A and the nozzle surface 31. The transfer space A is formed.

In this state, the second horizontal movement mechanism operates. By the operation of the second drive movement mechanism, the cap unit 5 moves in the second direction Y2 as shown in FIGS.
Placed in. That is, the cap unit 5 moves in the second direction from the retracted position P1 indicated by the solid line in FIGS. 1 and 2 and the imaginary line in FIGS. 15 and 16 toward the nozzle cap position P2 indicated by the solid line in FIGS. Move to Y2.

  When the cap unit 5 moves to the nozzle cap position P <b> 2, the nozzle cap member 50 moves upward in the vertical direction Z and elastically adheres to the nozzle surface 31 of the recording head 30. As a result, the ink ejection nozzles of the recording head 30 are closed, and the ink flow is suppressed, and floating dust, paper waste, and the like are suppressed from adhering to the nozzle surface 31.

  With the above operation, a series of operations such as image recording, cleaning of the nozzle surface 31 and capping of the nozzle surface 31 are completed. Next, when recording an image or the like, the following operation is performed. That is, the cap unit 5 is moved in the first direction Y1 so as to separate the nozzle cap member 50 from the nozzle surface 31 of the recording head 30 by the second horizontal movement mechanism, and is arranged at the retracted position P1. Next, the transport unit 2 is raised by the first lifting mechanism to bring the transport surface 22 </ b> A of the transport belt 22 closer to the nozzle surface 31 of the recording head 30. Thereby, it is possible to restore the initial state shown in FIGS. 1 to 3 and to record the next image or the like.

  According to the ink jet recording apparatus 1 of the first embodiment, the following effects are exhibited.

  In the first embodiment, since the ink adhering to the wiper member 41 is removed by bringing the water-soluble organic solvent having the above physical properties into contact with the wiper member 41, the ink hardly remains on the wiper member 41 after the removal. The water-soluble organic solvent having the physical properties is excellent in the effect of suppressing the increase in the viscosity of the ink, as shown in Examples described later. In other words, the water-soluble organic solvent is excellent in the effect of reducing the viscosity of the ink. Therefore, the ink adhering to the wiper member 41 is easily removed due to a decrease in viscosity when the water-soluble organic solvent comes into contact therewith. Thereby, it is possible to suppress the ink remaining on the wiper member 41 and thickened from being reattached to the nozzle surface 31.

  In the first embodiment, the ink removing unit includes a wiper case 40 that rotatably supports the wiper member 41, a cleaning position where the cleaning is performed by the wiper member 41, and when the cleaning is not performed. A wiper rotation drive mechanism 45 for rotating the wiper member 41 between a standby position for waiting for the wiper member, and a position where the wiper member 41 can come into contact with the wiper member 41 during the rotation of the wiper member 41. And a porous member 71 impregnated with a solvent. Therefore, the wiper member 41 can be brought into contact with the porous member 71 while the wiper member 41 is rotated by the wiper rotation drive mechanism 45. Thus, the water-soluble organic solvent can be reliably brought into contact with the wiper member 41 with a simple structure.

  In the first embodiment, the opening of the wiper case 40 that accommodates and supports the wiper member 41 can be closed by the wiper cap member 6. Therefore, after the ink of the wiper member 41 is removed by the porous member 71, even if the ink remains in the wiper member 41, the sealed space surrounded by the wiper case 40 and the wiper cap member 6. Therefore, the ink attached to the wiper member 41 can be prevented from being thickened. Further, when the cleaning is not performed, the porous member 71 can also be accommodated in the sealed space, so that it is possible to suppress thickening of the ink adhering to the porous member 71 and to suppress volatilization of the water-soluble organic solvent. be able to.

  In the first embodiment, the nozzle surface 31 of the recording head 30 after being cleaned by the wiper member 41 in the cleaning unit 4 is covered with the nozzle cap member 50.

  Therefore, it is possible to suppress floating dust, paper waste, and the like from adhering to the cleaned nozzle surface 31. In addition, the nozzle cap member 50 can block the ink discharge nozzles of the recording head 30 to suppress the ink flow from the recording head 30. Therefore, it is possible to further suppress the occurrence of defective ink ejection during predetermined recording.

Second Embodiment
Next, a second embodiment of the present invention will be described. About this 2nd Embodiment, it demonstrates centering around a different point from 1st Embodiment mainly, the same code | symbol is attached | subjected about the structure similar to 1st Embodiment, and detailed description is abbreviate | omitted. In the second embodiment, the description of the first embodiment is appropriately applied to points that are not particularly described. Also in the second embodiment, the same effects as in the first embodiment are achieved.

  FIG. 18 is a longitudinal sectional view showing a state in which the wiper opening of the cleaning unit according to the second embodiment is closed by a wiper cap member.

  As shown in FIG. 18, the recording apparatus 1 of the second embodiment further includes a cartridge 81 in which the water-soluble organic solvent is stored and the porous member 71 can be replenished with the water-soluble organic solvent. The cartridge 81 is detachably mounted in a cartridge mounting opening (not shown) provided on the side surface of the wiper case 40.

  In the second embodiment, the porous member 71 can be replenished with a water-soluble organic solvent from the cartridge 81. Further, when the cartridge 81 becomes empty, the porous member 71 can be continuously replenished with the water-soluble organic solvent by simply replacing the cartridge 81 with another cartridge 81.

<Other embodiments>
As mentioned above, although preferred embodiment of this invention was described, this invention can be implemented with a various form, without being limited to embodiment mentioned above.

  For example, in the above-described embodiment, the case where the wiper case 40 is used as the support member that supports the wiper member 41 has been described as an example, but the present invention is not limited thereto. As the support member, for example, a plate-like member or a rod-like member may be used in addition to the box-like member as in the embodiment.

  Moreover, although the said embodiment gave and demonstrated the case where the sponge-like porous member 71 was used as a solvent absorber, it is not limited to this. As the solvent absorber, in addition to the porous member 71, a material capable of absorbing the solvent such as a cloth-like member or a non-woven fabric may be used.

  Moreover, in the said embodiment, although the cap unit 5 is provided, the cap unit 5 is not essential in this invention.

  In the above embodiment, the transport unit 2 is moved with respect to the nozzle unit 3 so that the transport surface 22A and the nozzle surface 31 of the recording head 30 can be relatively approached or separated from each other. Not. For example, the nozzle unit 3 may be moved without moving the transport unit 2 so that the nozzle surface 31 of the recording head 30 and the transport surface 22A can be relatively approached or separated. Further, both the transport unit 2 and the nozzle unit 3 may be moved relative to each other so that the transport surface 22A and the nozzle surface 31 of the recording head 30 can be relatively approached or separated from each other.

  Further, although not described in the above embodiment, in the inkjet recording apparatus of the present invention, a series of operations such as recording of an image, cleaning of the nozzle surface 31 and capping of the nozzle surface 31 are all performed in a preset order. It is preferable to use a control device such as a computer having a memory in which a control program to be automatically executed is stored.

  The ink removing means described in the embodiment can obtain an excellent ink removing effect when the water-soluble organic solvent having the physical properties is used. For example, a solvent other than the water-soluble organic solvent is used. Even if it is used or when ink is removed by friction between the solvent absorber and the wiper member 41 without using a water-soluble organic solvent, the ink removal effect is better than that of the prior art described in the background art. Can be obtained.

  Below, an Example is given and this invention is demonstrated further more concretely.

(Preparation of pigment dispersion)
Phthalocyanine blue, styrene acrylic resin, glycerin, and ion-exchanged water as pigments were mixed in the proportions shown in Table 1 and kneaded with a media type disperser. A styrene acrylic resin having an acid value in the range of 150 to 250 was used. As a media type disperser, even when zirconia beads with a media diameter of 0.2 to 1.0 mm are used, a wet disperser (Asada Steel Corporation: Nano Glen Mill) equipped with a mechanism that gives optimum dispersion energy to each media is used. Using.

  The dispersion particle size of the pigment dispersion was adjusted so that the average particle size was 100 nm. For the particle size distribution measurement, a zeta sizer manufactured by Nano / Sysmex Corporation was used as a solution diluted 300 times with ion-exchanged water.

(Create ink)
The pigment dispersion obtained above and the materials shown in Table 2 are mixed in the proportions shown in Table 2, and after sufficiently stirring, the mixture is filtered under pressure with a filter having a pore diameter of 5 μm, thereby recording liquid (ink). Got.

(Evaluation of ink removal effect)
A porous member 71 is disposed in the wiper case 40 of the cleaning unit 4 shown in FIGS. 7 to 10, and each of the water-soluble organic solvents (resin solubilizers) shown in Tables 3 to 5 is attached to the porous member 71. After impregnation, the presence or absence of a non-ejection nozzle was confirmed by the following procedure, and the ink removal effect of each water-soluble organic solvent was evaluated.

  The evaluation procedure is as follows. That is, the porous member 71 is impregnated with each water-soluble organic solvent, purge (discharge of ink from the nozzle), cleaning of the nozzle surface 31 with the wiper member 41, and ink removal operation of the wiper member 41 with the porous member 71 (Rotating operation of the wiper member 41) was set as one set, and after a total of three sets, the opening of the wiper case 40 was closed by the wiper cap member 6.

  Next, at the time of 1 day and 1 month after closing the opening, after performing the above operation again for 3 sets, a check pattern (missing pin check pattern) was printed to confirm the presence or absence of a non-ejection nozzle. The evaluation results are shown in Tables 6-9. In Tables 6 to 9, “None” means that there was no non-ejecting nozzle (missing pin), and “Yes” means that there was a non-ejecting nozzle (missing pin). doing.

  From Table 6 to Table 9, by using a water-soluble organic solvent having a boiling point of 200 ° C. or higher and an SP value in the range of 9.5 to 13.7, a plurality of times are intermittently used in a long-term use. It can be seen that image defects (non-ejection nozzles) can be suppressed even when only maintenance is performed, and high image quality can be obtained.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Conveyance unit 3 Nozzle unit 4 Cleaning unit 5 Cap unit 6 Wiper cap member 22 Conveyance belt 22A Conveying surface 30 Recording head 31 Nozzle surface 40 Wiper case 41 Wiper member 42 Wiper accommodating part 43 Wiper opening part 50 Nozzle cap member 71 Porous member 71a Arc-shaped contact portion 81 Cartridge X Transport direction Y Lateral direction Y1 First direction Y2 Second direction T Recording paper (recording medium)

Claims (5)

A recording head having a nozzle surface on which a plurality of nozzles are formed;
A wiper member for cleaning the nozzle surface by moving relative to the recording head in a direction along the nozzle surface;
An ink removing unit capable of removing the ink from the wiper member by bringing a water-soluble organic solvent having a boiling point of 200 ° C. or more and a solubility parameter of 9.5 or more and 13.7 or less into contact with the wiper member to which the ink has adhered by the cleaning; With
The water-soluble organic solvent is a water-soluble ether solvent or a water-soluble diol solvent,
The water-soluble ether solvent, Ri diethylene glycol monoethyl ether, triethylene glycol monoethyl ether or triethylene glycol monobutyl ether der,
The ink removing means includes
A support member that rotatably supports the wiper member;
Drive means for rotating the wiper member between a cleaning position where the cleaning is performed by the wiper member and a standby position where the wiper member is waited when the cleaning is not performed;
A solvent absorber provided at a position where the wiper member can be contacted during rotation of the wiper member and at a position where the wiper member at the standby position is not in contact, and impregnated with the water-soluble organic solvent; Have
In the rotation operation of the wiper member from the cleaning position to the standby position, the wiper member is decelerated when the wiper member comes into contact with the solvent absorber so that the contact time between the wiper member and the solvent absorber becomes longer. that the ink jet recording apparatus.   The inkjet recording apparatus according to claim 1, wherein the ink contains a pigment as a coloring material.   3. The ink jet recording apparatus according to claim 1, wherein the recording head is a line head type in which the plurality of nozzles are arranged in a line in a direction intersecting a paper transport direction. The support member is a wiper case having a housing part that houses the wiper member and the solvent absorber, and an opening that can project at least a part of the wiper member to the outside of the housing part during the cleaning,
The cleaning is further provided with a wiper cap member for closing the opening of the wiper case when not performed, the ink jet recording apparatus according to any one of claims 1 to 3. Wherein the water-soluble organic solvent is stored, the solvent absorber to said further comprising a refillable cartridge a water-soluble organic solvent, an ink jet recording apparatus according to any one of claims 1 to 4.

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