JP4687328B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus. More specifically, the present invention relates to an ink jet recording apparatus having a cleaning unit that contacts a belt cleaning roller with a conveyance belt that conveys a recording medium to clean the conveyance belt.

  In an inkjet recording apparatus in which a recording medium is intermittently conveyed by an endless conveying belt wound around a plurality of conveying rollers, and ink is ejected from a recording head installed opposite to the conveying belt. When using a fabric with high ink permeability, such as a thin fabric, or when providing a print function for the entire surface of the recording medium that ejects ink around the recording medium, or by ejecting ink droplets from the recording head The generated ink mist may cause ink to adhere to the conveyor belt and contaminate the conveyor belt. Ink adhering to the conveyance belt returns to the recording medium conveyance path, and there is a problem that the back surface of a new recording medium is soiled at the next printing. As a countermeasure against this problem, it is known to provide a conveying belt cleaning means such as a method of abutting an absorbing roller that absorbs ink on the conveying belt, a method of abutting a blade, or the like.

  As the cleaning means, in a cleaning device that removes deposits adhered to the outer surface of the conveyor belt by pressing the cleaning roller against the outer surface of the conveyor belt that is hung on a pair of pulleys, a part of the cleaning roller is It has been disclosed to arrange so as to be inside (see, for example, Patent Document 1).

  Further, the blade has a blade that contacts the conveying belt, and an absorbing roller that is arranged downstream of the blade in the rotation direction of the conveying belt and contacts the conveying belt. The blade wipes the ink, and further absorbs the ink remaining after the wiping. A conveyor belt cleaning device that absorbs ink and removes ink from the conveyor belt is disclosed (see, for example, Patent Document 2).

The belt cleaning roller, the absorption roller, and the cleaning roller are all synonymous.
Japanese Patent Laid-Open No. 5-132120 JP 2004-137032 A

  Regarding the cleaning of the conveyor belt described above, Patent Document 1 describes that a rotating cleaning roller is brought into pressure contact with the outer surface of the rotating conveyor belt to remove deposits attached to the outer surface of the conveyor belt. The relationship between the rotation and stopping of the intermittent conveyance of the belt and the cleaning operation of the cleaning roller is not described.

  During cleaning of the conveyor belt, when the conveyor belt rotates, cleaning is performed by contacting the rotating conveyor belt with the rotating cleaning roller. However, a part of the ink adhering to the conveyor belt is sufficiently absorbed by the cleaning roller. In some cases, a so-called ink residue may be generated.

  In addition to the cleaning described above, cleaning is performed by contacting a rotating cleaning roller against the belt surface stopped when the transport belt is stopped, thereby enabling efficient cleaning that absorbs the ink remaining and does not generate ink remaining. Become.

  However, in cleaning when the conveyance belt is stopped, if the nip width in the rotation direction of the conveyance belt where the cleaning roller contacts the conveyance belt is smaller than the single conveyance width of the conveyance belt intermittently conveyed, There is a portion that does not stop within the nip width, and this portion only passes through the rotating nip portion, which causes a problem of uneven cleaning.

Further, as in Patent Document 2, the ink is wiped with a blade, and the ink remaining by the wiping is absorbed with an absorption roller, and the ink is removed from the transport belt, or a plurality of cleaning rollers are provided. This makes it possible to perform efficient cleaning without generating ink residue, but the cleaning means becomes complicated and the cost increases.
The present invention has been made in view of the above circumstances, and provides an ink jet recording apparatus having a transport belt cleaning unit that can efficiently remove ink adhering to a transport belt that transports a recording medium with a simple configuration. For the purpose.

The above object is achieved by the following configuration.
(1) A recording medium conveying unit that intermittently conveys the recording medium in a predetermined direction by an endless conveying belt wound around a plurality of conveying rollers, and a belt cleaning roller that contacts the conveying belt and rotates to perform cleaning. An inkjet recording apparatus that performs recording on the recording medium by ejecting ink from a recording head disposed opposite to the recording medium conveyance surface of the conveyance belt.
The rotating belt cleaning roller is movable toward and away from the conveyor belt, and the nip width in the rotational direction of the belt cleaning roller and the conveyor belt is a single feed width of the conveyor belt for intermittent conveyance. An ink jet recording apparatus having a larger nip width than the nip width.
(2) The inkjet according to (1), wherein the belt cleaning roller has an outer peripheral portion formed of a porous member having continuous pores, and is disposed on a surface other than the recording medium conveyance surface of the conveyance belt. Recording device.

According to the first aspect of the present invention, the nip width in the rotational direction of the conveyance belt where the belt cleaning roller and the conveyance belt come into contact with each other is made larger than a single feed width of the conveyance belt that is intermittently conveyed. As a result, when the conveyor belt is stopped intermittently during conveyance of the conveyor belt, all the parts within a single feed width of the conveyor belt come into contact with the rotating belt cleaning roller, thereby preventing uneven cleaning when the conveyor belt is stopped. Ink adhering to the conveyor belt can be efficiently removed. Further, even when the intermittent conveyance width is changed, the nip width can be set to an appropriate nip width corresponding to the intermittent conveyance width, and the conveyance belt can be effectively cleaned.

According to the second aspect of the present invention, by forming the outer peripheral portion of the belt cleaning roller with a porous member having continuous pores, the ink attached to the conveyance belt can be quickly absorbed by the belt cleaning roller, and the conveyance The belt can be cleaned efficiently.

  Embodiments of the present invention will be described below with reference to the drawings. The ink jet recording apparatus of the present invention is not limited to the following form.

  FIG. 1 is a perspective view showing a main part of an ink jet recording apparatus provided with a conveying belt cleaning means of the present invention.

  The carriage 16 accommodates the inkjet recording head 1, a head driver, a case, and the like, and is moved along the guide rail 18 in the main scanning direction indicated by X in the drawing along the guide rail 18 by a timing belt 17 that is rotated by driving of the motor M. It is reciprocated. In the present embodiment, the guide rail 18 is supported by the column 21.

  The flexible cable 19 having flexibility is a printed wiring pattern including data signal lines, power supply lines, etc., and transfers image data, control signals, etc. between the carriage 16 and a control board (not shown). Follow the movement.

  The linear encoder 20 detects the movement position by an optical sensor provided on the carriage 16.

  The recording medium 3 is intermittently conveyed by the conveying belt 4 in the sub-scanning direction of the moving direction indicated by the arrow Y in the figure.

  FIG. 2 is a schematic cross-sectional view illustrating a recording medium conveyance mechanism and a conveyance belt cleaning unit of the inkjet recording apparatus.

  A recording medium (recording paper, fabric, etc.) 3 is held intermittently by being held on the upper surface of a conveying belt 4 around which a plurality of conveying rollers 5A, 5B, 5D are wound, and is ejected from the inkjet recording head 1 at a recording unit. A recording image is formed by the ink droplets 2 and conveyed along the conveying direction of the conveying belt 4. The recording medium 3 conveyed by the conveyance belt 4 is separated from the conveyance belt 4 at the curved surface portion of the conveyance roller 5B, and is conveyed by a conveyance unit (not shown). The driven roller 5E presses the recording medium by its own weight, and exhibits the flatness of the recording medium.

  The conveyance roller 5B is intermittently driven and rotated by a driving unit (not shown), and the conveyance belt 4 around which the conveyance roller 5B is wound is intermittently rotated in the direction of arrow Y in the drawing.

  The material of the conveyor belt 4 is not particularly limited, but a material that has less stretchability and ink repellency is preferable. Examples thereof include an endless belt in which a glass cloth is coated with a fluororesin, an endless belt in which an aramid cloth is coated with a fluororesin, and a metal endless belt such as SUS.

  Next, the cleaning means 10 for the conveyor belt 4 according to the present invention will be described. The cleaning means 10 includes a belt cleaning roller (hereinafter also referred to as an absorption roller) 101, a squeezing roller 102, a cleaning rod 103, and a cleaning liquid 103A stored in the cleaning rod. The belt cleaning roller 101 and the squeezing roller 102 are configured to be replaceable.

  The cleaning unit 10 is moved in the arrow Z direction by a moving unit (not shown) so that the belt cleaning roller 101 can be brought into contact with and separated from the transport belt 4. The contact and separation of the belt cleaning roller 101 may be performed by moving the entire cleaning unit 10 or by moving a part of the cleaning unit 10 such as the belt cleaning roller 101 and the squeezing roller 102. The nip width can be changed by the movement of the belt cleaning roller 101 in the arrow Z direction.

  The belt cleaning roller 101 includes an outer peripheral portion formed of a metal cored bar such as SUS and a porous member having continuous pores. The porous member forming the outer peripheral portion is not limited, but preferably has excellent water absorption, low hardness, and water retention. In the present embodiment, a PVC (polyvinyl chloride) sponge having an Asker C hardness of 10 ° is used. Other examples include PVA (polyvinyl alcohol) sponge, polyurethane ruby cell (manufactured by Toyo Polymer Co., Ltd.), and the like.

  The belt cleaning roller 101 is disposed between conveyance rollers other than the recording medium conveyance surface of the conveyance belt 4 and abuts on the conveyance belt 4. The belt cleaning roller in contact with the conveyance belt is rotated by a rotation driving unit (not shown). In the present embodiment, as shown in FIG. 2, the rotation direction is the forward direction with respect to the conveyance belt rotation direction, but it is also possible to rotate in the reverse direction. The belt cleaning roller can be rotated as appropriate, such as constantly rotating or intermittently rotating the conveyor belt. In the present embodiment, the rotation is always performed.

  A part of the belt cleaning roller is immersed in the cleaning liquid stored in the cleaning tub, and is a downstream side of the belt cleaning roller rotating direction of the liquid contact portion of the belt cleaning roller and a contact portion between the conveyor belt and the belt cleaning roller. A squeezing roller is arranged on the upstream side in the rotation direction of the belt cleaning roller to press and squeeze the belt cleaning roller.

  The ink 6 adhering to the conveyance belt 4 that conveys the recording medium 3 that is intermittently conveyed passes through the conveyance roller 5B, and then is absorbed and wiped off by the rotating belt cleaning roller 101. During the rotation of intermittent conveyance, the conveyance belt is wiped off by the rotating belt cleaning roller while moving the contact portion with the belt cleaning roller. When the intermittent conveyance is stopped, the conveyance belt is stopped and wiped by the belt cleaning roller that rotates at the contact portion with the belt cleaning roller.

  By making the nip width in the rotation direction of the conveyor belt, where the belt cleaning roller and the conveyor belt contact each other, larger than the one-time feed width of the conveyor belt that intermittently conveys, All the parts within one feed width can come into contact with the belt cleaning roller.

  FIG. 3 is a schematic diagram showing a case where the nip width A1 is larger than the feed width B of one time. Arbitrary point C on the conveyor belt always stops within the nip width A1 when the conveyor belt 4 stops.

  FIG. 4 is a schematic diagram showing a case where the nip width A2 is smaller than the feed width B of one time. An arbitrary point C on the conveying belt has a portion that does not stop within the nip width A2 when the conveying belt 4 is stopped.

  When cleaning the conveyor belt, when the conveyor belt rotates, cleaning is performed by contacting the rotating conveyor belt against the rotating conveyor belt, but the cleaning ability of the belt cleaning roller decreases due to deterioration over time, etc. In addition, a part of the ink adhering to the conveying belt may be left without being sufficiently absorbed by the cleaning roller, so-called ink residue may occur.

In addition to cleaning when the transport belt is rotated, cleaning is performed by contacting a rotating cleaning roller against the belt surface stopped when the transport belt is stopped, so that the remaining ink is absorbed and no ink residue is generated. It becomes possible to perform cleaning.
That is, as shown in FIG. 4, when the nip width A2 is smaller than the one-time feed width B, an arbitrary point C on the transport belt is not stopped in the nip width A2 when the transport belt 4 is stopped. When the conveyance belt is stopped, a portion where the conveyance belt is cleaned by the belt cleaning roller and a portion where the conveyance belt is not cleaned may be generated, and cleaning unevenness may occur. However, as shown in FIG. If it is larger, the arbitrary point C on the conveyor belt is always stopped within the nip width A1 when the conveyor belt 4 is stopped. Therefore, the conveyor belt is cleaned by the belt cleaning roller when the conveyor belt is stopped. As a result, cleaning that does not cause uneven cleaning becomes possible.

  The belt cleaning roller that has contacted and cleaned the conveyor belt is immersed in the cleaning liquid stored in the cleaning rod disposed downstream of the belt cleaning roller rotation direction, and the ink and dirt absorbed during cleaning of the conveyor belt are dissolved and washed. Is done. The cleaned belt cleaning roller containing the cleaning liquid is further squeezed by a squeezing roller disposed downstream of the belt cleaning roller rotation direction, and the cleaning performance is recovered to rotate and move to the conveyor belt cleaning surface.

  The conveying belt cleaning operation, the belt cleaning roller cleaning operation, and the belt cleaning roller squeezing operation are continuously performed.

  In addition, when changing the single feed width of the conveyance belt intermittent conveyance, the nip width is changed by the movement of the belt cleaning roller in the direction of the arrow Z, and the single conveyance belt is conveyed intermittently. Can be kept larger than the width.

  Moreover, when the cleaning performance of the belt cleaning roller is lowered by separating the belt cleaning roller and the conveying belt by the movement of the belt cleaning roller in the arrow Z direction, the belt cleaning roller can be easily replaced. The cleaning performance of the belt cleaning roller can be maintained.

FIG. 2 is a perspective view showing a main part of an ink jet recording apparatus provided with a conveyor belt cleaning unit according to the present invention. FIG. 3 is a schematic cross-sectional view illustrating a recording medium transport mechanism and a transport belt cleaning unit of the ink jet recording apparatus according to the present invention. It is a schematic diagram which shows the relationship between nip width and feed width. It is a schematic diagram which shows the relationship between nip width and feed width.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording head 2 Ink droplet 3 Recording medium 4 Conveying belt 5A, 5B, 5D Conveying roller 5E Follower roller 6 Ink 10 Conveying belt cleaning means 101 Belt cleaning roller 102 Diaphragm roller 103 Cleaning pad 103A Cleaning liquid

Claims (2)

A conveying means for conveying a recording medium intermittently in a predetermined direction by an endless conveying belt wound around a plurality of conveying rollers, and a conveying belt having a belt cleaning roller that rotates in contact with the conveying belt and rotates . An ink jet recording apparatus that performs recording on the recording medium by ejecting ink from a recording head disposed opposite to the recording medium conveying surface of the conveying belt.
The rotating belt cleaning roller is movable toward and away from the conveyor belt, and the nip width in the rotational direction of the belt cleaning roller and the conveyor belt is a single feed width of the conveyor belt for intermittent conveyance. An ink jet recording apparatus having a larger nip width than the nip width. 2. The ink jet recording apparatus according to claim 1, wherein the belt cleaning roller has an outer peripheral portion formed of a porous member having continuous pores and is disposed on a portion other than a recording medium conveying surface of the conveying belt.

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