JP2004250208A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high quality image preventing a recording medium from being stained by removing an ink from a conveyer belt even when the ink is attached to the conveyer belt conveying the recording medium. <P>SOLUTION: This image forming apparatus is constituted of an inkjet head having a plurality of nozzles ejecting ink drops and the conveyer belt conveying the recording medium. In the image forming apparatus, a cleaning means cleaning a surface of the conveyer belt is arranged in a downstream side of an arrangement position of the inkjet head in a conveying direction of the recording medium. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus provided with a transport belt cleaning device applicable to a printer or the like using an ink jet recording method and an image forming method.
[0002]
[Prior art]
Ink jet printers (ink jet printers) perform printing by ejecting ink droplets from an ink jet head onto a recording medium, making it easy to reduce the size of the recording means and recording high-definition images at high speed. It can record on plain paper without requiring special processing, and has the advantages of low running cost, low noise, and easy recording of color images.
[0003]
Ink jet printers include a serial printing method in which the ink jet head moves and scans in a direction intersecting the transport direction of the recording medium, and a line print method in which the ink jet head is fixedly arranged in a direction intersecting the transport direction of the recording medium. There is a method.
[0004]
Further, as a device for transporting a recording medium such as an ink jet printer, a transport belt device using an endless belt stretched by a driving roller and a driven roller is known.
[0005]
The ink jet recording apparatus disclosed in Patent Document 1 has a heat source lamp provided with a reflector for preheating and heating the recording surface of a recording medium by radiant heat in a carriage driving direction so as to face the entire recording medium. .
[0006]
In the ink jet recording method disclosed in Patent Document 2, a recording liquid is adhered to a heated recording medium, and a liquid portion having a high vapor pressure in the recording liquid is rapidly vaporized to fix a residual component including a colorant and a solvent. This is an inkjet recording method to be performed.
[0007]
The ink jet recording apparatus disclosed in Patent Document 3 is provided with a plurality of hot plate portions for heating a sheet on the upstream side of a discharge roller for discharging a sheet on which recording has been performed by a recording unit.
[0008]
The recording paper conveyance processing device of the ink jet printer disclosed in Patent Document 4 determines the pixel density of a dot image to be written, and after a lapse of time when the recording paper is transferred from the recording writing means to the drying means. A control means for controlling the feed speed of the recording paper conveying means according to the pixel density is provided.
[0009]
The ink jet printer disclosed in Patent Document 5 relates to an ink jet printer that dries ink adhered on paper with warm air from a dryer, detects that a printed line has reached a drying position, and detects the temperature and air volume of the dryer. Is controlled.
[0010]
[Patent Document 1]
Japanese Patent No. 2606190 (Claims)
[0011]
[Patent Document 2]
Japanese Patent No. 2615567 (Claims)
[0012]
[Patent Document 3]
Japanese Patent No. 2810475 (Claims)
[0013]
[Patent Document 4]
Japanese Patent No. 2861124 (Claims)
[0014]
[Patent Document 5]
Japanese Patent No. 3036504 (Claims)
[0015]
[Problems to be solved by the invention]
As a first problem of the ink jet printer, there is an ink stain on a transport belt that transports a recording medium.
[0016]
In a serial print type ink jet printer, at the time of maintenance, the ink in the nozzle is moved by moving the ink jet head outward in the width direction intersecting the transport direction of the recording medium and ejecting ink droplets from the nozzle of the ink jet head. He is recovering from the obstruction. However, if inkjet recording is started without loading the recording medium at the normal position of the transport belt, there is a problem that ink adheres to the transport belt and stains the recording medium.
[0017]
In an image forming apparatus that forms an image by moving an inkjet head in a width direction of a cloth and ejecting ink droplets from nozzles to a recording medium formed of a wide cloth, ink passing through the cloth is conveyed. There is a problem that the recording medium is stained by adhering to the belt.
[0018]
In an ink jet printer using a line head, nozzles are arranged in a line over substantially the entire area in the width direction intersecting the transport direction of the recording medium.
[0019]
In order to prevent the nozzles from being clogged, idle discharge of ink to the transport belt is performed in an area where no recording medium exists. There is a problem that ink adheres to the transport belt and the recording medium is contaminated by the ink.
[0020]
As a second problem of the ink jet printer, there is a drying property of the ink. If the ink deposited on the recording medium is discharged and stacked outside the machine without drying, the ink image on the recording medium may be rubbed and disturbed, or may be transferred to the back surface of another recording medium. In addition, problems such as dirty hands may occur.
[0021]
In order to solve this, an ink drying unit is used. The ink drying unit is a heating roller disposed downstream of the nozzle position of the inkjet head in the transport direction of the transport belt. A heating roller having a built-in heating source is in contact with the outer peripheral surface of the transport belt, and fixes the ink image by contacting and heating the recording medium.
[0022]
However, in this case, the ink formed on the printed recording medium or the ink ejected during nozzle maintenance is placed on the transport belt and further adheres to the surface of the heating roller, and the recording medium is printed at the next sheet passing. A new problem arises that the surface becomes dirty.
[0023]
An object of the present invention is to improve the performance of removing ink adhered to a conveyor belt and a heating roller.
[0024]
[Means for Solving the Problems]
The above object is achieved by the following image forming apparatus and image forming method of the present invention.
[0025]
(1) In an image forming apparatus including an inkjet head having a plurality of nozzles for ejecting ink droplets and a transport belt for transporting a recording medium, the image forming apparatus includes: An image forming apparatus comprising a cleaning unit for cleaning a surface of a transport belt.
[0026]
(2) In an image forming apparatus including an inkjet head having a plurality of nozzles for ejecting ink droplets and a transport belt that transports and rotates a recording medium, the recording medium transport downstream of the arrangement position of the inkjet head. Cleaning means for cleaning the surface of the transport belt provided on the side thereof, a heating roller disposed downstream of the position of the first cleaning means in the transport direction of the recording medium, and a surface of the heating roller And a second cleaning means for cleaning the image forming apparatus.
[0027]
(3) An inkjet head having a plurality of nozzles for ejecting ink droplets, a transport belt for transporting the recording medium, and cleaning for cleaning the transport belt disposed downstream of the location where the inkjet head is transported on the recording medium. Means for cleaning the surface of the transport belt by pressing the cleaning member of the cleaning means against the surface of the transport belt prior to image formation by the ink jet head, and then moving the cleaning member to the surface of the transport belt. The recording medium on which an image has been formed by the inkjet head is transported by the transport belt.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0029]
[Inkjet recording device]
FIG. 1 is a perspective view of an ink jet recording apparatus as an example of an image forming apparatus, and FIG. 2 is a sectional view.
[0030]
<Inkjet head and ink supply system>
The ink jet recording apparatus shown in FIG. 1 is a so-called full line type color printer. Ink jet heads 1Y, 1M, 1C, and 1K each having a plurality of nozzles are arranged in a plurality of rows in the transport direction of the recording medium S. The plurality of nozzles 1Y, 1M, 1C, and 1K are arranged over the entire width of the print area of the recording medium S in a direction orthogonal to the transport direction of the recording medium S.
[0031]
The ink jet heads 1Y, 1M, 1C, and 1K are connected to ink tanks 3Y, 3M, 3C, and 3K via ink supply pipes 2Y, 2M, 2C, and 2K, respectively, and each color ink is supplied.
[0032]
The ink tanks 3Y, 3M, 3C, and 3K contain yellow ink, magenta ink, cyan ink, and black ink, respectively.
[0033]
The inkjet heads 1Y, 1M, 1C, and 1K eject ink droplets Dy, Dm, Dc, and Dk on demand from a plurality of nozzles by a piezoelectric element that is turned on and off by a head driver 7A connected to the control unit 7. .
[0034]
The aqueous ink is formed of a coloring agent composed of a dye or a pigment, a solvent composed of a polyhydric alcohol, an additive, and the like, and has an appropriate surface tension in order to improve the wettability to the recording medium S.
[0035]
<Conveying system for recording medium>
A recording medium (recording paper or the like) S is conveyed while being held on the upper surface of a conveyance belt 4 around which a plurality of conveyance rollers 5A and 5B and a tension roller 5C are wound, and is recorded by the inkjet heads 1Y, 1M, 1C, and 1C. A color image is formed by ink droplets Dy, Dm, Dc, and Dk ejected from 1K. The recording medium S on which the image is formed is pressed by the heating roller 9 including a heating source such as a halogen lamp and the conveyance roller 5B via the conveyance belt 4 and is heated, thereby heating the recording medium S. Is dried and fixed, and then separated from the conveyor belt 4 and discharged out of the apparatus.
[0036]
The transport belt 4 is formed of a heat-resistant material such as polyimide, polyamide imide, or aromatic polyamide resin, or a laminated material thereof.
[0037]
The recording medium S transported by the transport belt 4 is separated from the transport belt 4 at the curved surface of the transport roller 5B, and is discharged outside the apparatus by a discharge unit (not shown).
[0038]
The transport roller 5D is biased by a spring, and presses the transport roller 5A through the transport belt 4. A support plate (platen table) 6 for movably supporting the transport belt 4 is fixedly provided on the back side of the surface of the endless belt-shaped transport belt 4 that faces the inkjet heads 1Y, 1M, 1C, and 1K.
[0039]
The transport belt 4 is rotated by a downstream transport roller 5B connected to a drive source (not shown), and its operation is controlled by a motor driver 7B connected to the control means 7.
[0040]
A charger (electrostatic means) 8 is disposed near the transport roller 5A on the upstream side of the transport belt 4. The electrostatic charge applied to the surface (transport surface) of the transport belt 4 by the charger 8 causes the recording medium S to adhere to the surface of the transport belt 4 by electrostatic attraction. The charging device 8 is controlled to be turned on and off by a charging device driver 7C connected to the control means 7.
[0041]
[First cleaning means]
The first cleaning device 10 for the transport belt 4 of the present invention will be described.
[0042]
A first cleaning unit 10 having a web 11 for cleaning the surface of the transport belt 4 is disposed downstream of the transport of the recording medium at the position where the inkjet heads 1Y, 1M, 1C, and 1K are disposed. The web 11 of the first cleaning means 10 is wound around and supported by the original winding shaft 12 and the winding shaft 13, and further winds around the outer peripheral surface of the elastic roller 14. The web 11 is made of a nonwoven fabric or the like, and is wound up by a predetermined amount by a predetermined number of sheets passed or by a predetermined amount of conveyance of the conveyor belt 4 by a motor driver 7D connected to the control means 7.
[0043]
The elastic roller 14 is provided with a pressure release mechanism (not shown), which presses or releases the transport belt 4 via the web 11 so that the recording medium S does not come into contact with the web 11. .
[0044]
A tension mechanism (not shown) is provided on the main winding shaft 12, so that the web 11 does not come loose and come into contact with the recording medium S even when the pressing of the elastic roller 14 is released. Note that an elastic cleaning pad may be used instead of the web 11.
[0045]
[Second cleaning means]
The second cleaning device 20 for the transport belt 4 of the present invention will be described.
[0046]
The ink adhering to the surface of the transport belt 4 is cleaned by the first cleaning unit 10, but the residual ink is transferred to the heating roller 9 and cleaned by the second cleaning unit 20.
[0047]
The web 21 of the second cleaning means 20 is wound around and supported by the original winding shaft 22 and the winding shaft 23. The web 21 is made of a nonwoven fabric or the like, and is wound up by a predetermined amount every predetermined number of sheets passed or every predetermined amount of conveyance of the conveyor belt 4 by a motor driver 7E connected to the control means 7. Note that an elastic cleaning pad may be used instead of the web 21.
[0048]
[Another Embodiment of Cleaning Means]
FIG. 3 is a cross-sectional view of an ink jet recording apparatus provided with a cleaning unit according to another embodiment. Note that, in the reference numerals used in the drawings, portions having the same functions as those in FIG. 2 are denoted by the same reference numerals. Further, points different from the above embodiment will be described.
[0049]
A cleaning unit 30 having a web 31 for cleaning the recording medium S transport surface of the transport belt 4 and the surface of the heating roller 9 is disposed downstream of the transport of the recording medium at the position where the inkjet heads 1Y, 1M, 1C, and 1K are disposed. . The web 31 of the cleaning means 30 is wound around and supported by the original winding shaft 32 and the winding shaft 33, and further winds around the outer peripheral surface of the elastic roller 34. The web 31 is made of a nonwoven fabric or the like, and is wound up by a predetermined amount by the motor driver 7F connected to the control means 7 for every predetermined number of sheets passed or every time the conveyance belt 4 is conveyed by a predetermined amount.
[0050]
The elastic roller 34 is provided with a pressure release mechanism (not shown), which presses or releases the conveyor belt 4 via the web 31 so that the recording medium S and the web 31 do not come into contact with each other. .
[0051]
A tension mechanism (not shown) is provided on the main winding shaft 32, and the web 31 does not come loose and come into contact with the recording medium S even when the pressing of the elastic roller 34 is released.
[0052]
The web 31 sent out from the cleaning means first contacts the heating roller 9 to clean the outer peripheral surface thereof, and then contacts the conveyor belt 4 to clean the outer peripheral surface thereof. It is wound up. The reason why the cleaning operation is performed in this order is that the amount of ink ejected onto the conveyor belt 4 to prevent nozzle clogging is much larger than the amount of ink adhering to the outer peripheral surface of the heating roller 9. . If this cleaning order is reversed, the heating roller 9 will be soiled by the ink attached to the web 31.
[0053]
[Another Embodiment of Inkjet Recording Apparatus]
Although the ink jet recording apparatus shown in FIGS. 1 to 3 is a so-called full line type color printer, the present invention is not limited to this, and the ink jet head moves in a direction intersecting the transport direction of the recording medium. It is also possible to apply the cleaning means of the present invention to a serial print type ink jet recording apparatus which performs scanning by scanning.
[0054]
Further, the recording medium S is not limited to recording paper, and the ink jet recording apparatus of the present invention can be applied to cloth, plastic film, and the like.
[0055]
【The invention's effect】
As described above, according to the image forming apparatus and the image forming method of the present invention, even if the ink ejected from the nozzle of the inkjet head adheres to the transport belt or the heating roller, the web is applied to the transport belt or the heating roller. By cleaning the recording medium in contact with the recording medium, the problem that the recording medium is soiled when the paper is passed is eliminated, and a high-quality image can be obtained.
[Brief description of the drawings]
FIG. 1 is a perspective view of an ink jet recording apparatus which is an example of an image forming apparatus.
FIG. 2 is a cross-sectional view of the inkjet recording apparatus.
FIG. 3 is a cross-sectional view of an ink jet recording apparatus provided with a cleaning unit according to another embodiment.
[Explanation of symbols]
1Y, 1M, 1C, 1K Inkjet head 4 Transport belts 5A, 5B Transport rollers 6 Support plate (platen table)
7 Control Means 8 Charger 9 Heating Roller 10 First Cleaning Means 11, 21, 31 Webs 12, 22, 32 Main Winding Shafts 13, 23, 33 Winding Shafts 14, 34 Elastic Roller 20 Second Cleaning Means 30 Cleaning Means S Recording medium (recording paper, etc.)

Claims (13)

In an image forming apparatus comprising: an inkjet head having a plurality of nozzles for ejecting ink droplets; and a transport belt for transporting a recording medium, the transport belt is disposed downstream of the location where the inkjet head is disposed on the recording medium transport. An image forming apparatus comprising a cleaning unit for cleaning a surface. The nozzle according to claim 1, wherein the plurality of nozzles of the inkjet head are arranged in a direction intersecting a transport direction of the recording medium over substantially the entire width of a print area of the recording medium. Image forming device. The image forming apparatus according to claim 1, wherein the inkjet heads having the plurality of nozzles are arranged in a plurality of rows in a transport direction of the recording medium. The image forming apparatus according to claim 1, wherein the transport belt is an endless belt-like transport belt stretched over a plurality of rollers. The platen table is fixed to a side of the endless belt-shaped conveyance belt that is in contact with an inner surface of the conveyance belt, and the conveyance belt faces a nozzle of the inkjet head and the cleaning unit. Image forming apparatus. The image forming apparatus according to claim 1, wherein the cleaning unit includes a moving mechanism configured to press and release the cleaning belt. The image forming apparatus according to claim 1, wherein the cleaning unit is a web made of a nonwoven fabric. The image forming apparatus according to claim 1, wherein the cleaning unit is an elastic pad. 2. An electrostatic unit for generating an electrostatic charge is provided on an upstream side in a transport direction of the recording medium from an arrangement position of the inkjet head and on a side facing an outer peripheral surface of the transport belt. The image forming apparatus according to any one of the preceding claims. In an image forming apparatus including an inkjet head having a plurality of nozzles that eject ink droplets, and a transport belt that transports and rotates a recording medium,
A first cleaning unit that is provided on the downstream side of the recording medium transport at the position where the inkjet head is disposed and cleans the surface of the transport belt;
A heating roller disposed on the downstream side in the transport direction of the recording medium from an arrangement position of the first cleaning unit;
Second cleaning means for cleaning the surface of the heating roller;
An image forming apparatus comprising: The image forming apparatus according to claim 10, wherein the first cleaning unit cleans a surface of the transport belt and cleans a surface of the heating roller. An inkjet head having a plurality of nozzles for ejecting ink droplets, a transport belt for transporting a recording medium, and a cleaning unit disposed downstream of the location where the inkjet head is transported on the recording medium and cleaning the transport belt. Have
Prior to image formation by the inkjet head, after cleaning the surface of the transport belt by pressing the cleaning member of the cleaning unit against the surface of the transport belt,
An image forming method, wherein the cleaning member is retracted from a surface of the transport belt, and the recording medium on which an image has been formed by the inkjet head is transported by the transport belt. The recording medium on which an image has been formed by the inkjet head is dried by a heating roller disposed on the recording medium transport downstream side of the cleaning unit,
The image forming method according to claim 12, wherein the heating roller is cleaned by a cleaning unit.

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