JP2011056925A - Image forming device and treating liquid applying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of flying-about by rotation of a roller, when a treating liquid gathers in a ring shape in both end parts of the roller for applying the treating liquid. <P>SOLUTION: This image forming device includes a carrier roller 235 for carrying paper 100, an applying roller 232 for applying the treating liquid 201 to the paper 100 oppositely to the carrier roller 235, and a squeeze roller 233 for thinning a liquid film by supplying the treating liquid 201 to the applying roller 232. The applying roller 232 contacts with the carrier roller 235, and the squeeze roller 233 is arranged in contact with the applying roller 232. The length B in the axial direction of the applying roller 233 is longer than the length C in the axial direction of the carrier roller 235, and the length A in the axial direction of the squeeze roller 233 is longer than the length in the axial direction of the applying roller 232, and is formed in the relationship of A>B>C. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a processing liquid coating apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying apparatus, a plotter, and a complex machine of these, for example, an ink jet recording apparatus is known as an image forming apparatus of a liquid discharge recording method using a recording head for discharging ink droplets. . This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid ejection method is an apparatus that forms an image by ejecting liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only that an image having a meaning such as a character or a figure is applied to the medium, but also an image having no meaning such as a pattern is applied to the medium (simply liquid It also means that a droplet hits the medium). The “ink” is not limited to what is called ink, and is not particularly limited as long as it becomes a liquid when ejected. For example, a DNA sample, a resist, a pattern material, etc. Is also included. In addition, the “image” is not limited to a planar one, but includes an image given to a three-dimensionally formed image, and an image formed by three-dimensionally modeling a solid itself. In addition, the “image forming apparatus” is not limited to the liquid discharge type, but includes an apparatus that forms an image using an electrophotographic method.

  In such a liquid ejection type image forming apparatus, in order to form an image by forming ink containing a coloring material into droplets, feathering in which dots formed by the droplets are disturbed, and ink droplets of different colors When the ink is struck on the paper adjacent to each other, it may cause problems such as color bleeding, which causes the colors to mix with each other and the color boundary to become unclear. There is a problem that it takes.

  Therefore, as described in Patent Document 1, a pretreatment liquid that reacts with ink to prevent bleeding is applied by an application roller as described in the prior art, or the pretreatment liquid is ejected as described in Patent Document 2. It is performed by discharging from the head in a mist form (see also Patent Documents 3 and 4). An apparatus for applying a treatment liquid in a foam is also known (Patent Document 5).

  As a conventional coating apparatus, for example, as described in Patent Document 6, a recording medium coated with a pretreatment liquid is provided with a coating process path for applying a pretreatment liquid and a non-application coating unnecessary path. Some guide plates are provided on both the front and back surfaces of the recording medium so that they are guided from the vertically upward direction toward the paper feed unit.

JP 2002-137378 A Japanese Patent Laying-Open No. 2005-138502 Japanese Patent Laying-Open No. 2005-138502 JP 2003-205673 A JP 2009-012394 A JP 2002-137378 A

  However, when the processing liquid is applied to the recording medium with the roller, there is a problem that the processing liquid film swells from the peripheral surface of the roller and expands in a ring shape at both ends of the roller, and the liquid scatters.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce scattering of liquid when a processing liquid is applied to a recording medium with a roller.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
Image forming means for forming an image on a recording medium;
A coating apparatus for coating a treatment liquid on the recording medium,
The coating apparatus includes at least a transport roller that transports the recording medium, a coating roller that applies a processing liquid to the recording medium, and a squeeze roller that supplies the processing liquid to the coating roller,
The application roller is in contact with the conveying roller, and the squeeze roller is in contact with the application roller,
The axial length of the application roller is longer than the axial length of the transport roller, and the axial length of the squeeze roller is longer than the axial length of the application roller.

  Here, the squeeze roller is in contact with a liquid drop roller that drops the liquid on the peripheral surface of the squeeze roller, and the axial length of the liquid drop roller is longer than the axial length of the squeeze roller.

  The roller may have a configuration in which both end portions are chamfered.

The treatment liquid coating apparatus according to the present invention is:
In a processing liquid application apparatus for applying a processing liquid to a recording medium,
At least a conveying roller that conveys the recording medium, an application roller that applies a treatment liquid to the recording medium, and a squeeze roller that thins a liquid film on the application roller,
The application roller is in contact with the conveying roller, and the squeeze roller is in contact with the application roller,
The axial length of the application roller is longer than the axial length of the transport roller, and the axial length of the squeeze roller is longer than the axial length of the application roller.

  According to the image forming apparatus according to the present invention and the foam coating apparatus according to the present invention, the conveying roller that conveys the recording medium, the applying roller that applies the processing liquid to the recording medium, and the processing liquid is supplied to the applying roller. The squeeze roller is disposed, the application roller is in contact with the conveyance roller, the squeeze roller is in contact with the application roller, and the axial length of the application roller is longer than the axial length of the conveyance roller. Since the axial length of the squeeze roller is longer than the squeeze roller, the ring-shaped liquid pool generated at both ends of the application roller having a shorter length than the squeeze roller is reduced, and both ends of the transport roller having a shorter length than the application roller are reduced. Since the ring-shaped liquid pool generated at the portion is also reduced, the scattering of the liquid can be reduced.

1 is an overall configuration diagram illustrating an example of an image forming apparatus including a processing liquid coating apparatus according to a first embodiment of the present invention. It is typical side surface explanatory drawing of the application part of the coating device. It is a perspective explanatory drawing of the roller part of the application part. It is a plane explanatory view of a roller part similarly. It is typical side surface explanatory drawing of the application part of the process liquid coating device which concerns on 2nd Embodiment of this invention. It is a perspective explanatory view of the roller part of the application part of the application device. It is a perspective explanatory view of the roller part of the application part of the treatment liquid application device concerning a 3rd embodiment of the present invention. 6 is a perspective explanatory view of a roller portion of Comparative Example 1. FIG. It is a plane explanatory view of a roller part similarly. 10 is a schematic side explanatory view of an application part of Comparative Example 2. FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of the image forming apparatus according to the present invention including the first embodiment of the coating apparatus according to the present invention will be described with reference to FIG. FIG. 1 is an overall configuration diagram of the image forming apparatus.
The image forming apparatus accommodates a recording head unit 101 as an image forming unit that forms an image by ejecting liquid droplets onto a sheet 100 that is a recording medium, a conveyance belt 102 that conveys the sheet 100, and the sheet 100. A sheet feeding tray 103 and a coating apparatus 200 according to the present invention for coating a processing liquid on a sheet 100 that is a member to be coated are provided upstream of the recording head unit 101 in the sheet conveyance direction.

  The recording head unit 101 is composed of a line type liquid discharge head having a nozzle row in which a plurality of nozzles for discharging droplets are arranged in a length corresponding to the paper width. Yellow (Y), magenta (M), cyan The recording heads 101y, 101m, 101c, and 101k are provided with ink droplets of each color of (C) and black (K). Note that the recording head can be mounted on the carriage as a serial type image forming apparatus.

  The conveyor belt 102 is an endless belt, and is configured to circulate between the conveyor roller 121 and the tension roller 122. The paper 100 can be held on the transport belt 102 by, for example, a configuration that performs electrostatic suction, suction by air suction, or other known transport means. Further, a conveying means using a roller pair can also be used.

  The sheets 100 stored in the sheet feeding tray 103 are separated and fed one by one by a pickup roller 131 and sent to a registration roller pair 133 by a conveyance roller pair 132. The registration roller pair 133 causes the sheet 100 to be conveyed by a conveyance roller pair 134 at a predetermined timing. It is sent to the coating device 200 via the transport path 135, and the treatment liquid is applied by the coating device 200, and is sent and held on the transport belt 102.

  Then, it is conveyed by the circular movement of the conveyor belt 102, droplets of each color are ejected from the head unit 101, an image is formed, and then ejected to the ejection tray 104.

  The coating apparatus 200 is a recording medium that includes a container 202 containing a processing liquid 201, a pump 203 that pumps the processing liquid 201 from the container 202, and the processing liquid 201 that is supplied by the pump 203 via a supply path 204. And an application unit 208 that applies to the paper 100.

  Here, the treatment liquid 201 is a modifying material that modifies the surface of the paper 100 by being applied to the surface of the paper 100. For example, the treatment liquid 201 is applied in advance to the paper 100 (not limited to paper as a material as described above) without unevenness, so that moisture of the ink can quickly permeate the paper 100 and increase the color component. Fixing agent (setting agent) that prevents bleeding (feathering, bleeding, etc.) and back-through by increasing viscosity and further drying, and increases productivity (number of images output per unit time). is there.

  In terms of composition, this treatment liquid 201 is, for example, cellulose that promotes moisture permeation with respect to a surfactant (any one of anionic, cationic, nonionic, or a mixture of two or more thereof). And a solution to which a base such as hydroxypropyl cellulose and a talc fine powder are added. Furthermore, fine particles can be contained.

Next, details of the coating unit 208 of the coating apparatus 200 will be described with reference to FIGS. 2 is a schematic side view of the application portion, FIG. 3 is a perspective view of the roller portion, and FIG. 4 is a plan view for explaining the treatment liquid application.
The application unit 208 includes a conveyance roller 235 that conveys the paper 100, an application roller 232 that applies the treatment liquid 201 to the paper 100 so as to face the conveyance roller 235, and supplies the treatment liquid 201 to the application roller 232 to form a liquid film. And a squeeze roller 233 for reducing the thickness. The rotation direction of each roller is the direction indicated by the arrow in FIG.

  These rollers are arranged such that the application roller 232 is in contact with the conveyance roller 235 and the squeeze roller 233 is in contact with the application roller 232.

  Further, the axial length B of the application roller 233 is longer than the axial length C of the transport roller 235, and the axial length A of the squeeze roller 233 is longer than the axial length of the application roller B. A> B> C. That is, the rollers 235, 232, and 233 are lengthened in the order in which they are in contact with the conveying roller 235. The length C of the transport roller 235 is larger than the maximum dimension of the corresponding paper width of the image forming apparatus.

  With this configuration, the processing liquid 201 is scooped up along the surface (circumferential surface) of the squeeze roller 233 by the rotation of the squeeze roller 233 and transferred by the rotation in the state of the liquid film layer 201a. It collects in a valley portion with the roller 232 (treatment liquid 201b).

  At this time, as shown in FIG. 4, at both ends of the squeeze roller 233, the liquid film layer bulges from the surface of the roller 233 and expands into a ring shape (this is referred to as a “ring-shaped expansion portion”). This is a phenomenon that occurs at both ends of the roller because the liquid that is likely to come off from the end of the roller stays at the end due to surface tension.

  The ring-shaped expansion part 201 d generated in the squeeze roller 233 is automatically collected in the liquid tray 234 when the roller 233 is accommodated in the liquid tray 234.

  A liquid film layer 201c of the supplied processing liquid 201 is formed on the application roller 232 that is in contact with the squeeze roller 233, and is transferred to the transport roller 235 side by the rotation of the roller 233 (in the direction of the arrow in FIG. 2). .

  At this time, as shown in FIG. 4, although the ring-shaped expanded portion 201 f is generated at both ends of the application roller 232, the length B of the application roller 232 is shorter than the length A of the squeeze roller 233 ( A> B), the processing liquid 201b in the valley portion is squeezed by the squeeze roller 233, and the ring-shaped expansion portion 201f is suppressed to a very slight bulge.

  The liquid film layer 201c transferred by the application roller 232 is applied to the paper 100 (not shown in FIG. 2).

  At this time, since the length C of the transport roller 235 is shorter than the length B of the application roller 232 (B> C), generation of ring-shaped expansion portions at both ends of the transport roller 235 is suppressed. Can do.

Here, Comparative Example 1 will be described with reference to FIGS. 8 and 9, and Comparative Example 2 with reference to FIG. 10.
In Comparative Example 1, the axial length of the application roller 233 and the axial length of the squeeze roller 233 are the same. As described above, the processing liquid 201 is scooped up along the surface of the squeeze roller 233, transferred to the liquid film layer 201a, and collected as a processing liquid 201b in the valley with the application roller 232. At this time, at both ends of the two rollers 232 and 233, the liquid film layer swells from the roller surface to generate ring-shaped expansion portions 201d and 201f.

  At this time, since the axial length of the application roller 232 is the same as the axial length of the squeeze roller 233, the size of the ring-shaped expansion portion 201f generated in the application roller 232 is large (the amount of liquid is large). As shown in the figure, the processing liquid in the ring-shaped expansion part 201f is separated from the roller surface by the rotation of the application roller 232.

  In this case, the length of the roller is made larger than the width of the paper so that the liquid transfer to the paper does not come into contact with the ring-shaped convex portion 201d. However, the problem of liquid splattering is not solved.

  In Comparative Example 2, the application roller 232 is disposed above the squeeze roller 233, the transport roller 235 is disposed above the application roller 233, and the processing liquid of the ring-shaped expansion portion generated in the application roller 232 is liquid below gravity. The configuration is such that it is dropped onto the tray 234.

  In the configuration of Comparative Example 2, the processing liquid is applied to the sheet on the lower surface of the sheet. However, when a treatment liquid is applied as a pretreatment for an ink jet recording apparatus or the like, the treatment liquid is preferably applied immediately before printing as much as possible. This is because the reaction between the treatment liquid and the ink can be performed in a liquid state. For this reason, when the treatment liquid is applied by the ink jet recording apparatus, it is usually preferable to apply the treatment liquid to the upper surface of the recording medium. In the configuration of Comparative Example 2, it is not possible to meet the requirement for applying the treatment liquid in such an ink jet recording apparatus.

  In addition, if the coating is relatively slow, such a natural fall can be expected. However, when the recording speed increases and the rotation speed of the roller increases, all the droplets collected to the extent that they fall are centrifuged by the rotation of the roller. The problem will not be solved because it will be scattered in the device by force.

  On the other hand, according to the above embodiment, as described above, the treatment liquid can be applied to the upper surface of the paper, and the scattering of the treatment liquid from the roller can be reduced.

  As described above, the conveyance roller that conveys the recording medium, the application roller that applies the treatment liquid to the recording medium, and the squeeze roller that supplies the treatment liquid to the application roller, the application roller is in contact with the conveyance roller, The squeeze roller is in contact with the application roller, the axial length of the application roller is longer than the axial length of the transport roller, and the axial length of the squeeze roller is longer than the axial length of the application roller. Therefore, the ring-shaped liquid pool generated at both ends of the application roller having a shorter length than the squeeze roller is reduced, and the ring-shaped liquid pool generated at both ends of the transport roller having a shorter length than the application roller is also reduced. The processing liquid can be applied from the top surface of the recording medium.

Next, a treatment liquid coating apparatus according to a second embodiment of the present invention will be described with reference to FIGS. 5 is a schematic side view of the coating unit of the coating apparatus, and FIG. 6 is a perspective view of the roller portion.
Here, with respect to the squeeze roller 233, a liquid drop roller 236 for dropping the excess process liquid is disposed on a route along the surface of the squeeze roller 233 toward the application roller 232. By providing the liquid drop roller 236, the amount of liquid scooped up from the liquid tray 234 can be reduced, and the occurrence of ring-shaped expansion portions at both ends of the squeeze roller 233 or the amount of liquid can be suppressed.

  The axial length D of the liquid drop roller 236 is longer than the axial length A of the squeeze roller 233 (D> A). That is, the length C of the transport roller 235, the length B of the application roller 233, the length A of the squeeze roller 233, and the length D of the liquid drop roller 236 have a relationship of D> A> B> C. The length in the axial direction (longitudinal direction) is increased in the order of contact with 235.

  By comprising in this way, generation | occurrence | production of the ring-shaped expansion part in each roller can be reduced.

Next, a processing liquid coating apparatus according to a third embodiment of the present invention will be described with reference to FIG. FIG. 7 is an explanatory perspective view of the roller portion of the coating unit of the coating apparatus.
Here, chamfered portions 233 a, 232 a, and 235 a are provided at both ends of the squeeze roller 233, the application roller 232, and the transport roller 235. By providing the chamfer, the ring-shaped expansion portion is accommodated in the chamfer portion, so that protrusion from the roller surface can be suppressed.

  In the above embodiment, the processing liquid coating apparatus is described as applying the processing liquid to the paper before image formation. However, the processing liquid is applied on the paper on which the image is formed on the downstream side of the recording head unit. It can also be set as the structure which apply | coats.

  The processing liquid coating apparatus according to the present invention can also be applied to, for example, an electrophotographic image forming apparatus. For example, the resin fine particles are quickly fixed to the medium without disturbing fine particles containing resin such as toner on the medium such as paper, and after applying the fixer to the medium to which the resin fine particles are adhered. In addition, the present invention can also be applied to a fixing method and a fixing device, and an image forming method and an image forming apparatus using a fixing solution of resin fine particles capable of being applied in a minute amount so as not to cause a residual oil feeling.

100 Recording medium (paper)
DESCRIPTION OF SYMBOLS 101 Recording head unit 102 Conveyance belt 103 Paper feed tray 200 Processing liquid coating apparatus 201 Processing liquid 208 Application | coating part 232 Application roller 233 Squeeze roller 235 Conveyance roller 236 Liquid drop roller

Claims (4)

Image forming means for forming an image on a recording medium;
A coating apparatus for coating a treatment liquid on the recording medium,
The coating apparatus includes at least a transport roller that transports the recording medium, a coating roller that applies a processing liquid to the recording medium, and a squeeze roller that supplies the processing liquid to the coating roller,
The application roller is in contact with the conveying roller, and the squeeze roller is in contact with the application roller,
An image forming apparatus, wherein an axial length of the application roller is longer than an axial length of the conveying roller, and an axial length of the squeeze roller is longer than an axial length of the application roller.   The liquid drop roller for dropping liquid on the squeeze roller peripheral surface is in contact with the squeeze roller, and the axial length of the liquid drop roller is longer than the axial length of the squeeze roller. Image forming apparatus.   The image forming apparatus according to claim 1, wherein both ends of the roller are chamfered. In a processing liquid application apparatus for applying a processing liquid to a recording medium,
At least a conveying roller that conveys the recording medium, a coating roller that applies a processing liquid to the recording medium, and a squeeze roller that thins a liquid film on the coating roller,
The application roller is in contact with the conveying roller, and the squeeze roller is in contact with the application roller,
The coating apparatus, wherein an axial length of the application roller is longer than an axial length of the transport roller, and an axial length of the squeeze roller is longer than an axial length of the application roller.
A treatment liquid coating apparatus.

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