JP2012024989A - Image forming apparatus and treatment liquid coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the drive load if linear speeds differ between rollers when there is no treatment liquid between a squeeze roller and application roller.SOLUTION: Driving force of a drive source is transmitted to the application roller 209 and squeeze roller 207 via a driving force transmission mechanism (device) 400. The driving force transmission mechanism 400 has: a motor gear or a middle gear 404 to be revolved by the drive source; a gear 403 provided in a roller shaft 209 of the application roller 209 which gears to the middle gear 404; and the gear 402 of the squeeze roller 207 which gears to the reduction gear 403. The squeeze roller 207 is set up to revolve slower than the linear velocity of the application roller 209, an one-way clutch 401 is made to intervene between the gear 402 and the roller shaft 207a of the squeeze roller 207, and the driving force is transmitted in the direction to revolve the squeeze roller 207 in the revolving direction during application, and the driving force is not transmitted to the reverse direction.

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus including an apparatus for applying a processing liquid.

  2. Description of the Related Art 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, a liquid ejection recording type image forming apparatus (inkjet recording apparatus) using a recording head that ejects ink droplets is known. . 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 imparted to the medium but also an image having no meaning such as a pattern is imparted 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 image, and 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. A mist is applied from the head for application (see also Patent Document 3). An apparatus for applying a treatment liquid in a foam is also known (Patent Document 4).

  Further, as a coating apparatus for applying a coating liquid to a material to be coated, the apparatus main body is configured to include an offset gravure coater provided in the apparatus main body, and the offset gravure coater is disposed at the bottom. A gravure roll immersed in a liquid tank containing a coating liquid inside, an offset roll disposed above the gravure roll and coated with a coating rubber on the surface, and disposed above the offset roll and coated. There is a backup roll that presses the work material against the offset roll, and the gravure roll, the offset roll, and the backup roll are connected to a motor and can be driven independently (Patent Document 5).

JP 2002-137378 A Japanese Patent Laying-Open No. 2005-138502 JP 2003-205673 A JP 2009-012394 A JP-A-2005-193109

  By the way, when a coating roller for applying the processing liquid to the recording medium and a squeeze roller for thinning the liquid film on the coating roller are provided, and the processing liquid is applied to the recording medium by the roller, a small amount of the processing liquid is used. In order to apply, the linear speed of the squeeze roller is set slower than the linear speed of the application roller.

  However, when there is no processing liquid between the squeeze roller and the application roller, the driving load increases if the linear speed is different between the rollers. Therefore, the speed is constant when there is no processing liquid and the speed when there is processing liquid. In order to provide a difference, variable speed reduction means is provided for driving the squeeze roller, or each roller is driven by a separate drive system. As a result, there is a problem that the configuration becomes complicated.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to stably perform a small amount of coating without a coating unevenness or variation with a simple configuration.

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 device includes:
An application roller for applying a treatment liquid to the recording medium;
A squeeze roller that makes contact with the application roller and thins the liquid film on the application roller;
Driving force transmission means for transmitting a driving force to the application roller and the squeeze roller,
The driving force transmission means transmits the driving force so that the linear speed of the squeeze roller is slower than the linear speed of the application roller, and the squeeze roller receives the driving force only in the rotation direction during application. It was set as the structure provided with the means to transmit.

  Further, a driving load means for applying a predetermined rotational load to the squeeze roller can be provided.

The treatment liquid coating apparatus according to the present invention is:
A treatment liquid coating apparatus for applying a treatment liquid to a recording medium,
An application roller for applying a treatment liquid to the recording medium;
A squeeze roller that makes contact with the application roller and thins the liquid film on the application roller;
Driving force transmission means for transmitting a driving force to the application roller and the squeeze roller,
The driving force transmission means transmits the driving force so that the linear speed of the squeeze roller is slower than the linear speed of the application roller, and the squeeze roller receives the driving force only in the rotation direction during application. It was set as the structure provided with the means to transmit.

  According to the image forming apparatus of the present invention, the application roller that applies the processing liquid to the recording medium, the squeeze roller that makes contact with the application roller and thins the liquid film on the application roller, and the application roller and the squeeze roller are driven. Driving force transmitting means for transmitting force, and the driving force transmitting means transmits the driving force so that the linear speed of the squeeze roller is lower than the linear speed of the application roller, and is applied to the squeeze roller during application. Since the means for transmitting the driving force only in the rotational direction of the squeeze roller is provided, the squeeze roller rotates with the application roller when the frictional force between the application roller and the squeeze roller exceeds a predetermined value. When the frictional force between them is less than a predetermined value, the driving force is transmitted to the squeeze roller and rotates at a predetermined peripheral speed, so that the application roller and the squeeze Frictional force between the over La can reduce the driving load according to the peripheral speed difference when the above predetermined, with a simple structure, it can be stably performed the free trace coating coating unevenness or fluctuation.

  According to the processing liquid coating apparatus of the present invention, the coating roller that coats the processing liquid to the recording medium, the squeeze roller that makes contact with the coating roller and thins the liquid film on the coating roller, the coating roller, and the squeeze roller Driving force transmitting means for transmitting the driving force, the driving force transmitting means transmits the driving force so that the linear speed of the squeeze roller is slower than the linear speed of the application roller, and applies the application to the squeeze roller. Since the device is provided with means for transmitting the driving force only in the rotating direction at the time, the squeeze roller rotates with the application roller when the frictional force between the application roller and the squeeze roller exceeds a predetermined value, and the application roller and the squeeze When the frictional force between the rollers is less than a predetermined value, the driving force is transmitted to the squeeze roller and rotates at a predetermined peripheral speed, so Frictional force between the rollers can be reduced drive load due to peripheral speed difference when the above predetermined, with a simple structure, can be performed stably with no trace coating coating unevenness or fluctuation.

It is a whole lineblock diagram showing an example of an image forming device concerning the present invention provided with a processing fluid application device concerning the present invention. It is a perspective explanatory drawing with which it uses for detailed description of the application part of the coating device in the embodiment. It is a typical explanatory view of an application part similarly.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming 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 paper feed tray 103 and a processing liquid coating apparatus 200 according to the present invention for coating a processing liquid on the paper 100 that is a member to be coated on the upstream side of the recording head unit 101 in the paper transport direction are provided.

  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 via a conveyance path 135a. Then, after the treatment liquid is applied by the coating apparatus 200 and is applied to the conveyance path 135b in which the coating apparatus 200 is disposed, the coating liquid is fed onto the conveyance belt 102 and held by the conveyance roller pair 134.

  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 processing liquid coating apparatus 200 includes a deformable flexible member that contains the processing liquid 201, for example, a processing liquid container 202 formed by forming a PET film in a bag shape, and the processing liquid 201 on a sheet 100 that is a recording medium. An application unit 208 for application and a supply / recovery path 205 provided with a reversible pump 203 for supplying the treatment liquid 201 from the treatment liquid container 202 to the application unit 208 and collecting the treatment liquid 201 from the application unit 208 to the container 202 are provided. The supply / recovery path 205 is provided with an enlarged path 204 having a part of the inner diameter that cannot be held by the meniscus of the processing liquid 201.

  In this processing liquid coating apparatus 200, the processing liquid 201 in the processing liquid container 202 is sucked up by the pump 203 and supplied to the liquid chamber 206 in the coating unit 208 through the supply / recovery path 205 to prepare for coating. .

  The application unit 208 supplies a conveyance roller 210 that conveys the paper 100, an application roller 209 that applies the treatment liquid 201 to the paper 100 while being pressed against the conveyance roller 210, and supplies the treatment liquid 201 to the application roller 209. A squeeze roller 207 is provided in pressure contact with the application roller 209 to thin the liquid film on the application roller 209 together.

  Here, the application roller 209 is in contact with the conveyance roller 210, and the squeeze roller 207 is in contact with the application roller 209. Then, the processing liquid 201 supplied by the squeeze roller 207 forms a liquid film layer on the surface of the application roller 209 by the squeeze roller 207 and the application roller 209, and the recording medium on the transport roller 210 side by rotation of the application roller 209 ( The liquid film layer is transferred to the paper 100) and applied.

  When a predetermined time elapses after the application of the treatment liquid 201 is completed, the treatment liquid 201 in the liquid chamber 206 of the application unit 208 is collected by the pump 203 into the treatment liquid container 202 through the supply / recovery path 205.

  The expansion path 204 provided in the supply and recovery path 205 separates the air entering from the liquid chamber 206 and the processing liquid 201 during recovery, and only the processing liquid 201 is recovered in the processing liquid container 202. Since the air separated in the expansion path 204 accumulates in the expansion path 204, recovery is stopped when a predetermined amount of air accumulates in the expansion path 204. Thereby, it is possible to reliably prevent air from entering the processing liquid container 202.

  When the collection of the processing liquid 201 is completed, the process waits in a state where the expansion path 204 is filled with the processing liquid 201. Thereby, the surface area where the process liquid 201 and the air are in contact is reduced, and drying can be prevented.

  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 drive system of the coating unit of the treatment liquid coating apparatus according to the present invention will be described with reference to FIGS. 2 is a perspective explanatory view of the application portion, and FIG. 3 is a schematic side view of the same.
As described above, the application unit 208 includes the transport roller 210, the application roller 209, and the squeeze roller 207. The application roller 209 and the squeeze roller 207 are accommodated in a substantially sealed housing 211, and a part of the housing 211 is provided. Thus, the liquid chamber 206 is formed, and the squeeze roller 207 is disposed so as to be immersed in the processing liquid 201 in the liquid chamber 206.

  As described above, the application roller 209 is in contact with the transport roller 210, the squeeze roller 207 is in contact with the application roller 209, and the processing liquid 201 held in the liquid chamber 206 is pumped up by the squeeze roller 207. The rotation of the squeeze roller 207 supplies the pressure contact portion between the squeeze roller 207 and the application roller 209, and the pressure film forms a liquid film layer on the surface of the application roller 209. The liquid film layer is transferred to the recording medium (paper 100) and applied. The direction of rotation of each of the rollers 207, 209, and 210 at the time of application is the arrow direction in FIG.

Next, a mechanism (means) for transmitting driving force to the application roller 209 and the squeeze roller 210 will be described.
A driving force of a driving source (not shown) is transmitted to the application roller 209 and the squeeze roller 207 via a driving force transmission mechanism (means) 400. The driving force transmission mechanism 400 includes a motor gear or an intermediate gear 404 rotated by a driving source, a gear 403 provided on a roller shaft 209 of the application roller 209 that meshes with the intermediate gear 404, and a gear 402 of a squeeze roller 207 that meshes with the gear 403. And have.

  Here, the number of teeth (gear ratio) of the gear 403 on the application roller 209 side and the gear 402 on the squeeze roller 207 side is set so that the peripheral speed of the squeeze roller 207 is slower than the peripheral speed of the application roller 209. Further, the peripheral speed of the squeeze roller 207 is set so that the processing liquid 201 is not supplied more than necessary to the pressure contact portion between the application roller 209 and the squeeze roller 207. Note that by adjusting the peripheral speed of the squeeze roller 207, the amount of the processing liquid 201 passing through the pressure contact portion between the application roller 209 and the squeeze roller 207 can be adjusted, and the application amount applied to the paper 100 can be adjusted. .

  That is, the driving force transmission by the driving force transmission mechanism 400 is such that the peripheral speed of the squeeze roller 207 is within a range (speed) in which the processing liquid 201 can be supplied to the pressure contact portion between the application roller 209 and the squeeze roller 207 and The application amount of the treatment liquid 201 is set to be a peripheral speed at which a predetermined application amount is obtained.

  A one-way clutch 401 is interposed between the gear 402 on the squeeze roller 207 side and the roller shaft 207a of the squeeze roller 207. The one-way clutch 401 is configured to transmit a driving force in the direction in which the squeeze roller 207 is rotated in the rotation direction during application, and not to transmit a driving force in the reverse direction.

  Since it comprised in this way, first, when the gear 404 rotates with the drive source which is not shown in figure, a driving force is transmitted to the gear 403 and the application roller 209 rotates. Next, the gear 402 meshing with the gear 403 rotates. At this time, the driving force is transmitted from the gear 302 to the squeeze roller 207 only in the direction of the arrow in FIG.

  At this time, the driving force of the gear 402 is transmitted to the squeeze roller 207 when the squeeze roller 207 rotates with the application roller 209 at a predetermined peripheral speed or more due to the frictional force between the application roller 209 and the squeeze roller 207. Not (blocked). The predetermined peripheral speed here is a peripheral speed within a range where the treatment liquid 201 can be supplied to the application roller 209 and a predetermined application amount as described above.

  As a result, when the processing liquid 201 is not in the pressure contact portion between the application roller 209 and the squeeze roller 207 or the processing liquid 201 is not sufficient, and the frictional force between the application roller 209 and the squeeze roller 207 increases, the squeeze roller When 207 rotates around application roller 209, an increase in driving load due to a difference in peripheral speed between application roller 209 and squeeze roller 207 can be prevented. Further, it is possible to prevent wear of the rollers 207 and 209 due to slip generated between the rollers 209 and 207 when the frictional force is large.

  On the other hand, when the processing liquid 201 is supplied to the pressure contact portion between the application roller 209 and the squeeze roller 207 by the squeeze roller 207, the frictional force between the application roller 209 and the squeeze roller 207 is reduced to a predetermined frictional force or less. . As a result, the peripheral speed when the squeeze roller 207 rotates with the application roller 209 is slow, and the driving force of the gear 402 of the driving force transmission mechanism 400 is transmitted to the squeeze roller 207 via the one-way clutch 401. The squeeze roller 207 rotates at a predetermined peripheral speed.

  Note that a predetermined frictional force, that is, a frictional force that causes the squeeze roller 207 to slip may use a load such as a rotary bearing that acts on the rotational drive. For example, a driving load means 405 ( For example, when a forced load means such as a torque limiter is used, slip occurs more stably, and the squeeze roller 207 can be rotated at a predetermined peripheral speed.

  That is, by providing the driving load means, it becomes possible to arbitrarily set the frictional force between the application roller and the squeeze roller so that the driving force is transmitted to the squeeze roller. The rotational speed can be controlled to a predetermined rotational speed.

  Here, the squeeze roller 207 is controlled to have a predetermined peripheral speed by utilizing the slip between the application roller 209 and the squeeze roller 207, but the control means is not limited to this. For example, the predetermined peripheral speed is substantially the same as that of the application roller 209, and the difference in peripheral speed (the squeeze roller 207 is slower than the peripheral speed of the application roller 209) is set to be about the difference in peripheral speed generated by the component accuracy between the rollers. May be.

  In addition, the squeeze roller 207 rotates with the application roller 209 under a normal load, and slip occurs only when the viscosity increases due to evaporation of the processing liquid 201 in the liquid chamber 206, so that a predetermined peripheral speed is obtained. The peripheral speed of the squeeze roller 207 can also be determined. In this case, it is determined that the treatment liquid 201 is thickened, and the peripheral speed of the squeeze roller 207 when the driving force is transmitted to the squeeze roller 208 by the driving force transmission unit 400 is set slower than usual. Is preferred.

  There is a correlation between the viscosity of the treatment liquid 201 and the coating amount, and the higher the viscosity, the larger the coating amount. Further, there is a correlation between the peripheral speed of the squeeze roller 207 and the coating amount, and the coating amount decreases as the peripheral speed is low. The peripheral speed of the squeeze roller 207 is determined by the surface roughness of the squeeze roller 207 and, when the coating roller 209 is a rubber roller, depending on the physical properties, hardness, surface roughness, physical properties of the processing liquid, coating speed, etc. .

  According to the experimental results. In the processing liquid 201 in which the processing liquid having a viscosity of 5 to 10 mPa · s is evaporated by 20% and the viscosity is increased to 20 to 30 mPa · s, the peripheral speed of the squeeze roller 207 is 1 / 1.5 compared to the normal speed. When the speed was reduced to about 1/5, a good coating amount was obtained. That is, in this case, the driving force transmission means 400 (gear) is set so that the circumferential speed of the squeeze roller 207 is about 1 / 1.5 to 1/5 of the application roller 209.

  As described above, by using one drive source, it is possible to apply at a low cost, with a stable application amount, and with less energy.

  In this case, by making the peripheral speed of the application roller constant, the application conditions can be kept constant, and changes in application amount and unevenness can be reduced.

  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 image forming 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 application apparatus 201 Processing liquid 207 Squeeze roller 208 Application | coating part 209 Conveyance roller 400 Driving force transmission mechanism 401 One-way clutch

Claims (3)

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 device includes:
An application roller for applying a treatment liquid to the recording medium;
A squeeze roller that makes contact with the application roller and thins the liquid film on the application roller;
Driving force transmission means for transmitting a driving force to the application roller and the squeeze roller,
The driving force transmission means transmits the driving force so that the linear speed of the squeeze roller is slower than the linear speed of the application roller, and the squeeze roller receives the driving force only in the rotation direction during application. An image forming apparatus comprising a means for transmitting.   The image forming apparatus according to claim 1, further comprising a driving load unit that applies a predetermined rotational load to the squeeze roller. A treatment liquid coating apparatus for applying a treatment liquid to a recording medium,
An application roller for applying a treatment liquid to the recording medium;
A squeeze roller that makes contact with the application roller and thins the liquid film on the application roller;
Driving force transmission means for transmitting a driving force to the application roller and the squeeze roller,
The driving force transmission means transmits the driving force so that the linear speed of the squeeze roller is slower than the linear speed of the application roller, and the squeeze roller receives the driving force only in the rotation direction during application. A processing liquid coating apparatus comprising a means for transmitting.

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