JP5321027B2 - Image forming device, foam coating device - Google Patents

Description

  The present invention relates to an image forming apparatus and a foam 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, “image forming apparatus” means an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. "Image formation" is not only the application of images with meanings such as characters and figures to the medium, but also the addition of images with no meaning such as patterns to the medium (simply applying droplets to the medium) Also means landing). 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 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, conventionally, as described in Patent Document 1, before or after printing, a heating unit is used to prevent bleeding and promote ink drying after printing.
JP-A-8-323977

Further, as described in Patent Document 2, a pretreatment liquid that reacts with ink to prevent bleeding is applied by an application roller, or as described in Patent Document 3, the pretreatment liquid is applied from a liquid discharge head. For example, it is applied by discharging in a mist form.
JP 2002-137378 A Japanese Patent Laying-Open No. 2005-138502

  However, the provision of the heating device as described in Patent Document 1 described above has a problem that the power consumption of the device increases. Also, as described in Patent Documents 2 and 3, when the pretreatment liquid is applied by an application roller or a liquid discharge head, application unevenness occurs, and after reaction with ink in order to apply liquid excessively on the paper There is a problem with the quick-drying property of the paper, and in particular, the paper tends to curl or bend.

  The present invention has been made in view of the above-described problems, and enables liquid or gel, or both of which are foamed, to be applied with a uniform thickness, and the supply amount can be easily controlled. The purpose is to keep the quality of foam to be uniform.

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 foam application means for applying foam in which at least one of a liquid and a gel is applied to the recording medium or an intermediate member for application to the recording medium;
The foam applying means is
Foam generating means for generating the foam;
Application means for applying foam to the recording medium or the intermediate member;
The foam is introduced from the foam generating means, and the supply means for supplying the foam from a supply port to the application means,
Wherein the supply means,
Variable means for changing the size of the opening of the supply port;
A discharge port for discharging bubbles not supplied to the application means ;
Adjusting means capable of changing a fluid resistance through which bubbles discharged through a path connected from the discharge port pass ;
The supply means is introduced with an amount of foam that is excessive than the amount of foam supplied to the application means, and the discharged foam is adjusted by the adjusting means according to the size of the opening set by the variable means. It was to change the flow resistance through configuration.

The foam applicator according to the present invention is:
In a foam application device for applying a foam in which at least one of a liquid and a gel is applied to a member to be applied,
And foam generating means for generating a pre-Kiawah,
Application means for applying foam to the application member;
The foam is introduced from the foam generation means, and the supply means for supplying the foam from a supply port to the application means,
The supply means includes
Variable means for changing the size of the opening of the supply port;
A discharge port for discharging bubbles not supplied to the application means;
Adjusting means capable of changing a fluid resistance through which bubbles discharged through a path connected from the discharge port pass;
The supply means is introduced with an amount of foam that is excessive than the amount of foam supplied to the application means, and the discharged foam is adjusted by the adjusting means according to the size of the opening set by the variable means. It was set as the structure which changes the fluid resistance to pass.

The “bubble” in the present invention is a liquid or gel, or both of which are rounded by containing a gas such as air, and are formed by the surface tension of the liquid enclosing the gas, and are solid for a certain period of time. The one that can hold the target shape. The foam having such shape-retaining properties preferably has a bulk density of 0.05 g / cm ³ or less, a foam diameter distribution range of 10 μm to 1 mm, and an average foam diameter of 100 μm or less. In addition, the bubbles are formed in a single round shape, but when a plurality of bubbles are combined, the shape of each bubble takes a polyhedral shape due to surface tension.

  “Gel” means a colloidal solution or polymer compound dispersed in a dispersion medium loses its independent mobility due to the interaction, and the particles are connected to each other, forming a net-like or honeycomb-like structure. Means a solidified semi-solid substance. Also, “extended” means to extend and expand.

According to the onset bright, it is possible to apply the foam a uniform thickness, it can easily control the supply amount, so that more uniform maintain the quality of the foam to be applied.

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 foam 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 paper feed tray 103, and a foam application device (apparatus for applying bubbles to a member to be applied) 200 according to the present invention for applying bubbles to the paper 100, which is a member to be applied, upstream of the recording head unit 101 in the paper conveyance direction; It has.

  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.

  The paper 100 stored in the paper feed tray 103 is separated and fed one by one by a pickup roller 131, and is sent and held on the conveyor belt 102 via the conveyance path 135 by the conveyance roller pair 132 and a conveyance roller pair (not shown). The

  Then, the foam 210 is applied to the recording medium 100 as the application member to be conveyed by the conveyance belt 102 by the foam application device 200, and the foam 210 applied to the paper 100 is quickly dried, and the head unit 101. Then, droplets of each color are ejected to form an image, which is then discharged to the discharge tray 104.

  On the other hand, the foam application apparatus 200 includes a container 202 containing a liquid or gel or liquid and gel (hereinafter collectively referred to as “treatment liquid” or “setting agent”) 201 that can be in a foam state. Bubble generation as a bubble generation means for generating a bubble 210 in a state suitable for small-diameter application from the pump 203 for pumping the processing liquid 201 from the container 202 and the processing liquid 201 supplied by the pump 203 through the supply path 204. The bubble 210 is supplied from the unit 205 and the bubble generation unit 205 via the supply path 206 and introduced from the introduction port 231, and the bubble 210 extends in the width direction of the recording medium 100 (or an intermediate member). The foam 211 is supplied from the supply port 232 of the storage unit 211 and the storage unit 211, and is applied as a coating means for supporting the foam 210 on the peripheral surface and applying the foam 210 to the recording medium 100. And a roller 212.

  Further, the storage unit 211 can adjust the amount of the foam 210 supplied to the application roller 212 (the application amount by the application roller 212) by changing the fluid resistance of the foam 210 at the supply port 232, and the application Application amount / application region adjusting means 233 for restricting the supply region of the foam 210 to the roller 212 (application region by the application roller 212) by the opening / closing amount, and a discharge port for discharging the excess foam 210 not supplied to the application roller 212 234.

  A discharge path 235 leading to the container 202 is connected to the discharge port 234, and an adjustment for controlling the amount of bubbles 210 discharged from the discharge port 234 by adjusting the fluid resistance of the discharge port 234 is connected to the discharge path 235. A valve 236 and a discharge pump 237 that assists the discharge of the foam 210 from the discharge port 234 to the container 202 and also serves to eliminate the foam 210 by compressing the foam 210 (defoaming) are provided. The discharge destination is not limited to the container 202, and may be a separately provided waste liquid tank.

  Further, a thickness regulating means 214 for regulating the film thickness (coating film thickness) of the foam 210 carried on the application roller 212, and a cleaning member 215 for removing the foam 210 remaining on the peripheral surface of the application roller 212 after application. I have.

  Here, the treatment liquid 201 that can be in a foam state 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 the like (hydroxypropylcellulose etc.) and a solution to which a base such as talc fine powder is added. Furthermore, fine particles can be contained.

As the foam 210. cell content is intended preferably in the range generally of about 0.01g ^/ cm ³ ~0.1g ^/ cm 3 as bulk density.

  Here, “bubbles” are not liquid but semi-solid, and exhibit physical properties close to solids in terms of fluidity. That is, the bubbles 210 are generated from the processing liquid 201, but the generated “bubbles” themselves are not “liquid” or “gel”.

  Thus, by applying the foam 210 generated from the processing liquid 201 to the surface of the paper 100, the foam 210 contains a large amount of air so that a small amount of liquid can be applied. This improves the quick-drying property, and can output a high-quality image free from bleeding, show-through, density unevenness and the like.

That is, by applying the treatment liquid in the form of foam, there are the following advantages (effects) compared to the liquid or mist-like treatment liquid.
(1) Since foam contains a large amount of air, it is possible to apply a trace amount of liquid.
(2) Since the foam is close to solid, the coating film thickness can be easily adjusted by applying and scraping, etc., and since the peelability from the coating means is good at the time of coating from the coating means to the paper, Uniform application is possible.
(3) Since water does not easily penetrate into the fibers of the paper, wrinkles and curls are unlikely to occur on the paper.

  The advantages of such foam application do not depend on the type of treatment liquid, and the same effect can be obtained. The treatment liquid preferably has an effect of suppressing paper dust, and may have an effect of changing the background color of the paper.

  Furthermore, the use of “foam” as the processing agent for the recording medium in this way has a special effect during recording and processing at a particularly high speed as compared with a liquid processing agent. For example, when printing on continuous paper at a high speed as in a continuous book machine, it is necessary to rotate the roller or the like at high speed in order to catch up with the recording operation.

  When such a recording speed exceeds about 100 m / min, the centrifugal force generated by the high-speed rotation of the roller becomes very large, and in the case of a liquid processing agent, the processing agent is separated from the roller surface and scattered. There is a problem that the amount applied to the film is significantly reduced. In order to solve such problems by using a liquid processing agent, it may be possible to increase the viscosity of the liquid and make it difficult to scatter from the roller surface, but such a high viscosity liquid should be applied as a thin film. In addition, the load of the liquid supply / drainage operation increases, leading to an increase in the size of the transport pump and the complexity of the apparatus.

  On the other hand, the “bubbles” generated from the processing liquid are ordinary low-viscosity liquids during transport, have a small transport load, and exhibit a semi-solid property in a foamed state on the roller. The high-speed rotation will not follow and scatter. Further, as described above, it is advantageous for thin film coating on a recording medium. Furthermore, the remaining bubbles after application can be easily recovered as a low-viscosity liquid by defoaming by heating with a heater or the like, and all problems in high-speed application of liquid treatment agent application can be solved.

  By the way, in order to apply a uniform amount of foam in the width direction to a recording medium or a member to be coated such as an intermediate member for coating on the recording medium, it is necessary to sufficiently extend in that direction before coating. . However, since the bubbles are almost solid (semi-solid) and do not easily extend, it is difficult to extend in the width direction of the recording medium or the intermediate member. In addition, there are problems that it is difficult to control the amount of foam supplied to the application means, and that it is difficult to keep the bulk density, foaming density, and bubble diameter of the supplied foam uniform.

  Therefore, in the present invention, the supply means for supplying bubbles from the supply port to the application means for applying bubbles to the member to be coated has a discharge port for discharging bubbles not supplied to the application means, and is supplied to the application means. In addition to being able to apply liquid or gel or liquid and gel with a uniform thickness, the amount supplied can be easily controlled, and the amount of foam applied can be controlled. The quality can be kept uniform and the image quality can be improved.

First, an example of the foam production | generation part 205 in the foam application apparatus 200 is demonstrated with reference to FIG.
The foam generation unit 205 supplies a gas to the inside of the porous member 222, a container 221 that stores the processing liquid 201 supplied from the container 202 by the pump 203, a cylindrical porous member 222 disposed in the container 231, and the like. Gas supply means 223 to be provided. The gas supply means 223 can be configured to send air by a fan and a duct, for example. In addition, in order to sufficiently supply the processing liquid 201 that surrounds the porous member 222 and is in a bubble state so that the generated foam 210 does not spread randomly in the container 221, the one end side of the supply path 206 is It is formed in a shape surrounding the porous member 222, and a first slit 224 and a second slit 225 are provided at the inlet portion of the supply path 206 (portion where the porous member 222 is disposed).

  In the bubble generation unit 205, bubbles 210 are generated from the treatment liquid 201 by supplying gas to the porous member 222, and when the bubbles 210 are generated by supplying gas, the bubbles 210 have their own deposition force. By moving (supplied) in the supply path 206 and supplied to the storage unit 211 and stopping the supply of gas, the bubbles 210 are not accumulated and are not transferred. As described above, since the bubbles generated by the deposition force of the bubbles themselves are conveyed and supplied without using a special conveying means, the configuration is simplified.

Next, an example of the storage part 211 in the foam coating apparatus 200 will be described with reference to FIG. FIG. 3 is a schematic perspective view of the storage part.
As described above, the storage unit 211 includes an introduction port 231 through which the foam 210 is supplied from the foam generation unit 205 via the supply path 206, and a supply port 232 through which the foam 210 is supplied to the application roller 212. And a discharge port 234 that discharges excess foam 210 that has not been supplied to the application roller 212, and the supply port 232 includes application amount / application region adjusting means 233.

  In the storage unit 211, the foam 210 is fed into the foam storage container 300 from the foam generation unit 206 through the introduction port 231, and pushed out from the supply port 232 to the application roller 212 side. By closing the adjustment valve 236 and applying pressure by supply, the foam 210 extends in the paper width direction in the foam storage container 300. At this time, the adjustment bubble 236 is set to a pressure at which the bubbles 210 spread in the bubble storage container 300.

  Then, by opening the adjusting valve 236 at a predetermined timing, the foam 210 is introduced (supplied) into the foam reservoir 300 more than the amount supplied to the foam application roller 212, and the excess foam 210 is discharged from the discharge port 234. By discharging to 235, application is performed in a predetermined paper width direction without a shortage. The control valve 236 controls the fluid resistance so that the bubbles 210 are preferentially supplied to the application roller 212.

  Here, as shown in FIG. 4, the application amount / application area adjusting means 233 includes an adjustment plate 233 a that opens and closes the supply port 232 by moving up and down, or as shown in FIGS. 3 and 5. In addition, an adjustment plate 233b that opens and closes the supply port 232 by moving in the horizontal direction (corresponding to the width direction of the paper) can be provided along with the adjustment plate 233a in the vertical direction.

  In this case, in the configuration including the adjustment plate 233a shown in FIG. 4, the fluid resistance can be varied by varying the size of the supply port 232 in the vertical direction, and the coating area in the circumferential direction of the coating roller 212 is adjusted. This makes it possible to control the application area of the paper 100 in the transport direction. In the configuration including the adjustment plates 233a and 233b shown in FIG. 5, the application area in the circumferential direction of the application roller 212 can be adjusted by opening and closing, and the application area in the axial direction of the application roller 212 is adjusted. Accordingly, the application region in the width direction (direction orthogonal to the conveyance direction) with respect to the paper 100 can also be controlled. In the configuration shown in FIG. 5, the adjusting plate 233b is arranged in one direction. However, by arranging the adjusting plate 233b on both sides, it is possible to cope with the center reference sheet conveyance based on the center in the sheet width direction.

  Further, as shown in FIG. 6, the thickness regulating member 214 can arbitrarily adjust the coating film thickness by controlling the distance to the coating roller 212. For example, the thickness regulating member 214 can be controlled by a predetermined display from an operation display unit of the image forming apparatus. By performing the operation, the thickness regulating member 214 is moved and adjusted by a driving means (not shown) in a tangential direction or a normal direction with respect to the peripheral surface of the application roller 212. Thereby, the coating film thickness of foam can be set to an arbitrary value.

Next, 2nd Embodiment of the foam coating apparatus which concerns on this invention is described with reference to FIG. FIG. 7 is a schematic perspective explanatory view of a storage part in the foam coating apparatus.
The storage portion 211 is provided with an introduction port 231 on one side surface in the axial direction of the cylindrical foam storage container 700 and a discharge port 234 on the other side surface, and is screwed along the axial direction in the foam storage container 700. The transfer stirring member 701 is disposed, and the transfer stirring member 701 is rotated so that the bubbles 210 spread uniformly at a high speed to the supply port 232. Thereby, the bubble 210 can be transferred in a short time from the inlet 231 to the outlet 234 side.

  Further, the introduction port 231 is provided on the upper side of the foam storage container 700 and the discharge port 234 is provided on the lower side of the foam storage container 700, thereby efficiently recovering the foam in which the foam 210 is defoamed and the uniformity is lost. be able to. In other words, the defoamed bubbles use the property that the specific gravity increases and goes down. The discharge port 234 is preferably provided below the supply port 232, and more preferably provided at the lowermost part of the foam storage container 700.

Next, a third embodiment of the foam applicator according to the present invention will be described with reference to FIG. In addition, FIG. 8 is a schematic plan explanatory view of a storage unit in the foam coating apparatus.
Here, the bubble storage container 700 of the storage unit 211 has a path 711 that gradually narrows from the introduction port 231 toward the discharge port 234, and a direction along the discharge port 234 from the introduction port 231 of the path 711 (application roller). The supply port 232 is provided in the axial direction 212. With this configuration, the supply pressure of the bubbles 210 is uniform over the entire width direction of the supply port 232, and the bubbles 210 are filled in the entire storage portion 211 as the path 711 is narrowed. The time required until is reduced.

Next, a fourth embodiment of the foam coating apparatus according to the present invention will be described with reference to FIG. In addition, FIG. 9 is a schematic plan explanatory view of a storage unit in the foam coating apparatus.
Here, discharge ports 234 and 234 are disposed at both ends of the foam storage container 700, and an introduction port 231 is disposed between the discharge ports 234 and 234. A supply port 232 is provided along the direction in which the discharge port 234, the introduction port 231, and the discharge port 234 are arranged (the axial direction of the application roller 212). By configuring in this way, the foam 210 introduced from the inlet 231 spreads on both sides, and the distance that the foam 210 spreads in the container 700 is shortened, so that the foam 210 is stored in the storage unit 211 faster. Can do. Further, since the distance between the introduction port 231 and the discharge port 234 is shortened, the supply pressure of the bubbles 210 (pressure supplied to the application roller 212) can be kept more uniform.

  The discharge port 234 is preferably provided outside the application roller 212 (outside the supply port 232) in the paper width direction. By comprising in this way, the stay of the bubble 210 is lose | eliminated and the bubble which lost the uniformity by defoaming becomes easy to be discharged | emitted.

Next, an overview of the control unit of the image forming apparatus will be described with reference to a block diagram of FIG.
The control unit includes a CPU 801 that performs system control of the image forming apparatus, a ROM 802 that stores information such as programs executed by the CPU 801, a RAM 803 that is used as a working area, and an operation display unit that allows an operator to perform various settings. 804, various sensors 805 for detecting paper size and jam, various motors 806, I / O 807 for outputting control signals to various sensors 805 and various motors 806, and image reading device (scanner) 808 Various facsimile communication controls, including a read control unit 809 for controlling the print, a print control unit 811 for controlling the plotter unit (printing mechanism unit) 810, and a network control unit 812 for performing I / F control with the telephone line. A communication control unit 813 for performing control, a foam application control unit 814 for controlling the foam application device 200, and the like. To have.

  Here, the various sensors 805 include liquid end detection means for detecting whether or not the processing liquid 201 is in the container 202, and the various motors 806 include a pump 203, a coating roller 212, a supply amount / supply area. The motor includes a motor that rotates the adjusting unit 233, the thickness regulating unit 214, the conveying roller 121, the paper feeding roller 132, the pickup roller 131, and the like.

Next, an example of printing processing in this image forming apparatus will be described with reference to flowcharts shown in FIGS.
Referring to FIG. 11, when an image output request is received, it is determined whether or not the processing liquid (setting agent) application function is set to be effective. When the processing liquid application function is set to be effective, it is determined whether or not a predetermined amount or more of the processing liquid 201 is in the container 221 of the foam generation unit 205. At this time, after the predetermined amount or more of the processing liquid 201 is not contained in the container 221 of the foam generation unit 205, the pump 203 is driven to supply the processing liquid 201 from the container 202 into the container 221 of the foam generation unit 205. In addition, if a predetermined amount or more of the processing liquid 201 is contained, a gas is sent to the bubble generation unit 205 as it is, and generation of the bubbles 210 is started. As a result, the foam 210 is supplied to the foam storage unit 211 as described above and extended, and the excess foam 210 is discharged from the discharge port 234 via the discharge path 235.

  After that, as shown in FIG. 12, the application roller 212 and the conveyance belt 102 are started to be driven, the application amount / application area adjusting means 233 is opened at a predetermined timing, and the supply of the bubbles 210 to the surface of the application roller 212 is started. . As a result, the foam 210 is carried on the surface of the application roller 212, is regulated to a predetermined thickness by the thickness regulating member 214, and is transferred to the conveying belt 102 side.

  Therefore, the recording medium (paper) 100 is fed from the paper feeding unit (paper feeding cassette 103), and the recording medium 100 is sent to the conveying belt 102. Bubbles 210 on the recording medium 100 are generated by the application roller 212. After the application, the printing operation is started when the leading end of the recording medium 100 reaches the printing position by the head unit 101. On the other hand, when the supply of the foam 210 to the application roller 212 corresponding to the printing area on the paper 100 is finished, the application amount / application area adjusting means 213 of the foam storage unit 211 is closed and the foam 210 to the application roller 212 is closed. Stop supplying.

  Then, after discharging the recording medium 100 on which printing has been completed, the above-described processing from the paper feed is repeated until printing for the number of printed sheets is completed. When the number of printed sheets is reached, gas is fed into the bubble generating unit 205. Stop to stop foam generation. Thereafter, the operation of the paper feeding roller 131 and the conveying roller 132 is stopped, and after a predetermined time has elapsed, that is, after the predetermined time has elapsed when the cleaning of the application roller 212 is reliably completed, the driving operation of the conveying belt 102 and the application roller 212 is stopped To do.

  On the other hand, in FIG. 15, for example, when it is not necessary to apply the processing liquid bubbles 210 by using a special recording medium, the processing liquid application function is set to be invalid. If it is not set, the process proceeds to the process shown in FIG. 13, the application roller 212 and the transport belt 102 are driven, the recording medium 100 is fed from the paper feeding unit, and the head unit for the recording medium 100 is set. After the printing by 101, the paper is discharged, and when the number of prints is reached, the operation of the paper feed roller 131 and the transport roller 132 is stopped, and the operation of the transport belt 102 and the coating roller 212 is stopped after a predetermined time has elapsed. To do.

  Here, the application roller 212 is also rotated because the gap between the application roller 212 and the paper conveyance belt 102 is at most the paper thickness + the film thickness of the bubble 210. However, since it is less than the paper thickness, the application roller 212 is driven so that the conveyance of the recording medium 100 is not hindered.

  In the above embodiment, the foam application device is described as applying foam to the paper before image formation. However, the foam application device is arranged on the downstream side of the recording head unit to perform image formation. It can also be set as the structure which apply | coats a bubble on a paper. Moreover, although the said embodiment demonstrated in the example which produces | generates and apply | coats foam from the liquid which can be made into a foam state, this invention produces | generates foam from the gel which can be made into a foam state. The present invention can also be applied to an apparatus for applying to a member to be applied and an image forming apparatus provided with this apparatus.

  The foam coating apparatus according to the present invention can also be applied to, for example, an electrophotographic image forming apparatus. For example, without disturbing fine particles containing a resin such as toner on a medium such as paper, and applying a foamed fixer (hereinafter referred to as “fixing bubbles”) to the medium to which the fine resin particles are adhered, 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 in which resin fine particles are quickly fixed on a medium after coating and no residual oil feeling is generated on the medium.

  An example of application to an electrophotographic image forming apparatus will be described with reference to FIGS. 14 and 15 are enlarged explanatory views of a portion where the roller coating surface and the unfixed resin fine particles are in contact with each other in the roller coating unit, and FIG. 14 shows relative pressure applied on the contact surface between the coating roller and the recording medium. When the pressure is high, FIG. 15 shows the case where the pressure is relatively low. In addition, both the rotation direction of the application roller 1011 and the movement direction of the recording medium 1010 as the member to be applied are the arrow directions in the drawing.

  First, when the pressure on the contact surface between the application roller 1011 and the recording medium 1010 is high, the fixing bubble 1012 has a single layer structure of bubbles 1013 on the application surface of the application roller 1011 in the example shown in FIG. Therefore, the bubbles themselves are likely to adhere to the application surface of the application roller 1011 due to surface tension, and the fixing bubbles 1012 are only applied unevenly to the layer of resin fine particles (unfixed toner) 1015 on the recording medium 1010. The resin fine particles 1015 are attracted to the bubbles 1013 and are offset to the application surface of the application roller 1011.

  On the other hand, as shown in FIG. 14B, when the fixing bubble 1012 has a multi-layered bubble layer structure on the application surface of the application roller 1011, the bubbles can be embedded in the surface of the unfixed toner 1015 having irregularities. The fixing bubbles 1012 can be easily separated between the layers of the bubbles 1013, can be uniformly applied to the toner layer, and toner offset can be hardly caused.

  Therefore, when the pressure on the contact surface between the application roller 1011 and the recording medium 1010 is high, in order to prevent the unfixed toner 1015 from being offset to the application roller 1011, the average size of the bubbles generated in advance is set. If the film thickness of the fixing foam layer on the application roller 1011 is controlled so as to be the thickness of the plurality of bubble layers so that the bubble layer becomes a plurality of layers, the measurement is always performed on the application roller 1011. A fixing foam layer composed of a plurality of bubble layers is formed, and toner offset can be prevented.

  When the pressure on the contact surface between the application roller 1011 and the recording medium 1010 is low, the fixing bubble 1012 has a single-layer structure of bubbles 1013 on the application surface of the application roller 1011 as shown in FIG. Therefore, bubbles easily adhere to the surface of the unfixed toner 1015 having irregularities, the bubble layer is peeled off from the surface of the application roller 1011, and the fixing bubbles 1012 are applied to the unfixed toner 1015.

  On the other hand, as shown in FIG. 15B, when the fixing bubble 1012 has a multi-layered bubble layer structure on the application surface of the application roller 1011, the bubbles 1013 are strongly coupled to each other, so that the bubbles 1013 are placed on the application roller 1011 side. On the contrary, the unfixed toner 1015 adheres to the air bubble 1013, and as a result, the unfixed toner 1015 is offset on the surface of the application roller 1011.

  Therefore, when the pressure on the contact surface between the coating roller 1011 and the recording medium 1010 is low, the average size of the bubbles is measured in advance, and a fixed bubble having a single-layer bubble layer structure is formed on the coating roller surface. By controlling the thickness of the fixing foam layer as described above, a fixing foam film having a single-layer bubble layer structure is formed on the coating roller, and toner offset can be prevented under high pressure conditions. Further, in order to prevent the unfixed toner 1015 from being offset to the application roller 1011, if the bubble layer on the application roller 1011 is too thick, the bubble layer flows at the contact portion between the application roller 1011 and the recording medium 1010. Since the toner particles move along the flow, and a problem of flowing of the image occurs, it is preferable to control the film thickness of the fixing foam layer within a range in which fluidity does not occur.

  In this way, by controlling the film thickness of the fixing foam layer according to the size and pressure of the bubbles contained in the fixing foam, toner offset and image flow to the contact application means such as the application roller can be prevented. In addition, fixing by extremely minute application can be made possible.

  That is, using a softening agent that softens the resin fine particles by dissolving or swelling at least a part of the resin fine particles, the fixing solution is applied to the resin fine particles on the medium by contact coating means, and the resin fine particles are fixed to the medium. When the fixing solution is applied to the surface of the fine resin particles on the medium, the fixing solution is in the form of bubbles containing bubbles by coating the fine particles in contact with the fine particles. By controlling the film thickness of the layer according to the applied pressure, it is possible to prevent toner offset and image flow to a contact application means such as an application roller, and to enable fixing by extremely minute application. Further, the resin fine particles are highly effective for the toner fine particles used in the electrophotographic technology, and offset and image flow can be prevented by controlling the film thickness of the fixing foam layer according to the layer thickness of the resin fine particles.

1 is an overall configuration diagram of a first embodiment of an image forming apparatus including a foam coating apparatus according to the present invention. It is typical explanatory drawing which shows an example of the foam production | generation part of the same foam application apparatus. It is typical perspective explanatory drawing which shows an example of the storage part of the foam application apparatus. It is perspective explanatory drawing which similarly shows an example of an application quantity / application area | region adjustment means. FIG. 10 is a perspective explanatory view for explaining another example of the application amount / application area adjusting means. It is explanatory drawing similarly used for description of adjustment of a coating film thickness. It is a typical perspective explanatory view of a storage part in a 2nd embodiment of a foam application device concerning the present invention. It is typical plane explanatory drawing of the storage part in 3rd Embodiment of the foam coating apparatus which concerns on this invention. It is typical plane explanatory drawing of the storage part in 4th Embodiment of the foam coating apparatus which concerns on this invention. FIG. 2 is a block explanatory diagram illustrating an overview of a control unit of the image forming apparatus. It is a flowchart with which it uses for description of an example of the printing process by the control part. It is a flowchart with which it uses for description of the process which similarly follows FIG. It is a flowchart with which it uses for description of the process which similarly follows FIG. FIG. 4 is an enlarged explanatory view of a portion where a roller coating surface and unfixed resin fine particles are in contact with each other when the pressure applied on the contact surface between a coating roller and a recording medium is relatively high when applied to an electrophotographic image forming apparatus. . FIG. 6 is an enlarged explanatory view of a portion where the roller application surface and the unfixed resin fine particles are in contact with each other when the pressure on the contact surface between the application roller and the recording medium is relatively low.

Explanation of symbols

100: Recording medium (paper)
DESCRIPTION OF SYMBOLS 101 ... Recording head unit 102 ... Conveyor belt 103 ... Paper feed tray 200 ... Foam coating apparatus 201 ... Processing liquid (liquid or gel which becomes a foam state, or liquid and gel)
DESCRIPTION OF SYMBOLS 210 ... Bubble 205 ... Bubble production | generation part 211 ... Storage part 212 ... Application | coating roller 231 ... Introduction port 232 ... Supply port 233 ... Application amount / application area adjustment means 234 ... Discharge port

Claims (5)

Image forming means for forming an image on a recording medium;
A foam application means for applying foam in which at least one of a liquid and a gel is applied to the recording medium or an intermediate member for application to the recording medium;
The foam applying means is
Foam generating means for generating the foam;
Application means for applying foam to the recording medium or the intermediate member;
The foam is introduced from the foam generating means, and the supply means for supplying the foam from a supply port to the application means,
The supply means includes
Variable means for changing the size of the opening of the supply port;
A discharge port for discharging bubbles not supplied to the application means;
Adjusting means capable of changing a fluid resistance through which bubbles discharged through a path connected from the discharge port pass;
The supply means is introduced with an amount of foam that is excessive than the amount of foam supplied to the application means, and the discharged foam is adjusted by the adjusting means according to the size of the opening set by the variable means. An image forming apparatus characterized by changing a fluid resistance to pass.   2. The image forming apparatus according to claim 1, wherein a fluid resistance when the bubbles are discharged from the discharge port of the supply unit is larger than a fluid resistance when the bubbles are supplied from the supply port. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the discharge port of the supply unit is disposed below the supply port.   4. The image forming apparatus according to claim 1, wherein the discharge port of the supply unit is disposed outside the coating unit with respect to the width direction of the recording medium or the intermediate member. An image forming apparatus. In a foam application device for applying a foam in which at least one of a liquid and a gel is applied to a member to be applied,
And foam generating means for generating a pre-Kiawah,
Application means for applying foam to the application member;
The foam is introduced from the foam generation means, and the supply means for supplying the foam from a supply port to the application means,
The supply means includes
Variable means for changing the size of the opening of the supply port;
A discharge port for discharging bubbles not supplied to the application means;
Adjusting means capable of changing a fluid resistance through which bubbles discharged through a path connected from the discharge port pass;
The supply means is introduced with an amount of foam that is excessive than the amount of foam supplied to the application means, and the discharged foam is adjusted by the adjusting means according to the size of the opening set by the variable means. A foam coating apparatus characterized by changing a fluid resistance to pass.

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