JP2010155413A - Image forming apparatus and foam coating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that desired foam can not be produced when producing foam for next printing operation if excess foam is defoamed and liquefied to return to an original processing solution state after finishing printing operation for a medium to be recorded. <P>SOLUTION: The image forming apparatus includes: a recording head unit 101 forming an image on paper 100; a conveying belt 102 conveying the paper 100; and a foam coating device 200 applying the foam 210 obtained by foaming at least either processing solution of liquid and gel to the paper 100. A foam supply port 251 supplying the foam 210 to a coating part 208 applying the foam 210 to the paper 100 is arranged upward in a height direction relative to a foam producing means 205 producing the foam, and a foam supply path 06 from the foam producing part 205 to the foam supply port 251 is provided obliquely. <P>COPYRIGHT: (C)2010,JPO&INPIT

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, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging 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 giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a 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 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 ejected from the head and applied, or, as described in Patent Document 3, a treatment liquid for improving the ink fixing property is applied by a coating roller or the like before or after printing.

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

  However, when the pretreatment liquid or the posttreatment liquid is applied to the paper with the application roller or the liquid discharge head as in the conventional technique described above, the application unevenness occurs, and the ink is applied to excessively apply the liquid onto the paper. There is a problem with the quick-drying property of the paper after the reaction, and in particular, the paper tends to curl or bend, so that there is a problem that jamming or the like is likely to occur.

  In view of this, the present applicant has already proposed that a foam in which the processing liquid is made to be foamed is applied to a member to be coated such as a recording medium.

  However, bubbles generated when applied to a recording medium or the like may generate surplus bubbles (bubbles remaining without being applied) in the bubble movement path (conveyance path, etc.) after the printing operation on the recording medium is completed. become. In some cases, the surplus bubbles may disappear and be liquefied (return to the state of the original processing solution) before the next application.

  When the liquefied treatment liquid is present in the bubble movement path, the bubbles generated during the next bubble generation and the liquefied liquid are mixed, and bubbles having a desired bulk density cannot be obtained (“liquid” : The ratio of “air” will not reach the desired value.

  This invention is made | formed in view of said subject, and it aims at enabling it to perform the production | generation of a stable bubble.

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 a foam of at least one of a liquid and a gel to the recording medium,
The foam applying means is
Bubble generating means for generating the bubbles;
Application means for applying the foam to the recording medium or an intermediate member disposed between the recording medium and the recording medium;
A foam supply port for supplying the foam to the application means;
A bubble moving path along which the bubbles move from the bubble generating means to the bubble supply port,
The foam supply port is disposed above in the height direction with respect to the foam generating means,
It was set as the structure by which at least one part of the said bubble movement path | route was provided diagonally.

  Here, the bubble movement path is provided with a bubble refining means for making the bubble diameter smaller on the downstream side than the upstream side, and a portion provided obliquely on the bubble movement path is from the bubble refining means. Can also be configured on the upstream side.

  Moreover, it can be set as the structure provided with the liquid collection | recovery means which collect | recovers the liquid produced by the liquefaction of the said bubble through the part provided in the diagonal of the said bubble movement path | route.

  In this case, the liquid recovery means may be configured to communicate with the bubble moving path from the outside. The liquid recovery means may be a liquid recovery path provided in a member that forms the bubble movement path.

The foam coating apparatus according to the present invention is:
A foam application device for applying foam in which at least one of a liquid and a gel is applied to a member to be coated,
Bubble generating means for generating the bubbles;
Application means for applying the foam to the member to be applied;
A foam supply port for supplying the foam to the application means;
A bubble moving path along which the bubbles move from the bubble generating means to the bubble supply port,
The foam supply port is disposed above in the height direction with respect to the foam generating means,
It can be set as the structure by which at least one part of the said bubble movement path | route is provided diagonally.

The “bubble” in the present invention is a liquid or gel that contains a gas such as air and is rounded, and is formed by the surface tension of the liquid that encloses the gas, and maintains a three-dimensional shape for a certain period of time. What you can do. As the foam having such shape-retaining properties, the bulk density is 0.05 g / cm ³ or less, the bubble diameter distribution range is preferably 10 μm to 1 mm, and the average bubble diameter is preferably 100 μm or less. Bubbles are formed in a round shape as a single substance, 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.

  According to the image forming apparatus according to the present invention and the foam coating apparatus according to the present invention, since at least a part of the foam moving path from the foam generating means to the foam supplying means is provided obliquely, the foam is removed and liquefied. The liquid naturally flows backward to reduce the influence on the next bubble generation, and the bubbles can be stably generated.

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 including a 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 200 that applies foam to the paper 100 that is a member to be applied are provided upstream of the recording head unit 101 in the paper 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.

  The paper 100 accommodated in the paper feed tray 103 is sent out to a paper feed unit 132 composed of a paper feed roller 132a and a separation roller 132b that separates the paper one by one by a pickup roller 131 and conveys it downstream.

  The sheet 100 separated into one sheet by the paper feed unit 132 is conveyed to the intermediate conveyance roller pair 134 via the conveyance path 133, and the intermediate application roller pair 134 passes through the conveyance path 135 to the foam application device 200. It is transported between a foam application roller 232 that is a foam application member and a foam pressure roller 235 that is in pressure contact with the foam application roller 212. At this time, the foam 210 is applied and fed onto the conveyor belt 102 and held. The

  Then, the bubbles 210 applied by the bubble applying apparatus 200 are quickly dried, and the paper 100 is conveyed by the circular movement of the conveying belt 102, droplets of each color are ejected from the head unit 101, and an image is formed. It is discharged to the paper 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. A pump 203 that pumps the processing liquid 201 from the container 202, a foam generating unit 205 that will be described later in detail as a bubble generating means that generates bubbles 210a from the processing liquid 201 supplied via the supply path 204 by the pump 203, A foam supply path 206, which is a foam movement path through which the foam 210a generated by the foam generation unit 205 moves, and a shearing member (for example, a mesh member or a porous member) which is a bubble refinement means for the foam 210a moving through the foam supply path 206. ) A bubble generation unit 207 that generates a plurality of bubbles 210b, 210c, and 210 having small diameters by shearing a plurality of times at 241a, 241b, and 241c, and a bubble generation unit 207 An extending member 250 having a foam supply port 251 for extending the generated foam 210 in the paper width direction, and a foam application unit 208 that is an application means for applying the foam 210 to the recording medium (paper 100) are provided. .

  The foam application unit 208 includes a foam application roller 232, a transport roller 233 that faces the foam application roller 232, a foam storage unit 237 formed between the foam application roller 232 and the foam transport roller 233, and a foam application roller 232. The foam pressure roller 235 is opposed to the foam, the foam 210 supplied from the foam supply port 251 is stored in the foam reservoir 237, and the foam application roller 232 and the foam transport roller 233 rotate in the direction indicated by the arrow. As a result, the foam 210 passes through a slight gap between the foam application roller 232 and the foam transport roller 233, is carried on the surface of the foam application roller 232, and is transferred (applied) to the paper 100.

  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.

In addition, as described above, the bubble 210 is a liquid or gel that is rounded by containing a gas such as air, and is formed by the surface tension of the liquid that encloses the gas. It is preferable that the bulk density is 0.05 g / cm ³ or less, the bubble diameter distribution range is 10 μm to 1 mm, and the average bubble diameter is 100 μm or less. However, when a plurality of bubbles are combined, the shape of each bubble takes a polyhedral shape due to surface tension.

  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”.

  In this way, 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, and the application can be made uniform. 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 the foam contains a large amount of air, it can be applied in a small amount.
(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. 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.

  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 this image forming apparatus, the bubbles generated when applied to the recording medium remain as excess bubbles (bubbles remaining without being applied) on the bubble moving path after the printing operation to the recording medium is completed. The surplus bubbles may be defoamed and liquefied in the time until the next printing (application). Thus, if there is a liquefied treatment liquid on the bubble movement path (bubble conveyance path), the foam generated at the time of the next bubble generation and the liquid remaining after liquefaction are mixed, and whether the desired liquid as described above is obtained. This makes it impossible to obtain high density bubbles.

Accordingly, a first embodiment of a foam coating apparatus according to the present invention applied to this image forming apparatus will be described with reference to a schematic explanatory view of FIG.
First, the bubble generation unit 205 includes a container 220 that stores the processing liquid 201 supplied from the container 202 by the pump 203, and a gas supply unit that supplies the gas 222 to the processing liquid 201 in the container 220 via the gas supply path 223. 221. As shown in FIG. 1, a partition member 225 is provided in the container 220, and a liquid level detection sensor 226 including a detection electrode pin member and the like is disposed in a room partitioned by the partition member 225.

  In the bubble generation unit 205, bubbles 210a are generated from the processing liquid 201 by supplying the gas 222, and when the bubbles 222a are generated (generated) by supplying the gas 222, the bubbles 210a have their own deposition force. (The direction of deposition is not limited to the vertical direction.) By moving (transported) in the bubble supply path 206 by the flow of the introduced gas 222, the supply of the gas 222 is stopped, so that the bubbles 210a do not accumulate. Will not be transported. As described above, the bubbles generated by the deposition force of the bubbles themselves (or the combined gas flow) move without using any special transfer means, thereby simplifying the configuration of the bubble transfer.

  Then, the foam supply port 251 of the foam spreading unit 250 that supplies the foam 210 to the foam application unit 208 is disposed upward in the height direction with respect to the foam generation unit 205, and the foam generation unit 205 supplies the foam supply port. The foam supply path 206 formed by the foam supply path member 271 that is the foam movement path to the part 251 is provided obliquely. Note that only one shearing member 241 that is a bubble refinement means is shown, and the bubbles 210 are generated from the bubbles 210a. Further, the foam spreading section 250 is also arranged (or formed) facing the diagonally upward direction including the foam supply port 251 following the foam supply path 206.

  With this configuration, for example, when the image printing job (printing) is finished and the application operation by the foam application unit 208 is finished, the feeding of the gas 222 to the foam generation unit 205 is stopped and the generation of the bubbles 210a is stopped. The bubble generation operation for generating the bubbles 210 is also terminated. Even if the bubble generation (generation) operation is stopped, as shown in FIG. 3, the bubbles 210e and the bubbles 210 remain in the bubble supply path 206, and the remaining bubbles disappear and liquefy with time (FIG. 3). The defoamed bubbles are indicated by “bubbles 210e” shown in broken lines, and the liquefied state is indicated by “treatment liquid 201e”).

At this time, since the bubble supply path 206 is arranged obliquely in the vertical direction, the treatment liquid 201e generated by liquefaction naturally flows back toward the bubble generation unit 205 along the lower inner surface of the bubble supply path 206, The processing liquid 201ae remaining in the bubble supply path 206 during the next bubble generation is reduced. Thereby, it is possible to prevent the bulk density from being reduced by the treatment liquid 201e when foam is generated for the next printing operation, and it is possible to stably generate the foam having a desired bulk density.

  In this way, at least a part of the bubble moving path from the bubble generating means to the bubble supplying means is provided obliquely, so that the liquid that has been defoamed and liquefied naturally flows backward and affects the next bubble generation. Can be reduced, and foam can be generated stably.

Next, 2nd Embodiment of the foam coating apparatus which concerns on this invention is described with reference to the typical explanatory drawing of FIG.
Here, only the portion near the bubble supply port portion 251 of the bubble extending portion 250 is provided downward, but the portion up to the bubble supply port portion 251 is arranged or formed facing obliquely upward similarly to the bubble supply path 206. .

  In this case, since only the bubble supply port 251 is in the downward direction even if the remaining bubbles disappear, only a small amount of the liquefied treatment liquid 201e flows to the bubble application unit 208, and the majority Similar to the first embodiment, the air naturally flows backward toward the bubble generating unit 205 side.

Next, a third embodiment of the foam coating apparatus according to the present invention will be described with reference to the schematic explanatory view of FIG.
Here, the bubble supply path 206 from the bubble generation unit 205 to the bubble supply port 251 as a whole is obliquely upward, and a part (liquid liquid) that is obliquely upward after being once obliquely downward in a part of the foam supply path 206. The liquid collection path 262 is provided at the bottom of the liquid collection section 261 and leads the liquefied processing liquid 201e collected at the bottom of the liquid collection section 261 to the outside. The liquid recovery path 262 communicates with the recovery tank and the container 220 of the foam generating unit 205. An opening / closing valve 263 is provided in the liquid recovery path 262 (or the bottom of the liquid collection part 261).

  As a result, the opening / closing valve 263 is closed and the bubble collecting path 262 is closed at the time of normal foam application, and the opening / closing valve 263 is opened when the generation of bubbles and the generation of bubbles are stopped by stopping the printing operation, etc. The treated liquid 201e is guided to the outside through the liquid recovery path 262 and discharged to the bubble generating unit 205 or a recovery tank (not shown).

  In addition, the mesh member used as the shearing member 241 which is the bubble refining means is to refine the bubbles by passing the bubbles through the mesh member 241. However, since there is resistance to the liquid, the liquefied processing liquid is Naturally, it is difficult to pass through the shearing member 241. Therefore, by providing the liquid collecting portion 261 on the downstream side (in the bubble movement direction) of the shearing member 241, the liquefied processing liquid 201e on the upstream side of the miniaturization means (shearing member) can be recovered.

Next, a fourth embodiment of the foam coating apparatus according to the present invention will be described with reference to the schematic explanatory view of FIG. 6 and the perspective explanatory view of FIG.
Here, a shearing member 241a as a refinement means is provided in the foam supply path 206, which is a foam movement path, and a shearing member 241b as a refinement means is provided in the vicinity of the foam supply port 251 of the foam spreading member 250. . By providing the micronization means 241b in the vicinity of the bubble supply port 251, the liquefied processing liquid can easily flow back naturally.

  Further, the upstream shearing member 241a is a coarse mesh member, and the downstream shearing member 241b is a fine mesh member, so that the bubbles can be further refined. Note that the number of the finer means may not be plural, but in this case as well, the finer means is preferably arranged in the vicinity of the bubble supply port 251.

Next, a fifth embodiment of the foam coating apparatus according to the present invention will be described with reference to the schematic explanatory view of FIG.
Here, the foam supply path 206 and the foam recovery path 243 are formed by providing a partition wall member 242 that divides the inside of the foam supply path member 271 that forms the foam supply path 206, which is the foam movement path, in the vertical direction. The partition member 242 is provided with a plurality of holes 244 through the foam supply path 206 and the foam recovery path 243.

  As a result, the processing liquid 201e defoamed and liquefied in the bubble supply path 206 flows into the liquid recovery path 243 through the hole 244, and naturally flows through the liquid recovery path 242 and returns to the foam generation unit 205. The contact opportunity of the liquid 201e and the foam 210a can be reduced, and the influence on the bulk density when the foam is generated again can be suppressed. That is, the generated processing liquid 201e flows to the bubble generation unit 205, but when the bubble generation stop time is short, the wall surface after the processing liquid 201e flows becomes wet, and this residue is left when the bubbles are regenerated. The liquid may have an adverse effect on the bulk density of the foam. Therefore, in this embodiment, by separating the liquid recovery path 242 and the foam supply path 206, even when foam is generated again, the opportunity for the foam to come into contact with the wet wall surface is reduced, and the bulk density is stabilized. ing.

  Further, at this time, by connecting the outlet 245 of the liquid recovery path 242 to the lower part (processing liquid part) of the container 220 of the foam generating unit 205, when bubbles are generated at the time of the next bubble generation, the bubbles are recovered in the liquid recovery path 243 It becomes difficult to enter.

  In this embodiment, as shown in FIG. 9, the liquid recovery path 243 can be provided to the downstream side of the shearing member 241. In other words, since the liquefied processing liquid does not easily pass through the shearing member (miniaturization means) 241 formed of the mesh member, the liquid recovery path 243 is extended to the downstream side of the shearing member 241, so The liquefied processing liquid can also be reliably recovered.

  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. 10 and 11 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. FIG. When the pressure is high, FIG. 11 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. 10B, when the fixing bubble 1012 has a multi-layered bubble layer structure on the application surface of the application roller 1011, it is possible to embed bubbles 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.

  Further, 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. 11B, 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 moved toward the application roller 1011. 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 illustrating an example of an image forming apparatus according to the present invention. It is principal part typical explanatory drawing which shows 1st Embodiment of the foam coating apparatus which concerns on this invention. It is a principal part schematic explanatory drawing provided for effect | action description of the same embodiment. It is principal part typical explanatory drawing which shows 2nd Embodiment of the foam coating apparatus which concerns on this invention. It is principal part typical explanatory drawing which shows 3rd Embodiment of the foam coating apparatus which concerns on this invention. It is principal part typical explanatory drawing which shows 4th Embodiment of the foam coating apparatus which concerns on this invention. It is principal part perspective explanatory drawing which shows the same embodiment. It is principal part typical explanatory drawing which shows 5th Embodiment of the foam coating apparatus which concerns on this invention. It is a principal part schematic explanatory drawing which shows the other example of the same embodiment. 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)
210 ... Bubble 205 ... Bubble generating part 206 ... Bubble supply path (bubble movement path)
207: Foam generation unit 208 ... Foam application unit 232 ... Foam application roller 233 ... Foam transport roller 235 ... Foam pressure roller 250 ... Foam spreading member 251 ... Foam supply port

Claims (6)

Image forming means for forming an image on a recording medium;
A foam application means for applying a foam of at least one of a liquid and a gel to the recording medium,
The foam applying means is
Bubble generating means for generating the bubbles;
Application means for applying the bubbles to the recording medium or an intermediate member disposed between the recording medium and the recording medium;
A foam supply port for supplying the foam to the application means;
A bubble moving path along which the bubbles move from the bubble generating means to the bubble supply port,
The foam supply port is disposed above in the height direction with respect to the foam generating means,
An image forming apparatus, wherein at least a part of the bubble moving path is provided obliquely.   The bubble moving path is provided with bubble refining means for making the bubble diameter smaller on the downstream side than on the upstream side, and the part provided obliquely on the bubble moving path is on the upstream side with respect to the bubble refining means The image forming apparatus according to claim 1, wherein the image forming apparatus is provided in the image forming apparatus.   3. The image forming apparatus according to claim 1, further comprising a liquid recovery unit configured to recover a liquid generated by the liquefaction of the bubbles through a portion provided obliquely in the bubble movement path.   The image forming apparatus according to claim 3, wherein the liquid recovery unit communicates with the bubble moving path from the outside.   The image forming apparatus according to claim 3, wherein the liquid recovery unit is a liquid recovery path provided in a member that forms the bubble movement path. A foam application device for applying foam in which at least one of a liquid and a gel is applied to a member to be coated,
Bubble generating means for generating the bubbles;
Application means for applying the foam to the member to be applied;
A foam supply port for supplying the foam to the application means;
A bubble moving path along which the bubbles move from the bubble generating means to the bubble supply port,
The foam supply port is disposed above in the height direction with respect to the foam generating means,
A foam coating apparatus, wherein at least a part of the foam movement path is provided obliquely.

Images