JP5206552B2 - 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, 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 and the posttreatment liquid are applied to the paper with the application roller or the liquid discharge head as in the above-described prior art, uneven application occurs, and ink is applied to apply a large amount of 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.

  Therefore, the present applicant has already proposed that the processing liquid is foamed and applied to a member to be coated such as a recording medium, but when the foam is generated, the foam is conveyed using a mesh-like member. However, when it is configured to be subdivided, if the state where bubbles are not generated continues, the mesh-like member is clogged, resulting in a new problem that the generation efficiency of bubbles and the generation of homogeneous bubbles become difficult It was.

  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 apply a treatment liquid in a uniform thickness with a foam, and to maintain the quality of the foam to be applied. .

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 or an intermediate member for application to the recording medium,
The foam applying means is
In the process of transporting the foam generated from the treatment liquid, having a foam generating means for generating foam in a state suitable for application by subdividing by a mesh-like or porous foam shearing member,
The foam shearing member of the foam generating means is configured to be immersed in the processing liquid that is not foamed except when foam is generated, and can be taken out of the processing liquid when foam is generated.

  Here, it has a pump means for feeding the processing liquid to the foam generating means, and the pump means is driven except when the foam is generated to bring the processing liquid into a transport path in which the foam of the foam generating means is transported. It can be set as the structure provided with the control means which controls to send in.

  In addition, it has a transport path forming member that forms a transport path through which the foam of the foam generating means is transported, and inside the transport path forming member, the processing liquid is accommodated in the lower part, and the foam is formed in the upper part. Is formed, and the foam shearing member is disposed so as to be movable between a state immersed in the treatment liquid in the conveyance path member and a state taken out from the treatment liquid. And can.

  Moreover, the said foam production | generation means can have the said some foam shear member, and can be set as the structure by which these said foam shear members are integrated.

The foam coating apparatus according to the present invention is:
In a foam coating apparatus that applies a treatment liquid of at least one of a liquid and a gel to a coated member in a foam,
In the process of transporting the foam generated from the treatment liquid, having a foam generating means for generating foam in a state suitable for application by subdividing by a mesh-like or porous foam shearing member,
The foam shearing member of the foam generating means is configured to be immersed in the processing liquid that is not foamed except when foam is generated, and can be taken out of the processing liquid when foam is generated.

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, the processing liquid is applied in the form of foam and is suitable for application by being subdivided by the foam shearing member in the process of transporting the foam generated from the processing liquid. Since the foam in a state is generated, the foam shearing member is immersed in a non-foamed processing liquid except when the foam is generated, and the foam can be taken out of the processing liquid when the foam is generated. The gel can be applied in a uniform thickness by applying the foam, and drying is prevented by immersing the mesh member used for foam generation in the treatment liquid except when foam is generated. The clogging of the member is prevented, and stable quality 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 a first embodiment of 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. The present invention applies a bubble to a paper feed tray 103, a paper discharge tray 104 on which a paper 100 on which an image is formed is discharged, and a paper 100 that is a member to be applied on the upstream side of the recording head unit 101 in the paper transport direction. The foam application apparatus (apparatus which applies a foam to a to-be-coated member) 200 is 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.

  The paper 100 stored in the paper feed tray 103 is separated one by one by the pickup roller 131, fed by the transport roller 132, transported by the transport roller pair 133, 134 through the transport path 135, and then by the foam coating device 200. After the foam application, it is fed onto the conveyor belt 102 and held.

  Then, droplets of each color are ejected from the head unit 101 while being transported by the circular movement of the transport belt 102, and an image is formed on the paper 100 on which bubbles are applied. Thereafter, the paper 100 is discharged to the paper discharge tray 104. The

  On the other hand, the foam application apparatus 200 is a container that is a storage tank that contains a liquid or gel or liquid and gel (hereinafter collectively referred to as “treatment liquid” or “setting agent”) 201 that can be made into foam. 202, a pump 203 that pumps the processing liquid 201 from the container 202, a first bubble generation unit 205 that generates bubbles 210 a from the processing liquid 201 supplied via the supply path 204 by the pump 203, and first bubble generation A foam transport path 206 that is a path for sending the foam 210a from the unit 205, a second foam generation section 207 that generates a small foam (small foam) 210 by shearing the foam 210a transported in the foam transport path 206 a plurality of times, A foam application unit (foam application means) 208 for applying the foam 210 to the recording medium (paper 100) is provided.

  Here, the treatment liquid 201 that can be foamed 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.

  The first foam generation unit 205 supplies the high-pressure air 222 from the high-pressure air supply unit 221 to the processing liquid 201 in the foam generation container 220 via the high-pressure air supply path 223 and the mesh-like member 224, thereby generating foam. 210a is generated. By generating and filling bubbles 210a in the bubble generation container 220, the bubbles 210a are supplied toward the bubble application unit 208 via the bubble conveyance path 206 by the pressure. In addition, the pump 203 closes the supply path 204 so that the bubbles 210a and the process liquid 201 do not flow backward through the supply path 204 for supplying the processing liquid 201 during the generation of bubbles.

  The second foam generating unit 207 is one or a plurality of foam shearing members 241 (here, 241a to 241e) formed of a mesh-like member or a porous member (porous member) having a plurality of holes in the bubble transport path 206. 5), and the bubbles 210a conveyed in the bubble conveyance path 206 are sequentially sheared into bubbles 210b, 210c, 210d, and 201e whose diameters are reduced to be the final bubble shearing member 241 (241e). The bubble 210 having a size suitable for application is formed by passing through.

  That is, since the desired fine bubbles 210 suitable for coating and image formation cannot be obtained simply by generating by supplying the high-pressure air in the first bubble generating unit 205, the large-diameter bubbles generated by supplying the high-pressure air ( The large bubbles 210a are sheared by one or a plurality of bubble shearing members 241 to be refined into bubbles (small bubbles) 210 having a small diameter suitable for application and image formation.

  By doing so, it is possible to send the foam 210 suitable for application to the foam application unit 208 while efficiently generating the foam 210 while conveying the foam. In this case, since the bubbles are conveyed by the deposition force, the conveyance of the bubbles is also stopped by stopping the bubble generation of the first bubble generation unit 205.

In addition, if the size of the bubble in this case is demonstrated, the "large bubble" and "small bubble" which distinguish the size of a bubble are defined as follows.
Large bubbles: Refers to “first state bubbles”. It refers to a bubble that is produced using a liquid that becomes a bubble (or may be a gel or both), but that does not exhibit the effect of applying a “bubble” to be described later.
Small bubbles: Refers to “second state bubbles”. This refers to bubbles generated using large bubbles (first state bubbles), and the bubble diameter is smaller than large bubbles (first state bubbles). It refers to the foam that can exert the effect.

As described above, a bubble defined as a small bubble 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. The shape can be maintained, 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. Although formed, if a plurality of bonds are formed, the shape of each bubble takes a polyhedral shape due to surface tension.

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

  In this way, by applying the foam 210 to the surface of the paper 100, a small amount of application is possible by containing a large amount of air, the application can be made uniform, quick drying is improved, bleeding, show-through, A high-quality image without density unevenness can be output.

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 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.

  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. Further, 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.

  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.

Next, the drying preventing operation of the foam shearing member in this image forming apparatus will be described with reference to FIGS. 2 and 3 are schematic explanatory views for explaining different states of the bubble generating means.
First, when bubble generation is performed (when bubbles are generated), as described above, bubbles 210a are generated from the processing liquid 201 by the first bubble generation unit 205, and the bubbles 210a are bubble transfer paths of the second bubble generation unit 207. While being transported by the deposition force 206, it is sheared and subdivided by passing through the plurality of foam shearing members 241 a to 241 e, and sent to the foam application unit 208. At this time, the foam shearing members 241a to 241e are not immersed in the processing liquid 201.

  On the other hand, when the bubbles are not generated, as shown in FIG. 3, the supply path 204 is controlled by driving the pump 203 that feeds the processing liquid 201 from the container 202 that is a storage tank containing the processing liquid 201. The processing liquid 201 is forcibly supplied to the foam generation container 220 through the processing liquid until the foam shearing member 241 in the foam transport path 206 constituting the second foam generation unit 207 is immersed in the processing liquid 201. 201 is supplied from the container 202.

  In this case, as shown in FIGS. 2 and 3, the foam conveying path 206 applies a part where the foam shearing member 241 is disposed (part constituting the second foam generating unit 207) 206 a and the final stage foam 210. The part (supply path) 206b supplied to the part 208 is formed in a shape in which the supply path 206b rises upward from the final position of the path bent in the vertical direction, that is, the part constituting the second bubble generating part 207) 206a. Therefore, the processing liquid 201 is prevented from being supplied to the bubble supply unit 208 as it is.

  Therefore, since the foam shearing member 241 is immersed in the processing liquid 201 at times other than when foam is generated, the foam shearing member 241 is dried and the viscosity is increased even when the foam is not generated. Occurrence of clogging is prevented. Thereby, the bubble conveyance performance by the foam shearing member 241 is deteriorated, and problems such as the impossibility of passage of the foam through the foam shearing member 241 are prevented.

  In this way, in the process of transporting the foam generated from the processing liquid, the foam shearing member is subdivided to generate a foam in a state suitable for application, and the foam shearing member is immersed in the processing liquid except when the foam is generated. Since the composition can be taken out of the processing liquid at the time of generation, the processing liquid (liquid or gel) can be applied in a uniform thickness by foaming and applying the processing liquid (gel or gel). Drying is prevented by immersing in the treatment liquid except when foam is generated, clogging of the foam shearing member is prevented, and stable quality foam can be stably generated.

Next, a second embodiment of the present invention will be described with reference to FIGS. 4 and 5 are schematic explanatory views for explaining different states of the bubble generating means in the same embodiment.
Here, a partition wall 302 is provided in one container 301 and divided into a first portion 301a and a second portion 301b, the first portion 301a constitutes the first bubble generating unit 205, and the second portion 301b carries the bubbles. A path member is formed to constitute the second bubble generating unit 207. The partition wall 302 is formed at a height at which bubbles can move from the first bubble generation unit 207 to the second bubble generation unit 207.

  Although not shown in the drawings, the first foam generation unit 205 is supplied with the processing liquid 201 by a pump or the like, and is supplied with high-pressure air via the high-pressure air supply path 223 and the mesh member 224. As a result, the bubbles 201a are generated.

  In the second portion 301b of the container 301 forming the second foam generating unit 207, the processing liquid 201 is accommodated in the lower portion, and the foam transport path 206 is formed in which the foam is transported in the upper portion. A foam shearing unit 341 in which a plurality of foam shearing members 241a to 241e for shearing foam are integrated by a bridging portion 242 is provided so as to be capable of moving forward and backward (movable up and down) with respect to the second portion 301b of the container 301. The foam shearing member 241 is disposed so as to be movable between a state immersed in the processing liquid 201 in the transport path member (second portion 301b of the container 301) and a state discharged from the processing liquid 201. The configuration is as follows.

  A supply path member 303 that forms a transport path for supplying the generated foam 210 to the foam application unit is provided on the upper side of the second stage 301b of the container 301 downstream of the foam shearing member 241a. .

  Since it comprised in this way, when performing foam production | generation (at the time of foam production), as shown in FIG. 4, the foam shearing unit 341 is raised and the foam shearing member 241 is taken out from the processing liquid 201 ( This means that the part (hole or mesh opening) that performs bubble shearing is taken out of the processing liquid 201 and is located in the bubble transport path 206. In this state, bubbles 210 a are generated from the treatment liquid 201 by the first bubble generation unit 205, and the bubbles 210 a are sent to the second bubble generation unit 207 through the opening 304 above the partition wall 302. While being transported, the paper is sheared and subdivided by passing through the plurality of foam shearing members 241a to 241e, and sent to the foam application unit. That is, at this time, the foam shearing members 241a to 241e are not immersed in the processing liquid 201.

  On the other hand, when the bubble is not generated, the bubble shearing unit 341 is lowered in the arrow direction as shown in FIG. 5 so that the bubble shearing member 241 is immersed in the processing liquid 201.

  As a result, since the foam shearing member 241 is immersed in the treatment liquid 201 at times other than when foam is generated, the foam shearing member 241 is dried and the viscosity is increased even when the foam is not generated. Occurrence of clogging due to residues is prevented. Thereby, the bubble conveyance performance by the foam shearing member 241 is deteriorated, and problems such as the impossibility of passage of the foam through the foam shearing member 241 are prevented.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is an explanatory perspective view of the bubble generating means in the same embodiment.
Here, a step is provided in one container 401 and divided into a first portion 401a and a second portion 401b communicating with the first portion 401a. The first portion 401a constitutes the first bubble generating unit 205, and the second portion 401b The 2nd bubble production | generation part 207 is comprised.

  Although not shown in the drawings, the first foam generation unit 205 is supplied with the processing liquid 201 by a pump or the like, and is supplied with high-pressure air via the high-pressure air supply path 223 and the mesh member 224. As a result, bubbles are generated.

  The second foam generation unit 207 includes a plurality of partition walls 402 and a foam shear unit member 342 in which a plurality of mesh members (foam shear members) 241a to 241d are integrated in the second portion 401b of the container 401. Then, a bubble conveyance path 306 (the bubble movement path is indicated by an arrow 410) having a zigzag shape when seen in a plane is formed, and the second portion 402b is formed on the downstream side of the last stage foam shearing member 241d. A supply path 403 is provided as a conveyance path for supplying bubbles generated through the bubble application unit. Here, the foam shearing unit member 342 is arranged to be movable in the vertical direction.

  In this configuration, the foam shearing member 241 is immersed in the processing liquid by filling the inside of the container 401 with the processing liquid 201 at times other than when foam is generated. It is lifted in the indicated direction (upward) to open the space between the foam shearing unit member 342 and the bottom surface of the second portion 401b, and the processing liquid 201 is extracted from the container 401 until the liquid level of the processing liquid 201 reaches the state shown in the drawing. Thereafter, the foam shearing unit member 342 is returned to the state shown in FIG.

  Alternatively, as shown in FIG. 7, when the bubble 401 is not generated, the bubble shearing member 241 is immersed in the processing liquid by filling the inside of the container 401 with the processing liquid 201. The processing liquid 201 is extracted from the container 401 until the liquid level reaches a state shown in FIG. 7 (a state where the liquid member has been lowered to the lowest end of the mesh member 341). In this case, the foam shearing unit member 342 can be fixedly disposed in the container 401.

Next, an outline of the control unit of the image forming apparatus in these embodiments 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.

  The foam application control unit 814 controls the first foam generation unit 205 of the foam application device 200 to control generation, storage, supply to the application roller 232, and the like.

  Further, in the configuration of the first embodiment, the foam application control unit 814 drives the pump 203 to send the processing liquid 201 from the container 202 to the inside of the transport path 206 when the foam is not generated. The foam shearing member 241 is soaked in the processing liquid 201 by filling 201, and when the foam is generated, the pump 203 is driven reversely so that the processing liquid 201 once filled in the transport path 206 is contained in the foam generation container 220. Until the foam shearing member 241 is removed from the processing liquid 201 (ie, is not immersed in the processing liquid 201).

  Further, in the configuration of the second embodiment, the foam application control unit 814 is a drive means (for example, a motor, a rank and pinion gear, a link mechanism) that moves the foam shearing member unit 341 up and down (advances and retreats with respect to the processing liquid 201). In the case other than the time of foam generation, the driving means is driven to lower the foam shearing member unit 341 so that the foam shearing member 241 is immersed in the processing liquid 201. At the time of foam generation, control is performed to reversely drive the drive means to raise the foam shearing member unit 341 and to remove the foam shearing member 241 from the processing liquid 201 (to make it not immersed in the processing liquid 201).

  The various sensors 805 include temperature / humidity detection means for detecting environmental conditions, processing liquid end detection means for detecting whether or not the processing liquid 201 is in the container 202, and the like.

Therefore, a first example of the control of the drying prevention operation of the foam shearing member by the foam application control unit will be described with reference to the flowchart of FIG. In addition, although it demonstrates by the structure of 1st Embodiment below, as above-mentioned, it is the same also about other embodiment.
First, it is determined whether or not there is a print job (requires a printing operation). If there is a print job, preparation is performed for foam generation for discharging the foam shearing member 241 immersed in the processing liquid 201 from the processing liquid 201. In the first embodiment described above, a part of the processing liquid 201 that is desired to be injected into the foam transport path 206 and the foam generation container 220 is returned to the container 202 by driving the pump 203 in the reverse direction. The processing liquid 201 is removed and the foam shearing member 241 is taken out from the processing liquid 201.

  When the bubble generation preparation is completed, high pressure air is supplied from the high pressure air supply unit 222 to the first bubble generation unit 205 to start generation of bubbles, and the generated bubbles 210 are applied to the application roller 232 of the bubble application unit 208. When the foam application unit 208 is ready to apply foam, the printing operation is started.

  Next, when the printing operation is completed, when a predetermined time has passed since the previous printing operation (for example, 30 minutes) (when left for a predetermined time), a drying prevention process in which the foam shearing member 241 is immersed in the processing liquid 201 is performed. Do. In the first embodiment described above, the pump 203 is driven to rotate forward to inject the processing liquid 201 from the container 202 into the foam generation container 220 and the foam transport path 206, so that the foam transport path 206 is filled with the processing liquid 201 and the foam is supplied. The shear member 241 is immersed in the processing liquid 201.

Next, a second example of controlling the drying prevention operation of the foam shearing member by the foam application control unit will be described with reference to the flowchart of FIG.
When the power OFF instruction signal is input, the anti-drying process is performed in which the foam shearing member 241 is immersed in the processing liquid 201 as described above.

  In this way, when the power of the apparatus is turned off, it is impossible to predict the time until the power is turned on next. Therefore, when the power is turned off, a dry prevention process is performed in which the foam shearing member 241 is immersed in the processing liquid 201. Is left for a long time to prevent the foam shearing member 241 from being clogged.

Next, a third example of control of the drying prevention operation of the foam shearing member by the foam application control unit will be described with reference to the flowchart of FIG.
When the power OFF instruction signal is input, the drying prevention process completion signal is output after the drying prevention process of immersing the foam shearing member 241 in the processing liquid 201 as described above. In response to this, the CPU 801 of the control unit shuts down the power supply of the apparatus.

  Thus, when the power of the apparatus is turned off, it is not possible to predict the time until the power is turned on next time. Therefore, when the power is turned off, a drying prevention process for immersing the foam shearing member 241 in the treatment liquid 201 is performed. This prevents the foam shearing member 241 from being clogged for a long time.

  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 the example which produces | generates and apply | coats foam from the liquid which can be made into foam, this invention produces | generates foam from the gel which can be made into foam, and is covered. The present invention can also be applied to an apparatus for applying to an application member and an image forming apparatus including 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, After application, the resin fine particles are quickly fixed on the medium, and the present invention can be applied to a fixing method and a fixing device, and an image forming method and an image forming apparatus that do not cause a residual oil feeling on the medium.

  An example of application to an electrophotographic image forming apparatus will be described with reference to FIGS. 12 and 13 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. 12 shows relative pressure applied on the contact surface between the coating roller and the recording medium. When the pressure is high, FIG. 13 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 coating roller 1011 and the recording medium 1010 is high, the fixing bubble 1012 has a single-layer structure of bubbles 1013 on the coating surface of the coating 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. 12B, 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.

  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. 13B, 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 illustrating an example of an image forming apparatus including a foam coating apparatus according to a first embodiment of the present invention. It is principal part typical explanatory drawing which shows the state at the time of the foam production | generation used for description of the foam shearing member drying prevention operation | movement in the same embodiment. It is principal part typical explanatory drawing which shows the state at the time other than the time of bubble production | generation similarly. It is principal part typical explanatory drawing which shows the state at the time of the bubble production | generation of the foam production | generation means in 2nd Embodiment of this invention. It is principal part typical explanatory drawing which shows the state at the time other than the time of bubble production | generation similarly. It is an isometric view explanatory drawing used for description of the foam production | generation means in 3rd Embodiment of this invention. It is an isometric view explanatory drawing used for description of the other example of the embodiment. FIG. 3 is a block diagram for explaining a control unit of the image forming apparatus. It is a flowchart which shows the 1st example of control of the foam shearing member drying prevention operation by a foam application control part. It is a flowchart which shows the 2nd example of control of the foam shearing member drying prevention operation by a foam application control part. It is a flowchart which shows the 3rd example of control of the foam shearing member drying prevention operation by a foam application control part. 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. 5 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 pressure on the contact surface between the application roller and the recording medium is relatively low.

100: Recording medium (paper)
DESCRIPTION OF SYMBOLS 101 ... Recording head unit 102 ... Conveyor belt 103 ... Paper feed tray 200 ... Foam application apparatus (foam application means)
201 ... Treatment liquid (foaming liquid or gel or liquid and gel)
DESCRIPTION OF SYMBOLS 205 ... 1st foam production | generation part 206 ... Foam conveyance path | route 207 ... 2nd foam production | generation part 208 ... Foam application part 210 ... Foam 232 ... Application roller 235 ... Pressure roller 241 ... Foam shearing member

Claims (5)

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 or an intermediate member for application to the recording medium,
The foam applying means is
In the process of conveying the foam generated from the treatment liquid, having a foam generating means for generating foam in a state suitable for coating by subdividing by a mesh-like or porous foam shearing member,
An image forming apparatus characterized in that the foam shearing member of the foam generating means can be immersed in the processing liquid that is not foamed except when foam is generated, and can be taken out of the processing liquid when foam is generated.   There is a pump means for feeding the processing liquid to the foam generating means, and the pump means is driven to send the processing liquid into a transport path in which the foam of the foam generating means is transported except when the foam is generated. The image forming apparatus according to claim 1, further comprising a control unit configured to perform the control.   It has a conveyance path forming member that forms a conveyance path through which bubbles of the bubble generating means are conveyed, and inside the conveyance path forming member, the processing liquid is accommodated in the lower part, and the bubbles are conveyed in the upper part. The foam shearing member is disposed so as to be movable between a state immersed in the processing liquid in the transport path member and a state discharged from the processing liquid. The image forming apparatus according to claim 1.   4. The image forming apparatus according to claim 1, wherein the foam generating unit includes a plurality of the foam shearing members, and the plurality of foam shearing members are integrated. 5. In a foam application apparatus that applies a foam of at least one of liquid and gel to a member to be coated,
In the process of conveying the foam generated from the treatment liquid, having a foam generating means for generating foam in a state suitable for coating by subdividing by a mesh-like or porous foam shearing member,
A foam coating apparatus characterized by being immersed in the processing liquid that is not foamed except when foam is generated by a foam shearing member of the foam generating means, and capable of being taken out of the processing liquid when foam is generated.

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