JP3992413B2 - Image forming method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  In the present invention, a fluid having a predetermined concentration and / or a predetermined color is generated by changing a mixing ratio of a plurality of coating liquids based on an image signal, and the fluid is guided to an image receptor to form an image. The present invention relates to a forming method and an apparatus.
[0002]
[Prior art]
  In U.S. Pat. No. 3,416,153 (hereinafter referred to as Prior Art Document 1), unnecessary droplets are removed by passing charged ink droplets generated continuously at regular intervals through an electric field modulated by an image signal. It is shown that an image is formed by deflecting and selectively landing on an image support. This method is called a continuous ink jet method because ink droplets are continuously ejected.
[0003]
  U.S. Pat. No. 3,946,398 (hereinafter referred to as Prior Art Document 2) discloses a recording medium in which ink is pushed out by deformation of a piezo vibrator modulated by an image signal, and the pushed ink droplet is ejected from an orifice. What is landed on is shown. This method is called a piezo ink jet method.
[0004]
  In U.S. Pat. No. 4,490,728 (hereinafter referred to as Prior Art Document 3), ink is rapidly expanded by heating of a heater modulated by an image signal, and ink is ejected from an orifice by the gas of the rapidly expanded ink. What is landed on the recording medium is shown. This method is called a thermal ink jet method because ink droplets are ejected by heat.
[0005]
  In U.S. Pat. No. 4,109,282 (hereinafter referred to as Prior Art Document 4), a valve called a flap valve is provided in a flow path for guiding two liquids of a clear ink and a black ink to a substrate for image formation. A printing apparatus is disclosed in which the flow path of each ink is opened and closed by displacing the valve, and the two liquids are mixed to a desired concentration and transferred onto a substrate. As a result, an image having the same gray scale information as the image information displayed on the TV screen can be printed out.
[0006]
  Here, it is disclosed that a voltage is applied between a valve of a flap valve and an electrode provided on an opposite surface thereof, and the valve is displaced by mechanically deforming the valve itself by its electrostatic attraction. Yes. Further, the ink is sucked out from the tip of the flap valve to the paper by a capillary phenomenon acting on the ink between the fibers of the print paper.
[0007]
  Japanese Patent Laid-Open No. 63-291663 (hereinafter referred to as Prior Art Document 5) describes mixing of two liquids of dark and light in a coating head and continuously discharging them from a slot, and then mixing the mixture onto a web transported opposite to the slot. A continuous application of liquid is shown. That is, there is no generation of foreign matter with a uniform coating film thickness over the entire coating width, and a coating solution having a concentration gradient with respect to the running direction of the web is continuously applied, and is uniform in the width direction. It can be applied by thickness.
[0008]
[Problems of the prior art]
  According to the method (continuous ink jet method) disclosed in the prior art document 1, it is possible to remove an unnecessary droplet by modulating an electric field and draw an arbitrary image. It is necessary to provide a mechanism for independently modulating the electric field for each nozzle provided, which makes it difficult to reduce the size of the nozzle. For this reason, it is difficult to form a large number of nozzles corresponding to the pixels at high density. Further, only a part of the continuously ejected droplets is used for image formation, and there is a problem that it is not suitable for high speed because it is removed without using many other droplets. Furthermore, since ink is ejected continuously, there is a lot of wasted ink, and there is a problem that the obtained print is expensive.
[0009]
  According to the method (piezo ink-jet method) shown in the prior art document 2, it is possible to draw an arbitrary image by ejecting only the droplets used for image creation, and only the necessary ink is ejected. There is no waste and a relatively inexpensive print can be obtained. However, in order to achieve high image quality, it is necessary to arrange the nozzles at high density. In this case, there is a problem that the image is disturbed by the interaction of the flying ink droplets.
[0010]
  According to the method (thermal ink jet method) shown in the prior art document 3, it is possible to draw an arbitrary image as in the case of the piezo ink jet method. Can be obtained. However, if the nozzles are made high density in order to achieve high image quality, there is a problem that the image is disturbed by the interaction of flying ink droplets. Moreover, since all of the prior art documents 1 to 3 fly the droplet at high speed and hit the image receiving paper, when the droplet collides with the image receiving paper, a part thereof is not captured by the image receiving paper but becomes a fine mist. It has also been pointed out that it scatters and leaks into the installation environment of the printing apparatus and contaminates the environment.
[0011]
  According to the method disclosed in Prior Art Document 4, since the ink ejected from the nozzles is applied directly onto the paper, if there is paper thickness or paper irregularities, the image is faithfully reproduced with respect to the electrical signal. However, there is a problem that it cannot be reproduced on paper. For this reason, it has not yet been used in earnest. Further, since the ink used is limited to two types, there is a problem that a color image cannot be recorded. Furthermore, because ink is drawn by the capillary action that acts between the ink and paper fibers, it is easily affected by the paper quality. When the paper quality changes, the image quality changes, and the same quality paper is used. Even in this case, there is a problem that the image cannot be faithfully reproduced due to partial non-uniformity of the fiber structure.
[0012]
  According to the method disclosed in Prior Art Document 5, an image having a density gradient in the running direction of the web to be coated can be formed, but the density in the width direction of the web (direction orthogonal to the running direction). It cannot have a gradient. For this reason, it is impossible to apply a coating liquid whose color and density change for each pixel in accordance with the image signal.
[0013]
OBJECT OF THE INVENTION
  The present invention has been made in view of such circumstances, can form a high-quality image at high speed, does not waste the coating liquid, can reduce the size of the nozzle, and adversely affects the installation environment. An image forming method that can form images stably without being affected by the thickness, surface condition, surface waviness and non-uniformity of the fiber structure of the final image receptor such as paper This is the first purpose. It is a second object of the present invention to provide an image forming apparatus that is directly used for carrying out this method.
[0014]
[Structure of the invention]
  According to the present invention, a first object is to provide a plurality of coating liquids including an image forming liquid and a transparent liquid.TheWhile changing the mixing ratio based on the image signalLiquid outletAnd let this dischargeLiquid outletAn image forming method for forming an image by shifting to an image receptor that moves relative to the image receptor, the pixels being arranged in a direction substantially perpendicular to the relative movement direction of the image receptorProvided for eachMultipleLiquid outletA plurality of coating solutions based on the image signalMixing ratioIt is achieved by an image forming method characterized in that it is ejected as a continuous flow while being determined, and is continuously applied to the image receptor to form an image.
[0015]
  Here, a plurality of coating solutions can be continuously applied in a layered manner in the coating thickness direction without being mixed homogeneously. Formed for each pixelLiquid outletIn a slit shape that continues in the width direction of the image receptor (a direction substantially perpendicular to the relative movement direction)Liquid outletOpen in and each corresponding to each pixelLiquid outletThe coating liquid discharged from this slit shapeLiquid outletThe belt-shaped coating solution can be applied to the image receptor.
[0016]
  The application density of the pixels can be controlled by changing the mixing ratio of at least one application liquid to a transparent liquid that becomes substantially transparent after drying, and this non-transparent application liquid (application liquid having optical density). In this case, by keeping the volume flow rate of the entire coating solution substantially constant, the flow of the coating solution can be made smooth to prevent image quality deterioration. At least one transparent liquid is supplied with its supply pressure substantially constant regardless of the image signal, and the discharge amount of the transparent liquid is changed by controlling the discharge amount of another coating liquid mixed with the transparent liquid. You may make it make it.
[0017]
  The plurality of coating solutions to be used preferably have a property of being layered in the coating thickness direction, and at least one of a viscosity difference, a specific gravity difference, a surface tension difference, and a temperature difference is preferably small. It is most desirable that the difference, specific gravity difference, surface tension difference, and temperature difference are all small. In this way, the coating stability is increased and it is more suitable for improving the image quality. Here, the state of overlapping in layers includes a state where adjacent coating liquids are mixed within a minute distance from the boundary.
[0018]
  Of the plurality of coating liquids that are ejected in an overlapping manner, at least one of the outermost coating liquids can be a transparent liquid that becomes substantially transparent after drying, and this transparent liquid is an undercoat liquid that contacts the surface of the image receptor. By doing so, it is possible to prevent the influence of non-uniformity such as the surface state of the image receptor surface and to improve the image quality.
[0019]
  Image receptor,Liquid outletThe intermediate image receptor to which the coating liquid discharged from the medium is transferred, and the final image receptor to which the coating liquid is transferred from the intermediate image receptor. In this case, the undercoat liquid of the outermost layer may be a layer in contact with the surface of the intermediate image receptor so as to cover the surface of the final image when transferred to the final image receptor.
[0020]
  Conversely, the undercoat liquid may be laminated so as to be the uppermost layer when applied to the intermediate image receptor, and the undercoat liquid may come into contact with the surface of the final image receptor when transferred to the final image receptor. In addition, when coating is performed using an intermediate image receptor, consideration is given so that the coating solution can be smoothly transferred to the final image receptor when transferred from the intermediate image receptor to the final image receptor. For example, the adhesion force between the intermediate image receptor and the coating solution in contact with it, or the cohesive force in this coating solution is the cohesive force in the liquid and between the other coating solutions, and the coating solution in contact with the final image receptor. And set smaller than any of the adhesive forces.
[0021]
  AdjacentLiquid outletIf they are deviated from each other in a non-orthogonal direction with respect to the relative movement direction of the image receptor, the interval between adjacent pixels can be narrowed to improve the image quality. Adjacent in this caseLiquid outletBy correcting the image signal in accordance with the amount of deviation, image shift can be prevented.
[0022]
  Liquid outletIf the coating liquid is always discharged even during a period when no image is formed, the flow of the coating liquid becomes stable. In this case, the coating liquid unnecessary for image formation isLiquid outletRemoved and collected while being transferred to the image receptor.
[0023]
  According to the present invention, the second object is to change the mixing ratio of the plurality of coating liquids including the image forming liquid and the transparent liquid based on the image signal.Liquid outletAnd let this dischargeThe liquid discharge port for recording liquidAn image forming apparatus that forms an image by shifting to an image receptor that moves relative to the image receptor, the pixels arranged in a direction substantially perpendicular to the relative movement direction of the image receptorSet for eachMultipleLiquid outletA recording head for continuously guiding a plurality of coating liquids ejected as a continuous flow from the image receiver, andLiquid outletDischarge amount control means for controlling the supply amount of a plurality of coating liquids to be supplied to each, and based on the image signalLiquid outletAnd a control unit that determines a mixing ratio of the plurality of coating liquids discharged from the control unit and controls the discharge amount control unit.
[0024]
  Discharge amount control means from the supply path of the coating liquidLiquid outletIt can be formed by a discharge amount control valve provided in the passage leading to. For example, it is formed by a diaphragm valve using a piezo element. This discharge amount control valve is provided for each pixel arranged in the width direction of the recording head, and the flow rate is controlled by any one of the opening degree, the opening time, the number of opening times, or a combination thereof. Further, the discharge amount control means may be formed by a pump having a variable discharge amount. This pump can be composed of, for example, a piezo element and a check valve provided for each pixel arranged in the width direction of the recording head. In this case, the flow rate is controlled by any one or a combination of the operation speed, operation time, operation frequency of the pump.
[0025]
  Of course, all of the plurality of coating liquids may be controlled separately by a discharge control valve or a discharge amount control valve formed by a pump. You may make it supply with a substantially constant pressure irrespective of an image signal. In this case, the transparent liquid supplied at the substantially constant pressure decreases as the discharge amount of the other coating liquid increases or decreases. That is, the total flow rate of all coating solutions isLiquid outletTherefore, the discharge amount of the transparent liquid can be automatically controlled by the discharge amount of other coating liquids. In this way, the number of ejection amount control means provided in the recording head is reduced, and the configuration of the recording head is simplified.
[0026]
  Liquid outletMay be provided for each pixel arranged in the width direction of the image receptor, or a plurality of pixels may be provided in the moving direction of the image receptor for each pixel.Liquid outletAlternatively, coating liquids having different colors or different properties may be supplied. Provided for many pixelsLiquid outletMay be divided into a plurality of groups in the width direction of the image receptor, and the discharge of the coating liquid from some groups may be stopped in accordance with the width of the image receptor or the width of the image. In this case, wasteful consumption of the coating liquid can be prevented, and a recovery processing amount is reduced when an unnecessary coating liquid that does not contribute to the coating is removed and collected.
[0027]
  The transfer of the coating liquid from the recording head to the image receptor can be performed by various methods. For example, on the top, bottom or side of the recording headLiquid outletOpen thisLiquid outletIt is possible to use a slot coating method in which an image receptor is moved on a certain surface at a constant interval to form an image.
[0028]
  In addition, a slide coating method can be used in which an inclined surface descending toward the image receptor is formed on the upper surface of the recording head, and the coating liquid discharged onto the inclined surface flows down on the inclined surface and is guided to the image receptor. Further, a curtain coating method may be used in which the coating liquid supplied from the recording head flows down from the inclined surface onto the image receptor via the guide plate. The image receptor itself may be a final image receptor such as a printing paper, but may be formed by an intermediate image receptor and a final image receptor. In this case, the intermediate image receptor is interposed between the recording head and the final image receptor and transfers the coating solution received from the recording head to the final image receptor. possible.
[0029]
[Action]
  Based on the image signal, the control unitLiquid outletThe mixing ratio of the coating liquid leading to is determined, and the color and concentration of the mixed liquid are controlled. A plurality of coating liquids forming this mixed liquid (recording liquid)Liquid outletIs discharged as a continuous flow and transferred to an image receptor. As a result, an image is formed on the image receptor. Here, since the coating solution is applied as a continuous flow, waste is not generated in the coating solution, and a high-quality image can be formed at high speed.
[0030]
Embodiment
  FIG. 1 is a diagram showing an embodiment by a slot coating method, FIG. 2 is a perspective view showing an internal structure of a recording head used here, FIG. 3 is an enlarged sectional view of the recording head, and FIG. Figure 5Liquid outletIt is a figure which shows the example of arrangement | sequence.
[0031]
  In FIG. 1, reference numeral 10 denotes a recording head, and this recording head 10 has a large number of openings on its upper surface.Liquid outlet12 and one slit-like undercoat liquid discharge port 14. On the upper surface of the recording head 10, an image receptor 16 made of recording paper is transferred in one direction (right side) while being pressed by the recording head 10 at a constant pressure. Reference numeral 18 denotes a driving roller which feeds the image receptor 16 in one direction (right side) with the driven roller 20 interposed therebetween. A tension roller 22 is located on the opposite side of the drive roller 18 and the driven roller 20 with the recording head 10 interposed therebetween. The tension roller 22 applies a certain tension to the image receiver 16 with the image receiver 16 sandwiched between the driven roller 24 and the tension roller 22.
[0032]
  Reference numeral 26 denotes a drive motor for the drive roller 18, and 28 denotes a control unit. Of the recording head 10Liquid outlet12 is provided independently for each pixel in the width direction of the image receiver 16 (direction substantially orthogonal to the transfer direction). eachLiquid outletFrom 12, a mixed liquid, that is, a recording liquid, in which the mixing ratio of the image forming liquid and the transparent liquid is controlled based on the image signal is discharged. Here, the image forming liquid is, for example, black ink, and the transparent liquid is transparent ink. By changing the mixing ratio of both, the image density can be changed in multiple steps (for example, 256 steps). The mixing ratio is controlled by the control unit 28 as follows.
[0033]
  That is, in the recording head 10, as shown in FIG. 3, an image forming liquid supply path 30 and a transparent liquid supply path 32 are formed in the width direction.Liquid outlet12 is partitioned into two passages 36 and 38 by a partition wall 34 (FIG. 3), and these passages 36 and 38 communicate with the image forming liquid supply path 30 and the transparent liquid supply path 32, respectively. The other ends of these passages 36 and 38 areLiquid outlet12 is an image forming liquid discharge port 36A and a transparent liquid discharge port 38A (FIG. 2). The passages 36 and 38 are provided with an image forming liquid discharge amount control valve 40 and a transparent liquid discharge amount control valve 42 as application liquid discharge amount control means, respectively.
[0034]
  A constant pressure image forming liquid (ink) is supplied to the image forming liquid supply path 30 from a pump 44 shown in FIG. In FIG. 4, 46 is a damper that absorbs the pulsation of the discharge pressure of the pump 44 and keeps the discharge pressure constant. 48 is a filter. Similarly, a transparent liquid having a constant pressure is supplied to the transparent liquid supply path 32 from the pump, and the configuration thereof is the same as that of the supply path of the image forming liquid.
[0035]
  These image forming liquid and transparent liquid are supplied to the image forming liquid supply path 30 and the transparent liquid supply path 32 from the image forming liquid supply port 50 and the transparent liquid supply port 52 shown in FIG.
[0036]
  Similarly, the undercoat liquid is guided to the undercoat liquid supply path 56 through the undercoat liquid supply port 54 (FIG. 2) by a pump (not shown). The undercoat liquid supply path 56 is formed long in the width direction of the recording head 10, and the slit-like undercoat liquid discharge port 14 is in communication therewith. As shown in FIGS. 1 and 3, the undercoat liquid discharge port 14 is provided with respect to the feeding direction (right direction) of the image receiver 16.Liquid outlet12 upstream. Therefore, after the undercoat liquid is uniformly applied to the recording surface of the image receiver 16,Liquid outletThe mixed liquid discharged from 12, that is, the recording liquid is applied.
[0037]
  The image forming liquid discharge amount control valve 40 and the transparent liquid supply amount control valve 42 can have the same structure. For example, a diaphragm valve driven by a piezo element is suitable. The control valves 40 and 42 and the passages 36 and 38 for accommodating the control valves 40 and 42 can be made by using a micromachine manufacturing method to which a technique used in a manufacturing process of a semiconductor element or the like is applied. . In FIG.Liquid outletAlthough 12 is drawn with a large interval, it is actually provided with a very narrow pixel interval.
[0038]
  EachLiquid outletIn order to reduce the coating interval by 12, the two are adjacent to each other as shown in FIG.Liquid outlet12 may be deviated in the feeding direction of the image receiver 16. 5A is adjacent.Liquid outlet 12Are alternately displaced in the opposite direction, and FIG.Liquid outlet12 are arranged so as to be displaced in order in a certain direction. In these FIG. 5, the image receptor 16 is fed to the right. Thus eachLiquid outletWhen 12 is displaced, it is needless to say that the control unit 28 needs to change the operation timing of the control valves 40 and 42 for different pixels in accordance with the displacement amount.
[0039]
  According to this embodiment, the control unit 28 determines the open / close timing and open / close time ratio of the control valves 40 and 42 so as to obtain a mixing ratio corresponding to the density of each pixel based on the image signal. To control. As a result, a predetermined amount of image forming liquid and transparent liquid corresponding to each pixel density are obtained.Liquid outlet12 is discharged. On the other hand, a predetermined amount of undercoat liquid is always discharged from the undercoat liquid discharge port 14 in the form of a strip, a plane, or a film. For this reason, when the image receptor 16 is fed in a certain direction by the motor 26, first, the undercoat liquid is applied to a uniform thickness and the base is processed. in additionLiquid outletAs a result, a recording liquid of a predetermined density is formed on the image receiver 16.
[0040]
  In this case, the distance between the recording head 10 and the image receptor 16 isLiquid outlet12 and the undercoat liquid discharge port 14RecordIt is determined by the balance between the discharge pressure of the liquid and the undercoat liquid and the tension of the image receiver 16. Within this interval, a liquid pool, that is, a bead B, is formed by the image forming liquid I, the transparent liquid D, and the undercoat liquid U. The image forming liquid I in the bead B is neatly transferred to the image receiver 16 without being disturbed so as to form an image without being disturbed.
[0041]
  According to this embodiment, as shown in FIG. 3, the streamline of the undercoat liquid U in the bead B bends from the undercoat liquid discharge port 14 to the upstream side (left side) and then returns to the downstream side (right side). Since the undercoat liquid U is transparent, there is no inconvenience even if the streamline is disturbed in the bead B. Since the image forming liquid I and the transparent liquid D are supplied over the undercoat liquid U that has been U-turned and rectified on the upstream side in the bead B, the image forming liquid I is a transparent liquid. It flows without disturbance along with D, and a good image can be formed.
[0042]
  In this embodiment,Liquid outletAs shown in FIG. 3, the undercoat liquid discharge port 12 and the undercoat liquid discharge port 14 are curved toward the downstream side (right side) along the streamline on the downstream end wall surface, and toward the downstream side. The shape was pointed. For this reason, the flow line of the coating liquid is not particularly disturbed and smoothly flows on the undercoat liquid. Further, since the transparent liquid discharge port 38A (FIG. 2) is located downstream of the image forming liquid discharge port 36A, the transparent liquid D is interposed between the image forming liquid I and the upper surface of the recording head 10. For this reason, even if the transparent liquid D comes into contact with the upper surface of the recording head 10 and a delay occurs, the delay of the image forming liquid I is reduced and the image quality is further improved.
[0043]
  In this embodiment, eachLiquid outlet12 is supplied with one image forming liquid and one transparent liquid, so that an image having a single color and changing in density is formed. However, multiple color image forming liquids (for example, yellow, magenta, cyan and black)Liquid outletA color image can be formed by ejecting from the liquid.
[0044]
  It is desirable to add a fading preventing agent for preventing deterioration of the recording liquid due to ultraviolet rays or oxidation to the undercoat liquid, transparent liquid or image forming liquid. Examples of the anti-fading agent include an antioxidant, an ultraviolet absorber, and a certain metal complex. Examples of the antioxidant include a chroman compound, a coumaran compound, a phenol compound (for example, hindered phenols), a hydroquinone derivative, a hindered amine derivative, and a spiroindane compound. In addition, compounds described in JP-A 61-159644 are also effective.
[0045]
  Examples of ultraviolet absorbers include benzotriazole compounds (US Pat. No. 3,533,794, etc.), 4-thiazolidone compounds (US Pat. No. 3,352,681 etc.), benzophenone compounds (Japanese Patent Laid-open No. Sho 56-56). 2784, etc.) and other compounds described in JP-A Nos. 54-48535, 62-136641, 61-88256, and the like. Further, an ultraviolet absorbing polymer described in JP-A-62-260152 is also effective. US Pat. Nos. 4,241,155, 4,245,018, columns 3-36, 254,195, columns 3-8, JP-A-62-174741, 61 -88256, Japanese Patent Application Nos. 62-234103, 62-31096, Japanese Patent Application No. 62-230596, and the like.
[0046]
  Examples of useful anti-fading agents are described in JP-A-62-215272. The anti-fading agent for preventing fading of the dye transferred to the image receiving material may be previously contained in the image receiving material, or may be supplied from the outside to the image receiving material by a method such as transferring from the dye donating material. May be. The above antioxidants, ultraviolet absorbers, and metal complexes may be used in combination. Moreover, you may use said antioxidant, a ultraviolet absorber, and a metal complex as an emulsion.
[0047]
[Other Embodiments]
  FIG. 6 is a perspective view of a recording head according to another embodiment. This recording head 10A is the same as the recording head 10 shown in FIG.Liquid outletA slit shape that is long in the width direction on the downstream side of 12Liquid outlet12A is opened.
[0048]
  According to this embodiment, each pixel was ejectedRecordLiquid is slitLiquid outletSince 12A is continuously integrated in the width direction,RecordThe liquid is applied in the form of a wide band or sheet. For this reason, it becomes possible to apply | coat stably. In addition, the lamination with the undercoat liquid is performed stably, which is suitable for improving the image quality.
[0049]
[Other Embodiments]
  FIG. 7 is a conceptual diagram of another embodiment, and FIG. 8 is a perspective view showing the inside of a recording head used here. FIG. 9 is a schematic diagram showing the relationship between the adhesive force and cohesive force of the liquid. This embodiment is of the slot coating type similar to that shown in FIGS. 1 to 6, except that the recording head 10B forms an image on the final image receiver 16B via the intermediate image receiver 16A.
[0050]
  The intermediate image receiver 16A has a cylindrical shape, and the recording head 10B supplies the coating liquid I and the undercoat liquid U to the upper edge of the intermediate image receiver 16A. Here, since the recording head 10B is configured in the same manner as that described with reference to FIGS. The recording head 10B is held by the guide posts 100, 100 so as to be movable up and down, and auxiliary rollers 102, 102 attached to both the left and right side surfaces are brought into rolling contact with both ends of the upper edge of the intermediate image receiver 16A, so that the recording head 10B and the intermediate image are transferred. The distance from the receptor 16A is kept constant.
[0051]
  The coating liquid (recording liquid) and the transparent liquid discharged from the recording head 10B are placed on the intermediate image receiver 16A and are conveyed downward by the rotation of the intermediate image receiver 16A in the counterclockwise direction. A final image receptor 16B such as a recording sheet is pressed by the pressure roller 104 and travels at the same speed on the lower edge of the intermediate image receptor 16A. For this reason, on the intermediate image receptor 16A.RecordThe liquid and undercoat liquid are transferred to the final image receptor 16B. The final image receptor 16B is fed to the right in FIG. 7 at a constant speed by the guide roller 106 and the guide belt 108, and on the way by the heater 110.RecordThe liquid and undercoat liquid are dried. Reference numeral 112 denotes a suction box provided between the guide belts 108, which sucks the final image receptor 16 </ b> B onto the upper surface of the guide belt 108 so as to be brought into close contact with the guide belt 108 and transport it.
[0052]
  Reference numerals 114 and 114 denote cleaning rollers that are brought into contact with the intermediate image receptor 16A to clean the surface, and 116 and 118 are heaters and charging electrodes, which heat and charge the surface of the intermediate image receptor 16A.RecordA pretreatment is performed to facilitate the adhesion of the liquid and the undercoat liquid. 120 and 122 were supplied by the recording head 10B.RecordA heater and a drying air blowing duct for predrying the liquid and the undercoat liquid.
[0053]
  Reference numeral 124 denotes a liquid recovery blade which serves as a coating liquid recovery means. The blade 124 peels off and collects liquid that is not necessary for image formation from the intermediate image receiver 16A. In additionRecordSince the application state can be stabilized by always discharging the liquid and the undercoat liquid from the recording head 10B, the liquid is always supplied, while unnecessary liquid is removed by the blade 124 to stabilize the image formation. It can be made. A cleaning roller 126 further cleans the surface removed by the blade 124.
[0054]
  The recording head 10B has an undercoat liquid discharge port 14 as shown in FIG.Liquid outlet12 is located upstream of the intermediate image receptor 16A. That is, in FIG. 8, the intermediate image receptor 16A travels from left to right. For this reasonRecordThe liquid is superimposed on the undercoat liquid and is placed on the intermediate image receptor 16A. With this primerRecordWhen the liquid laminate is transferred to the final image receptor 16B, the undercoat liquid is placed on the surface of the final image receptor 16B.
[0055]
  Also, an undercoat liquid applied to the intermediate image receptor 16A andRecordIn order for the liquid to be smoothly transferred to the final image receptor 16B, the following conditions are required. FIG. 9 is a schematic diagram of each layer for explaining the relationship between the adhesive force of the liquid and the cohesive force in the liquid at this time. In this figure, the intermediate image receptor 16A is M, the undercoat liquid is U,Recording liquidIs the final image receptor 16B and P is the adhesion force acting between them._MU, F_U-I, F_I-PUndercoat liquid andRecordF is the cohesive force in the liquid._U-U, F_IIAnd At this time, F_MUEach liquid and the surface state of the receivers 16A and 16B are set in advance so that is minimized.
[0056]
  hereRecording liquidMay uniformly mix the image forming liquid and the transparent liquid. For exampleLiquid outletMixing can be performed by providing a honeycomb-shaped or pipe-shaped static mixer for stirring the liquid. Further, if the liquid in close contact with the intermediate image receptor 16A is a transparent liquid such as a transparent liquid, the cohesive force of the liquid in close contact may be minimized.
[0057]
[Other Embodiments]
  FIG. 10 is a cross-sectional view of a recording head according to another embodiment. The recording head 10 </ b> C is used in a slot coating method similar to that in FIG. 7, and the supply amount of the image forming liquid supplied from the image forming liquid supply path 30 is controlled by the image forming liquid discharge amount control valve 40. The transparent liquid is supplied in two layers so as to sandwich the image forming liquid from both sides. That is, one transparent liquid supply path 32A always discharges a constant amount, and the other transparent liquid supply path 32B discharges from the discharge port by the transparent liquid discharge amount control valve 42 so that stable application can be performed. At this time, the total volume flow rate of the transparent liquid and the image forming liquid is controlled to be substantially constant.
[0058]
  Here, since the total flow rate of the transparent liquid and the image forming liquid supplied from the transparent liquid supplying paths 32A and 32B and the image forming liquid supplying path 30 is considered to have a substantially constant fluid pressure, the downstream of the transparent liquid supplying path 32A. It is almost determined by the cross-sectional area of the channel on the side. Accordingly, the flow rate of the transparent liquid discharged from the transparent liquid supply path 32A is increased or decreased as the total flow rate of the transparent liquid and the image forming liquid supplied from the transparent liquid supply path 32B and the image forming liquid supply path 30 as other coating liquids increases. Decrease. For this reason, a discharge amount control valve is not required in the flow path of the transparent liquid supply path 32A, and the configuration of the recording head 10C is simplified.
[0059]
  Furthermore, the undercoat liquid discharge port 14 isLiquid outletThe opening is upstream of 12. For this reason, the flow line of the undercoat liquid that is always supplied from the undercoat liquid supply path 56 may be folded upstream in the bead B, but has a three-layer structure in which the image forming liquid is sandwiched from both sides with a transparent liquid.RecordSince the liquid is sent over the stable undercoat liquid, image distortion does not occur. The image forming liquid is sandwiched between transparent liquids on both sides.Liquid outletThe liquid in direct contact with the inner wall surface 12 becomes a transparent liquid, and the flow of the image forming liquid becomes smooth and the image quality is further improved.
[0060]
[Other Embodiments]
  FIG. 11 is a cross-sectional view of a recording head 10D according to another embodiment, and FIG. 12 shows the recording head 10D.RecordIt is sectional drawing which shows the laminated structure of a liquid typically. The recording head 10D is used for forming a color image by the slot coating method described above.
[0061]
  The recording head 10D includes four color image forming liquid supply paths 30D (Y), 30D (M), 30D (C), and 30D for yellow (Y), magenta (M), cyan (C), and black (K). (K),Liquid outletFour image forming liquid discharge amount control valves 40D for controlling the discharge amount of each of these image forming liquids to the passage communicating with 12D, and transparent between both color image forming liquids and on both sides of these laminates Two transparent liquid supply passages 32D for supplying the liquid (D), and transparent liquid supply amount control valves 42D (Y), 42D (M), 42D (C) for controlling the amount of the transparent liquid supplied in the vicinity of each image forming liquid ), 42D (K), and two transparent liquid supply amount control valves 42D for controlling the transparent liquid supply amount supplied to both surfaces of the laminate. Here, the transparent liquid (D) entering between the image forming liquids of the respective colors is supplied in place of the changed image forming liquid when the supply amount of the image forming liquid is changed, thereby reducing the thickness of the laminate. Has a function to keep it almost constant. Further, the transparent liquid covering both surfaces of the laminated body is set to a constant flow rate regardless of the image signal.
[0062]
  The cross-sectional structure of the laminate at this time is as shown in FIG. In this figure, Y, M, C, and K are image forming liquids (inks) of respective colors, and the supply amounts thereof are modulated based on image signals. When the image forming liquids (Y, M, C, K) of each color are stacked in the order of Y, M, C, K from the side closer to the intermediate image receptor 16A as shown in FIG. 11, the stacked body of FIG. Will be located on the intermediate image receiver 16A side. Further, in this laminate, the case where two color image forming liquids overlap in the thickness direction of the coating film is shown. However, by supplying a transparent liquid (D) instead of all the image forming liquids, Of course, two or more colors (three colors or four colors) may be mixed.
[0063]
  The surface (front surface side) and the lower surface (intermediate image receptor side) of the laminate are each covered with a transparent liquid (D), but the transparent liquid supply amount control valve 42D is controlled so that the supply amount thereof is controlled by an image signal. May be controlled. In this case, the transparent liquid supplied in the vicinity of each image forming liquid supply passage opening functions to prevent the image forming liquid from adhering to the inner wall of the recording head. Moreover, you may make it apply | coat another transparent liquid (DD) also to the both end surfaces of the width direction of this laminated body. In this case, another transparent liquid supply path may be added to the recording head 10D.
[0064]
  In this embodiment, the laminate is formed in the final image receptor 16B and dried because the image forming liquids (Y, M, C, K) and the transparent liquid (D) of each color are applied in an orderly manner and are not mixed with each other. In the obtained image, streaky unevenness corresponding to each color in each pixel can be recognized. In order to remove such unevenness, each pixelLiquid outletIt is preferable to mix the image forming liquid and the transparent liquid just before 12D. For this purpose, for example, a so-called static mixer such as a thin plate honeycomb shape or a pipe type spiral shape is preferably provided in the middle of the mixed solution.
[0065]
[Other Embodiments]
  FIG. 13 is a diagram showing an outline of another embodiment, FIG. 14 is a sectional view of the recording head, and FIG.Recording liquidFIG. This embodiment shows a coating apparatus by a slide coating method.
[0066]
  Reference numeral 10E denotes a recording head, which is provided on one side (left side) of the intermediate image receiver 16A and from this position to the intermediate image receiver 16A.Recording liquidSupply. On the other side (right side) of the intermediate image receiver 16A, the final image receiver 16B is pressed by the pressure roller 200, and at this position, from the surface of the intermediate image receiver 16A.Recording liquidIs transferred to the final image receptor 16B. Here, the final image receptor 16B is fed almost vertically from the upper side to the lower side by the guide roller 202 and the guide belt 204, and is dried by the heater 206 halfway after the application.
[0067]
  As shown in FIG. 14, the recording head 10E has an inclined surface 208 on its upper surface. The inclined surface 208 is inclined so as to descend toward the intermediate image receptor 16A, and its lower edge is horizontal in the width direction and is close to the intermediate image receptor 16A. The inclined surface 208 has an undercoat liquid discharge port 14E and a firstLiquid outlet12E1, secondLiquid outlet12E2 is open. The undercoat liquid discharge port 14E has a slit shape continuous in the width direction.Liquid outlet12E1 and 12E2 are provided separately for each pixel.
[0068]
  The undercoat liquid used here is supplied from the undercoat liquid supply path 56E, and the adhesive force or cohesive force with the intermediate image receptor 16A is set smaller than the adhesive force or cohesive force of other image forming liquids or transparent liquids. AlsoLiquid outletEach of 12E1 and 12E2 has a three-layer structure in which image forming liquids B and A, the discharge amounts of which are controlled by the image forming liquid discharge amount control valve 40E, are sandwiched by transparent liquids from both sides.Recording liquidIs discharged. 30E and 30E are supply flow paths for the image forming liquids (A and B), and 32E is a supply path for the transparent liquid supplied to both sides of each image forming liquid (A and B). 42E is eachLiquid outletIt is a transparent liquid supply amount control valve that controls one of the transparent liquids for 12E1 and 12E2.
[0069]
  According to this embodiment, as shown in FIG. 15, the image forming liquids A and B are layered while being sandwiched between transparent liquids, flow down the inclined surface 208 in an orderly manner, and are transferred to the intermediate image receiver 16A. The image forming liquids A and B controlled in response to the image signal are controlled by correcting the operation timing of the control valves 40E and 42E so that they have the same phase on the intermediate image receptor 16A.
[0070]
  In FIG. 13, reference numerals 210 and 210 denote cleaning rollers, and 212 denotes a heater, which improves the wettability of the liquid by performing a pretreatment on the surface of the intermediate image receptor 16A. Reference numeral 214 denotes an exhaust pump, and 216 denotes a decompression chamber. The decompression chamber 216 faces the coating liquid moving part between the recording head 10E and the intermediate image receiver 16A from below, and air is mixed between the coating liquid and the intermediate image receiver 16A to prevent the image from being disturbed. It is something to prevent. Reference numeral 218 denotes a heater for predrying the applied liquid. Reference numeral 220 denotes a blade as a coating liquid collecting means, and 222 denotes a cleaning roller, which removes and collects a coating liquid that is not necessary for image formation, for example, an unnecessary coating liquid on the front end side or rear end side of an image.
[0071]
[Other Embodiments]
  FIG. 16 is a cross-sectional view of a recording head according to another embodiment. This recording head 10F is used for the slide coating method similar to that shown in FIG. 13, and the same parts as those of the recording head 10E shown in FIGS. 14 and 15 is that a recovery switching plate 230 as a coating liquid recovery means and a coating liquid recovery path 232 are added to the inclined surface 208.
[0072]
  The recovery switching plate 230 is closed during normal image formation, and a coating liquid is placed on the upper surface of the recovery switching plate 230 to flow down to the intermediate image receiver 16A. Unnecessary coating liquid before and after image formation is guided to the coating liquid collection path 232 by opening the collection switching plate 230. As described above, the recovery switching plate 230 is opened before the coating liquid is transferred to the intermediate image receptor 16A so that the recovery can be performed. In addition, the structure is simple and suitable for miniaturization.
[0073]
  When forming a final image whose width is narrower than the effective recording width of the recording head 10F, it is sufficient to discharge the coating liquid (image forming liquid, transparent liquid, and undercoat liquid) by a necessary width. for that purposeLiquid outletThe control valve is closed so that unnecessary liquid is not discharged from the liquid, and the discharge ports for transparent liquid and undercoat liquid are also grouped into multiple discharge blocks in the width direction, and liquid is selectively selected from only the part corresponding to the width of the final image. It is desirable to discharge it. In this way, it is possible to reduce the load on the blade 220 (see FIG. 13) and the recovery switching plate 230 for removing and recovering unnecessary liquid and reducing the cleaning load on the intermediate image receptor 16A.
[0074]
[Other Embodiments]
  FIG. 17 is a diagram showing an outline of another embodiment. This embodiment is based on the slide coating method similar to that shown in FIG. In this figure, the same parts as those in FIG. The difference from the one shown in FIG. 13 is that the recording head 10G is not provided with the undercoat liquid discharge port 14E (FIGS. 14 to 16), but instead is provided with an undercoat liquid application roller 240 that is in rolling contact with the intermediate image receptor 16A. It is a thing.
[0075]
  The undercoat liquid application roller 240 is in contact with the intermediate image receptor 16A on the upstream side of the decompression chamber 216 to apply the undercoat liquid. This undercoat liquid is formed on the surface of the intermediate image receptor 16A.RecordAs described above, the adhesive force with the surface of the intermediate image receptor 16A is set to be sufficiently small or the cohesive force in the undercoat liquid is set to be sufficiently small so that separation from the liquid can be performed smoothly. .
[0076]
[Other Embodiments]
  FIG. 18 is a diagram showing an outline of another embodiment. This embodiment shows a curtain coating method. The recording head 10H used here is configured in substantially the same manner as the slide coating type recording heads 10E to 10G described with reference to FIGS.
[0077]
  IeRecordThe liquid rides on an inclined surface 242 formed to be inclined toward one side on the upper surface of the recording head 10H, and flows down above the intermediate image receptor 16A. In the vicinity of the lower edge of the inclined surface 242, the guide plate 244 is opposed substantially vertically. ThereforeRecordThe liquid moves from the lower edge of the inclined surface 242 to the guide plate 244 and flows down to the intermediate image receiver 16A. The guide plate 244 has edges formed on both edges for restricting the change in the coating width of the recording head 10H. IeRecordWhen the liquid flows down the surface of the guide plate 244,RecordAlthough there is a problem that the liquid gathers in the center due to the surface tension of the liquid and the film thickness becomes thin on both sides, it is possible to prevent the width from changing by providing this edge. In addition, the wind flows while flowing from the lower edge of the guide plate 244 to the intermediate image receptor 16A.RecordThe windshield plate 246 surrounds this area so that the liquid does not shake.
[0078]
  Further, a blade 248 that can contact and be separated from the guide plate 244 is provided. This blade 248 is unnecessary for image formation.RecordWhen the liquid is removed and recovered, it contacts the intermediate image receptor 16A. Reference numeral 250 denotes a preliminary drying heater, 252 a pressure roller, 254 a guide roller, 256 a drying heater, 258 a cleaning roller, 260 a blade, and 262 a heater.
[0079]
[Other Embodiments]
  FIG. 19 is a diagram showing an outline of another embodiment. This embodiment is based on the curtain coating method as in FIG. 18, but flows down from the guide plate 244.Record18 differs from that of FIG. 18 in that the liquid is led directly to the final image receptor 16 without going through the intermediate image receptor 16A (see FIG. 18).
[0080]
  That is, below the guide plate 244, the final image receiver 16 such as paper is fed at a constant speed by the guide belt 270 and the guide roller 272. The image receptor 16 flows down from the guide plate 244.RecordThe liquid is guided and thisRecordThe liquid is dried with a heater 247. According to this embodiment, it is possible to apply at a high speed as in FIG. 18, and an image can be formed at a high speed.
[0081]
[Other Embodiments]
  FIG. 20 is a cross-sectional view of a recording head according to another embodiment. The recording head 10I opens downward.Liquid outlet12I is provided. The final image receptor 16 isLiquid outlet12I is sent close to and below the 12I.Liquid outletA coating liquid recovery switching plate 280 as a coating liquid recovery means is provided between 12I and the image receptor 16 so as to be movable back and forth.
[0082]
  That is, the recovery switching plate 280 is formed long in the width direction of the recording head 10I,Liquid outletThe edge that enters the bottom of 12I has a thin plate shape, and the other edge is bent upward in an L shape. The upper surface is inclined so as to descend from the thin plate-shaped end edge toward the other end edge. Further, the inner side of the L-shaped portion is long in the width direction of the recording head 10I.Liquid suction port282 is open.
[0083]
  Therefore, the thin plate-like tip of the recovery switching plate 280 isLiquid outletIf you enter below 12I,Liquid outletDischarged from 12IRecordThe liquid flows on the recovery switching plate 280 and flows to the L-shaped bent portion side. Then, the liquid is sucked from the coating liquid suction port 282 and removed and collected. This recovery switching plate 280Liquid outletIf you leave from below 12I,Liquid outletDischarged from 12IRecordThe liquid can be transferred to the image receiver 16 to form an image.
[0084]
[Other Embodiments]
  Each of the above embodiments is representative of a so-called slot coating method, slide coating method, and curtain coating method, but the present invention is not limited to these. For example, a composite type of these or a method in which these are modified may be used.
[0085]
  When the recording head is not used for a long time, the solute precipitates or solidifies as the liquid solvent evaporates. This causes a problem that the liquid discharge port and the liquid passage of the recording head are clogged. In order to avoid this, it is preferable to flow a liquid (cleaning liquid) for cleaning the recording head at the end of use. Further, when the recording head is not used, it is possible to obtain a great effect by covering the surface of the recording head (especially the inclined surface) with a cover and preventing the liquid from coming into contact with the outside air. As cleaning liquidLiquidA liquid that dissolves the solidified component contained in the liquid is desirable, but an undercoat liquid or a transparent liquid that becomes substantially transparent after drying can also have this function.
[0086]
  Image forming liquid, clear liquid, undercoat liquid, etc.LiquidIt is effective for uniform coating to control the recording head and the ambient temperature around the recording head to be the same. Also, in the case of slot type, between the recording headLiquidTemporarily hold the final image receptor or intermediate image receptor temperature beforeLiquidOr the same as the recording head is effective for uniform coating. Top during applicationLiquidIf you replaceThe liquidIt is preferable to provide a heat exchange part in the middle of the coating liquid storage tank and the coating liquid feeding pipe so that the temperature reaches a predetermined temperature before reaching the recording head.
[0087]
  The above embodiment has been described as forming an image. That is, the description has been made on the assumption that an image is drawn two-dimensionally on a sheet of paper or film. However, the present invention is suitable for the manufacture of industrial products with spatially varying color and density, such as mosaic filters used in image displays such as liquid crystal color displays, that is, color filters in which yellow, magenta, and cyan colors are repeatedly arranged in a mosaic pattern. Can be used. Furthermore, the present invention can also be applied to the manufacture of industrial products that form spatially repeatable patterns.
[0088]
【The invention's effect】
  As described above, the first aspect of the present invention provides a plurality of lines arranged in a direction (width direction) substantially orthogonal to the relative movement direction of the image receptor.Liquid outletSince the coating liquid is ejected as a continuous flow and continuously applied to the image receptor, the amount of wasted ink is small and high-speed image formation is possible, and a different electric field is formed for each pixel. Since there is no need, the size of the nozzle can be reduced. In addition, the image disturbance due to the interaction between ink droplets as in the ink jet method and the installation environment are not adversely affected, and the image can be stably formed without being affected by the thickness or surface condition of the image receptor. Can do.
[0089]
  Liquid outletAre arranged in parallel for each pixel.Liquid outletFrom a plurality of coating liquids in the coating thickness direction to make a continuous flowLiquid outletIt is possible to discharge in the form of a band integrated in the parallel arrangement direction. In this case, for each pixelLiquid outletThe slit-shapedLiquid outletOpen in this slit shapeLiquid outletWhat is necessary is just to unite and make it a belt | band | zone inside.
[0090]
  At least one of the coating liquids is a transparent liquid that becomes substantially transparent after drying, and the mixing ratio is changed while keeping the volume flow rate of the entire coating liquid of the transparent liquid and the image forming liquid (ink) substantially constant. Thus, the concentration can be changed (claim 3). Further, at least one transparent liquid is supplied with its supply pressure substantially constant regardless of the image signal, and the discharge amount of the transparent liquid is controlled by controlling the discharge amount of the other coating liquid mixed with the transparent liquid. It can also be changed (claim 4).).
[0091]
  Liquid outletBy using at least one outermost layer of the coating liquid discharged from the liquid as a transparent liquid, this can be used as an undercoat liquid to improve the surface condition of the image receptor and improve the image quality, or to separate the coating liquid from the intermediate image receptor. Can be improved (claims)5,6, 7,8). When using an intermediate image receptor, by setting the coating solution so that the adhesion force or cohesion force of the liquid contacting the intermediate image receptor surface is smaller than the adhesion force or cohesion force between the other coating solution layers. It is possible to smoothly transfer the coating liquid from the intermediate image receptor to the final image receptor.9, 10).
[0092]
  Adjacent for small pixel spacingLiquid outletMay be displaced in the relative movement direction of the image receptor. In this case, image deviation can be prevented by applying temporal correction to the image image signal for each pixel corresponding to this deviation.11). During the period when the image is not formed, the coating liquid is continuously applied, for example, by continuously discharging a transparent liquid, thereby enabling stable image formation.12). In this case, the unnecessary coating solution isLiquid outletAnd removal between the image receptor and the image receptor.
[0093]
  Claim13According to the invention, an image forming apparatus used directly for carrying out the method of claim 1 is obtained.Liquid outletMay be provided for each pixel lined up in the width direction of the image receptor.14)For one pixelLiquid outletAre divided into several in the moving direction of the image receptorSupply different coating liquid from each liquid outlet.This makes it easier to manufacture the recording head.15). Also for adjacent pixelsLiquid outletAre adjacent if they are offset from each other in the direction of movement of the image receptorLiquid outletIncreases the interval of the recording head and improves the productivity of the recording head.16).
[0094]
  eachLiquid outletIs slit-shapedLiquid outletIf the coating solution is continuous in the width direction, the coating solution can be laminated in a strip shape and discharged smoothly (claims17). A certain amount of recording head does not change depending on the image signal.undercoatA slit-like shape that discharges liquid in a band shapeundercoatUndercoating with a simple configuration by providing a liquid discharge portLiquidCan be supplied smoothly (claims)18). The recording head has a slot coating method (claim)19, 20), Slide coating method (claims)21), Curtain coating method (claim)22) And the like according to various coating methods. In addition, it is possible to provide a means for removing and collecting the coating liquid in the middle, and in this case, it is possible to form a more stable image by continuously discharging the coating liquid.23).
[0095]
  The image receptor is applied directly on the recording head as a sheet or film like paper.liquid(Claims)24), The coating liquid may be transferred to the final image receptor such as paper via the intermediate image receptor (claims).25). In this case, by performing a pretreatment that stabilizes the surface state of the intermediate image receptor, it is less susceptible to fluctuations in the surface state of the final image receptor, and higher quality image formation becomes possible.
[0096]
  Discharge amount control means from the coating liquid supply pathLiquid outletIt can be formed by a discharge amount control valve provided in the passage leading to (claim)26). Also, this discharge amount control meansLiquid outletThe discharge amount from each discharge port may be controlled by a pump provided for each (claim)27). At least one of the plurality of coating liquids may be a transparent liquid, and at least one transparent liquid may be supplied with its supply pressure substantially constant regardless of the image signal. In this case, the discharge amount control means can be omitted for the transparent liquid, and the configuration of the recording head can be simplified.28).
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment according to a slot coating method.
FIG. 2 is a perspective view showing the internal structure of the recording head.
FIG. 3 is an enlarged sectional view of the recording head.
FIG. 4 is a conceptual diagram of a supply path for coating liquid
[Figure 5]Liquid outletDiagram showing an example array
FIG. 6 is a perspective view of a recording head according to another embodiment.
FIG. 7 is a conceptual diagram of another embodiment.
FIG. 8 is a perspective view of the recording head.
FIG. 9liquidSchematic explaining the relationship between the adhesive force and cohesive force
FIG. 10 is a cross-sectional view of a recording head according to another embodiment.
FIG. 11 is a cross-sectional view of a recording head according to another embodiment.
FIG.RecordSectional view schematically showing the laminated structure of the liquid
FIG. 13 is a diagram showing an outline of another embodiment.
FIG. 14 is a sectional view of the recording head.
FIG. 15RecordDiagram showing liquid layer structure
FIG. 16 is a cross-sectional view of a recording head according to another embodiment.
FIG. 17 is a diagram showing an outline of another embodiment.
FIG. 18 is a diagram showing an outline of another embodiment
FIG. 19 is a diagram showing an outline of another embodiment.
FIG. 20 is a cross-sectional view of a recording head according to another embodiment.
[Explanation of symbols]
  10, 10A-10I Recording head
  12, 12E, 12ILiquid outlet
  12A slit-shapedLiquid outlet
  14, 14E Undercoat liquid outlet
  16 Image receptor
  16A intermediate image receptor
  16B Final image receptor
  28 Control unit
  30, 30D, 30E, 32I Image forming liquid supply path
  32, 32A, 32B, 32D, 32E, 32I Transparent liquid supply path
  40, 40D, 40E, 40I Image forming liquid discharge amount control valve (application liquid discharge amount control means)
  42, 42D, 42E, 42I Transparent liquid discharge amount control valve (application liquid discharge amount control means)
  124, 220, 248 Blade as coating solution recovery means
  230, 280 Recovery switching plate as coating liquid recovery means

Claims (28)

While a plurality of coating solutions including an image forming liquid and the clear liquid is changed based on the mixing ratio of it to the image signals discharged from the liquid discharge port, and shifts to the image receptor to move relative to the liquid discharge port An image forming method for forming an image by:
A plurality of coating liquids are ejected as a continuous flow while determining a mixing ratio based on the image signal from a plurality of liquid ejection ports arranged for each pixel arranged in a direction substantially orthogonal to the relative movement direction of the image receptor. An image forming method comprising: continuously coating the image receptor to form an image. The liquid discharge ports are divided and arranged in parallel for each pixel arranged in a direction substantially orthogonal to the relative movement direction of the image receptor, and a plurality of coating liquids discharged from each liquid discharge port as a continuous flow are overlapped in the coating thickness direction. 2. The image forming method according to claim 1, wherein the liquid discharge ports are integrated in the direction in which the liquid discharge ports are juxtaposed and formed into a belt shape and transferred to the image receptor.   At least one of the plurality of coating liquids is a transparent liquid that becomes substantially transparent after drying, and the transparent liquid and the optical density are maintained while maintaining a substantially constant volume flow rate of the entire coating liquid including the transparent liquid. The image forming method according to claim 1, wherein the image density is changed by changing a mixing ratio with another coating liquid having a stencil.   The image according to any one of claims 1 to 3, wherein the at least one coating liquid is a transparent liquid that becomes substantially transparent after drying, and the at least one transparent liquid is supplied at a substantially constant supply pressure regardless of the image signal. Forming method. The image forming method according to any one of claims 1 to 4 , wherein at least one of the plurality of coating liquids ejected in a layered manner from the liquid ejection port is a transparent liquid that is substantially transparent after drying. 6. The image forming method according to claim 5 , wherein the transparent liquid is an undercoat liquid in contact with the surface of the image receptor. The image forming method according to claim 1, wherein the plurality of layered coating liquids ejected from the liquid ejection port are transferred to the final image receptor via the intermediate receptor. 8. The image forming method according to claim 7 , wherein at least one of the plurality of coating liquids is a substantially transparent undercoat liquid after drying, and the undercoat liquid is located in an outermost layer in contact with the surface of the intermediate image receptor. The adhesive force between the intermediate image receptor and the coating solution in contact with the intermediate image receptor is set to be smaller than both the cohesive force within and between the multiple coating solutions and the adhesion force between the final image receptor and the coating solution in contact therewith. The image forming method according to claim 7 or 8 , wherein: The cohesive force in the undercoat liquid in contact with the intermediate image receptor surface is smaller than any of the cohesive forces in and between other coating liquids and the adhesion force between the final image receptor and the coating liquid in contact therewith. The image forming method according to claim 7 or 8 , wherein the image forming method is set. Liquid discharge ports adjacent to each other are offset from one another in a non-orthogonal direction with respect to the relative movement direction of the image receptor, the image signal is corrected in advance so as to prevent the displacement of the image due to the displacement of the liquid discharge ports for each pixel the image forming method according to claim 1-10, which are. The plurality of coating liquids continue to be discharged from the liquid discharge port even during the output period of the image signal that does not form an image, and the plurality of coating liquids discharged during the output period of the image signal that does not form an image are the liquid discharge port and the image receptor. the image forming method according to claim 1 to 11 to be recovered and removed to and from. An image receptor that discharges from a liquid discharge port while changing a mixing ratio of a plurality of coating liquids including an image forming liquid and a transparent liquid based on an image signal, and moves the recording liquid relative to the liquid discharge port . An image forming apparatus for forming an image by shifting,
A recording head for guiding the continuous image receptor plurality of coating liquid discharged as a continuous flow from a plurality of liquid discharge ports kicked set for each pixel aligned in a direction substantially perpendicular to the relative movement direction of said image receptor ,
A discharge amount control means for controlling a supply amount of a plurality of coating liquids supplied to each liquid discharge port ;
A control unit that determines a mixing ratio of a plurality of coating liquids discharged from each liquid discharge port based on an image signal and controls the discharge amount control unit;
An image forming apparatus comprising: 14. The image forming apparatus according to claim 13 , wherein one liquid discharge port is provided for each pixel of the image arranged in the width direction of the image receptor. Liquid discharge ports corresponding to each pixel is formed in plurality in the direction of movement of the image receptor, the image forming apparatus according to claim 13 you supplying different coating liquid from the liquid discharge port. The image forming apparatus according to claim 14 , wherein the liquid discharge ports for adjacent pixels are offset from each other in the transfer direction of the image receptor. In the recording head, a liquid discharge port corresponding to each pixel is connected in the width direction of the image receptor, and the coating liquid discharged from each liquid discharge port is integrated in the width direction of the image receptor and discharged in a band shape The image forming apparatus according to claim 13 , wherein a liquid discharge port is formed. The recording head, a slit-shaped undercoating liquid discharge port for discharging to the constantly fixed amount of undercoating liquid does not change by the image signals in a wide band in the width direction of the image receptor, the discharge amount is changed by the image signal Eki吐 The image forming apparatus according to claim 13 , wherein the image forming apparatus is formed independently from the outlet . The image forming apparatus according to claim 13 , wherein the liquid discharge port is opened on the upper surface of the recording head, and the image receptor is transferred with its lower surface facing the upper surface of the recording head. 19. The image forming apparatus according to claim 13 , wherein the liquid discharge port is opened on the lower surface of the recording head, and the image receptor is transferred with its upper surface facing the lower surface of the recording head. The recording head is inclined so that the upper surface descends toward the image receiver, the lower edge of this inclined surface is horizontal in the width direction of the image receiver, and the lower edge moves relative to the lower edge. The liquid discharge port is opened to the inclined surface and the coating liquid discharged from each liquid discharge port flows down on the inclined surface and is guided to the image receptor. The image forming apparatus according to any one of 13 to 18 . The upper surface of the recording head is inclined, and the lower edge of the inclined surface is horizontal in the width direction of the image receptor, and the coating liquid discharged from the liquid discharge port opening on the inclined surface and flowing down on the inclined surface is inclined. The image forming apparatus according to claim 13 , further comprising a substantially vertical guide plate that is guided downward from a lower edge of the surface to be guided to an image receptor. The image forming apparatus according to any one of claims 13 to 22 , further comprising a coating liquid collecting means for removing and collecting the coating liquid from the recording head to the image receiving surface. The image forming apparatus according to claim 13 , wherein the image receptor is a sheet-like final image receptor. Image receptor is formed by the intermediate image receptor and the final image receptor, either of claims 13 to 23 coating solution supplied from the recording head is to be transferred to the final image receptor through the intermediate image receptor Such an image forming apparatus. 14. The image forming apparatus according to claim 13, wherein the discharge amount control means is formed by a discharge amount control valve provided in a passage from the coating liquid supply path to the liquid discharge port . 14. The image forming apparatus according to claim 13, wherein the discharge amount control means is formed by a pump that changes a supply amount of the coating liquid. At least one coating liquid is a transparent liquid that becomes substantially transparent after drying. The transparent liquid is supplied at a substantially constant pressure regardless of the image signal, and the other coating liquid is discharged based on the image signal by the discharge amount control means. The image forming apparatus according to claim 13 , wherein the image forming apparatus is controlled.

Images