JP2013139087A - Image recording apparatus, pre-drying apparatus, image recording method, and pre-drying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control distribution of the amount of moisture of a recording medium to which treatment liquid is evenly applied to smooth the distribution of the amount of moisture after the application of ink and to suppress the deformation of paper.SOLUTION: An image recording apparatus includes: a treatment liquid application means for evenly applying the treatment liquid containing a flocculant that flocculates components in an ink to at least a recording area of the recording medium; a pre-drying means for pre-drying the recording medium to which the treatment liquid is applied, and distributing the amount of moisture of the treatment liquid in the recording area; an image recording means for recording an image by applying the ink to the recording area of the recording medium which has been pre-dried; an ink distribution calculation means for calculating the distribution of the amount of moisture of the applied ink; a treatment liquid distribution calculation means for calculating the distribution of the amount of moisture of the treatment liquid for smoothing the distribution of the amount of moisture in the recording area after the application of the ink; and a control means that controls the pre-drying means, and regards the distribution of the amount of moisture of the treatment solution as the distribution calculated by the treatment liquid distribution calculation means.

Description

  The present invention relates to an image recording apparatus, a preliminary drying apparatus, an image recording method, and a preliminary drying method, and more particularly to a technique for forming an image by ejecting ink onto a recording medium to which a treatment liquid is applied.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus having an ink jet head in which a large number of nozzles are arranged is known as an image recording apparatus. This ink jet recording apparatus forms an image by ejecting ink as droplets from nozzles while moving an ink jet head and a recording medium relatively to form dots on the recording medium.

  At this time, depending on the type of the recording medium and the type of ink, the ink that has landed on the recording medium may permeate into the recording medium, causing the dots formed on the recording medium to spread and spread. The quality of the rendered image may be significantly degraded. Further, when another ink droplet is subsequently ejected so as to overlap (contact with) at least a part of the ink droplet on the recording medium, so-called landing interference occurs in which the ink droplets are mixed with each other. Sometimes.

  In order to prevent such image deterioration due to dot bleeding or spreading or landing interference, an ink jet that reacts two liquids of the processing liquid and ink on the recording medium to prevent dot bleeding or spreading or landing interference. Recording devices have been proposed. However, since the processing liquid and the ink are applied to the recording medium, the amount of the liquid increases by the amount of the processing liquid, and there is a problem that the recording medium is easily curled after recording.

  In addition, there is a problem that a water amount distribution is generated on the recording medium between a region where ink is ejected and a region where ink is not ejected, thereby causing wrinkles and cuckling. The generation of wrinkles and cockles will be described using an example in which an image corresponding to the image data shown in FIG.

  FIG. 21B is a schematic cross-sectional view of the paper P to which the treatment liquid and the ink are applied, and a graph showing the moisture content of each region of the paper P. As shown in the figure, after the treatment liquid is uniformly applied to the recording surface of the paper P, ink is ejected onto a region where an image is formed. Therefore, the amount of moisture applied differs for each region of the paper P. Here, the amount of water refers to the amount of water that is a solvent of the treatment liquid and the amount of water that is the solvent of the ink.

  FIG. 21C is a schematic cross-sectional view when the entire surface of the paper P to which the treatment liquid and ink have been applied as shown in FIG. 21B is uniformly dried, and the surface temperature of each region of the paper P. It is the graph which showed the moisture content. As shown in the figure, the distribution of surface temperature and moisture content occurs on the dried paper P.

  FIG. 21D is a schematic diagram illustrating the upper surface of the paper P after drying. As shown in the drawing, a difference in shrinkage due to a difference in water amount occurs at the boundary between the area where ink is ejected and the area where ink is not ejected, and fixing wrinkles occur. Further, deformation (cuckling) due to overdrying occurs in an area where ink is not ejected.

  In order to deal with such a problem, Patent Document 1 discloses a technique for controlling the amount of both of the treatment liquid and the ink so as to be constant so that the sum of the amount of water of the treatment liquid and the amount of moisture of the ink applied per unit area of the recording medium is constant. Have been described. According to this technique, since the surface shape after applying the liquid to the recording medium can be made constant throughout the entire surface, the shape of the recording medium can be made uniform by performing a certain correction process thereafter. It can be stabilized.

JP 2007-118373 A

  A roller coating method is suitably used for applying the treatment liquid to the recording medium. According to the roller coating method, it is possible to form a thin layer with a low viscosity treatment liquid over the entire surface of the recording medium.

  However, the technique of Patent Document 1 requires a discharge mechanism for selectively applying a treatment liquid, and has a problem that it is difficult to apply an apparatus based on roller coating.

  The present invention has been made in view of such circumstances, and an image recording apparatus and a pre-drying apparatus that control the moisture distribution of a recording medium to which a processing liquid is uniformly applied to suppress paper deformation during drying. An object of the present invention is to provide an image recording method and a preliminary drying method.

  In order to achieve the above object, one aspect of the image recording apparatus includes: a processing liquid applying unit that uniformly applies a processing liquid containing an aggregating agent that aggregates components in ink to at least a recording area of a recording medium; Pre-drying means for pre-drying the recording medium to which the liquid has been applied, the pre-drying means for distributing the water content of the treatment liquid in the recording area, and the ink being applied to the recording area of the pre-dried recording medium. An image recording means for recording an image, an ink distribution calculating means for calculating a distribution of the moisture content of the applied ink, and a moisture content of the processing liquid for smoothing the distribution of the moisture content in the recording area after the ink application. And a control means for controlling the pre-drying means so that the moisture content distribution of the treatment liquid is a distribution calculated by the treatment liquid distribution calculation means.

  According to the present embodiment, the distribution of the moisture content of the processing liquid for smoothing the distribution of the moisture content in the recording area after application of ink is calculated, and by controlling the preliminary drying means, the moisture content of the processing liquid is controlled. Since the distribution is set to the distribution calculated by the processing liquid distribution calculation means, the distribution of the water content of the recording medium to which the processing liquid is uniformly applied is controlled, and the distribution of the water content after ink application is smoothed. Therefore, deformation of the paper during drying can be suppressed.

  The pre-drying means pre-drys each unit area divided into a plurality of recording areas, the ink distribution calculating means calculates the amount of water of ink applied to the recording area for each unit area, and the processing liquid distribution calculating means It is preferable to calculate the moisture content of the treatment liquid for each unit region for smoothing the moisture content distribution for each unit region.

  Thereby, it is possible to appropriately smooth the moisture content distribution in the recording area of the recording medium.

  The processing liquid distribution calculating means calculates the water content of the processing liquid for each unit region so that the sum of the water content of the ink applied by the image recording means and the water content of the pre-dried processing liquid is within a predetermined range. It is preferable to calculate. Thereby, it is possible to appropriately smooth the moisture content distribution in the recording area of the recording medium.

  The preliminary drying means preferably includes a heating means for heating the recording area. Thereby, the recording medium can be appropriately preliminarily dried.

  As the heating means, hot air blowing means for blowing hot air to the recording area, laser irradiation means for irradiating the recording area with laser light, and heater means for heating in contact with the recording medium provided with the treatment liquid can be applied. Thereby, the recording medium can be appropriately preliminarily dried.

  The preliminary drying means may include a cooling means for cooling the recording area.

  As the cooling means, a cold air blowing means for blowing cold air to the recording area, and a water cooling means for cooling in contact with the recording medium before the treatment liquid is applied can be applied. Thereby, the recording medium can be appropriately cooled and preliminarily dried.

  In order to achieve the above object, one aspect of a pre-drying apparatus is a method in which an ink is applied to a recording medium in which a treatment liquid containing a flocculant for aggregating components in the ink is uniformly applied to at least a recording area. In a pre-drying apparatus that pre-drys before an image is recorded, a drying unit that distributes the water content of the processing liquid in the recording area of the recording medium to which the processing liquid is applied, and the distribution of the water content of the applied ink An ink distribution calculating means for calculating the water content, a processing liquid distribution calculating means for calculating the water content distribution of the processing liquid for smoothing the water content distribution in the recording area after ink application, and a drying means for controlling the processing. Control means for setting the distribution of the water content of the liquid to a distribution calculated by the processing liquid distribution calculation means.

  According to the present embodiment, the distribution of the moisture content of the processing liquid is calculated by calculating the distribution of the moisture content of the processing liquid for smoothing the distribution of the moisture content in the recording area after ink application, and controlling the drying means. Is set to the distribution calculated by the processing liquid distribution calculating means, so that the distribution of the water content of the recording medium to which the processing liquid is uniformly applied is controlled to smooth the distribution of the water content after applying the ink. Therefore, deformation of the paper during drying can be suppressed.

  In order to achieve the above object, one aspect of an image recording method includes a treatment liquid application step for uniformly applying a treatment liquid containing an aggregating agent for aggregating components in ink to at least a recording region of a recording medium, and a process A pre-drying step of pre-drying the recording medium to which the liquid has been applied, wherein the pre-drying step has a distribution in the moisture content of the treatment liquid in the recording area, and the ink is applied to the recording area of the pre-dried recording medium. An image recording process for recording an image, an ink distribution calculating process for calculating the distribution of the moisture content of the applied ink, and a moisture content of the processing liquid for smoothing the distribution of the moisture content in the recording area after the ink application In the pre-drying step, and a control step that sets the distribution of the moisture content of the treatment liquid to the distribution calculated in the treatment liquid distribution calculation step.

  In order to achieve the above object, one aspect of the pre-drying method is a recording medium in which a treatment liquid containing an aggregating agent for aggregating the components in the ink for aggregating the components in the ink is uniformly applied to at least the recording area. In a predrying method in which the ink is preliminarily dried before an image is recorded, a drying process is provided for providing a distribution of the moisture content of the processing liquid in the recording area of the recording medium to which the processing liquid is applied. An ink distribution calculating step for calculating the distribution of the moisture content of the ink, a processing liquid distribution calculating step for calculating the distribution of the moisture content of the processing liquid for smoothing the distribution of the moisture content in the recording area after ink application, The pre-drying step includes a control step in which the moisture content distribution of the treatment liquid is set to the distribution calculated in the treatment liquid distribution calculation step.

  According to the present invention, the moisture distribution of the recording medium to which the treatment liquid is uniformly applied can be controlled to smooth the moisture distribution after the ink application, so that deformation of the paper during drying is suppressed. can do.

Overall configuration diagram showing an embodiment of an inkjet recording apparatus Schematic view of the treatment liquid drying unit from the top Block diagram showing schematic configuration of control system of inkjet recording apparatus The figure which shows the process liquid drying process unit which dries the process liquid of the paper P and the paper P A cross-sectional schematic diagram of the paper P in each process, and a graph showing the distribution of the surface temperature and moisture content of each region of the paper P The figure which shows the change of the moisture content of each area | region of the paper P in each process. The figure which shows the process liquid drying process unit which dries the process liquid of the paper P and the paper P Overall configuration diagram showing an embodiment of an inkjet recording apparatus Schematic view of paper P and processing liquid drying processing unit viewed from the processing liquid drying processing drum side Overall configuration diagram showing an embodiment of an inkjet recording apparatus Schematic view of the paper P, the processing liquid drying processing unit, and the image recording unit viewed from above. Diagram for explaining the drying gradient at the boundary of the image The figure for demonstrating the drying gradient of the process liquid drying process part with respect to an ink drying process part Overall configuration diagram showing an embodiment of an inkjet recording apparatus Block diagram showing schematic configuration of control system of inkjet recording apparatus Schematic view of paper P and local cooling unit viewed from above A cross-sectional schematic diagram of the paper P in each process, and a graph showing the distribution of the surface temperature and moisture content of each region of the paper P Schematic view of paper P and local cooling unit viewed from above Overall configuration diagram showing an embodiment of an inkjet recording apparatus Schematic diagram showing paper P and local cooling processing unit 332 Illustration to explain the occurrence of wrinkles and cockles

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< Overall configuration of inkjet recording apparatus >>
FIG. 1 is an overall configuration diagram showing an embodiment of an ink jet recording apparatus according to the present embodiment.

  The ink jet recording apparatus 100 uses a water-based ink (an ink in which a coloring material such as a dye or a pigment is dissolved or dispersed in water and a solvent soluble in water) on a paper (sheet) P to form an image by an ink jet method. A sheet-fed inkjet printer for recording, and a processing liquid application unit 110 that applies a predetermined processing liquid mainly to the surface (image recording surface, hereinafter simply referred to as a recording surface) of paper P as a recording medium, and a processing liquid application A processing liquid drying processing unit 120 that performs a drying process on the paper P to which the processing liquid is applied in the unit 110, and an ink jet method using a water-based ink on a recording surface of the paper P that has been subjected to a drying process in the processing liquid drying processing unit 120. The image recording unit 130 for recording an image and the ink drying processing unit 140 for drying the paper P on which the image is recorded by the image recording unit 130 are configured.

<Processing liquid application part>
The processing liquid application unit 110 is a processing liquid application unit that applies a predetermined processing liquid to the recording surface of the paper P. The treatment liquid application unit 110 mainly includes a treatment liquid application drum 112 that conveys the paper P, and a treatment liquid application unit 114 that applies a predetermined treatment liquid to the recording surface of the paper P conveyed by the treatment liquid application drum 112. , And is configured.

  The treatment liquid application drum 112 is formed in a cylindrical shape and is driven to rotate by a motor (not shown). The treatment liquid application drum 112 conveys the paper P while winding the paper P around the peripheral surface by gripping and rotating the front end of the paper P with a gripper (not shown).

  The treatment liquid application unit 114 applies the treatment liquid to the recording surface of the paper P conveyed by the treatment liquid application drum 112 by a roller. The processing liquid application unit 114 includes a coating roller that applies the processing liquid to the paper P, a processing liquid tank that stores the processing liquid, a pumping roller that pumps up the processing liquid stored in the processing liquid tank and supplies the processing liquid to the coating roller. Consists of The application roller is provided corresponding to the width of the paper P, is pressed against the paper P, and applies the treatment liquid applied to the peripheral surface thereof to the paper P. As a result, the treatment liquid is uniformly applied to the recording surface of the paper P conveyed by the treatment liquid application drum 112.

  In this example, the processing liquid is uniformly applied to the recording surface of the paper P by roller application, but the method for uniformly applying the processing liquid is not limited to this. For example, a configuration that uses an inkjet head or a configuration that applies uniformly by spraying may be employed.

  Further, the treatment liquid may be uniformly applied to at least the recording area of the recording surface of the paper P, not the entire recording surface. The recording area refers to an area where an image can be recorded in an image recording unit described later.

  This processing liquid has a function of aggregating the color material in the water-based ink ejected onto the recording surface of the paper P by the image recording unit 130 in the subsequent stage. By applying such a treatment liquid to the recording surface of paper P and ejecting water-based ink, high-quality printing can be performed without causing landing interference even when using general-purpose printing paper. It can be carried out.

<Processing liquid drying processing section>
The processing liquid drying processing unit 120 is a preliminary drying unit (preliminary drying device) that performs a drying process on the paper P on which the processing liquid is uniformly applied to the recording surface. The processing liquid drying processing unit 120 mainly includes a processing liquid drying processing drum 122 that transports the paper P, a paper transport guide 124, and a processing liquid drying processing unit that dries the paper P transported by the processing liquid drying processing drum 122. 126.

  The treatment liquid drying treatment drum 122 is constituted by a frame assembled in a cylindrical shape, and is rotated by being driven by a motor (not shown). The treatment liquid drying processing drum 122 conveys the paper P by gripping and rotating the front end of the paper P with a gripper (not shown).

  The paper transport guide 124 is disposed along the transport path of the paper P by the processing liquid drying processing drum 122 and guides the transport of the paper P.

  The processing liquid drying processing unit 126 is installed inside the processing liquid drying processing drum 122 and blows hot air toward the recording surface of the paper P conveyed by the processing liquid drying processing drum 122 to perform a drying process.

  FIG. 2 is a schematic view of the processing liquid drying processing unit 126 as viewed from above (from the center of the processing liquid drying processing drum 122). In the treatment liquid drying processing unit 126, a plurality of fans 200 are arranged in a matrix so as to face the recording surface of the paper P. In the example shown in FIG. 2, a total of 24 fans 200 are provided with 3 rows in the transport direction and 8 columns in the direction orthogonal to the transport direction. Note that the number of rows and the number of columns in which the fan 200 is arranged is not particularly limited.

  On the top of these 24 fans 200, a heater (air heating device) (not shown) is provided. The fan 200 blows the air heated by the heater to the paper P conveyed by the processing liquid drying processing drum 122 by the rotation. That is, the processing liquid drying processing unit 126 can blow hot air locally on each area of the paper P by individually controlling each fan 200.

  The treatment liquid drying processing unit 120 is configured as described above. The paper P delivered from the processing liquid application drum 112 of the processing liquid application unit 110 is received by the processing liquid drying processing drum 122. The treatment liquid drying processing drum 122 conveys the paper P by gripping and rotating the front end of the paper P with a gripper. At this time, the treatment liquid drying treatment drum 122 conveys the recording surface of the paper P inward. In the process in which the paper P is conveyed by the processing liquid drying processing drum 122, hot air is blown onto the recording surface from each fan 200 of the processing liquid drying processing unit 126 installed inside the processing liquid drying processing drum 122. It is dried. Thereby, an ink aggregation layer is formed on the recording surface of the paper P.

<Image recording part>
The image recording unit 130 ejects droplets of inks (water-based inks) of C, M, Y, and K on the recording surface of the paper P and draws a color image on the recording surface of the paper P. It is. The image recording unit 130 mainly includes an image recording drum 132 that conveys the paper P, and an inkjet head 134C that ejects C, M, Y, and K ink droplets onto the paper P that is conveyed by the image recording drum 132. 134M, 134Y, and 134K.

  The image recording drum 132 is formed in a cylindrical shape and is driven to rotate by a motor (not shown). The image recording drum 132 conveys the paper P while winding the paper P around the circumferential surface by gripping and rotating the front end of the paper P with a gripper (not shown). The image recording drum 132 has a plurality of suction holes (not shown) formed in a predetermined pattern on the peripheral surface thereof. The sheet P wound around the peripheral surface of the image recording drum 132 is conveyed while being sucked and held on the peripheral surface of the image recording drum 132 by being sucked from the suction holes. Thereby, the paper P can be conveyed with high smoothness.

  Note that the suction from the suction holes acts only within a certain range, and the paper P is attracted and held on the peripheral surface of the image recording drum 132 at least at the ink ejection positions by the ink jet heads 134C, 134M, 134Y, and 134K. Thus, the suction area is set.

  The mechanism for attracting and holding the paper P on the peripheral surface of the image recording drum 132 is not limited to the above-described suction method using negative pressure, and a method using electrostatic suction can also be employed.

  The respective ink jet heads 134C, 134M, 134Y, and 134K are arranged at regular intervals along the conveyance path of the paper P by the image recording drum 132. The inkjet heads 134C, 134M, 134Y, and 134K are constituted by line heads corresponding to the paper width. The inkjet heads 134C, 134M, 134Y, and 134K are arranged orthogonal to the conveyance direction of the paper P by the image recording drum 132, and are arranged so that the nozzle surfaces thereof face the peripheral surface of the image recording drum 132. Is done. Each of the inkjet heads 134C, 134M, 134Y, and 134K discharges ink droplets from the nozzle row formed on the nozzle surface toward the image recording drum 132, thereby causing the paper P to be conveyed by the image recording drum 132. Record an image.

  The image recording unit 130 is configured as described above. The paper P delivered from the processing liquid drying processing drum 122 of the processing liquid drying processing unit 120 is received by the image recording drum 132. The image recording drum 132 conveys the paper P by gripping and rotating the front end of the paper P with a gripper. The paper P delivered to the image recording drum 132 is sucked from the suction hole of the image recording drum 132 and sucked and held on the outer peripheral surface of the image recording drum 132. The paper P is transported in this state and passes through the inkjet heads 134C, 134M, 134Y, and 134K. Then, during the passage, ink droplets of the respective colors C, M, Y, and K are ejected from the inkjet heads 134C, 134M, 134Y, and 134K onto the surface, and a color image is drawn on the surface. Since the ink aggregation layer is formed on the surface of the paper P, a high-quality image can be recorded without causing feathering or bleeding.

  Thereafter, the sheet P is delivered to the ink drying processing unit 140 after the suction is released.

<Ink drying processing section>
The ink drying processing unit 140 performs drying processing on the paper P after image recording, and removes moisture remaining on the surface of the paper P. The ink drying processing unit 140 mainly includes a transport belt 142 that transports the paper P on which an image is recorded, and an ink drying processing unit 144 that performs a drying process on the paper P transported by the transport belt 142. .

  The conveyor belt 142 has an endless structure and is wound around a pair of rollers (not shown). The paper P is placed on the transport belt 142, and the transport belt 142 transports the paper P as the rollers rotate.

  The ink drying processing unit 144 performs a drying process by blowing hot air toward the recording surface of the paper P transported by the transport belt 142. A plurality of ink drying processing units 144 may be arranged according to the processing capability of the ink drying processing unit 144, the conveyance speed (= printing speed) of the paper P, and the like. That is, the paper P received from the image recording unit 130 is disposed so as to be dried while being transported by the transport belt 142.

  The ink drying processing unit 140 is configured as described above. The paper P delivered from the image recording drum 132 of the image recording unit 130 is received by the transport belt 142. The transport belt 142 transports the placed paper P. The paper P is dried by the ink drying processing unit 144. That is, hot air is blown onto the recording surface to perform a drying process.

<Control system>
FIG. 3 is a block diagram showing a schematic configuration of a control system of the ink jet recording apparatus 100 of the present embodiment.

  As shown in the figure, the inkjet recording apparatus 100 includes a system controller 160, a communication unit 162, an image memory 164, a conveyance control unit 166, a processing liquid application control unit 168, a processing liquid drying control unit 170, an image recording control unit 172, An ink drying control unit 174, an operation unit 176, a display unit 178, and the like are provided.

  The system controller 160 functions as a control unit that performs overall control of each unit of the inkjet recording apparatus 100 and also functions as a calculation unit that performs various calculation processes. The system controller 160 includes a CPU, a ROM, a RAM, and the like, and operates according to a predetermined control program. The ROM stores a control program executed by the system controller 160 and various data necessary for control.

  The communication unit 162 includes a required communication interface, and transmits and receives data to and from the host computer 180 connected to the communication interface.

  The image memory 164 functions as a temporary storage unit for various data including image data, and data is read and written through the system controller 160. Image data captured from the host computer via the communication unit 162 is stored in the image memory 164.

  The conveyance control unit 166 controls the conveyance system of the paper P in the inkjet recording apparatus 100. That is, the processing liquid application drum 112 in the processing liquid application unit 110, the processing liquid drying processing drum 122 in the processing liquid drying processing unit 120, the image recording drum 132 in the image recording unit 130, and the transport belt 142 of the ink drying processing unit 140 are driven. Control.

  The transport control unit 166 controls the transport system in accordance with a command from the system controller 160 so that the paper P is transported without delay from the processing liquid applying unit 110 to the ink drying processing unit 140.

  The processing liquid application control unit 168 controls the processing liquid application unit 110 in accordance with a command from the system controller 160. Specifically, the driving of the treatment liquid application unit 114 is controlled so that the treatment liquid is appropriately applied to the paper P conveyed by the treatment liquid application drum 112.

  The processing liquid drying control unit 170 controls the processing liquid drying processing unit 120 in accordance with a command from the system controller 160. Specifically, the driving of the processing liquid drying processing unit 126 is controlled so that the paper P conveyed by the processing liquid drying processing drum 122 is appropriately dried.

  The image recording control unit 172 controls the image recording unit 130 in accordance with a command from the system controller 160. Specifically, the drive of the inkjet heads 134C, 134M, 134Y, and 134K is controlled so that a predetermined image is recorded on the paper P conveyed by the image recording drum 132.

  The ink drying control unit 174 controls the ink drying processing unit 140 in accordance with a command from the system controller 160. Specifically, the drive of the ink drying processing unit 144 is controlled so that hot air is appropriately blown to the paper P conveyed by the conveyance belt 142.

  The operation unit 176 includes necessary operation means (for example, operation buttons, a keyboard, a touch panel, and the like), and outputs operation information input from the operation means to the system controller 160. The system controller 160 executes various processes in accordance with the operation information input from the operation unit 176.

  The display unit 178 includes a required display device (for example, an LCD panel or the like), and displays required information on the display device in response to a command from the system controller 160.

  As described above, the image data to be recorded on the paper P is taken into the inkjet recording apparatus 100 from the host computer via the communication unit 162. The captured image data is stored in the image memory 164.

  The system controller 160 performs necessary signal processing on the image data stored in the image memory 164 to generate dot data. Then, the drive of each inkjet head 134C, 134M, 134Y, 134K of the image recording unit 130 is controlled according to the generated dot data, and the image represented by the image data is recorded on the paper.

  The dot data is generally generated by performing color conversion processing and halftone processing on image data. The color conversion processing is processing for converting image data expressed in sRGB or the like (for example, RGB 8-bit image data) into ink amount data of each color of ink used in the inkjet recording apparatus 100 (in this example, C, It is converted into ink amount data for each color of M, Y, and K.) The halftone process is a process of converting the ink amount data of each color generated by the color conversion process into dot data of each color by a process such as error diffusion.

  The system controller 160 performs color conversion processing and halftone processing on the image data to generate dot data for each color. Then, according to the generated dot data of each color, the drive of the corresponding ink jet head is controlled to record the image represented by the image data on the paper.

<< First Embodiment >>
A first embodiment of the ink jet recording apparatus 100 configured as described above will be described. In the present embodiment, the system controller 160 calculates the water content distribution of the ink applied to the paper P from the image data recorded on the paper P, and smoothes the water content distribution in the recording area of the paper P after ink application. The distribution of the moisture content of the treatment liquid for conversion is calculated, and the treatment liquid drying processing unit 120 performs a drying process so that the calculated distribution of the moisture content of the treatment liquid is obtained.

  First, local drying control of the processing liquid on the recording surface of the paper P will be described.

  FIG. 4 is a diagram showing the paper P conveyed by the processing liquid drying processing drum 122 and the processing liquid drying processing unit 126 for drying the processing liquid on the paper P. As described above, the treatment liquid drying processing unit 126 includes a total of 24 fans 200 with 3 rows in the transport direction and 8 columns in the direction orthogonal to the transport direction. Here, the position of each fan 200 is specified as A row, B row, C row in the transport direction, and 1 column, 2 columns,..., 8 columns in the direction orthogonal to the transport direction.

  The paper P on which the processing liquid is uniformly applied to the entire recording surface in the processing liquid applying unit 110 is conveyed to a position facing the 24 fans 200 by the processing liquid drying processing drum 122. In the present embodiment, on the recording surface of the paper P, for each region facing each fan 200, the A row, B row, C row in the transport direction, one column in the direction orthogonal to the transport direction, two columns,. , 8 columns, 24 regions are virtually divided, and the drying process is performed using the regions divided into 24 regions as unit regions.

  First, the system controller 160 acquires image data to be recorded on the paper P from the host computer via the communication unit 162 and stores it in the image memory 164.

  Next, the system controller 160 calculates the distribution of ink application amount (water content) in the recording area of the paper P based on the image data stored in the image memory 164. That is, the system controller 160 functions as an ink distribution calculation unit.

  In the present embodiment, the ink moisture amount for each unit region is calculated, and the distribution for each unit region is calculated. This calculation process can be performed by a known method. In this case, ink is applied to the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P, and no ink is applied to the other areas. Shall.

  Further, the system controller 160 calculates the distribution of the water content of the processing liquid for smoothing the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. To do. Specifically, for each unit region, the distribution of the water content of the processing liquid so that the sum of the water content of the processing liquid after the processing liquid drying process and the water content of the ink after ink application falls within a certain range R. Is calculated.

  Here, a distribution is calculated in which the water content of the processing liquid in the three regions of the A row, the second column, the A row, the seventh column region, and the B row, fifth column region of the paper P is smaller than the water content of the other regions. To do. Thus, the system controller 160 functions as a processing liquid distribution calculation unit.

  Accordingly, the processing liquid drying control unit 170 receives the instructions for the processing liquids in the three areas of the area A row 2 column, the area A row 7 column, and the area B row 5 column of the paper P according to a command from the system controller 160. Each fan 200 is controlled to reduce the amount of moisture. That is, the treatment liquid drying control unit 170 functions as a preliminary drying control unit.

  Specifically, when the sheet P passes through a position facing the processing liquid drying processing unit 126, the three fans 200 of A row 2 column, A row 7 column, and B row 5 column are rotated at high speed. Thus, the drying of the treatment liquid in the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P facing the fan 200 is promoted more than the other areas. . The other fans 200 are rotated or stopped at a low speed.

  As a result, in the unit area of the paper P, the water content of the processing liquid can be reduced in the area of A row and 2 columns, the area of A row and 7 columns, and the area of B row and 5 columns as compared with the other areas. As described above, the treatment liquid drying control unit 170 can control the drying of the treatment liquid on the recording surface of the paper P locally (selectively) so that the moisture content of the treatment liquid is distributed. it can.

  Next, a description will be given of the distribution of moisture amount when the processing liquid drying process is controlled and an image corresponding to the image data shown in FIG. FIG. 5A is a schematic cross-sectional view of the sheet P on which the processing liquid is applied to the recording surface by the processing liquid applying unit 110, and a graph showing the distribution of the surface temperature and moisture content of each region of the paper P. In the treatment liquid application unit 110, the treatment liquid is uniformly applied to the recording surface of the paper P by roller application, so that the moisture content distribution of the paper P is constant in each region.

  The system controller 160 calculates the water content distribution of the ink on the paper P based on the image data shown in FIG. 21A (ink distribution calculating step). For example, the water content of the ink for each unit region may be calculated.

  Next, the system controller 160 calculates the water content distribution of the processing liquid for smoothing the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. Calculate (treatment liquid distribution calculation step). In this case, a distribution is calculated in which the water content in the region to which ink is applied is smaller than the water content in other regions.

  Then, as described with reference to FIG. 4, the processing liquid drying control unit 170 performs processing liquid drying according to a command from the system controller 160 so as to further accelerate the drying of the processing liquid in the region to which ink is applied. Each fan 200 of the processing unit 126 is controlled.

  FIG. 5B is a schematic cross-sectional view of the paper P dried by the treatment liquid drying processing unit 120 and a graph showing the moisture content distribution in each area of the paper P. As shown in the figure, the surface temperature of the region to which ink is applied is increased by the control of each fan 200 by the treatment liquid drying control unit 170. In addition, as the temperature rises, the amount of water in the region decreases more than in other regions.

  Thereafter, the image recording unit 130 applies ink to the recording surface of the paper P. FIG. 5C is a schematic cross-sectional view of the paper P to which ink has been applied, and a graph showing the moisture content distribution in each region of the paper P. As shown in the figure, the amount of water is increased in the region to which ink has been applied. However, as shown in FIG. 5B, the amount of water in the treatment liquid in the region to which ink is applied is reduced in advance as compared to other regions. Therefore, the amount of water is smoothed in the region where ink is applied and the region where ink is not applied, and the difference between the amount of water between the region where the amount of water is the maximum and the region where the amount of water is the minimum is kept within a certain range. ing.

  Finally, the entire surface of the paper P is dried uniformly by the ink drying processing unit 140. FIG. 5D is a schematic cross-sectional view of the dried paper P and a graph showing the moisture content distribution in each area of the paper P. As shown in the figure, since the difference in water content between the area where ink is applied and the area where ink is not applied is within a certain range in advance, the surface temperature distribution of the paper P after the drying process is also smooth. It has become a thing.

  FIG. 5E is a schematic diagram showing the recording surface of the paper P after drying. As shown in the figure, since there is no difference in moisture content or overdrying, fixing wrinkles and cockles that occurred in FIG. 21D do not occur.

  In this way, the distribution of the moisture content of the ink applied to the paper P is calculated from the image data recorded on the paper P in the system controller 160, and the distribution of the moisture content of the ink and the processing liquid after the ink application is smoothed. As described above, even when the processing liquid is uniformly applied to the entire recording area of the recording medium by performing the drying process in the processing liquid drying processing unit 120 and controlling the distribution of the moisture content of the processing liquid, Generation of wrinkles and cockles due to drying after recording can be prevented.

  Here, the treatment liquid drying process for the area where ink is applied and the area where ink is not applied has been described. However, in an actually recorded image, the amount of ink applied varies from area to area. In such a case, the air blowing amount of each fan 200 may be controlled according to the ink application amount.

  That is, the drying strength is increased by increasing the air volume of the facing fan 200 for a region where the ink application amount is large, and the opposing fan 200 is configured for the region where the ink application amount is small. By reducing the air volume, the drying strength is lowered, and for the area where ink is not applied, by controlling the drying strength further by stopping the opposing fan 200, the amount of ink applied can be reduced. A corresponding treatment liquid can be dried. In order to perform finer drying process control, it is preferable that the air volume adjustment of the fan 200 be performed steplessly.

FIG. 6 shows a unit area a and a unit area b of paper P having different image densities, i.e., water amounts of applied inks i ₁ , i ₂ , i ₃ (i ₁ <i ₂ <i ₃ ), respectively. FIG. 6 is a diagram showing a change in the amount of water in each step of the unit region c, where the horizontal axis shows each step in the inkjet recording apparatus 100 and the vertical axis shows the amount of water in each region of the paper P.

  As shown in the figure, first, in the treatment liquid application process by the treatment liquid application unit 110, the treatment liquid is uniformly applied to the entire surface of the paper P, and thus the water content in the regions a to c similarly increases.

  Next, in the treatment liquid drying process (preliminary drying process) by the treatment liquid drying processing unit 120, the applied ink is weak in the region a where the amount of water is the smallest, strong in the region b where the ink is the next smallest, and further in the region c where the amount is the largest. It is strongly dried. That is, the air volume of the fan 200 facing each area is controlled so that the area a <area b <area c. As a result, as shown in FIG. 6, the water content in each region at the end of the treatment liquid drying step satisfies region a> region b> region c.

Next, in the image recording process by the image recording unit 130, inks containing moisture amounts of i ₁ , i ₂ , and i ₃ are applied to the regions a, b, and c, respectively. At this time, the difference in the moisture content between the region (region b, region c) having the maximum water content and the region (region a) having the maximum water content among the region a, region b, and region c is within a certain range R. Yes.

  Finally, in the ink drying process by the ink drying processing unit 140, the entire surface of the paper P is uniformly dried. Since the water content in the regions a, b, and c before the drying process is within the predetermined range R, overdrying does not occur even if drying is performed according to the region where the water content is maximum, and fixing is performed. The generation of wrinkles and cockles can be suppressed.

<< Modification of First Embodiment >>
In the treatment liquid drying processing unit 126 of the first embodiment, the plurality of fans 200 are arranged in a matrix, but an embodiment in which the fans are arranged in a row is also possible.

  FIG. 7A is a schematic view of the paper P conveyed by the processing liquid drying processing drum 122 and the processing liquid drying processing unit 126 ′ as viewed from above. In the processing liquid drying processing unit 126 ′, eight fans 200 are arranged in a line in the transport direction so as to face the recording surface of the paper P.

  A method for selectively drying the processing liquid uniformly applied to the recording surface of the paper P by the processing liquid drying processing unit 126 ′ will be described.

  As shown in FIG. 7A, the sheet P on which the processing liquid is uniformly applied to the entire recording surface in the processing liquid applying unit 110 is conveyed to a position facing the processing liquid drying processing unit 126 ′. Here, it is assumed that the drying process is particularly promoted for the three areas of the A-line and 2-column area of the paper P, the A-row 7-column area, and the B-row 5 column area.

  First, when the region A of the sheet P reaches a position facing each fan 200, the processing liquid drying control unit 170 performs the second fan 200 from the left and the fan 200 in the seventh column from the left at high speed. Rotate to The other fans 200 are rotated at a low speed or stopped. As a result, the drying process can be promoted particularly for the area of the A row and the second column of the paper P and the area of the A row and the seventh column.

  Next, the processing liquid drying control unit 170 rotates the fifth fan 200 from the left at a high speed when the B row area of the paper P reaches the position facing each fan 200, and the other fans 200 are checked. Rotate or stop at low speed. As a result, the drying process can be promoted particularly for the area of B rows and 5 columns of the paper P.

  Finally, the processing liquid drying control unit 170 rotates or stops all the fans 200 at a low speed when the area of the C row of the paper P reaches a position facing each fan 200.

  By controlling in this way, among the areas of the paper P, the water content of the processing liquid is reduced in the area of the A row and the second column, the area of the A row and the seventh column, and the area of the B row and the fifth column as compared with the other areas. be able to. That is, the processing liquid drying control unit 170 can dry the processing liquid locally on the recording surface of the paper P for each unit area by the processing liquid drying processing unit 126 ′.

  Until now, in order to dry the processing liquid on the recording surface of the paper P, the fan 200 that blows hot air on the recording surface of the paper P has been used. However, the means for drying the processing liquid is not limited to this.

  For example, as in the processing liquid drying processing unit 210 shown in FIG. 7B, a plurality of laser irradiation units 212 that irradiate the recording surface of the paper P with laser light and dry the processing liquid may be used.

  When the laser irradiation units 212 are arranged in a row as shown in FIG. 7B, the same control as described with reference to FIG. The treatment liquid can be selectively dried. Further, a mode in which the laser irradiation units 212 are arranged in a matrix is also possible. In this case, the control may be the same as the control described with reference to FIG.

  In this modification, the length of the divided area of the paper P in the transport direction can be determined as appropriate. What is necessary is just to be larger than the ventilation area length in the conveyance direction of the fan 200, or the irradiation area length in the conveyance direction of the laser irradiation part 212.

<< Second Embodiment >>
FIG. 8 is an overall configuration diagram showing an embodiment of the ink jet recording apparatus according to the present embodiment. The processing liquid drying processing unit 120 in this embodiment includes a processing liquid drying processing unit 128 instead of the processing liquid drying processing unit 126 shown in FIG. The processing liquid drying processing unit 128 is disposed on the surface of the paper transport guide 124 as shown in FIG.

  FIG. 9 is a schematic view of the paper P transported by the processing liquid drying processing drum 122 and the processing liquid drying processing unit 128 embedded in the paper transport guide 124 as viewed from the processing liquid drying processing drum 122 side. In the processing liquid drying processing unit 128, a plurality of rubber heaters 220 are arranged in a matrix so as to face the back surface of the paper P (the back surface of the recording surface). In the example shown in FIG. 9, a total of 24 rubber heaters 220 are provided, with 3 rows in the transport direction and 8 columns in the direction orthogonal to the transport direction. Note that the number of rows and the number of columns in which the rubber heater 220 is arranged is not particularly limited.

  As described above, the rubber heater 220 is configured to be able to locally heat the 24 regions of the paper P by contacting the paper P from the back surface of the paper P. In addition, the paper transport guide 124 made of a member having high thermal conductivity incorporates a rubber heater 220, and the rubber heater 220 heats the contact surface between the paper transport guide 124 and the paper P so that the paper P is heated. You may comprise.

  Next, local processing liquid drying processing control when the processing liquid drying processing unit 128 is used will be described.

  First, the system controller 160 calculates the distribution of ink application amount (water content) in the recording area of the paper P based on the image data stored in the image memory 164. In the present embodiment, the ink moisture amount for each unit region is calculated, and the distribution for each unit region is calculated. In the same manner as before, ink is applied to the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P, and ink is applied to the other areas. Shall not be.

  Next, the system controller 160 calculates the water content distribution of the processing liquid for smoothing the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. calculate. As before, the distribution of the water content of the processing liquid in the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P is calculated smaller than the other areas. To do.

  When the paper P passes through the position facing the processing liquid drying processing unit 128 in accordance with a command from the system controller 160, the processing liquid drying control unit 170 has a row A, column 2, row A 7, column B, row 5, The temperature of the three rubber heaters 220 is increased, and the temperature of the other rubber heaters 220 is decreased. As a result, the three areas of the sheet A facing the rubber heater 220, that is, the A row and 2 column area, the A row and 7 column area, and the B row and 5 column area are heated to a higher temperature than the other areas. . Therefore, in these three regions, drying of the treatment liquid is promoted more than the other regions.

  As described above, the processing liquid drying processing unit 128 is used to promote the drying of the processing liquid in the region where the amount of applied ink is larger than in the other regions, so that the water content of the processing liquid can be distributed. .

  The rubber heaters 220 may be arranged in a line as described with reference to FIG.

  Further, the processing liquid drying processing drum 122 is configured to convey the paper P while winding the paper P around the peripheral surface, similar to the processing liquid application drum 112 and the image recording drum 132, and the processing liquid drying processing drum A mode in which the processing liquid drying processing unit 128 shown in FIG. 9 is arranged is also possible. In this case, when the processing liquid drying processing drum 122 is configured so that two sheets of paper P can be conveyed by one rotation, the processing liquid drying processing units 128 shown in FIG. 9 may be arranged at two locations.

  Further, the fan 200, the laser irradiation unit 212, and the rubber heater 220 may be combined to heat the paper P locally.

<< Third Embodiment >>
FIG. 10 is an overall configuration diagram showing an embodiment of the ink jet recording apparatus according to the present embodiment. In the ink jet recording apparatus 100 according to the present embodiment, the treatment liquid drying processing unit 120 and the image recording unit 130 are integrally configured.

  FIG. 11 is a schematic view of the paper P conveyed by the platen (not shown in FIG. 11, reference numeral 250 in FIG. 10), the processing liquid drying processing unit 120, and the image recording unit 130 as viewed from above. As shown in the figure, the processing liquid drying processing unit 120 and the image recording unit 130 include a processing liquid drying processing unit 230, ink jet heads 240C, 240M, 240Y, and 240K, a carriage 260 on which these are mounted, and a conveyance direction of the carriage 260. The guide member 262 guides the movement in the direction orthogonal to the direction.

  The carriage 260 is configured to be freely movable along the guide member 262 by driving means (not shown).

  The processing liquid drying processing unit 230 is arranged on the upstream side in the transport direction of the paper P with respect to the ink jet heads 240C, 240M, 240Y, and 240K. The processing liquid drying processing unit 230 includes a laser irradiation unit 232, and the laser irradiation unit 232 irradiates the recording surface of the paper P with laser light to dry the processing liquid applied to the recording surface of the paper P. .

  The ink jet heads 240 </ b> C, 240 </ b> M, 240 </ b> Y, and 240 </ b> K eject ink droplets of C, M, Y, and K onto the paper P conveyed by the platen 250 to form an image on the recording surface of the paper P.

  Next, local processing liquid drying processing control when the processing liquid drying processing unit 230 is used will be described.

  First, the system controller 160 calculates the distribution of ink application amount (water content) in the recording area of the paper P based on the image data stored in the image memory 164. In the present embodiment, the ink moisture amount for each unit region is calculated, and the distribution for each unit region is calculated. In the same manner as before, ink is applied to the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P, and ink is applied to the other areas. Shall not be.

  The sheet P to which the processing liquid is applied by the processing liquid applying unit 110 is transferred to the platen 250 and is transported in the transport direction by the platen 250.

  Here, the system controller 160 calculates the distribution of the water content of the processing liquid to smooth the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. calculate. That is, a distribution in which the water content of the processing liquid in the three areas of the A row, the second column, the A row, the seventh column area, and the B row, fifth column area of the paper P is smaller than the other areas is calculated.

  In response to a command from the system controller 160, the processing liquid drying control unit 170 moves the carriage 260 perpendicular to the transport direction of the paper P when the area of the A line of the paper P passes the position facing the processing liquid drying processing unit 230. The laser beam is irradiated from the laser irradiation unit 232 to the A row 2 column region and the A row 7 column region of the paper P. The other areas of the A row are irradiated with the laser beam weakly or the irradiation is stopped.

  When the sheet P is further conveyed by the platen 250, the area A of the sheet P reaches a position facing the inkjet heads 240C, 240M, 240Y, and 240K, and the area B of the sheet P is subjected to the treatment liquid drying process. A position facing the unit 230 is reached.

  In response to a command from the system controller 160, the image recording control unit 172 and the processing liquid drying control unit 170 move the carriage 260 in a direction orthogonal to the conveyance direction of the paper P, and use the inkjet heads 240C, 240M, 240Y, and 240K to make paper. Ink is applied to the area of the A row and 2 columns of P and the area of the A row and 7 columns, and the laser irradiation unit 232 irradiates the area of the B rows and 5 columns of the paper P with laser light. The other areas of the B row are irradiated with laser light weakly or the irradiation is stopped.

  When the sheet P is further conveyed by the platen 250, the area of the B line of the sheet P reaches a position facing the inkjet heads 240C, 240M, 240Y, and 240K, and the area of the C line of the sheet P is treated with the treatment liquid drying process. A position facing the unit 230 is reached.

  In response to a command from the system controller 160, the image recording control unit 172 moves the carriage 260 in a direction orthogonal to the conveyance direction of the paper P, and uses the inkjet heads 240C, 240M, 240Y, and 240K to set the B row and the fifth column of the paper P. Ink is applied to the area. Further, the treatment liquid drying control unit 170 weakly irradiates the laser beam to the area of the C line of the paper P or stops the irradiation according to a command from the system controller 160.

  When the sheet P is further conveyed by the platen 250, the area of the C line of the sheet P reaches a position facing the ink jet heads 240C, 240M, 240Y, and 240K.

  In response to a command from the system controller 160, the image recording control unit 172 moves the carriage 260 in a direction orthogonal to the conveyance direction of the paper P, but does not apply ink to the C line area of the paper P.

  As described above, by using the processing liquid drying processing unit 230, it is possible to perform drying control in accordance with the distribution of the water content of the ink, and it is possible to provide the distribution of the water content of the processing liquid.

  As shown in FIG. 12A, when the image C is recorded on the paper P, the surface (edge) of the image C is likely to be clogged, resulting in fixing wrinkles. In order to prevent this, as shown in FIG. 12B, the portion where the amount of applied ink is large is strongly dried, and the drying gradient is gradually reduced toward the direction where the amount of applied ink is small. Should be given. Thereby, the deformation | transformation in the boundary part of the image C can be prevented.

  In addition, if the ink drying processing unit 140 performs heat treatment intensively in a region where the amount of applied ink is large, wrinkles may occur at the boundary portion. In order to prevent this, the treatment liquid drying processing unit 120 may have a drying gradient by heating a range that is slightly wider than the region with a large amount of ink. Thereby, the deformation | transformation in a boundary part can be prevented.

  For example, as shown in FIG. 13A, the ink drying processing unit 140 is configured to be able to dry by being divided into 30 regions of 6 rows × 5 columns, A row 1 column, C row 5 column, E When the amount of ink applied is large in the three areas of the fifth row and the fifth column, it is necessary to heat the three areas strongly.

  In this case, in the processing liquid drying processing unit 120, as shown in FIG. 13 (b), for the areas of A row, 1 column, B row, 3 columns, and C row, 3 columns including the above three regions in advance. The drying process may be performed.

  By performing the treatment liquid drying process in this manner, it is possible to prevent deformation at the boundary portion.

<< Fourth Embodiment >>
In the present embodiment, local cooling is performed on the paper P before the treatment liquid is applied.

  FIG. 14 is an overall configuration diagram showing an embodiment of the ink jet recording apparatus according to the present embodiment. 1 is different from the ink jet recording apparatus 100 shown in FIG. 1 in that a paper cooling unit 150 is provided. In the present embodiment, the paper cooling unit 150 and the processing liquid drying processing unit 120 constitute a preliminary drying means (preliminary drying device).

  The sheet cooling unit 150 is provided in the front stage of the processing liquid applying unit 110 and performs local cooling on the paper P before the processing liquid is applied. The sheet cooling unit 150 includes a conveyance belt 152 that conveys the sheet P, and a local cooling processing unit 154 that performs local cooling on the sheet P conveyed by the conveyance belt 152.

  The conveyance belt 152 is a conveyance unit that loads and conveys the paper P, and is configured in the same manner as the conveyance belt 142 of the ink drying processing unit 140. As long as the paper P is placed and transported, other transport means such as a transport drum may be used.

  The local cooling processing unit 154 is installed in the upper part of the conveyance belt 152, and is configured to be able to blow air downward. The local cooling processing unit 154 performs local cooling of the paper P by blowing cold air toward the recording surface of the paper P conveyed by the conveying belt 152. The paper P that has been locally cooled by the local cooling processing unit 154 is delivered to the processing liquid application drum 112 of the processing liquid application unit 110 by the conveyor belt 142.

  FIG. 15 is a block diagram showing a schematic configuration of a control system of the inkjet recording apparatus 100 of the present embodiment. 3 is different from the block diagram shown in FIG. 3 in that a sheet cooling unit 150 and a sheet cooling control unit 175 are provided. Further, the conveyance belt 152 of the sheet cooling unit 150 is controlled by the conveyance control unit 166.

  The sheet cooling control unit 175 controls the sheet cooling unit 150 in accordance with a command from the system controller 160. Specifically, the driving of the local cooling processing unit 154 is controlled so that the paper P conveyed by the conveying belt 152 is appropriately locally cooled.

  FIG. 16 is a schematic view of the paper P transported by the transport belt 152 and the local cooling processing unit 154 as viewed from above. The local cooling processing unit 154 has a plurality of fans 300 arranged in a matrix so as to face the recording surface of the paper P. In the example shown in FIG. 16, a total of 24 fans 200 are provided, with 3 rows in the transport direction and 8 columns in the direction orthogonal to the transport direction. Note that the number of rows and the number of columns in which the fan 200 is arranged is not particularly limited. Here, the position of each fan 300 is specified as A row, B row, C row in the transport direction, and 1 column, 2 columns,..., 8 columns in the direction orthogonal to the transport direction.

  At the top of these 24 fans 300, a cooler (air cooling device) (not shown) is provided. The fan 300 blows the air cooled by the cooler to the paper P transported by the transport belt 152 by the rotation thereof. That is, the local cooling processing unit 154 can blow the cold air locally on each area of the paper P by individually controlling each fan 300.

  The paper P is transported to a position facing the 24 fans 300 by the transport belt 152. In the present embodiment, on the recording surface of the paper P, for each region facing each fan 300, the A row, B row, C row in the transport direction, one column in the direction orthogonal to the transport direction, two columns,. , 8 rows, 24 regions are virtually divided, and the cooling process is performed using the regions divided into 24 regions as unit regions.

  Next, the local drying process of the processing liquid of the inkjet recording apparatus 100 configured as described above will be described.

  First, the system controller 160 acquires image data to be recorded on the paper P from the host computer via the communication unit 162 and stores it in the image memory 164.

  Next, the system controller 160 calculates the distribution of ink application amount (water content) in the recording area of the paper P based on the image data stored in the image memory 164. In the present embodiment, the ink moisture amount for each unit region is calculated, and the distribution for each unit region is calculated. Here, it is assumed that ink is applied to the three areas of the A row and the second column area of the paper P, the A row and the seventh column area, and the B row and the fifth column area, and no ink is applied to the other areas. To do.

  Further, the system controller 160 calculates the distribution of the water content of the processing liquid for smoothing the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. To do. In this case, a distribution is calculated in which the moisture content of the processing liquid in the three areas of the A row, the second column, the A row, the seventh column area, and the B row, fifth column area of the paper P is smaller than the other areas.

  The paper P delivered to the paper cooling unit 150 is transported to a position facing the local cooling processing unit 154 by the transport belt 152. In response to a command from the system controller 160, the sheet cooling control unit 175 locally cools an area other than the three areas of the A row, the second column area, the A row, the seventh column area, and the B row, the fifth column area of the paper P. Thus, each fan 300 is controlled. That is, when the paper P passes through the position facing the local cooling processing unit 154, A row 1 column, 3-6 column, 8 column, B row 1-4 column, 6-8 column, C row 1-8. By rotating the 21 fans 300 in a row at a high speed, A row 1 column, 3 to 6 columns, 8 columns, B row 1 to 4 columns, 6 to 8 columns of the paper P facing these fans 300, 21 regions of C rows 1 to 8 columns are locally cooled. The other fans 300 are rotated or stopped at a low speed.

  The paper P that has been locally cooled by the local cooling processing unit 154 is conveyed to the processing liquid application unit 110, and the processing liquid is uniformly applied to the entire recording surface.

  Next, the paper P is delivered to the processing liquid drying processing unit 120 and conveyed to a position facing the 24 fans 200 of the processing liquid drying processing unit 126 by the processing liquid drying processing drum 122.

  The processing liquid drying control unit 170 controls each fan 200 so as to reduce the processing liquid uniformly over the entire area of the paper P according to a command from the system controller 160. That is, all the fans 200 are set to the same rotation amount.

  Since the regions other than the three regions of the A row and 2 column region, the A row and 7 column region, and the B row and 5 column region are locally cooled, the three surface temperatures rise. In addition, as the temperature rises, the amount of water in the region decreases more than in other regions.

  As a result, in the unit area of the paper P, the water content of the processing liquid can be reduced in the area of A row and 2 columns, the area of A row and 7 columns, and the area of B row and 5 columns as compared with the other areas. In this way, by locally controlling the drying of the processing liquid with respect to the recording surface of the paper P by the paper cooling unit 150 and the processing liquid drying control unit 170, the water content of the processing liquid can be distributed. it can.

  The system controller 160 uses the treatment liquid drying control unit 170 to treat the moisture of the treatment liquid in the three areas of the A row, the second column, the A row, the seventh column area, and the B row, fifth column area of the paper P. Each fan 200 may be controlled to reduce the amount. That is, when the sheet P passes through the position facing the processing liquid drying processing unit 126, the three fans 200 of A row 2 column, A row 7 column, and B row 5 column may be rotated at high speed. Thereby, the drying of the processing liquid in the three areas of the A-line, 2-column area, the A-row-7-column area, and the B-row-5-column area of the paper P facing the fan 200 can be further promoted. .

  Next, a description will be given of the distribution of moisture amount when the processing liquid drying process is controlled and an image corresponding to the image data shown in FIG.

  First, the system controller 160 calculates the water content distribution of the ink on the paper P based on the image data shown in FIG. For example, the water content of the ink for each unit region may be calculated.

  Next, the system controller 160 calculates the water content distribution of the processing liquid for smoothing the distribution of the sum of the water content of the ink on the paper P and the water content of the processing liquid after the ink is applied in the image recording unit 130. calculate. Here, a distribution is calculated in which the amount of water in the region to which ink is applied is smaller than the amount of water in other regions.

  Next, as described with reference to FIG. 16, the sheet cooling unit 150 controls each fan 300 of the local cooling processing unit 154 in response to a command from the system controller 160 in an area other than the area to which ink is applied. .

  FIG. 17A is a schematic cross-sectional view of the paper P locally cooled by the paper cooling unit 150 and a graph showing the distribution of the surface temperature and the amount of moisture in each region of the paper P. In the paper cooling unit 150, the moisture content distribution of the paper P is constant, and the surface temperature of the locally cooled region is lowered.

  Thereafter, the processing liquid is uniformly applied to the recording surface of the paper P by the processing liquid applying unit 11. FIG. 17B is a schematic cross-sectional view of the paper P at this time, and a graph showing the distribution of the surface temperature and moisture content of each region of the paper P. In the treatment liquid application unit 110, the treatment liquid is uniformly applied to the recording surface of the paper P by roller application, so that the moisture content distribution of the paper P is constant in each region. Further, the surface temperature is lowered in the region where the paper cooling unit 150 is locally cooled.

  Next, the entire surface of the paper P is uniformly dried by the processing liquid drying processing unit 120. FIG. 17C is a schematic cross-sectional view of the paper P at this time, and a graph showing the distribution of the surface temperature and the amount of moisture in each region of the paper P. As shown in the figure, since the surface temperature of the region to which ink is not applied is locally cooled, the surface temperature of the region to which ink is applied relatively increases. As the temperature rises, the amount of water in the area to which ink is applied decreases from that in the area to which ink is not applied.

  Thereafter, the image recording unit 130 applies ink to the recording surface of the paper P. FIG. 17D is a schematic cross-sectional view of the paper P to which ink has been applied, and a graph showing the moisture content distribution in each region of the paper P. As shown in the figure, the amount of water is increased in the region to which ink has been applied. However, as shown in FIG. 17C, the water content of the treatment liquid in the region to which the ink is applied is reduced in advance compared to the other regions. Therefore, the amount of water is smoothed in the region where ink is applied and the region where ink is not applied, and the difference between the amount of water between the region where the amount of water is the maximum and the region where the amount of water is the minimum is kept within a certain range. ing.

  Finally, the entire surface of the paper P is dried uniformly by the ink drying processing unit 140. FIG. 17E is a schematic cross-sectional view of the dried paper P and a graph showing the distribution of the surface temperature and the amount of moisture in each region of the paper P. As shown in the figure, since the difference in water content between the area where ink is applied and the area where ink is not applied is within a certain range in advance, the surface temperature distribution of the paper P after the drying process is also smooth. It has become a thing.

  FIG. 17F is a schematic diagram illustrating the recording surface of the paper P after drying. As shown in the figure, since there is no difference in moisture content or overdrying, fixing wrinkles and cockles that occurred in FIG. 21D do not occur.

  In this way, the distribution of the moisture content of the ink applied to the paper P is calculated from the image data recorded on the paper P in the system controller 160, and the distribution of the moisture content of the ink and the processing liquid after the ink application is smoothed. In this way, the local cooling is performed in the sheet cooling unit 150, and then the drying process is performed in the processing liquid drying processing unit 120, whereby the distribution of the moisture content of the processing liquid can be controlled, and the processing liquid can be applied to the entire recording area of the recording medium. Even in such a case, generation of wrinkles and cockles due to drying after image recording can be prevented.

  As described above, the region to which ink is applied in the treatment liquid drying processing unit 120 may be locally heated to promote drying. By performing the treatment liquid drying process in this manner, the surface temperature of the paper P can be made more uniform, and the margin for suppressing the occurrence of cockle and wrinkles is increased.

  Here, the local cooling process for the area where ink is applied and the area where ink is not applied has been described. However, in an actually recorded image, the amount of ink applied varies from area to area. In such a case, the air blowing amount of each fan 300 may be controlled according to the ink application amount.

  In other words, the cooling temperature is lowered by increasing the air flow of the facing fan 300 for a region where the ink application amount is small, and the opposing fan 300 is used for the region where the ink application amount is large. By reducing the air volume, the cooling temperature is increased, and for the area where ink is not applied, the cooling is not performed by stopping the opposite fan 300, and the control is performed according to the amount of ink applied. The treatment liquid can be dried. In order to perform finer local cooling control, it is preferable that the air volume adjustment of the fan 300 can be performed steplessly.

  Further, the fan 300 may be arranged in a line as in the treatment liquid drying process described with reference to FIG.

<< Fifth Embodiment >>
The means for partially cooling the paper P is not limited to the fan 300 that blows cold air. For example, a nozzle unit 320 in which a large number of nozzles 322 for blowing cool air onto the recording surface of the paper P may be used as in the local cooling processing unit 310 shown in FIG.

    FIG. 18 is a schematic view of the paper P transported by the transport belt 152 and the local cooling processing unit 310 disposed on the top of the transport belt 152 so as to face the paper P, as viewed from above. The local cooling processing unit 310 can cool the entire area of the first to third rows when the recording surface of the paper P is virtually divided into one row, two rows, and three rows in the direction orthogonal to the transport direction. A nozzle unit 320b capable of cooling the third row region, a nozzle unit 320c capable of cooling the first row region, and a nozzle unit 320d capable of cooling the second row region.

  When the local cooling processing unit 310 is used to locally cool the area of row A and column 1 of paper P and the area of row B and column 2 as shown in FIG. Cold air is blown from the nozzles of the nozzle unit 320c when the nozzle unit 320c is conveyed to a position facing the nozzle unit 320c, and the area of the B row and the second column of the paper P is conveyed to a position facing the nozzle unit 320d. Cold air may be blown from the nozzle.

<< Sixth Embodiment >>
FIG. 19 is an overall configuration diagram showing an embodiment of an ink jet recording apparatus according to the present embodiment. The sheet cooling unit 150 in this embodiment includes a conveyance drum 330 instead of the conveyance belt 152 shown in FIG. 14 and a local cooling processing unit 332 instead of the local cooling processing unit 154. As shown in FIG. 14, the local cooling processing unit 332 is disposed inside the conveyance drum 330.

  FIG. 20 is a schematic diagram showing a sheet P conveyed by the conveyance drum 330 and a local cooling processing unit 332 incorporated in the conveyance drum 330. The local cooling processing unit 332 is a surface (conveyance surface) of the conveyance drum 330. ) Is seen through.

  The metal pipe 340 cools the surface of the transport drum 330 by circulating water, and calculates the moisture content of the processing liquid for each unit region for smoothing the moisture content distribution for each unit region. It is a (heat exchange unit) and is configured such that water is injected from one side of the metal tube 340 and water flows out from the other side. The liquid circulating through the metal tube 340 may be a liquid other than water. A plurality of local cooling processing units 332 are arranged in a direction in which the metal pipe 340 is orthogonal to the transport direction so as to face the back surface of the paper P (the back surface of the recording surface). In the example shown in FIG. 20, four metal tubes 340 are provided in a direction orthogonal to the transport direction. The arrangement of the metal tube 340 is not particularly limited.

  As described above, the metal tube 340 is configured to locally cool the four regions of the paper P from the back surface of the paper P by locally cooling the transport drum 330 in contact with the paper P. .

  The local cooling processing unit 332 may be configured not to cool the transport drum but to cool the platen on which the paper P is placed and transported.

  Further, the fan 300, the nozzle unit 320, and the metal tube 340 may be combined to cool the paper P locally.

  The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention.

  In the present specification, the processing performed by the system controller 160 may be performed by the host computer 180 and input to the inkjet recording apparatus 100 via the communication unit 162.

  DESCRIPTION OF SYMBOLS 100 ... Inkjet recording device 110 ... Processing liquid application part, 114 ... Processing liquid application unit, 120 ... Processing liquid drying processing part, 122 ... Processing liquid drying processing drum, 124 ... Paper conveyance guide, 126, 126 ', 128, 210 , 230 ... processing liquid drying processing unit, 130 ... image recording unit, 140 ... ink drying processing unit, 150 ... paper cooling unit, 154, 332 ... local cooling processing unit, 175 ... paper cooling control unit, 170 ... processing liquid drying control Part, 200, 300 ... fan, 212, 232 ... laser irradiation part, 220 ... rubber heater, 340 ... metal tube, P ... paper

Claims (13)

A treatment liquid applying means for uniformly applying a treatment liquid containing an aggregating agent for aggregating components in the ink to at least a recording area of the recording medium;
Pre-drying means for pre-drying the recording medium to which the treatment liquid has been applied, the pre-drying means for giving a distribution to the water content of the treatment liquid in the recording area;
Image recording means for recording the image by applying the ink to a recording area of the pre-dried recording medium;
An ink distribution calculating means for calculating a distribution of water content of the applied ink;
A treatment liquid distribution calculating means for calculating a moisture content distribution of the treatment liquid for smoothing the moisture content distribution in the recording area after the ink application;
Control means for controlling the pre-drying means and setting the distribution of water content of the treatment liquid to a distribution calculated by the treatment liquid distribution calculation means;
An image recording apparatus comprising: The preliminary drying means performs preliminary drying for each unit area divided into a plurality of the recording areas,
The ink distribution calculating means calculates the moisture content of the ink applied to the recording area for each unit area;
The image recording apparatus according to claim 1, wherein the processing liquid distribution calculating unit calculates a water content of the processing liquid for each unit region for smoothing a water content distribution for each unit region.   The processing liquid distribution calculating means calculates the water content of the processing liquid such that the sum of the water content of the ink applied by the image recording means and the water content of the processing liquid after the preliminary drying is within a predetermined range. The image recording apparatus according to claim 2, wherein the image recording apparatus calculates the unit area.   The image recording apparatus according to claim 1, wherein the preliminary drying unit includes a heating unit that heats the recording area.   The image recording apparatus according to claim 4, wherein the heating unit is a hot air blowing unit that blows hot air on the recording area.   The image recording apparatus according to claim 4, wherein the heating unit is a laser irradiation unit that irradiates the recording area with a laser beam.   The image recording apparatus according to claim 4, wherein the heating unit is a heater unit that contacts and heats the recording medium to which the processing liquid is applied.   The image recording apparatus according to claim 4, wherein the preliminary drying unit includes a cooling unit that cools the recording area.   The image recording apparatus according to claim 8, wherein the cooling unit is a cold air blowing unit that blows cold air onto the recording area.   The image recording apparatus according to claim 8, wherein the cooling unit is a water cooling unit that contacts and cools the recording medium before the treatment liquid is applied. In a pre-drying apparatus for pre-drying a recording medium on which a treatment liquid containing an aggregating agent for aggregating components in the ink is uniformly applied to at least a recording area before the image is recorded by applying the ink.
Drying means for giving a distribution to the moisture content of the treatment liquid in the recording area of the recording medium to which the treatment liquid is applied;
An ink distribution calculating means for calculating a distribution of water content of the applied ink;
A treatment liquid distribution calculating means for calculating a moisture content distribution of the treatment liquid for smoothing the moisture content distribution in the recording area after the ink application;
Control means for controlling the drying means and setting the distribution of water content of the treatment liquid to a distribution calculated by the treatment liquid distribution calculation means;
Pre-drying device equipped with. A treatment liquid application step for uniformly applying a treatment liquid containing an aggregating agent for aggregating components in the ink to at least a recording region of the recording medium;
A pre-drying step of pre-drying the recording medium to which the treatment liquid has been applied, wherein the pre-drying step has a distribution in the water content of the treatment liquid in the recording area;
An image recording step of recording an image by applying the ink to a recording area of the pre-dried recording medium;
An ink distribution calculating step for calculating a distribution of water content of the applied ink;
A treatment liquid distribution calculating step of calculating a moisture content distribution of the treatment liquid for smoothing the moisture content distribution in the recording area after the ink application;
In the preliminary drying step, a control step of setting the distribution of the moisture content of the treatment liquid to a distribution calculated by the treatment liquid distribution calculation step;
An image recording method comprising: In a pre-drying method of pre-drying a recording medium on which a treatment liquid containing an aggregating agent for aggregating components in the ink is uniformly applied to at least a recording region before the image is recorded by applying the ink.
A drying step for providing a distribution in the moisture content of the processing liquid in the recording area of the recording medium to which the processing liquid has been applied;
An ink distribution calculating step for calculating a distribution of water content of the applied ink;
A treatment liquid distribution calculating step of calculating a moisture content distribution of the treatment liquid for smoothing the moisture content distribution in the recording area after the ink application;
In the preliminary drying step, a control step of setting the distribution of the moisture content of the treatment liquid to a distribution calculated by the treatment liquid distribution calculation step;
Pre-drying method with.

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