JP2012066497A - Image forming apparatus and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and image forming method which highly accurately form a glossy image with gloss in which roughness is restrained, in image formation with the use of ultraviolet curable ink, without increasing the size of the configuration of the apparatus and complicating the configuration.SOLUTION: The image forming apparatus 100 has press rollers 106 and receiving rollers 103 in a pair on a suction holding device 102 for supporting a recording medium WK and between an ink head 107 for ejecting ultraviolet curable ink IK onto the recording medium WK and a UV light source 110 irradiating the ultraviolet curable ink IK with ultraviolet. The press rollers 106 and receiving rollers 103 are each formed cylindrical and, in cooperation with each other, press the ultraviolet curable ink attached to the surface of the recording medium WK and convey the recording medium WK downstream in the direction of sub-scanning. The press roller 106 and receiving roller 103 press the ultraviolet curable ink IK attached to the recording medium WK by the ink head 107.

Description

  The present invention relates to an image forming apparatus and an image forming method for forming a desired image on the surface of a recording medium using ultraviolet curable ink that is cured by being irradiated with ultraviolet rays.

  Conventionally, ink droplets are ejected from a recording head while moving the recording head intermittently while moving the ink head in a direction (main scanning direction) orthogonal to the recording medium conveyance direction (sub-scanning direction). An ink jet image forming apparatus for forming an image, a so-called ink jet printer is known. Among such image forming apparatuses, there is an image forming apparatus that forms a desired image using ultraviolet curable ink that is cured by receiving ultraviolet rays.

  In general, ultraviolet curable ink has a low so-called wettability with respect to a recording medium, so that it is difficult to form a glossy glossy image with a sense of unevenness in the formed image. For this reason, for example, in the following patent document, after the ultraviolet curable ink is once attached to the transfer belt, the ultraviolet curable ink attached to the transfer belt is transferred to the recording medium by pressing the transfer belt against the recording medium. An image forming apparatus for forming an image is disclosed. Patent Document 2 below discloses an image forming apparatus that transfers ultraviolet curable ink onto a recording medium via a cylindrical glass drum as an image forming apparatus of a transfer system similar to the above.

JP 2007-15241 A Japanese Patent Laid-Open No. 01-133746

  However, in an image forming apparatus provided with such an intermediate carrier such as a transfer belt or a glass drum, an image transfer mechanism including an intermediate carrier for transferring an image to a recording medium has a large and complicated configuration. Therefore, there has been a problem that the overall configuration of the image forming apparatus is increased in size and complexity.

  The present invention has been made to address the above problems, and its object is to form a glossy glossy tone with reduced unevenness without increasing the size and complexity of the apparatus configuration in image forming with ultraviolet curable ink. It is an object of the present invention to provide an image forming apparatus and an image forming method capable of accurately forming the above image.

  In order to achieve the above object, a feature of the present invention according to claim 1 is that an ink head that discharges ultraviolet curable ink that is cured by being irradiated with ultraviolet rays onto a recording medium, an ink head, and the recording medium Displacement means for relatively displacing each other, UV irradiation means for irradiating and curing the ultraviolet curable ink attached to the recording medium, and an ink head and the UV irradiation means disposed between the ink head and the UV irradiation means and attached to the recording medium And a pressing means having a pressing tool for pressing the ultraviolet curable ink.

  According to the characteristic of the present invention according to claim 1 configured as described above, the image forming apparatus includes an ink head that discharges an ultraviolet curable ink to a recording medium and an ultraviolet curable ink attached to the recording medium. Is provided with a pressing means having a pressing tool for pressing the ultraviolet curable ink attached to the recording medium. That is, the image forming apparatus discharges ultraviolet curable ink directly from the ink head to the recording medium, and then presses the ultraviolet curable ink attached to the recording medium. For this reason, the image forming apparatus according to the present invention eliminates the need for a large-scale transfer mechanism and spreads the ultraviolet curable ink attached to the recording medium on the recording medium by pressing means having a simpler configuration than the transfer mechanism. be able to. This makes it possible to accurately form a glossy and glossy image with reduced unevenness without increasing the size and complexity of the apparatus configuration.

  According to another aspect of the present invention according to claim 2, in the image forming apparatus, the press unit further includes a recording medium that is disposed to face the pressing tool via the recording medium and is pressed by the pressing tool. There is a support to support.

  According to another aspect of the present invention according to claim 2 configured as described above, the image forming apparatus includes a receiver that is disposed to face the pressing tool via a recording medium. Thereby, since the recording medium pressed by the pressing tool is supported, the ultraviolet curable ink on the recording medium can be more reliably pressed and spread. This makes it possible to accurately form a glossy glossy image with a more suppressed unevenness.

  In another aspect of the present invention according to claim 3, in the image forming apparatus, the pressing tool and the receiving tool in the pressing unit are configured of a material having one surface that is flexible with respect to the other surface. There is to be.

  According to another aspect of the present invention according to claim 3 configured as described above, in the image forming apparatus, one of the surface of the pressing member and the surface of the receiving member in the pressing unit is flexible with respect to the other. Consists of materials. In this case, for example, the pressing tool can be made of a metal material such as an aluminum material or a stainless steel material, and the receiving tool can be made of a resin material or a rubber material. Thereby, the ultraviolet curable ink on a recording medium can be more reliably pressed and spread. As a result, it is possible to accurately form a glossy glossy image with a more suppressed unevenness.

  According to a fourth aspect of the present invention, in the image forming apparatus, the displacing unit displaces the ink head along one of two orthogonal directions in the same plane. And feed driving means for displacing the recording medium along the other of the two orthogonal directions.

  According to another aspect of the present invention according to claim 4 configured as described above, in the image forming apparatus, the displacement unit displaces the ink head along one of two orthogonal directions. And feed driving means for displacing the recording medium along the other direction. That is, the present invention can also be applied to a so-called paper moving type ink jet printer. In this case, the pressing tool that presses the ultraviolet curable ink is constituted by a roller body, and the roller body is driven by the feed driving means so that the pressing means and the displacing means can be combined with each other. The configuration of the forming apparatus can be easily and compactly configured.

  Another feature of the present invention according to claim 5 is that, in the image forming apparatus, the feed driving means is disposed upstream of the ink head in the other of the two orthogonal directions and is in a roll shape. A recording medium holding means for holding the wound recording medium, and a recording medium winding means that is arranged downstream of the UV irradiation means in the other of the two orthogonal directions and winds the recording medium in a roll shape. It is in having.

  According to another aspect of the present invention according to claim 5 configured as described above, the image forming apparatus includes a recording medium in which the feed driving unit is disposed upstream of the ink head and holds the recording medium wound in a roll shape. A medium holding unit and a recording medium winding unit that is arranged downstream of the UV irradiation unit and winds the recording medium in a roll shape. Accordingly, a long recording medium can be held without being damaged before and after image formation and during image formation, and image formation can be performed with high accuracy. In this case, the recording medium holding unit and the recording medium winding unit may be configured to unilaterally convey the recording medium from the recording medium holding unit to the recording medium winding unit, or once from the recording medium holding unit. You may comprise so that an image can be formed, rewinding the sent recording medium.

  According to still another aspect of the present invention according to claim 6, in the image forming apparatus, the pressing tool in the pressing unit includes a roller body for pressing the ultraviolet curable ink attached to the recording medium. It is in.

  According to another aspect of the present invention according to claim 6 configured as described above, in the image forming apparatus, the pressing tool in the pressing means is configured by a roller body. Thereby, the pressing tool makes line contact with the recording medium, and can press the ultraviolet curable ink with a stronger force. Further, the recording medium can be conveyed while pressing the ultraviolet curable ink by rotating a pressing tool constituted by a roller body. Thereby, the configuration of the image forming apparatus can be made compact.

  According to a seventh aspect of the present invention, in the image forming apparatus, the ultraviolet curable ink attached to the recording medium is irradiated with ultraviolet rays to be semi-cured between the ink head and the press unit. The pre-UV irradiation means.

  According to another aspect of the present invention according to claim 7 configured as described above, the image forming apparatus irradiates the ultraviolet curable ink attached to the recording medium with ultraviolet rays between the ink head and the press means. Pre-UV irradiation means for semi-curing is provided. Accordingly, it is possible to prevent the ultraviolet curable ink from adhering to the pressing tool, the ultraviolet curable ink from being mixed on the recording medium, and the ultraviolet curable ink from being excessively spread by the pressing.

  Another feature of the present invention according to claim 8 resides in that the image forming apparatus includes surface modifying means for modifying the surface of the recording medium before the ultraviolet curable ink adheres.

  According to another aspect of the present invention according to claim 8 configured as described above, the image forming apparatus includes surface modifying means for modifying the surface of the recording medium before the ultraviolet curable ink is attached. ing. In this case, the surface modification means of the recording medium is an apparatus for improving the wettability, fixing property and adhesion density of the recording medium with respect to the ultraviolet curable ink. Specifically, the corona discharge treatment apparatus, plasma An irradiation processing apparatus and an EB (electron beam) irradiation processing apparatus. As a result, the wettability, fixability, and adhesion density of the recording medium are improved, so that the image formation accuracy can be improved.

  The present invention can be implemented not only as an invention of an image forming apparatus but also as an invention of an image forming method in an image forming apparatus.

  Specifically, as shown in claim 9, an ink discharge step of discharging ultraviolet curable ink that is cured by irradiation of ultraviolet rays onto the recording medium, and pressing the ultraviolet curable ink attached to the recording medium. And a curing step of irradiating the pressed ultraviolet curable ink on the recording medium with ultraviolet rays for curing. According to this, the same effect as the image forming apparatus can be expected.

1 is a schematic cross-sectional view schematically showing a configuration of a main part of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a plan view schematically showing a configuration of a main part of the image forming apparatus shown in FIG. 1. FIG. 2 is a block diagram of a control system for controlling the operation of the image forming apparatus shown in FIG. 1. (A), (B) is a schematic diagram for showing the state of the ultraviolet curable ink discharged onto the recording medium WK, and (A) is the ultraviolet curable type discharged from the ink head and attached to the recording medium. It is a cross-sectional schematic diagram which shows ink, (B) is a cross-sectional schematic diagram which shows the ultraviolet curable ink of the state expanded by the press roller and the receiving roller. It is a cross-sectional schematic diagram which shows typically the structure of the principal part of the image forming apparatus which concerns on the modification of this invention. It is a cross-sectional schematic diagram which shows typically the structure of the principal part of the image forming apparatus which concerns on the other modification of this invention. It is a cross-sectional schematic diagram which shows typically the structure of the principal part of the image forming apparatus which concerns on the other modification of this invention. It is a cross-sectional schematic diagram which shows typically the structure of the principal part of the image forming apparatus which concerns on the other modification of this invention.

  Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view schematically showing a configuration of a main part of the present invention in an image forming apparatus 100 according to the present invention. 2 is a plan view schematically showing the configuration of the main part of the present invention in the image forming apparatus 100 shown in FIG. FIG. 3 is a block diagram of a control system for controlling the operation of the image forming apparatus 100. Note that each drawing referred to in the present specification is schematically represented by exaggerating some of the components in order to facilitate understanding of the present invention. For this reason, the dimension, ratio, etc. between each component may differ. This image forming apparatus 100 forms a desired character, symbol, figure, or other image by attaching ultraviolet curable ink that cures when irradiated with ultraviolet rays to the surface of a roll-like or sheet-like recording medium WK. Inkjet printer.

(Configuration of Image Forming Apparatus 100)
The image forming apparatus 100 includes two suction holding devices 102 in a substantially box-shaped housing 101 whose upper surface is open. These suction holding devices 102 are mechanical devices for holding the recording medium WK on which an image is formed, and are placed on the upper surface of a box-shaped main body 102a extending in the depth direction (Y-axis) direction of FIG. 102b is formed, and a vacuum device 102c is provided at the bottom of the main body 102a. The mounting surface 102b is a flat table on which the recording medium WK on which an image is formed is mounted. The housing 101 is in a state where the mounting surfaces 102b of the two suction holding devices 102 are positioned flush with each other. Are exposed on the open upper surface. A plurality of suction holes 101d penetrating into the main body 101a are formed on the mounting surface 102b.

  On the other hand, the vacuum device 102c is a pump device for discharging the air in the main body portion 102a to make the inside of the main body portion 102a have a negative pressure, and its operation is controlled by a controller 120 described later. The negative pressure generated in the main body portion 102a by the vacuum device 102c has such a magnitude that the recording medium WK on the mounting surface 102b does not float. These suction holding devices 102 are respectively arranged on both sides of the receiving roller 103 through the receiving roller 103 in the housing 101.

  The receiving roller 103 is a cylindrical body for supporting the recording medium WK positioned between the two suction holding devices 102, and is around the axis line with the upper surface exposed between the two suction holding devices 102 in the housing 101. Is rotatably supported. The receiving roller 103 is made of a material that is more flexible than the material that forms the surface of the pressing roller 105 described later. In the present embodiment, the receiving roller 103 is made of EPDM (ethylene / propylene rubber). The receiving roller 103 is formed to have a length corresponding to the width of the recording medium WK conveyed on the placement surface 102b.

  A recording media holding device 104 and a recording media take-up device 105 are respectively arranged outside the suction holding device 102 in the direction (left and right direction in the figure) in which the two suction holding devices 102 and the receiving roller 103 are arranged. The recording medium holding device 104 is a mechanical device for holding the recording medium WK wound in a roll shape and sending the recording medium WK onto the suction holding device 102 in cooperation with the recording medium winding device 105. The device 102 is provided on the right side in the figure while being supported by the housing 101.

  On the other hand, the recording medium take-up device 105 cooperates with the recording medium holding device 104 to guide the recording medium WK onto the suction holding device 102 and to take up the recording medium WK after image formation in a roll shape. It is provided in a state supported by the housing 101 on the left side of the suction holding device 102 in the figure. These recording media holding device 104 and recording media winding device 105 are controlled to be rotated by a controller 120 described later. That is, the recording medium holding device 104 and the recording medium winding device 105 correspond to the feed driving means according to the present invention. Note that the left-right direction (X-axis direction) in FIG. 1 that transports the recording medium WK is the sub-scanning direction, and the illustrated depth direction (Y-axis direction) orthogonal to the X-axis direction is the main scanning direction. In FIG. 1, the left side is the front side of the image forming apparatus 100, and the right side is the rear side of the image forming apparatus 100.

  A pressing roller 106 is provided above the receiving roller 103 so as to face the receiving roller 103. The pressing roller 106 is a cylindrical body for pressing the ultraviolet curable ink attached on the recording medium WK in cooperation with the receiving roller 103, and has a width of the recording medium WK conveyed on the mounting surface 102b. Corresponding length is formed. The pressing roller 106 is in a state where it can be brought into contact with and separated from the exposed upper surface of the receiving roller 102, that is, a state in which the gap between the exposed upper surface of the receiving roller 103 and the lower surface of the pressing roller 106 is adjustable. Supported by the mechanism.

  The surface of the pressure roller 106 is made of a material harder than the surface of the receiving roller 103. In the present embodiment, the entire pressing roller 106 is made of stainless steel. A blade 106 a is provided on the upper left surface of the pressing roller 106 in the figure. The blade 106a is a rubber spatula for removing foreign matter such as ultraviolet curable ink and dust attached to the pressing roller 106.

  The ink head 107 is disposed above the suction holding device 102 on the upstream side (right side in the drawing) of the recording medium WK with respect to the pressing roller 106 via a guide rail (not shown) provided in parallel with the placement surface 102b. Is supported. The guide rail is a long plate-like body that supports the ink head 107 in a slidable state along the main scanning direction (Y-axis direction). A part of a drive belt (not shown) installed along the Y-axis direction is fixed to the back surface (right side surface in the drawing) of the ink head 107. The drive belt is displaced along the Y-axis direction by the rotational drive of the Y-axis direction scan motor 108. That is, the ink head 107 is displaced in the Y-axis direction along the guide rail by the Y-axis direction scan motor 108 via the drive belt.

  The ink head 107 is a mechanical device that includes a plurality of ink nozzles (indicated by point groups in FIG. 2) that eject droplets of ultraviolet curable ink that is cured by being irradiated with ultraviolet rays toward the recording medium WK. The operation is controlled by the controller 120. This ink head 107 is provided for each of a plurality of (for example, four) different colors of ultraviolet curable ink (indicated by broken lines in FIG. 2), and these ink heads 107 are placed in one box. In the accommodated state, the guide rail is slidably supported. That is, the ink head 107 prints a color image on the surface of the recording medium WK by a combination of a plurality of (for example, four) different colors of ultraviolet curable ink.

  Above the suction holding device 102 on the upstream side (right side in the drawing) of the recording medium WK with respect to the ink head 107, a long surface modifying device 109 is provided in parallel with the mounting surface 102b. Yes. The surface modifying device 109 improves the surface properties of the recording medium WK before the ultraviolet curable ink is adhered by the ink head 107, specifically, wettability, fixing property and adhesion density with respect to the ultraviolet curable ink. It is a mechanical device. The surface modification device 109 is formed to have a length corresponding to the width of the recording medium WK conveyed on the mounting surface 102 b, and the operation is controlled by the controller 120. In the present embodiment, the surface modification device 109 is a corona discharge device that modifies the surface of the recording medium WK by irradiating the surface with corona discharge.

  On the other hand, a long UV light source 110 is provided above the suction holding device 102 on the downstream side (left side in the drawing) of the recording medium WK with respect to the pressing roller 106 in a state parallel to the mounting surface 102b. Yes. The UV light source 110 is a long optical device in which LED light sources (not shown) that emit ultraviolet rays having a wavelength that promotes curing of the ultraviolet curable ink are arranged in the main scanning direction and the sub-scanning direction, respectively. The UV light source 110 is formed to have a length corresponding to the width of the recording medium WK conveyed on the mounting surface 102 b, and the operation is controlled by the controller 120.

  The pressing roller 106, the ink head 107, the surface modification device 109, and the UV light source 110 are covered with a long upper cover (not shown) that constitutes the upper housing of the image forming apparatus 100. An operation panel 111 is provided on the upper surface of the upper cover to give instructions to the image forming apparatus 100 and display information from the image forming apparatus 100. A stand 112 is provided below the casing 101 to support the image forming apparatus 100 and to move the image forming apparatus 100 to a position desired by the operator.

  The controller 120 is configured by a microcomputer including a CPU, a ROM, a RAM, and the like, and is stored in advance in a storage device such as a ROM in accordance with an instruction from the user or an instruction from the external computer device 130 connected via the interface 121. Various operations of the image forming apparatus 100 are controlled by executing the stored control program. Specifically, the controller 120 controls the operations of the recording medium holding device 104, the recording medium winding device 105, the ink head 107, the Y-axis direction scan motor 108, the surface modification device 109, and the UV light source 110, respectively. . The external computer device 130 is a personal computer (so-called personal computer) provided with an input device 131 composed of a keyboard and a mouse and a display device 132 composed of a liquid crystal display.

(Operation of Image Forming Apparatus 100)
Next, the operation of the image forming apparatus 100 configured as described above will be described. First, the operator connects the external computer device 130 and the image forming apparatus 100 (controller 120) via the interface 121, and turns on the power of the external computer device 130 and the image forming apparatus 100, respectively. As a result, the external computer device 130 enters a standby state in which it waits for an instruction from the operator by executing a predetermined control program (not shown). Also, the image forming apparatus 100 waits for an instruction from the external computer device 130 after returning the origin of the ink head 107 by executing a predetermined control program (not shown) stored in the ROM in the controller 120 in advance. It will be in a standby state.

  Next, the operator sets the recording medium WK that is an object of image formation on the suction holding device 102. Specifically, the operator sets the roll sheet-shaped recording medium WK on the recording medium holding device 104, and then pulls out the recording medium WK from the roll body and sets it on the placement surface 102b of the suction holding device 102. That is, the operator holds the recording medium WK between the receiving roller 103 and the pressing roller 106 on the placement surface 102b. Next, the operator operates the operation panel 111 to further feed out the recording medium WK and set the leading end side of the recording medium WK in the recording medium winding device 105.

  Next, the operator operates the external computer device 130 to instruct the image forming apparatus 100 to output image data, and causes the image forming apparatus 100 to start image formation. As a result, the image forming apparatus 100, specifically, the controller 120 built in the image forming apparatus 100, relative to the ink head 107 and the recording medium WK based on the image data output from the external computer device 130. While changing the positional relationship, the operation of the ink head 107 is controlled to execute image forming processing on the recording medium WK.

  The image forming process for the recording medium WK is executed in the order of the surface modification process, the printing process, the press process, and the curing process for the recording medium WK. Specifically, the controller 120 controls the operation of the vacuum device 102c of the suction holding device 102 to generate a negative pressure in the main body portion 102a and suck the recording medium WK on the mounting surface 102b. The operations of the holding device 104 and the recording medium take-up device 105 are controlled to start the conveyance of the recording medium WK (see the arrow in FIG. 2). In this case, the controller 120 drives the recording medium holding device 104 and the recording medium winding device 105 to rotate in the directions indicated by the arrows.

  In this case, the controller 120 controls the operations of the recording medium holding device 104 and the recording medium winding device 105 to convey the recording medium WK in a state where a predetermined tension is applied to the recording medium WK. As a result, the receiving roller 103 and the pressing roller 106 that press the recording medium WK start to rotate in the rotational direction corresponding to the conveyance direction of the recording medium WK. In addition, the controller 120 controls the operation of the surface modification device 109 and starts the surface modification process for the recording medium WK as the conveyance of the recording medium WK starts. As a result, the surface of the recording medium WK has improved wettability, fixability and adhesion density with respect to the ultraviolet curable ink.

  Next, the controller 120 executes an image printing process on the recording medium WK that has been surface-modified by the surface-modifying device 109 and is conveyed immediately below the ink head 107. Specifically, the controller 120 ejects ultraviolet curable ink droplets from the ink nozzles while displacing the ink head 107 in the main scanning direction based on image data representing a print image output from the external computer device 130. (See arrow in FIG. 2). As a result, the recording medium WK forms an image for each main scan of the ink head 107 and is conveyed from the position immediately below the ink head 107 to the downstream side in the sub-scanning direction, that is, toward the receiving roller 103 and the pressing roller 106. . In this case, the ultraviolet curable ink IK discharged onto the surface of the recording medium WK is attached to the recording medium WK in a state of rising substantially in a hemispherical shape as shown in FIG.

  Next, the controller 120 performs a press process on the ultraviolet curable ink IK on the recording medium WK. Specifically, the controller 120 controls the operations of the recording medium holding device 104 and the recording medium winding device 105, respectively, and receives the recording medium WK to the side of the roller 103 and the pressing roller 106 (see arrows in FIG. 4). ). As a result, the receiving roller 103 and the pressing roller 106 press the recording medium WK from above and below while rotating (see the arrow in FIG. 2) by frictional contact with the recording medium WK. As a result, the ultraviolet curable ink IK attached to the surface of the recording medium WK is pressed and spread in a planar shape by being pressed by the pressing roller 103 and the receiving roller 102 as shown in FIG. 4B.

  Then, the recording medium WK on which the ultraviolet curable ink IK is spread is conveyed to the UV light source 110 side. As a result, the UV curable ink IK attached to the surface of the recording medium WK has a sense of unevenness as the adjacent UV curable inks IK are connected to each other. The operator can adjust the height position of the pressing roller 106 to adjust the force for holding the recording medium WK, that is, the pressing force for pressing the ultraviolet curable ink IK. The degree to which IK is spread can be adjusted. Further, the ultraviolet curable ink IK adhering to the pressing roller 106 is scraped off by the blade 106a.

  Next, the controller 120 performs a curing process for the ultraviolet curable ink IK attached to the surface of the recording medium WK. Specifically, the controller 120 controls the operation of the UV light source 110 to irradiate the recording medium WK conveyed below the UV light source 110 downstream in the sub-scanning direction with ultraviolet rays. Accordingly, the ultraviolet curable ink IK attached on the recording medium WK is cured in a state where it is spread out. As a result, a glossy glossy image with reduced unevenness is formed on the recording medium WK.

  Then, the recording medium WK that has been subjected to the curing process of the ultraviolet curable ink IK is wound up by the recording medium winding device 105. As described above, the controller 120 forms an image by continuously executing the surface modification process, the printing process, the pressing process, and the curing process while performing the printing process on the image data output from the external computer device 130. To do. Then, the controller 120 performs surface modification processing, printing processing, press processing, and curing processing on all image data, and after the recording medium WK formed with the image is wound by the recording medium winding device 111, the image The formation process ends.

  As can be understood from the above description of the operation, according to the above embodiment, the image forming apparatus 100 uses the ink head 107 that discharges the ultraviolet curable ink IK to the recording medium WK and the ultraviolet curable material attached to the recording medium WK. Between the UV light source 110 for irradiating the mold ink IK with ultraviolet rays, there is provided a pressing means comprising a pressing roller 106 and a receiving roller 103 for pressing the ultraviolet curable ink attached to the recording medium WK. That is, the image forming apparatus 100 directly discharges the ultraviolet curable ink IK from the ink head 107 to the recording medium WK, and then presses the ultraviolet curable ink IK attached to the recording medium WK. Therefore, according to the image forming apparatus 100 of the present invention, a large-scale transfer mechanism is not necessary, and the ultraviolet curable ink IK attached to the recording medium WK by pressing means having a simpler configuration than the transfer mechanism is used as the recording medium WK. Can be pushed up. This makes it possible to accurately form a glossy and glossy image with reduced unevenness without increasing the size and complexity of the apparatus configuration.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention. In each drawing explaining the following modified example, the same reference numerals are given to the same components as those in the above embodiment, and the description thereof will be omitted.

  For example, in the above-described embodiment, the image forming apparatus 100 is configured to form an image while transporting the recording medium WK from the recording medium holding apparatus 104 to the recording medium winding apparatus 105 in only one direction. However, the image forming apparatus 100 may be configured to form an image while reciprocating the recording medium WK between the recording medium holding apparatus 104 and the recording medium winding apparatus 105. That is, the controller 120 reciprocates between the recording medium holding device 104 and the recording medium winding device 105 in a state where a predetermined tension is applied to the recording medium WK, and the recording medium holding device 104 and the recording medium winding device. The operation of 105 is controlled.

  In the above-described embodiment, the press unit included in the image forming apparatus 100 is configured by the pair of pressing rollers 106 and the receiving roller 103. However, the press unit included in the image forming apparatus 100 is not necessarily limited to the above embodiment as long as it has a pressing tool that presses the ultraviolet curable ink IK attached to the recording medium WK. For example, as shown in FIG. 5, the pressing unit can be configured by only the pressing roller 103 that presses the recording medium WK below the upper surface of the platen 101. According to this, since the receiving roller 102 is unnecessary, the configuration of the image forming apparatus 100 can be simplified.

  The pressing roller 106, which is a pressing tool constituting the pressing means, can also be configured in a shape other than the roller shape. For example, in the pressing tool constituting the pressing means, the portion for pressing the ultraviolet curable ink attached to the recording medium WK may be formed in a flat shape. Further, the pressing means may press the recording medium WK in a state where at least one of the pressing tool and the receiving portion is heated by the heating means. According to this, curing of the ultraviolet curable ink IK can be promoted.

  In the above embodiment, the pressing roller 106 and the receiving roller 103 constituting the pressing unit are made of a material whose surface of the receiving roller 103 is more flexible than the surface of the pressing roller 106. Thereby, it is possible to more effectively press the ultraviolet curable ink attached to the recording medium WK. However, when the pressing means is composed of a pressing tool and a receiving tool, it is only necessary that one surface is made of a material that is flexible with respect to the other surface. That is, the surface of the pressure roller 106 can be made of a material that is more flexible than the surface of the roller 103. When the pressing means is composed of a pressing tool and a receiving tool, the ultraviolet curable ink attached to the recording medium WK can be pressed even if the pressing tool surface and the receiving tool surface are made of the same material. Is natural.

  In the embodiment, the image forming apparatus 100 is configured to cure the ultraviolet curable ink IK pressed by the pressing roller 106 and the receiving roller 103 by irradiating the UV light source 110 with ultraviolet rays. However, for example, as shown in FIG. 6, by providing a pre-UV light source 110 a between the ink head 107 and the pressing roller 106, the ultraviolet curable ink IK attached on the recording medium WK is pressed by the pressing roller 106 and the receiving roller. Before pressing by 103, it may be preliminarily irradiated with ultraviolet rays and semi-cured. According to this, since the ultraviolet curable ink is semi-cured before being pressed by the pressing roller 106, the ultraviolet curable ink adheres to the pressing roller 106, and the ultraviolet curable ink adjacent to each other on the recording medium WK. It is possible to prevent color mixing and excessive spreading due to the pressing of the ultraviolet curable ink on the recording medium WK.

  In the above-described embodiment, the image forming apparatus 100 includes the surface modification device 109 on the upstream side in the sub-scanning direction with respect to the ink head 107. The surface modification device 109 may be any device other than a corona discharge treatment device, for example, a plasma irradiation treatment, as long as it is a device for improving the wettability, fixability, and adhesion density of the recording medium WK with respect to the ultraviolet curable ink IK. An apparatus, an EB (electron beam) irradiation processing apparatus, or the like can be used. Further, when there is no need to darely improve the wettability, fixability and adhesion density of the recording medium WK, the surface modification device 109 can be omitted (see FIG. 8).

  Further, in the above-described embodiment, the image forming apparatus 100 displaces the ink head 105 in the main scanning direction by driving the Y-axis direction scan motor 108 and uses the recording medium holding device 104 and the recording medium winding device 105 to record the recording medium. A so-called paper moving type in which WK is displaced in the sub-scanning direction is used. That is, the Y-axis direction scan motor 108, the recording media holding device 104, and the recording media take-up device 105 constitute displacement means according to the present invention. However, the displacement means only needs to be configured by a mechanism that relatively displaces the ink head 107 and the recording medium WK, and is not necessarily limited to the above embodiment.

  For example, the image forming apparatus 100 is so-called flat configured to displace the ink head 107 in two orthogonal directions (X-axis direction and Y-axis direction) within the same plane with respect to the recording medium WK fixed on the plane. It may be a bed format. In this case, the pressure roller 106, the surface modification device 109, and the UV light source 110 may be configured to be displaced together with the ink head 107. Further, for example, if the ink head 107 is arranged over the entire width direction of the recording medium WK, the ink head 107 and the recording medium WK are relatively displaced in one direction (for example, the pressure roller 106, the ink head 107, the surface modification). An image can be formed by fixing the quality device 109 and the UV light source 110 and transporting only the recording medium WK.

  In the above embodiment, the image forming apparatus 100 is configured such that the recording medium WK is conveyed on the suction holding apparatus 102 by the recording medium holding apparatus 104 and the recording medium winding apparatus 105. However, the recording medium WK can also be conveyed by the receiving roller 103 and the pressing roller 106 that press the recording medium WK.

  For example, the image forming apparatus 100 shown in FIG. 7 includes a platen 113 that has a flat portion and is curved toward the front and rear of the image forming apparatus 100 instead of the suction holding device 102. Yes. The platen 113 is a mounting table on which a part of the recording medium WK is mounted and supported on the plane portion, and is formed to extend in the depth direction (Y axis) direction of FIG. The pressing roller 106 disposed opposite to the receiving roller 103 disposed in the platen 113 is rotationally driven by an X-axis direction feed motor 114 (shown by a broken line in FIG. 3) whose driving is controlled by the controller 120. . That is, the recording medium WK is conveyed on the platen 113 along the sub-scanning direction (X-axis direction in the drawing) by being sandwiched between the receiving roller 103 and the pressing roller 106.

  In the image forming apparatus 100 shown in FIG. 7, the recording media holding device 104 and the recording media take-up device 105 are provided at the lower part of the rear side and the front side of the image forming apparatus 100 in the stand 112 that supports the image forming apparatus 100. Each is arranged. In this case, the recording medium holding device 104 supports the roll sheet-shaped recording medium WK and is rotationally driven so that the recording medium WK can be easily guided to the platen 113 where image formation is performed under the control of the controller 120. On the other hand, the recording medium take-up device 105 takes up the recording medium WK that has been subjected to image formation and discharged from the platen 113 under the operation control by the controller 120.

  In the image forming apparatus 100 shown in FIG. 7 configured as described above, the recording medium WK conveyed on the platen 113 by the rotation of the pressing roller 106 by the drive control of the X-axis direction feed motor 114 by the controller 120 is used. In the same manner as in the above-described embodiment, the surface modification process, the printing process, the pressing process, and the curing process are executed to perform image formation. In this case, the recording medium holding device 104 is controlled by the controller 120 to send out the recording medium WK according to the conveyance speed of the recording medium WK conveyed by the pressing roller 106 on the platen 113. In addition, the recording medium take-up device 105 takes up the recording medium WK every time the recording medium WK is discharged from the platen 101 by a predetermined amount.

  In the image forming apparatus 100 shown in FIG. 7, in addition to the recording medium WK wound in a roll shape, the A row (for example, A0 size or A1 size) or the B row (for example, B0 size or B1 size). It is also possible to set a piece of paper having a standard size such as the recording medium WK. Specifically, like the roll-shaped recording medium WK, the operator holds the recording medium WK in a piece of paper between the receiving roller 103 and the pressing roller 106 on the platen 113. In this case, since the recording medium WK is a piece of paper, the recording medium holding device 104 and the recording medium winding device 105 are not used.

  Further, the image forming apparatus 100 shown in FIG. 7 conveys the recording medium WK along the sub-scanning direction by rotationally driving the pressing roller 106 while the recording medium WK is sandwiched between the pressing roller 106 and the receiving roller 103. Configured. However, the displacement means for transporting the recording medium WK is not limited to the above modification. For example, the recording medium WK may be conveyed by rotating the receiving roller 103 instead of or in addition to the pressing roller 106.

  For example, as shown in FIG. 8, a cylindrical grid roller 115 extending along the horizontal direction in the figure is provided on the flat surface portion of the platen 113 with its upper surface exposed, and opposed to the grid roller 115. In this state, a plurality of (for example, four) pinch rollers 116 having a cylindrical portion can be provided at substantially equal intervals. In this case, the grid roller 115 is rotationally driven by the X-axis direction feed motor 114 whose drive is controlled by the controller 120. The grid roller 115 and the pinch roller 116 convey the recording medium WK along the sub-scanning direction while sandwiching the recording medium WK from the vertical direction in the figure.

WK ... recording media, IK ... UV curable ink,
DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus 101 ... Housing | casing 102 ... Adsorption holding | maintenance apparatus, 102a ... Main-body part, 102b ... Mounting surface, 102c ... Vacuum apparatus, 102d ... Suction hole, 103 ... Receiving roller, 104 ... Recording media holding apparatus, DESCRIPTION OF SYMBOLS 105 ... Recording medium winding device, 106 ... Pressure roller, 106a ... Blade, 107 ... Ink head, 108 ... Y-axis direction scan motor, 109 ... Surface modification device, 110 ... UV light source, 111 ... Operation panel, 112 ... Stand 113 ... Platen, 114 ... X-axis direction feed motor, 115 ... Grid roller, 116 ... Pinch roller,
120 ... Controller,
130: External computer device.

Claims (9)

An ink head that discharges ultraviolet curable ink that is cured by being irradiated with ultraviolet rays onto a recording medium;
A displacement means for relatively displacing the ink head and the recording medium;
UV irradiation means for irradiating and curing the ultraviolet curable ink attached to the recording medium with ultraviolet rays;
An image forming apparatus comprising: a pressing unit that is disposed between the ink head and the UV irradiation unit and includes a pressing tool that presses the ultraviolet curable ink attached to the recording medium. The image forming apparatus according to claim 1,
The pressing means is further
An image forming apparatus comprising: a receiving tool that supports the recording medium that is disposed to face the pressing tool via the recording medium and is pressed by the pressing tool. The image forming apparatus according to claim 2,
The image forming apparatus according to claim 1, wherein the pressing tool and the receiving tool in the pressing unit have one surface made of a material that is flexible with respect to the other surface. The image forming apparatus according to claim 1, wherein:
The displacement means is
Scan driving means for displacing the ink head along one of two orthogonal directions in the same plane;
An image forming apparatus comprising: a feed driving unit configured to displace the recording medium along the other of the two orthogonal directions. The image forming apparatus according to claim 4,
The feed driving means includes
A recording medium holding means for holding the recording medium which is disposed upstream of the ink head in the other of the two orthogonal directions and wound in a roll shape;
An image forming apparatus comprising: a recording medium winding unit disposed downstream of the UV irradiation unit in the other of the two orthogonal directions and winding the recording medium in a roll shape. The image forming apparatus according to claim 1, wherein:
The image forming apparatus according to claim 1, wherein the pressing tool in the pressing means includes a roller body for pressing the ultraviolet curable ink attached to the recording medium. The image forming apparatus according to claim 1, wherein:
An image forming apparatus, comprising: a pre-UV irradiation unit for irradiating the ultraviolet curable ink attached to the recording medium with ultraviolet rays and semi-curing the ink between the ink head and the press unit. The image forming apparatus according to claim 1, wherein:
An image forming apparatus comprising surface modifying means for modifying the surface of the recording medium before the ultraviolet curable ink is attached. An ink ejection step for ejecting an ultraviolet curable ink that is cured by being irradiated with ultraviolet rays onto a recording medium;
A pressing step for pressing the ultraviolet curable ink attached to the recording medium;
An image forming method comprising: a curing step of irradiating the pressed ultraviolet curable ink on the recording medium with ultraviolet rays to cure.

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