JP2010164910A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of printing an image on an electrophoretic display medium in the same manner that an image is printed on a regular paper by ejecting ink and the like. <P>SOLUTION: The image forming apparatus includes a display medium conveying means conveying a display medium sheet having a sheet type display element layer where electrophoretic elements are arranged and displaying a color corresponding to a direction of an electric field applied to each electrophoretic element, to a printing position, a common electrode disposed opposite to a rear surface of the display medium sheet in the printing position, a recording medium conveying means conveying a recording medium sheet wherein a potential corresponding to a charge of a charged particle on the surface thereof is transmitted to the rear surface, to a printing position opposed to the display surface of the display medium sheet, a charged particle ejecting means ejecting charged particles onto the surface of the recording medium sheet in the printing position, a common electrode control means applying a prescribed potential to the common electrode during charge particle ejection and an ejection conveyance means conveying the recording medium sheet after the charged particles are stuck and the display medium sheet so that the electric field directions applied to the electrophoretic elements of the display medium sheet are not changed, to part the sheets. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

  In recent years, various electronic paper technologies have been developed to promote a paperless society. Japanese Patent Application Laid-Open No. 2004-151561 discloses a technique for displaying an image by forming an electrostatic image on a charged photoconductor, bringing electronic paper into close proximity, and moving a charged pigment in the electronic paper according to the electrostatic latent image. It is disclosed (see Patent Document 1). The above technique forms an image on an electrophoretic electronic paper using an electrophotographic system.

JP 2005-91565 A

  The present invention provides an image forming apparatus capable of printing an image on an electrophoretic display medium in the same manner as printing an image on plain paper by discharging ink or the like (inkjet or the like).

  An image forming apparatus according to the present invention has a sheet-type display element layer in which a plurality of electrophoretic elements are arranged in a plane, and displays on the surface of the display element layer according to the direction of an electric field applied to each electrophoretic element. The display medium sheet for displaying the color to be displayed on the display surface side is disposed so as to face the display medium conveying means for conveying the display medium sheet to a preset printing position and the back surface of the display medium sheet conveyed to the printing position. And a display surface of the display medium sheet conveyed to the printing position, the common electrode and a sheet-like recording medium sheet in which a potential corresponding to the charge of the charged particles is transmitted to the back side when charged particles adhere to the surface A recording medium conveying means for conveying the recording medium so as to face the recording medium, and a charged particle discharging means for discharging charged particles to the surface of the recording medium sheet conveyed to the printing position and arranged to face the display medium sheet In the period in which the charged particle discharge means discharges charged particles, the common electrode control means for applying a predetermined potential to the common electrode, and the recording in which the charged particles discharged by the charged particle discharge means are attached to the surface Discharging and conveying means for separating the medium sheet and the display medium sheet disposed opposite to the recording medium sheet while conveying both of them so that the direction of the electric field applied to the electrophoretic element in the display medium sheet does not change. Prepare.

  The image forming apparatus according to the present invention includes a sheet-type display element layer in which a plurality of electrophoretic elements are arranged in a plane, and the surface of the display element layer according to the direction of an electric field applied to each electrophoretic element. The display medium sheet for displaying the color displayed on the display surface side is opposed to the display medium conveying means for conveying the display medium sheet to a preset printing position, and the back surface of the display medium sheet conveyed to the printing position. When the charged particles adhere to the surface of the common electrode disposed, an annular recording medium sheet is transmitted to the back surface side according to the charge of the charged particles, and the display surface of the display medium sheet at the printing position And a recording medium conveying means for conveying the recording medium sheet so that the back surface of the recording medium sheet faces, and charged particles on the surface of the recording medium that is conveyed to the printing position and arranged to face the display medium sheet. The charged particle discharging means for discharging, the common electrode control means for applying a predetermined potential to the common electrode, and the electric field applied to the electrophoretic element of the display medium sheet during the period in which the charged particle discharging means discharges the charged particles. Discharging means for transporting and discharging the display medium sheet from the state of being opposed to the recording medium to which the charged particles are attached so as not to change the direction.

  According to the present invention, an image can be formed on a display medium sheet by discharging charged particles to a recording medium sheet without discharging charged particles to the display medium sheet. Therefore, it is possible to display an image on the display medium sheet in the same manner as printing an image on a paper medium without polluting the display medium sheet. In addition, since the recording medium sheet and the display medium sheet to which the charged particles are attached are transported apart so as to maintain the electric field direction of the display medium sheet, the image formed on the display medium sheet is discharged while being maintained. can do.

  The image forming apparatus may display the display medium sheet so that the surface side of the display element layer of the display medium sheet is displayed in the same color before the display medium sheet is conveyed to the printing position by the display medium conveying unit. It is good also as providing the reset means which gives the electric field corresponding to the color displayed on the said surface side with respect to all the said electrophoretic elements of an element layer. According to this configuration, the image can be repeatedly displayed on the display medium sheet after the image is formed, and the display medium sheet can be reused.

  In addition, the recording medium conveying unit includes a collecting unit that collects the charged particles discharged to the recording medium after the recording medium sheet is separated from the display medium sheet from the state where the recording medium sheet is opposed to the recording medium sheet. The medium conveying unit may convey the recording medium sheet after the charged particles are collected by the collecting unit to the printing position. According to this configuration, the recording medium sheet can be reused, and the collected charged particles can also be reused.

1 is a block diagram of an image forming apparatus according to an embodiment. 1 is a cross-sectional view illustrating a schematic configuration of an image forming apparatus according to an embodiment. It is the figure which represented typically the structure of the electronic paper in embodiment. (A) is sectional drawing of an electrophoretic element in the case of displaying black on the display surface of electronic paper. (B) is sectional drawing of an electrophoretic element in the case of displaying white on the display surface of electronic paper. (C) is a cross-sectional view of the electrophoretic element when black is displayed on the display surface of the right side portion of the electrophoretic element. (A) is a figure which shows the state of the protection sheet and electrophoretic element in the case of displaying black on the display surface of electronic paper. (B) is a figure which shows the state of the protection sheet and electrophoretic element in the case of displaying white on the display surface of electronic paper. (C) is a figure which shows the state of a protection sheet and an electrophoretic element in the case of displaying black on the display surface of the right side part of an electrophoretic element.

  Hereinafter, an image forming apparatus according to the present invention will be described with reference to the drawings. The image forming apparatus in the present embodiment is an ink jet serial printer that forms an image on electronic paper. FIG. 1 is a block diagram of an image forming apparatus according to the present embodiment.

<Configuration>
The image forming apparatus 2 includes a control unit 7, a paper feeding unit 12, an EP sheet conveying unit 14, an image forming unit 16, and a paper discharge unit 18. The control unit 7 includes a CPU (Computer Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), or an ASIC (Application Specific Integrated Circuit), and is externally connected to the image forming apparatus 2. Image data is received from a device such as a PC (not shown), and a control signal corresponding to the image data is sent to each unit connected to the control unit 7 to control each unit. Hereinafter, each unit other than the control unit 7 will be described with reference to FIG. FIG. 2 is a cross-sectional view illustrating a schematic configuration of the image forming apparatus 2. An alternate long and short dash line indicates a conveyance path 4 from the paper feeding to the paper ejection.

  The paper feed unit 12 includes a paper feed tray 8 on which the electronic paper 6 is loaded, and a paper feed roller 10 that feeds the electronic paper 6 set in the paper feed tray 8 one by one. The paper feed roller 10 is rotationally driven by a driving means such as a stepping motor (not shown), separates one electronic paper 6 from the electronic paper 6 loaded on the paper feed tray 8, and sends it to the transport path 4.

  The EP sheet conveyance unit 14 includes a guide plate 40 that guides conveyance of the fed electronic paper 6, reset electrodes 42 a and 42 b disposed above and below the conveyance path 4 of the electronic paper 6, and the electronic paper 6. A transport roller 44 that feeds the electronic paper 6 to a printing position for forming an image, and a transport driven roller 46 that rotates following the rotation of the transport roller 44. The reset electrodes 42 a and 42 b apply a predetermined voltage to the electronic paper 6 sent out by the paper supply unit 12 to reset the display surface potential of the electronic paper 6.

  Here, the resetting of the electronic paper 6 and the display surface potential in the present embodiment will be described with reference to FIGS. FIG. 3 is a diagram schematically showing the structure of the electronic paper 6 in the present embodiment. As shown in FIG. 3, the electronic paper 6 includes a first substrate 6a, a second substrate 6b, an electrophoretic element P, and a binder 6c. In FIG. 3, the upper direction is the display surface side, and the lower direction is the back surface side. The first substrate 6a and the second substrate 6b are resin substrates, and the resin substrate of the first substrate 6a is transparent. Between the first substrate 6a and the second substrate 6b, a plurality of electrophoretic elements P are arranged close to each other in a planar shape and fixed by a light-transmitting binder 6c. The electrophoretic element P has a diameter of about several tens of microns and a substantially spherical shape, but each size and shape are not completely the same.

  FIG. 4 is a cross-sectional view schematically showing the structure and state of the electrophoretic element P. FIG. 4A shows the state of the electrophoretic element P when black is displayed on the display surface of the electronic paper 6. Each electrophoretic element P is microencapsulated, and a liquid dispersion medium DM containing black pigment particles BG and white pigment particles WG having a diameter of about several nanometers is enclosed in a polymer film as a capsule wall CW. Has been. In the present embodiment, each black pigment particle BG is charged to minus (−), and each white pigment particle WG is charged to plus (+). The positions of the black pigment particles BG and the white pigment particles WG in the capsule wall CW are defined by an electric field applied from the outside, and are stably maintained by the dispersion medium DM.

  Therefore, when displaying black on the display surface of the electronic paper 6, a predetermined electric field in the direction of arrow E1 is generated between the first substrate 6a and the second substrate 6b of each electrophoretic element P. As a result, the negative (−) charged black pigment particles BG move to the display surface side in the capsule wall CW, and the positive (+) charged white pigment particles WG move to the back side in the capsule wall CW. The display surface of the electronic paper 6 is displayed in black.

  FIG. 4B shows the state of the electrophoretic element P when white is displayed on the display surface of the electronic paper 6. When the white color is to be displayed by the electrophoretic element P, a predetermined electric field in the direction of the arrow E2 is generated, contrary to the black display described above. Thereby, the positive (+) charged white pigment particle WG moves to the display surface side in the capsule wall CW, and the negative (−) charged black pigment particle BG moves to the back side in the capsule wall CW. The display surface of the electronic paper 6 is displayed in white.

  Note that the color that can be displayed simultaneously by one electrophoretic element P is not one color, and there is a state where one electrophoretic element P displays both white and black at the same time as shown in FIG. 4C. . For example, when an electric field in the direction of arrow E1 is generated between the first substrate 6a and the second substrate 6b on the right side of the electrophoresis element P in the state of FIG. On the right side, the black pigment particles BG move so as to approach the front surface side, and the white pigment particles WG move so as to approach the back surface side. Thereby, black is displayed only on the display surface of the right side portion of the electrophoretic element P.

  In the reset of the display surface potential of the electronic paper 6 in the present embodiment, a voltage is first applied to the reset electrodes 42a and 42b so as to generate a predetermined electric field in the direction of the arrow E1, and black is displayed on the display surface. Thereafter, a voltage is applied so as to generate a predetermined electric field in the arrow E2 direction opposite to the E1 direction, and white is displayed on the display surface of the electronic paper 6.

  Returning to FIG. 2, the description of each part will be continued. The image forming unit 16 includes a protective sheet transport unit 20 that transports the protective sheet 19, a common electrode 22, an ink discharge unit 24, and an ink recovery unit 26. The protective sheet 19 is a recording medium such as an OHP (Overhead Projector) sheet made of a material such as non-conductive thin plastic, and has a width equal to or larger than the paper width of the electronic paper 6 and has a ring shape. Yes. The protective sheet conveying unit 20 is configured by arranging a plurality of protective sheet conveying rollers 50 on the surface side of the ring-shaped protective sheet 19. The protective sheet conveying unit 20 drives each protective sheet conveying roller 50 by a driving means such as a stepping motor (not shown) to convey the protective sheet 19 in the direction of arrow A. That is, as shown in FIG. 2, the protective sheet 19 is transported horizontally with respect to the common electrode 22 between the end portions 22 a and 22 b of the common electrode 22, which will be described later. Carry U-turn in the direction. Further, the protective sheet conveyance unit 20 conveys the protective sheet 19 by rotating the protective sheet conveyance roller 50 so as to synchronize with the conveyance of the electronic paper 6.

  The common electrode 22 has substantially the same width as the electronic paper 6 and is disposed so as to be in contact with the back side of the electronic paper 6 conveyed to the printing position. The potential of the common electrode 22 is maintained at 0 v by the control unit 7. ing.

  The ink discharge unit 24 includes a carriage 60 and an ink cartridge 62. Under the control of the control unit 7, the carriage 60 reciprocates in the main scanning direction orthogonal to the transport direction of the electronic paper 6 by driving a drive motor (not shown). The ink cartridge 62 is supported by the carriage 60 and includes an ink head 64. The ink head 64 is disposed so as to face the surface of the protective sheet 19, and a plurality of dots of ink droplets charged positively (+) by an ink charging electrode (not shown) is used as a control signal from the control unit 7. Accordingly, the ink is discharged onto the protective sheet 19. The ink uses viscous dye ink or pigment ink, and a predetermined potential difference that can display an image by the electrophoretic element P of the electronic paper 6 is between the display surface and the back surface of the electronic paper 6. The ink is charged so that it occurs.

  The ink collecting unit 26 includes an ink removing unit 26 a configured by a scraper or the like that removes ink adhering to the protective sheet 19, and an ink containing unit 26 b that collects the removed ink and stores it in the ink cartridge 62. Including. The ink removing unit 26a is pivotally supported on the upper part of the ink cartridge 62 so as to be in contact with the surface of the protective sheet 19, and every time the protective sheet 19 passes through the ink removing unit 26a by the rotational driving of the protective sheet transport roller 50, The ink attached to the protective sheet 19 is removed. The ink storage unit 26 b is disposed on the top of the ink cartridge 62, collects the ink removed by the ink removal unit 26 a, and stores the ink in the ink cartridge 62. Note that a mechanism for wiping the surface of the protective sheet 19 after the ink is removed by the ink recovery unit 26 may be provided.

  Here, the display of the electronic paper 6 sandwiched between the protective sheet 19 and the common electrode 22 will be described with reference to FIG. FIG. 5A shows the state of the protective sheet 19 and the electrophoretic element P when the charged ink adheres to the protective sheet 19, that is, when black display is performed. In this case, an ink droplet 66 having a charge amount (+ E) that generates a predetermined electric field in the E1 direction in which the white pigment particles WG and the black pigment particles BG of the electrophoretic element P can move is attached to the protective sheet 19. Yes. As a result, a potential of + E is generated on the display surface of the electrophoretic element P, and an electric field in the E1 direction is generated on the electrophoretic element P. Accordingly, the black pigment particles BG that are negatively charged (−) move to the display surface side of the electrophoretic element P, and the white pigment particles WG that are positively (+) charged are on the back surface side of the electrophoretic element P. Moving. In this way, the display surface of the electrophoretic element P is displayed in black corresponding to the position of the protective sheet 19 to which the charged ink is applied, and an image is formed on the display surface of the electronic paper 6.

  On the other hand, FIG. 5B shows the state of the protective sheet 19 and the electrophoretic element P when the charged ink is not attached to the protective sheet 19, that is, when white display is performed. In this case, since the charged ink is not attached to the protective sheet 19, the electric field applied to the electrophoretic element P does not change. Therefore, the state reset by the reset electrodes 42a and 42b, that is, the state where the display surface of the electronic paper 6 is displayed in white is maintained.

  FIG. 5C shows a state of the electrophoretic element P when charged ink is attached on the protective sheet 19 corresponding to the right side portion of the electrophoretic element P. In this case, since the ink droplet 66 having the charge amount (+ E) is attached on the protective sheet 19 corresponding to the right side portion of the electrophoretic element P, the right side portion of the electrophoretic element P is predetermined in the E1 direction. The electric field is generated. Therefore, among the black pigment particles BG located on the back side of the electronic paper 6, the black pigment particles BG on the right side move to the display surface side of the electrophoretic element P, and the display surface on the right side of the electrophoretic element P Displayed in black.

  Returning to FIG. 2, the paper discharge unit 18 will be described. The paper discharge unit 18 includes a paper discharge roller 28, a paper discharge driven roller 29, an inclined member 30, and a paper discharge tray 32 on which the discharged electronic paper 6 is placed. The inclined member 30 is configured by a taper or the like having a predetermined inclination angle, and is disposed so as to be in contact with the protective sheet 19 at the end 22 b of the common electrode 22. The paper discharge roller 28 is rotationally driven by a driving unit such as a stepping motor, and the electronic paper 6 on which an image is formed by the image forming unit 16 is rotated by the paper discharge driven roller 29 that rotates in accordance with the rotational drive of the paper discharge roller 28. Between the paper discharge roller 28 and the paper discharge tray 32.

<Operation>
Next, the operation of the image forming apparatus 2 will be described. When the control unit 7 accepts image data for image formation, under the control of the control unit 7, the paper feed unit 12 rotates the paper feed roller 10 to load the electronic paper loaded on the paper feed tray 8. One sheet 6 is separated and sent downstream in the transport path 4. The delivered electronic paper 6 is applied with a voltage that generates a predetermined electric field in the E1 direction by the reset electrodes 42a and 42b, and displays the display surface of the electronic paper 6 in black. Thereafter, a voltage that generates a predetermined electric field in the E2 direction is applied to display the display surface of the electronic paper 6 in white, and the display surface potential of the electronic paper 6 is reset. The sequentially reset electronic paper 6 reaches the conveyance roller 44 along the guide plate 40, and is sandwiched between the conveyance roller 44 and the conveyance driven roller 46 by the rotation driving of the conveyance roller 44 and faces the ink head 64. Sequentially sent to the printing position.

  When the electronic paper 6 is transported to the printing position, the carriage 60 moves in the main scanning direction, discharges a plurality of dots of ink droplets charged by the ink head 64 onto the protective sheet 19, and an image in units of rows forms the protective sheet 19. Printed on. As a result, an electric field in the E1 direction for displaying black is applied to the display surface of the electronic paper 6 facing the position of the protective sheet 19 to which the ink droplets have adhered, and an image for one row is also displayed on the display surface of the electronic paper 6. Is formed. The protective sheet 19 is sequentially conveyed so as to synchronize with the conveyance of the electronic paper 6, and the reciprocating movement by the carriage 60 and the discharge of the charged ink by the ink head 64 are repeatedly performed on the protective sheet 19 as described above. Thus, an image for one page is formed on the display surface of the electronic paper 6.

  Then, under the control of the control unit 7, the protective sheet conveyance roller 50 and the electronic paper conveyance roller 44 are driven to rotate synchronously, and the position of the protective sheet 19 on which the ink is adhered and the position of the electronic paper 6 on which the image is formed The protective sheet 19 and the electronic paper 6 are simultaneously conveyed from the end 22a to the end 22b of the common electrode 22 so that they do not shift. At the end 22 b of the common electrode 22, the protective sheet 19 is U-turned along the inclined member 30 in the direction of arrow A, and the electronic paper 6 is held between the paper discharge roller 28 and the paper discharge driven roller 29. And is discharged to the paper discharge tray 32.

Thereby, at the end 22b of the common electrode 22, the protective sheet 19 and the electronic paper 6 to which the charged ink droplets are attached are simultaneously separated from the common electrode 22, and the electric field direction of the electrophoretic element P of the electronic paper 6 is changed. Gradually move away. Therefore, although the electric force applied to the electrophoretic element P of the electronic paper 6 is reduced, the direction of the electric field does not change, so that the image formed on the electronic paper 6 is discharged to the paper discharge tray 32 while being maintained.

  The protective sheet 19 to which the charged ink is attached is conveyed along the inclined member 30 at the end 22 b of the common electrode 22, and then U-turned by the rotation of the protective sheet conveying roller 50, so that the ink cartridge 62 To the top. Ink adhering to the protective sheet 19 is removed by the ink removing unit 26 a disposed on the upper part of the ink cartridge 62, and the removed ink is collected by the ink containing unit 26 b and stored in the ink cartridge 62. The protective sheet 19 is sequentially transported in synchronization with the transport of the electronic paper 6 every time the electronic paper 6 is fed by the rotational driving of the protective sheet transport roller 50 after the charged ink is collected. Re-transferred to printing position.

  In the above-described embodiment, an image similar to the image recorded on the protective sheet 19 can be obtained by transporting the electronic paper 6 between the common electrode 22 and the protective sheet 19 and applying the charged ink to the protective sheet 19. Can be displayed on the electronic paper 6. Therefore, it is not necessary to provide an electrode for displaying an image as in the conventional electronic paper, and the electronic paper 6 can be transported to printed in the same manner as a paper sheet.

  Moreover, since the display surface potential of the electronic paper 6 can be reset and white can be displayed on the display surface before displaying the image on the electronic paper 6, the user uses the electronic paper 6 on which the image is formed. Even after that, the image can be repeatedly displayed on the electronic paper 6 and reused. Furthermore, since the ink droplets adhering to the protective sheet 19 can be removed and collected in the ink cartridge 62, the protective sheet 19 and the ink can be reused.

Hereinafter, modifications of the embodiment according to the present invention will be described.
(1) In the above-described embodiment, the annular protective sheet 19 has been described as being conveyed in an annular shape. However, every time one electronic paper 6 is fed, a protective sheet equivalent to the paper size of the electronic paper 6 is used. 19 may be set on the surface of the electronic paper 6. In this case, the transport path of the protective sheet 19 is substantially parallel to the transport path of the electronic paper 6, and the electronic paper 6 and the protective sheet 19 are transported simultaneously to the printing position. Further, the protective sheet discharge roller for discharging the protective sheet 19 to which the ink is attached is rotated and conveyed along the inclined member 30, and the electronic paper 6 and the protective sheet 19 are separated at the end 22 b of the common electrode 22. To do. The conveyed protection sheet 19 is discharged to a discharge tray for the protection sheet.
In the above case, since the protective sheet 19 is discharged in the same manner as the electronic paper 6, the protective sheet 19 and ink cannot be reused as in the embodiment, but the discharged protective sheet is collected and recycled. It may be.

(2) In the above-described embodiment, the potential of the common electrode 22 is described as being maintained at 0 v. However, a voltage other than 0 v may be applied to the common electrode 22. In this case, as in the embodiment, the ink is charged so that a predetermined potential difference that can be displayed by the electrophoretic element P of the electronic paper 6 is generated in the electronic paper 6.

(3) In the above-described embodiment, the electronic paper 6 is a medium supplied to the image forming apparatus 2 and the protective sheet 19 is described as a medium built in the image forming apparatus 2 in advance. Alternatively, the protective sheet 19 may be laminated as a multilayer sheet. In this case, the electronic paper 6 and the protective sheet 19 are simultaneously fed and conveyed to the printing position, and after the charged ink is ejected to the protective sheet 19, the electronic paper 6 and the protective sheet 19 are overlapped. The paper is ejected. Therefore, in this case, after the electronic paper 6 and the protective sheet 19 are discharged, the user can peel off the protective sheet 19 from the electronic paper 6 so that the image displayed on the electronic paper 6 can be visually recognized.

(4) In the above-described embodiment, the ink is charged in the ink head 64, but the ink may be charged and held in the ink cartridge 62.
(5) In the above-described embodiment, each electrophoretic element P is encapsulated with the dispersion medium DM containing white and black pigment particles. However, the color of the pigment particles may be only one color, It may be other than white or black. For example, when the pigment particle has one color, the dispersion medium DM is colored in a color having different light transmissivity. In this way, when a predetermined electric field in which the pigment particles can move is generated in the electrophoretic element P, the pigment particles move to the surface side, and the color of the pigment particles is displayed on the surface. Further, when a predetermined electric field in the reverse direction is generated in the electrophoretic element P, the pigment particles move to the back side, and the color of the dispersion medium DM is displayed on the surface. Therefore, the electrophoretic element can be driven so that color is developed according to the change in the direction of the electric field.

(6) In the above-described embodiment, the ink head 64 is described as a serial head. However, a line type ink head or a block type ink head may be used. For example, in the case of a line-type ink head, the ink head has the same width as that of the protective sheet 19, is provided with ink discharge ports having a predetermined number of dots in the print head width and the sub-scanning direction, and discharges ink droplets in units of rows. In this case, ink droplets charged on the protective sheet 19 conveyed with the ink head fixed are ejected. In the case of a block-type ink head, the ink head includes ink discharge ports having a predetermined number of dots in the sub-scanning direction and the main scanning direction, and discharges ink droplets in units of blocks. In this case, as in the embodiment, the carriage 60 is reciprocated in the main scanning direction, and ink droplets are ejected onto the protective sheet 19 in units of blocks.

(7) In the above-described embodiment, it has been described that ink is used. However, solid particles such as toner may be charged and discharged onto the protective sheet 19 or the electronic paper 6. In this case, when discharging to the electronic paper 6, the charged particles attached to the electronic paper 6 after the image formation may be removed with a brush or the like.

(8) In the above-described embodiment, the black pigment particle BG of the electrophoretic element P is negatively charged and the white pigment particle WG is positively charged. However, the black pigment particle BG is positive and the white pigment is positive. The particles WG may be negatively charged.

  DESCRIPTION OF SYMBOLS 2 ... Image forming apparatus, 4 ... Conveyance path, 6 ... Electronic paper, 7 ... Control part, 8 ... Paper feed tray, 10 ... Paper feed roller, 12 ... Feed Paper part, 14 ... EP sheet conveying part, 16 ... Image forming part, 18 ... Discharge part, 19 ... Protective sheet, 20 ... Protective sheet conveying part, 22 ... Common electrode 24... Ink ejection unit, 26... Ink collection unit, 26 a... Ink removal unit, 26 b... Ink storage unit, 28. DESCRIPTION OF SYMBOLS 30 ... Inclined member, 32 ... Paper discharge tray, 40 ... Guide plate, 42 ... Reset electrode, 44 ... Conveyance roller, 46 ... Conveyance driven roller, 50 ... Protection Sheet transport roller, 60... Carriage, 62... Ink cartridge, 64. Nkuheddo

Claims (4)

It has a sheet-type display element layer in which a plurality of electrophoretic elements are arranged in a plane, and the color displayed on the surface of the display element layer is displayed on the display surface side according to the direction of the electric field applied to each electrophoretic element Display medium conveying means for conveying the display medium sheet to be set to a preset printing position;
A common electrode arranged to face the back surface of the display medium sheet conveyed to the printing position;
When charged particles adhere to the surface, a sheet-like recording medium sheet in which a potential corresponding to the charge of the charged particles is transmitted to the back side is opposed to the display surface of the display medium sheet conveyed to the printing position. A recording medium conveying means for conveying;
Charged particle ejection means for ejecting charged particles onto the surface of the recording medium sheet conveyed to the printing position and disposed opposite the display medium sheet;
In a period in which the charged particle discharging means discharges charged particles, a common electrode control means for applying a predetermined potential to the common electrode;
The direction of the electric field applied to the electrophoretic element in the display medium sheet, the recording medium sheet having the charged particles discharged by the charged particle discharge means attached to the surface thereof, and the display medium sheet disposed opposite to the recording medium sheet An image forming apparatus comprising: a discharge conveyance unit that separates the two while conveying the two so as not to change. It has a sheet-type display element layer in which a plurality of electrophoretic elements are arranged in a plane, and the color displayed on the surface of the display element layer is displayed on the display surface side according to the direction of the electric field applied to each electrophoretic element Display medium conveying means for conveying the display medium sheet to be set to a preset printing position;
A common electrode arranged to face the back surface of the display medium sheet conveyed to the printing position;
When the charged particles adhere to the surface, an electric potential corresponding to the charge of the charged particles is transmitted to the back surface side. An annular recording medium sheet is formed at the printing position with the display surface of the display medium sheet and the back surface of the recording medium sheet. Recording medium transporting means for transporting annularly so as to face each other,
Charged particle ejection means for ejecting charged particles onto the surface of the recording medium conveyed to the printing position and disposed opposite the display medium sheet;
In a period in which the charged particle discharging means discharges charged particles, a common electrode control means for applying a predetermined potential to the common electrode;
Discharging means for transporting and discharging the display medium sheet away from a state of being opposed to the recording medium to which the charged particles are attached so that an electric field direction applied to an electrophoretic element of the display medium sheet is not changed; An image forming apparatus comprising:   Before the display medium sheet is conveyed to the printing position by the display medium conveying unit, all the electrophoresis of the display element layer is displayed so that the surface side of the display element layer of the display medium sheet is displayed in the same color. The image forming apparatus according to claim 1, further comprising a reset unit that applies an electric field corresponding to a color to be displayed on the surface side to the element. The recording medium conveying means includes a collecting means for collecting the charged particles discharged onto the recording medium after the recording medium sheet is separated from the display medium sheet from the state in which the recording medium sheet is opposed to the recording medium sheet.
The image forming apparatus according to claim 2, wherein the recording medium conveying unit conveys the recording medium sheet after the charged particles are collected by the collecting unit to the printing position.

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