JP2011164145A - Device and method for recording image to electronic paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the quality of an image recorded on electronic paper. <P>SOLUTION: Electronic paper which has charged color particles and displays an image, as a result of migration of the charged color particles in the thickness direction of the electronic paper is supplied, into a region in which an electric field is generated in the thickness direction. A voltage for generating an electric field in the region is controlled by a voltage control section for controlling the voltage so that the value of the voltage varies with time. Thus the quality of an image recorded on electronic paper can be improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image recording apparatus and an image recording method for electronic paper.

  There is an electronic paper image recording apparatus that records an image by applying a voltage to electronic paper that displays an image by controlling the position of charged colored particles (for example, Patent Document 1).

JP 2009-251048 A

With such an electronic paper image recording apparatus, an image can be recorded on the electronic paper, but the image quality of the image recorded on the electronic paper may be low.
Accordingly, an object of the present invention is to improve the image quality of an image recorded on electronic paper.

The main invention for solving the above problems is:
An image carrier for carrying a latent image;
A facing member facing the image carrier,
An electronic paper having colored charged particles and displaying the image by moving the colored charged particles in the thickness direction, and a supply unit for supplying the paper between the image carrier and the opposing member;
By applying a voltage to the facing member, an electric field is generated along the thickness direction therebetween, and the colored charged particles are moved in the thickness direction to display an image corresponding to the latent image on the electronic paper. A voltage applying unit to be
A voltage controller that controls the voltage applied to the opposing member such that the value of the voltage varies with time;
It is an image recording device to electronic paper characterized by having.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

1 is a cross-sectional view schematically showing a configuration of an electronic paper 100. FIG. It is the schematic diagram which showed the mode of the colored charged particle in an image part and a non-image part. It is the schematic which shows the structure of the image recording apparatus 1 to electronic paper. It is a block diagram which shows the structure of the image recording apparatus 1 to electronic paper. FIG. 5A is a diagram illustrating a state in which the colored charged particles start to move after the electric field is generated. FIG. 5B is a diagram illustrating an aggregation state of colored charged particles. FIG. 5C is a diagram for explaining the diffusion movement state of the colored charged particles. FIG. 5D is a diagram for explaining a state where the colored charged particles are released from the aggregated state. FIG. 5E is a diagram showing an ideal arrangement of colored charged particles. FIG. 6A is a diagram illustrating a voltage applied to the facing roller 52 during image recording. FIG. 6B is a diagram illustrating another example of the voltage applied to the facing roller 52 during image recording. FIG. 6C is a diagram illustrating a voltage applied to the facing roller 52 during image erasing. It is the schematic which shows the structure of another image recording device. It is the schematic which shows the structure of another image recording device. It is the figure which showed the other example (sine wave) of the voltage applied to the opposing roller. It is the figure which showed the other example (triangular wave) of the voltage applied to the opposing roller. FIG. 11A is a diagram illustrating another example (step wave) of a voltage applied to the facing roller 52 during image recording. FIG. 11B is a diagram illustrating another example (step wave) of the voltage applied to the facing roller 52 during image recording.

  At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

That is, an image carrier that carries a latent image;
A facing member facing the image carrier,
An electronic paper having colored charged particles and displaying the image by moving the colored charged particles in the thickness direction, and a supply unit for supplying the paper between the image carrier and the opposing member;
By applying a voltage to the facing member, an electric field is generated along the thickness direction therebetween, and the colored charged particles are moved in the thickness direction to display an image corresponding to the latent image on the electronic paper. A voltage applying unit to be
A voltage controller that controls the voltage applied to the opposing member such that the value of the voltage varies with time;
It is an image recording device to electronic paper characterized by having.
According to such an image recording apparatus for electronic paper, the image quality of an image recorded on the electronic paper can be improved.

An image recording apparatus for such electronic paper,
Of the potential in the image portion of the latent image and the potential in the non-image portion, the smaller one is V1, and the larger one is V2,
The voltage control unit may control the voltage so that a value of the voltage varies within a range of V1 or more and V2 or less.
According to such an image recording apparatus for electronic paper, the image quality of an image recorded on the electronic paper can be improved.

An image recording apparatus for such electronic paper,
The voltage control unit may control the voltage so that a value of the voltage becomes V1 or V2.
According to such an image recording apparatus for electronic paper, the image quality of an image recorded on the electronic paper can be further improved.

An image recording apparatus for such electronic paper,
The supply unit supplies the electronic paper on which an image is displayed in the middle,
The voltage application unit includes:
The electrons that generate an electric field along the thickness direction by applying a voltage to the counter member, move the colored charged particles in the thickness direction, and are supplied between the electrons by the supply unit to display an image. Erase the image on the paper,
The voltage controller is
Of the potential in the image portion of the latent image and the potential in the non-image portion, the smaller one is V1, and the larger one is V2,
The voltage may be controlled such that the voltage value fluctuates including at least one of a value greater than V2 and a value less than V1 and a value greater than or equal to V1 and less than or equal to V2.
According to such an electronic paper image recording apparatus, it is possible to appropriately erase the electronic paper image.

Further, an electronic paper having colored charged particles and displaying an image by moving the colored charged particles in the thickness direction is provided between an image carrier that carries a latent image and an opposing member that faces the image carrier. Supplying,
Applying a voltage to the opposing member, and controlling the voltage applied to the opposing member so that the value of the voltage varies with time,
By generating an electric field along the thickness direction during the period, and moving the colored charged particles in the thickness direction,
Displaying an image corresponding to the latent image on the electronic paper;
A method for recording an image on electronic paper.
According to such an image recording method on electronic paper, the image quality of an image recorded on electronic paper can be improved.

=== First Embodiment ===
In the following first embodiment, a configuration example of the image recording apparatus 1 that records an image on the electronic paper 100 will be described.
Note that the image recording apparatus 1 according to the present embodiment is a dedicated image recording apparatus having a function of recording an image on the electronic paper 100, or a function of recording an image on the electronic paper 100 and an image of the electronic paper 100. It can be used as an image recording and erasing apparatus having both the erasing function.
First, prior to the description of the image recording apparatus 1, the configuration of the electronic paper 100 will be described. Subsequently, the configuration of the image recording apparatus 1 will be described.

<<< Example of Configuration of Electronic Paper 100 >>>
A configuration example of the electronic paper 100 will be described with reference to FIGS. FIG. 1 is a cross-sectional view schematically showing the configuration of the electronic paper 100. FIG. 2 is a schematic diagram showing a state of colored charged particles in an image part and a non-image part.

  The electronic paper 100 has colored charged particles, and displays images by moving the colored charged particles in the thickness direction. In other words, the electronic paper 100 displays an image using electrophoresis of colored electrophoretic particles.

  As shown in FIG. 1, the electronic paper 100 according to this embodiment includes a display layer 103, an upper insulating layer 141 provided on the upper surface of the display layer 103, and a lower insulating provided on the lower surface of the display layer 103. A layer 142 and a sealing portion 107 are provided.

  In the electronic paper 100, the upper insulating layer 141 forms the display surface 121, and the display layer 103 is visually recognized through the upper insulating layer 141 so that an image can be recognized. In addition, the electronic paper 100 may be either flexible or non-flexible, but the electronic paper 100 according to the present embodiment has flexibility.

  The display layer 103 includes a microcapsule 131 and a binder 132 which are accommodation parts for positively charged white particles and negatively charged black particles as an example of colored charged particles, and a plurality of microcapsules 131 are fixed by the binder 132 ( Held). In addition, the plurality of microcapsules 131 are disposed as a single layer (one by one without overlapping in the thickness direction) so as to be arranged in the vertical and horizontal directions between the upper insulating layer 141 and the lower insulating layer 142. .

  Each microcapsule 131 has a capsule body 133 which is a shell, and the inside (internal space) is filled (enclosed) with an electrophoretic dispersion. The electrophoretic dispersion filled in the capsule body 133 is obtained by dispersing (suspending) positively charged white particles and negatively charged black particles in a liquid phase dispersion medium. For dispersion of positively charged white particles and negatively charged black particles in the liquid phase dispersion medium, one or more of paint shaker method, ball mill method, media mill method, ultrasonic dispersion method, stirring dispersion method and the like are used. Can be combined.

  Positively charged white particles are positively charged white electrophoretic particles, and negatively charged black particles are negatively charged black electrophoretic particles. As described above, by using the positively charged white particles and the negatively charged black particles, monochrome display on the electronic paper 100 is possible.

  In the present embodiment, the charge amount of the positively charged white particles is smaller than the charge amount of the negatively charged black particles (the positively charged white particles are slightly charged).

  As the positively charged white particles and the negatively charged black particles, any particles can be used as long as they have electric charges. Although not particularly limited, pigment particles, resin particles, or composite particles thereof can be used. At least one is preferably used.

  Examples of the pigment constituting the pigment particles include black pigments such as aniline black, carbon black, and titanium black, white pigments such as titanium oxide and antimony oxide, and one or more of these are combined. Can be used. Of these, titanium black is preferably used as negatively charged black particles and titanium oxide is preferably used as positively charged white particles (these are also used in this embodiment).

  Examples of the resin material constituting the resin particles include acrylic resin, urethane resin, urea resin, epoxy resin, polystyrene, polyester, and the like, and one or more of these are combined. Can be used.

  The composite particles include, for example, those in which the surface of the pigment particles is coated with a resin material or other pigment, those in which the surface of the resin particles is coated with a pigment, or a mixture in which the pigment and the resin material are mixed at an appropriate composition ratio. And particles composed of Examples of particles obtained by coating the surface of pigment particles with other pigments include those obtained by coating the surface of titanium oxide particles with silicon oxide or aluminum oxide.

  Regarding positively charged white particles and negatively charged black particles, smaller particles are preferably used in consideration of dispersibility in a liquid phase dispersion medium. Specifically, the average particle size is preferably about 10 to 500 nm, and more preferably about 20 to 300 nm. By setting the average particle diameter of the positively charged white particles and the negatively charged black particles in the above range, aggregation of the positively charged white particles and the negatively charged black particles and sedimentation of the positively charged white particles and the negatively charged black particles can be prevented. The positively charged white particles and the negatively charged black particles can be maintained in the liquid phase dispersion medium.

  Then, when such positively charged white particles and negatively charged black particles move in the thickness direction of the electronic paper 100 within the microcapsule 131, an image is displayed.

  That is, although details will be described later, in a portion (that is, a black image portion) where an image is desired to be displayed on the electronic paper 100, the negatively charged black particles are on the upper insulating layer 141 (display surface 121) side in the thickness direction. The positively charged white particles respectively move to the lower insulating layer 142 side (see the left diagram in FIG. 2), and are positively charged at the portion where the image is not desired to be displayed (that is, the white image portion (white background portion)). The movement of the particles is such that the white particles move to the upper insulating layer 141 (display surface 121) side in the thickness direction, and the negatively charged black particles move to the lower insulating layer 142 side (see the right diagram in FIG. 2). By being controlled, monochrome display on the electronic paper 100 is performed. The movement control of the particles causes the image recording apparatus 1 to generate an electric field along the thickness direction, and the direction of the electric field is downward (the direction from the upper insulating layer 141 toward the lower insulating layer 142) in the former part. 2) (see the left diagram in FIG. 2), and in the latter part, the direction of the electric field is upward (the direction from the lower insulating layer 142 toward the upper insulating layer 141) (see the right diagram in FIG. 2). It will be realized by controlling the direction of.

  The specific gravity of the positively charged white particles and the negatively charged black particles is preferably set to be approximately equal to the specific gravity of the liquid phase dispersion medium. Thereby, the positively charged white particles and the negatively charged black particles can stay in a certain position in the liquid phase dispersion medium for a long time even after being subjected to the action of an electric field.

  The binder 132 is supplied, for example, for the purpose of bonding the upper insulating layer 141 and the lower insulating layer 142, and for fixing each microcapsule 131 between the upper insulating layer 141 and the lower insulating layer 142. For the binder 132, a resin material that is excellent in affinity (adhesion) with the upper insulating layer 141, the lower insulating layer 142, and the capsule body 133 and that has excellent insulating properties is preferably used.

  Each of the upper insulating layer 141 and the lower insulating layer 142 disposed to face each other with the display layer 103 interposed therebetween is configured by a sheet-like (flat plate) member having insulation properties. Such an upper insulating layer 141 and a lower insulating layer 142 have a function of protecting the display layer 103 (microcapsule 131).

  The upper insulating layer 141 is light transmissive in order to form the display surface 121, that is, substantially transparent (colorless transparent, colored transparent, or translucent). Thereby, the state of the display layer 103 (the state of positively charged white particles and negatively charged black particles in each microcapsule 131), that is, the image (information) displayed on the electronic paper 100 is visually recognized from the display surface 121 side. can do. On the other hand, the lower insulating layer 142 may or may not be light transmissive as in the upper insulating layer 141 (in this embodiment, the lower insulating layer 142 is substantially opaque).

  The sealing unit 107 is for preventing moisture from entering the electronic paper 100 and suppressing deterioration in display performance of the electronic paper 100. The sealing portion 107 is provided between the upper insulating layer 141 and the lower insulating layer 142 so as to be along the edge portions thereof. The sealing layer 107 hermetically seals the display layer 103.

<<< Example of Configuration of Image Recording Apparatus 1 >>>
Next, a configuration example of the image recording apparatus 1 will be described with reference to FIGS. 3 and 4. FIG. 3 is a schematic sectional view of the image recording apparatus 1. FIG. 4 is a block diagram of the image recording apparatus 1.

  As shown in FIG. 3, the image recording apparatus 1 according to the present embodiment includes a charging unit 30, an exposure unit 40, and an electric field along the rotation direction of a photoconductor 20 as an example of an image carrier that carries a latent image. A generation unit 50 (opposite roller 52 as an example of an opposing member), a transport unit 60 as an example of a supply unit, and a controller that controls these units and the like and operates as the image recording apparatus 1 80.

  The photoconductor 20 has a metal cylindrical conductive substrate and a resin-made photosensitive layer formed on the outer peripheral surface thereof for holding static electricity. The photoconductor 20 is rotatable about a central axis, and in the present embodiment, rotates in the clockwise direction as indicated by an arrow in FIG.

  The charging unit 30 is for charging the photoconductor 20. The charging unit 30 includes a charging roller 30a. In the present embodiment, the charging roller 30a charges the photoconductor 20 to V1 = −500 volts.

  The exposure unit 40 forms a latent image on the charged photoreceptor 20 by irradiating a laser. The exposure unit 40 includes a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and charges a modulated laser based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. The irradiated photoconductor 20 is irradiated. In the present embodiment, a laser is irradiated to a portion corresponding to the former of the image portion and the non-image portion (background portion) of the latent image (in this section, it corresponds to the black image portion in the electronic paper 100). The portion on the photoconductor 20 is called an image portion, and the portion on the photoconductor 20 corresponding to the white image portion (white background portion) is called a non-image portion (background portion)). V1 = −500 volts to V2 = −50 volts (a latent image having an image portion of V2 = −50 volts and a non-image portion (background portion) of V1 = −500 volts is obtained).

  The electric field generating unit 50 is for generating an electric field in the thickness direction of the electronic paper 100 and moving the positively charged white particles and the negatively charged black particles of the electronic paper 100 in the thickness direction. The electric field generation unit 50 includes a counter roller 52 and a voltage application unit 54 (see FIG. 4).

  The facing roller 52 is a rotatable roller that faces the photoconductor 20. When the electronic paper 100 is positioned between the photoconductor 20 and the counter roller 52, the counter roller 52 cooperates with the photoconductor 20 and presses the electronic paper 100 between them (in other words, photosensitivity). The body 20 and the opposing roller 52 are in pressure contact with each other with the electronic paper 100 interposed therebetween at the nip portion), and rotate in a direction opposite to the rotation direction as the photoconductor 20 rotates. The contact portion of the opposing roller 52 that comes into contact with the photoreceptor 20 via the electronic paper 100 is made of rubber.

  The voltage application unit 54 applies a voltage to the opposing roller 52 when the electronic paper 100 is positioned therebetween (that is, the opposing roller 52 has a function as a voltage application unit). This generates an electric field along the thickness direction of the electronic paper 100 between the photoconductor 20 and the opposing roller 52, and moves the positively charged white particles and the negatively charged black particles of the electronic paper 100 in the thickness direction. .

  The voltage application unit 54 applies different voltages when recording an image and when erasing the image. That is, during image recording, positively charged white particles and negatively charged black particles move so that an image corresponding to the latent image is displayed on the electronic paper 100, and during image erasure, positively charged white particles and negatively charged particles are displayed. A voltage is applied so that the charged black particles move and the image of the electronic paper 100 displaying the image is erased. The specific voltage to be applied will be described in detail later.

  The transport unit 60 is for transporting the electronic paper 100. The transport unit 60 includes a paper cassette 62, a paper feed roller 64 positioned above the paper cassette 62, a transport roller 66 positioned on the photoconductor 20 side when viewed from the paper feed roller 64, and paper discharge (not shown). And a roller. The paper feed roller 64 is a roller for feeding the electronic paper 100 accommodated in the paper cassette 62. The transport roller 66 is a roller that transports the electronic paper 100 fed by the paper feed roller 64 between the photoconductor 20 and the opposing roller 52. The paper discharge roller is a roller for discharging the electronic paper 100 on which an image is displayed or erased from the image recording apparatus 1. These rollers are driven by a motor (not shown).

  The controller 80 is a control unit (control unit) for controlling the image recording apparatus 1. The controller 80 includes an interface unit 81, a CPU 82, a memory 83, and a unit control circuit 84. The controller 80 also functions as a voltage control unit that controls the voltage applied to the opposing roller 52.

  The interface unit 81 transmits and receives data between the host computer which is an external device and the image recording apparatus 1. The CPU 82 is an arithmetic processing unit for controlling the entire image recording apparatus 1. The memory 83 is for securing an area for storing a program of the CPU 82, a work area, and the like, and includes storage elements such as a RAM and an EEPROM. The CPU 82 controls each unit via the unit control circuit 84 in accordance with a program stored in the memory 83.

<<< Aggregation of Positively Charged White Particles and Negatively Charged Black Particles >>>
As described above, when an electric field along the thickness direction of the electronic paper 100 is generated, the positively charged white particles and the negatively charged black particles move in the microcapsule 131, thereby displaying an image.
In order to generate an electric field along the thickness direction, a DC voltage is conventionally applied to the counter roller 52.
Here, when a black image is displayed on the electronic paper 100, when a DC voltage is applied to the opposing roller 52 and an electric field along the thickness direction of the electronic paper 100 is generated upward, When the positively charged white particles move upward and the negatively charged black particles move downward (see FIG. 5A), a white image is displayed (see FIG. 5E).
At this time, when a DC voltage is applied as in the prior art, the electric field in the thickness direction does not change with time, and the negatively charged black particles that should have moved downward are moved to the positively charged white particles group that has moved upward. A state occurs in which it is surrounded and cannot be removed (see FIG. 5B). In such an agglomerated state, a black portion is mixed with a portion where a white image is to be displayed, and a clear white image is not displayed.

In order to eliminate such deterioration in image quality, during image recording, the voltage application unit 54 applies a voltage obtained by superimposing an AC voltage on a DC voltage to the opposing roller 52, and the controller 80 controls the voltage to control the electronic voltage. The electric field generated along the thickness direction of the paper 100 is temporarily weakened (see FIG. 6A, details will be described later). Thereby, the state of aggregation of particles as shown in FIG. 5C is relaxed from the state of aggregation shown in FIG. 5B, and after the state where particles have escaped from the state of aggregation as shown in FIG. 5D, the ideal shown in FIG. Therefore, it is possible to improve the image quality during image recording.
Hereinafter, an example of the operation at the time of image recording will be specifically described.

<<< Example of operation during image recording >>>
An example of the operation of the image recording apparatus 1 during image recording will be described with reference to FIGS. 2 and 6A. FIG. 6A is a diagram illustrating a voltage applied to the facing roller 52 when an image is recorded. The voltage applied to the facing roller 52 is a voltage obtained by superimposing an AC voltage on a DC voltage, and the value of the superimposed voltage varies with time.

  Here, the AC voltage means a voltage whose magnitude and direction periodically change with time, and the waveform shape does not matter (for example, any of sine wave, rectangular wave, triangular wave, sawtooth wave, etc.) Including the concept). In the present embodiment, a voltage in which rectangular waves are superimposed as shown in FIG. 6 is applied. The period of the superimposed voltage (rectangular wave) is 10 msec.

  Note that various operations of the image recording apparatus 1 during image recording are mainly realized by the controller 80. In particular, this embodiment is realized by the CPU 82 processing a program stored in the memory 83. And this program is comprised from the code | cord | chord for performing the various operation | movement demonstrated below.

  When an image signal and a control signal from the host computer are input to the controller 80 via the interface unit 81, the photoconductor 20 rotates under the control of the unit controller 84. Note that the paper cassette 62 contains the electronic paper 100 on which no image is displayed.

  The photoconductor 20 is sequentially charged to V1 = −500 volts by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image is formed in the area by the exposure unit 40. That is, if the area corresponds to the image portion of the latent image, the area is irradiated with laser. As a result, a latent image having an image portion of V2 = −50 volts and a non-image portion (background portion) of V1 = −500 volts is formed on the photoreceptor 20.

  The latent image formed on the photoconductor 20 reaches a position facing the counter roller 52 as the photoconductor 20 rotates. On the other hand, the electronic paper 100 is transported between the photosensitive member 20 (in other words, a latent image) and the opposing roller 52 by the transport unit 60, and is positioned therebetween. Then, with the electronic paper 100 positioned therebetween, a voltage is applied to the counter roller 52 by the voltage application unit 54, and an electric field along the thickness direction of the electronic paper 100 is generated therebetween. Thus, an image corresponding to the latent image is displayed on the electronic paper.

  Specifically, as shown in FIG. 6A, the voltage application unit 54 supplies the counter roller 52 with the smaller one of the potential in the image portion and the potential in the non-image portion (in this embodiment, V1 (−500) volts. ) Above, a voltage whose value fluctuates within the range of the larger one (V2 (−50) volts in this embodiment) or less is applied. That is, when the voltage shown in FIG. 6A is applied to the opposing roller 52, the value of the voltage applied to the opposing roller 52 varies within a range between V1 and V2 with the passage of time.

  In the period T1, when the image portion of the latent image is located at the facing position, when the application is made, the photosensitive member 20 side (upper side) is VL = -50 volts (V2 volts), and the opposing roller 52 side ( Since VT = −400 volts on the lower side, as shown in the left diagram of FIG. 2, an electric field is generated downward (in the direction from the upper insulating layer 141 to the lower insulating layer 142 of the electronic paper 100). Then, the negatively charged black particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side and the positively charged white particles move to the lower insulating layer 142 side by the action of the electric field.

  Next, in the period T2, when the image portion of the latent image continues to exist at the facing position and the application is performed, the photosensitive member 20 side (upper side) has VL = −50 volts (V2 volts) and the facing roller. Since VT = −150 volts on the 52 side (lower side), as shown in the left diagram of FIG. 2, the downward electric field (direction from the upper insulating layer 141 toward the lower insulating layer 142 of the electronic paper 100) appear. Then, the negatively charged black particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side and the positively charged white particles move to the lower insulating layer 142 side by the action of the electric field.

  Here, regarding the image portion of the latent image, when comparing the electric field in the period T1 and the electric field in the period T2, the directions of the electric fields are both the same direction, and the magnitude of the electric field in the period T1 is larger than that in the period T2. That is, the electric field is weaker in the period T2 than in the period T1. Then, in the period T2, the movement of the negatively charged black particles moving upward in the period T1 becomes dull, and the negatively charged black particles are affected by the interparticle repulsion with other particles. Similarly, the positively charged white particles also move downward while being affected by the repulsive force between particles. For this reason, each particle moves while diffusing. Therefore, the aggregation state of the positively charged white particles and the negatively charged black particles is relaxed.

  In this way, positively charged white particles that would normally move downward are moved upward by periodically repeating the strength of the electric field in a short time during which the image portion of the latent image exists at the opposite position. The state where the negatively charged black particle group that has moved is surrounded by the group of negatively charged black particles and cannot be removed is eliminated. As a result, only the positively charged white particles move downward and only the negatively charged black particles move upward. Therefore, the portion located between the electronic paper 100 does not include a white portion. A black image is displayed (the part becomes a black image portion).

  On the other hand, when the non-image portion of the latent image is positioned at the facing position in the period T1, when the application is performed, the photosensitive member 20 side (upper side) is V0 = −500 volts (V1 volts), and the facing roller. Since VT = −400 volts on the 52 side (lower side), as shown in the right diagram of FIG. 2, the electric field upward (direction toward the upper insulating layer 141 from the lower insulating layer 142 of the electronic paper 100) is appear. Then, due to the action of the electric field, positively charged white particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side, and negatively charged black particles move to the lower insulating layer 142 side.

  Next, in the period T2, the non-image portion of the latent image continues to exist at the facing position, and when the application is performed, the photoconductor 20 side (upper side) is V0 = −500 volts (V1 volts) and facing. Since VT = −150 volts on the roller 52 side (lower side), as shown in the right diagram of FIG. 2, the electric field is upward (direction toward the upper insulating layer 141 from the lower insulating layer 142 of the electronic paper 100). Will occur. Then, due to the action of the electric field, positively charged white particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side, and negatively charged black particles move to the lower insulating layer 142 side.

  Here, when the electric field in the period T1 and the electric field in the period T2 are compared with respect to the non-image portion of the latent image, the directions of the electric fields are the same, but the magnitude of the electric field in the period T1 is smaller than that in the period T2. . That is, the electric field is stronger in the period T2 than in the period T1. Then, in the period T2, the negatively charged black particles that have been able to escape from the aggregation state due to the weak electric field in the period T1 move downward without being affected by the interparticle repulsion with other particles. . Similarly, the positively charged white particle group also moves upward without surrounding the negatively charged black particle.

  In this way, the negatively charged black particles that would otherwise move downward are directed upward by periodically repeating the strength of the electric field in a short time when the non-image portion of the latent image exists at the facing position. The state of being surrounded by the positively charged white particle group that has moved to the point of being unable to escape is eliminated. As a result, only the negatively charged black particles move downward, and only the positively charged white particles move upward. Therefore, the portion located between the electronic paper 100 does not include a black portion. A white image is displayed (the portion becomes a white image portion (white background portion)).

  Therefore, when the image portion of the latent image is located at the facing position, a black image is displayed on the electronic paper 100, and when the non-image portion is located at the facing position, a white image is displayed on the electronic paper 100. Therefore, the latent image having the image portion and the non-image portion is transferred (copied) to the electronic paper 100.

  As described above, in the present exemplary embodiment, the voltage application unit 54 applies a voltage to the counter roller 52 to generate an electric field along the thickness direction between the photoconductor 20 and the counter roller 52, so that colored charging is performed. The image corresponding to the latent image is displayed on the electronic paper 100 by moving the particles in the thickness direction. That is, the controller 80 (voltage control unit) controls the voltage so that the value of the voltage applied to the facing roller 52 varies with time. Thus, the controller 80 controls the magnitude of the electric field generated between the image portion of the photoconductor and the opposing roller 52 to display a black and white image corresponding to the latent image on the electronic paper 100.

  And the operation | movement for displaying the image mentioned above is performed continuously. That is, the electronic paper 100 is transported by the transport unit 60, and different portions of the electronic paper 100 are sequentially fed into the space (nip part). On the other hand, different portions of the photoconductor 20 on which the latent image is formed are sequentially fed into the space (the facing position) by the rotation of the photoconductor 20. In the meantime, images corresponding to the latent images are sequentially displayed on the portions of the electronic paper 100 (latent images are sequentially transferred to the electronic paper 100).

  The electronic paper 100 on which image display (transfer) is completed is discharged from the image recording apparatus 1 by a discharge roller.

=== Second Embodiment ===
In the following second embodiment, another embodiment of the image recording apparatus 1 that records an image on the electronic paper 100 having the configuration described in detail above will be described.

  The configuration of the image recording apparatus 1 according to the present embodiment is the same as the configuration of the image recording apparatus 1 detailed in the first embodiment.

  Further, the image recording apparatus 1 according to the present embodiment can be used as an image recording dedicated apparatus or an image recording erasing apparatus as in the first embodiment.

  As already described, when the particles in the microcapsules of the electronic paper 100 are in an agglomerated state (see FIG. 5B), a black portion is mixed with a portion where a white image is to be displayed, and a clear white image is not displayed.

In order to eliminate such deterioration in image quality, during image recording, the voltage application unit 54 applies a voltage obtained by superimposing an AC voltage on a DC voltage to the opposing roller 52, and the controller 80 controls the voltage to control the electronic voltage. The electric field generated along the thickness direction of the paper 100 is temporarily extinguished (see FIG. 6B, details will be described later). Thereby, the state of aggregation of particles as shown in FIG. 5C is relaxed from the state of aggregation shown in FIG. 5B, and after the state where particles have escaped from the state of aggregation as shown in FIG. 5D, the ideal shown in FIG. Therefore, it is possible to improve the image quality during image recording.
Hereinafter, an example of the operation at the time of image recording will be specifically described.

<<< Example of operation during image recording >>>
An example of the operation of the image recording apparatus 1 in the present embodiment during image recording will be described with reference to FIGS. 2 and 6B. FIG. 6B is a diagram illustrating a voltage applied to the facing roller 52 when an image is recorded. The voltage applied to the facing roller 52 is a voltage obtained by superimposing an AC voltage on a DC voltage, and the value of the superimposed voltage varies with time.

  Here, the AC voltage means a voltage whose magnitude and direction periodically change with time, and the waveform shape does not matter (for example, any of sine wave, rectangular wave, triangular wave, sawtooth wave, etc.) Including the concept). In the present embodiment, a voltage in which rectangular waves are superimposed as shown in FIG. 6 is applied. The period of the superimposed voltage (rectangular wave) is 10 msec.

  Note that various operations of the image recording apparatus 1 during image recording are mainly realized by the controller 80. In particular, this embodiment is realized by the CPU 82 processing a program stored in the memory 83. And this program is comprised from the code | cord | chord for performing the various operation | movement demonstrated below.

  When an image signal and a control signal from the host computer are input to the controller 80 via the interface unit 81, the photoconductor 20 rotates under the control of the unit controller 84. Note that the paper cassette 62 contains the electronic paper 100 on which no image is displayed.

  The photoconductor 20 is sequentially charged to V1 = −500 volts by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image is formed in the area by the exposure unit 40. That is, if the area corresponds to the image portion of the latent image, the area is irradiated with laser. As a result, a latent image having an image portion of V2 = −50 volts and a non-image portion (background portion) of V1 = −500 volts is formed on the photoreceptor 20.

  The latent image formed on the photoconductor 20 reaches a position facing the counter roller 52 as the photoconductor 20 rotates. On the other hand, the electronic paper 100 is transported between the photosensitive member 20 (in other words, a latent image) and the opposing roller 52 by the transport unit 60, and is positioned therebetween. Then, with the electronic paper 100 positioned therebetween, a voltage is applied to the counter roller 52 by the voltage application unit 54, and an electric field along the thickness direction of the electronic paper 100 is generated therebetween. Thus, an image corresponding to the latent image is displayed on the electronic paper.

  Specifically, as shown in FIG. 6B, the voltage application unit 54 supplies the counter roller 52 with the smaller one of the potential in the image portion and the potential in the non-image portion (in this embodiment, V1 (−500) volts. ) Above, a voltage whose value fluctuates within the range of the larger one (V2 (−50) volts in this embodiment) or less, and a voltage such that the value becomes V1 or V2 is applied.

  That is, when the voltage shown in FIG. 6B is applied to the counter roller 52, a voltage that periodically sets the electric field generated between the counter roller 52 and the photoconductor 20 to zero is applied to the counter roller 52.

  In the period T1, when the image portion of the latent image is located at the facing position, when the application is made, the photosensitive member 20 side (upper side) is VL = -50 volts (V2 volts), and the opposing roller 52 side ( Since VT = −500 volts on the lower side, as shown in the left diagram of FIG. 2, a downward electric field (a direction from the upper insulating layer 141 toward the lower insulating layer 142 of the electronic paper 100) is generated. Then, the negatively charged black particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side and the positively charged white particles move to the lower insulating layer 142 side by the action of the electric field.

  Next, in the period T2, when the image portion of the latent image continues to exist at the facing position and the application is performed, the photosensitive member 20 side (upper side) has VL = −50 volts (V2 volts) and the facing roller. On the 52 side (lower side), since VT = −50 volts, no electric field is generated (zero electric field). Therefore, neither the negatively charged black particles nor the positively charged white particles in the electronic paper 100 are affected by the electric field, so that the movement in each direction is interrupted.

  Here, regarding the image portion of the latent image, when the electric field in the period T1 is compared with the electric field in the period T2, an electric field is generated in the period T1, but no electric field is generated in the period T2. That is, in the period T2, the electric field in the period T1 disappears. Then, in the period T2, there is no momentum in the movement of the negatively charged black particles that have moved upward in the period T1, and the negatively charged black particles are affected by the interparticle repulsion with other particles. Similarly, the positively charged white particles are also affected by the repulsive force between the particles, and the downward movement is interrupted. For this reason, each particle moves while being more diffused. Therefore, the aggregation state of the positively charged white particles and the negatively charged black particles is relaxed.

  In this way, the presence or absence of an electric field is periodically repeated in a short time when the image portion of the latent image exists at the facing position, so that positively charged white particles that should have moved downward are normally upward. The state where the negatively charged black particle group that has moved is surrounded by the group of negatively charged black particles and cannot be removed is eliminated. As a result, only the positively charged white particles move downward and only the negatively charged black particles move upward. Therefore, the portion located between the electronic paper 100 does not include a white portion. A black image is displayed (the part becomes a black image portion).

  Applying the voltage shown in FIG. 6B to the counter roller 52 can completely extinguish the electric field by reducing the magnitude of the electric field to zero rather than weakening the electric field by reducing the magnitude of the electric field. Enclosed particles can escape more easily. Therefore, as compared with applying the voltage shown in FIG. 6A, the effect of eliminating the state of being surrounded and unable to escape is remarkable.

  On the other hand, when the non-image portion of the latent image is positioned at the facing position in the period T1, when the application is performed, the photosensitive member 20 side (upper side) is V0 = −500 volts (V1 volts), and the facing roller. Since the 52 side (lower side) is also VT = −500 volts, no electric field is generated.

  Next, in the period T2, the non-image portion of the latent image continues to exist at the facing position, and when the application is performed, the photoconductor 20 side (upper side) is V0 = −500 volts (V1 volts) and facing. Since VT = −50 volts on the roller 52 side (lower side), as shown in the right diagram of FIG. 2, the electric field is upward (direction toward the upper insulating layer 141 from the lower insulating layer 142 of the electronic paper 100). Will occur. Then, due to the action of the electric field, positively charged white particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side, and negatively charged black particles move to the lower insulating layer 142 side.

  Here, regarding the non-image portion of the latent image, when the electric field in the period T1 is compared with the electric field in the period T2, no electric field is generated in the period T1, but an electric field is generated in the period T2. That is, the electric field is stronger in the period T2 than in the period T1. Then, in the period T2, the negatively charged black particles that have been able to escape from the aggregated state due to the disappearance of the electric field in the period T1 move downward without being affected by the interparticle repulsion with other particles. . Similarly, the positively charged white particle group also moves upward without surrounding the negatively charged black particle.

  In this way, the negatively charged black particles that would otherwise move downward are upwardly generated by periodically repeating the presence / absence of an electric field in a short time during which the non-image portion of the latent image exists at the opposite position. The state of being surrounded by the positively charged white particle group that has moved to the point of being unable to escape is eliminated. As a result, only the negatively charged black particles move downward, and only the positively charged white particles move upward. Therefore, the portion located between the electronic paper 100 does not include a black portion. A white image is displayed (the portion becomes a white image portion (white background portion)).

  Therefore, when the image portion of the latent image is located at the facing position, the electronic paper 100 displays a black image, and when the non-image portion is located at the facing position, the electronic paper 100 displays a white image. Therefore, the latent image having the image portion and the non-image portion is transferred (copied) to the electronic paper 100.

  As described above, in the present exemplary embodiment, the voltage application unit 54 applies a voltage to the counter roller 52 to generate an electric field along the thickness direction between the photoconductor 20 and the counter roller 52, so that colored charging is performed. The image corresponding to the latent image is displayed on the electronic paper 100 by moving the particles in the thickness direction. That is, the controller 80 (voltage control unit) controls the voltage so that the value of the voltage applied to the facing roller 52 varies with time. Thus, the controller 80 controls the electronic paper 100 to display a black and white image corresponding to the latent image by controlling the presence or absence of an electric field generated between the image portion of the photoreceptor and the counter roller 52.

  And the operation | movement for displaying the image mentioned above is performed continuously. That is, the electronic paper 100 is transported by the transport unit 60, and different portions of the electronic paper 100 are sequentially fed into the space (nip part). On the other hand, different portions of the photoconductor 20 on which the latent image is formed are sequentially fed into the space (the facing position) by the rotation of the photoconductor 20. In the meantime, images corresponding to the latent images are sequentially displayed on the portions of the electronic paper 100 (latent images are sequentially transferred to the electronic paper 100).

  The electronic paper 100 on which image display (transfer) is completed is discharged from the image recording apparatus 1 by a discharge roller.

=== Third Embodiment ===
The image recording apparatus 1 according to the first and second embodiments can have not only a function of recording an image on the electronic paper 100 but also a function of erasing the image of the electronic paper 100. This will be specifically described below.

<<< About the afterimage of electronic paper when erasing images >>>
As described above, the image recording apparatus 1 according to the first and second embodiments can record an image on the electronic paper 100 as a result of executing the image recording operation.

  On the other hand, when confidential information is displayed on the image recorded on the electronic paper in this way, the user wants to delete the confidential information so that the confidential information is not leaked (at this time) It is no longer necessary to display the confidential matter on the electronic paper 100).

  Here, when an image already recorded on electronic paper is to be erased, conventionally, an erasing method has been adopted in which the electronic paper is a blank sheet.

  In this erasing method, all the parts of the electronic paper are uniformly made to be a white image portion. Therefore, when the white paper is insufficient, an already recorded image (image to be erased) remains thin ( (Afterimage of the image to be erased may appear) (Naturally, if all the parts of the electronic paper are made to be a black image portion instead of a white image portion (for convenience, it is made black paper) Also, afterimage may appear if the black paper is insufficient. In such a case, confidential matters are leaked.

  In order to prevent leakage of such confidential matters, the voltage application unit 54 applies a voltage obtained by superimposing an AC voltage on a DC voltage to the opposing roller 52 at the time of erasing the image, and the controller 80 controls this voltage. The direction of the electric field generated along the thickness direction of the electronic paper 100 is reversed (details will be described later). As a result, an image to be erased is overwritten by a repetition of a black image and a white image, so it is appropriate that the image to be erased remains thin (an afterimage of the image to be erased appears). Will be deterred. That is, according to the image recording apparatus 1 according to the present embodiment, the image on the electronic paper 100 is appropriately erased (the purpose of preventing leakage of confidential matters can also be properly achieved). Hereinafter, an example of the operation at the time of erasing an image will be specifically described.

<<< Example of operation when deleting images >>>
An example of the operation of the image recording apparatus 1 when erasing an image will be described with reference to FIGS. 2 and 6C. FIG. 6C is a diagram illustrating a voltage applied to the facing roller 52 when an image is erased. The voltage applied to the facing roller 52 is a voltage obtained by superimposing an AC voltage on a DC voltage, and the value of the superimposed voltage varies with time.

  Here, the AC voltage means a voltage whose magnitude and direction periodically change with time, and the waveform shape does not matter (for example, any of sine wave, rectangular wave, triangular wave, sawtooth wave, etc.) Including the concept). In the present embodiment, a voltage in which rectangular waves are superimposed as shown in FIG. 6C is applied. The period of the superimposed voltage (rectangular wave) is 10 msec.

  When an image signal and a control signal from the host computer are input to the controller 80 via the interface unit 81, the photoconductor 20 rotates under the control of the unit controller 84. Note that the paper cassette 62 accommodates the electronic paper 100 displaying an image (an erasure target recorded in advance by the above-described image recording).

  The photoconductor 20 is sequentially charged to V1 = −500 volts by the charging unit 30 at the charging position while rotating.

  The charged area of the photoconductor 20 reaches an exposure position as the photoconductor 20 rotates, and a latent image is formed in the area by the exposure unit 40. That is, if the area corresponds to the image portion of the latent image, the area is irradiated with laser. As a result, a latent image having an image portion of V2 = −50 volts and a non-image portion (background portion) of V1 = −500 volts is formed on the photoreceptor 20.

  The charged portion on the photoconductor 20 reaches a position facing the counter roller 62 as the photoconductor 20 rotates. On the other hand, the electronic paper 100 is transported between the photosensitive member 20 (a charged portion on the photosensitive member 20) and the counter roller 60 by the transport unit 60, and is positioned therebetween. Then, with the electronic paper 100 positioned therebetween, a voltage is applied to the counter roller 52 by the voltage application unit 54, and an electric field along the thickness direction of the electronic paper 100 is generated therebetween. As a result, the image of the electronic paper 100 conveyed in the meantime is erased from the electronic paper 100.

  Specifically, as shown in FIG. 6C, the voltage application unit 54 supplies the counter roller 52 with the smaller one of the potential in the image portion and the potential in the non-image portion (in this embodiment, V1 (−500) volts. ) A voltage that fluctuates so as to include at least one of a smaller value and a larger value (in this embodiment, V2 (−50) volts) and a value not less than V1 and not more than V2 is applied. To do. That is, the voltage application unit 54 applies a voltage that periodically inverts the direction of the electric field generated between the counter roller 52 and the photoconductor 20.

  In the period T1, when the image portion of the latent image is located at the facing position, when the application is made, the photosensitive member 20 side (upper side) is VL = -50 volts (V2 volts), and the opposing roller 52 side ( Since VT = −600 volts on the lower side, as shown in the left diagram of FIG. 2, an electric field is generated downward (in the direction from the upper insulating layer 141 to the lower insulating layer 142 of the electronic paper 100). Then, due to the action of the electric field, the negatively charged black particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side, and the positively charged white particles move to the lower insulating layer 142 side. A black image will be displayed at a portion located between 100 (the portion becomes a black image portion).

  Next, in the period T2, when the image portion of the latent image continues to exist at the facing position and the application is performed, the photosensitive member 20 side (upper side) has VL = −50 volts (V2 volts) and the facing roller. Since VT = 50 volts on the 52 side (lower side), as shown in the left diagram of FIG. 2, an upward electric field (direction toward the upper insulating layer 141 from the lower insulating layer 142 of the electronic paper 100) is generated. To do. Then, due to the action of the electric field, the negatively charged black particles in the electronic paper 100 move to the lower insulating layer 142 side, and the positively charged white particles move to the upper insulating layer 141 (display surface 121) side. A white image will be displayed at a portion located between 100 (the portion becomes a white image portion (white background portion)).

  On the other hand, when the non-image portion of the latent image is positioned at the facing position in the period T1, when the application is performed, VL = −500 volts (V1 volts) on the photosensitive member 20 side (upper side), the facing roller Since VT = −600 volts on the 52 side (lower side), as shown in the left diagram of FIG. 2, the downward electric field (direction from the upper insulating layer 141 toward the lower insulating layer 142 of the electronic paper 100) appear. Then, due to the action of the electric field, the negatively charged black particles in the electronic paper 100 move to the upper insulating layer 141 (display surface 121) side, and the positively charged white particles move to the lower insulating layer 142 side. A black image will be displayed at a portion located between 100 (the portion becomes a black image portion).

  Next, in the period T2, the non-image portion of the latent image continues to exist at the facing position, and when the application is performed, the photoreceptor 20 side (upper side) is VL = −500, and the opposing roller 52 side (lower side). VT = 50 volts, an electric field is generated upward (in the direction from the lower insulating layer 142 to the upper insulating layer 141 of the electronic paper 100) as shown in the right diagram of FIG. Then, due to the action of the electric field, the negatively charged black particles in the electronic paper 100 move to the lower insulating layer 142 side, and the positively charged white particles move to the upper insulating layer 141 (display surface 121) side. A white image will be displayed at a portion located between 100 (the portion becomes a white image portion (white background portion)).

  That is, in the period T1, the electronic paper 100 displays a black image when the electric field direction is downward, and in the period T2, the electronic paper 100 displays a black image when the electric field direction is upward. Then, since the voltage value repeats 50 volts and −600 volts by the application of the alternating voltage, the electronic paper 100 is a newly displayed image in which a black image and a white image are repeated and displayed. (The image to be erased) will be erased (that is, a repeated black image and white image will overwrite the image to be erased).

  As described above, in the present embodiment, the controller 80 controls the voltage applied to the opposing roller 52 so as to change the direction of the electric field in the thickness direction of the electronic paper 100 with time. The image of the electronic paper 100 conveyed in the thickness direction is erased by moving in the thickness direction. As a result, an image to be erased is overwritten by a repetition of a black image and a white image, so it is appropriate that the image to be erased remains thin (an afterimage of the image to be erased appears). Will be deterred.

  Then, the above-described operation for deleting the image is continuously executed. That is, the electronic paper 100 is transported by the transport unit 60, and different portions of the electronic paper 100 on which an image to be erased is displayed are sequentially fed into the space (nip portion). On the other hand, different portions of the charged photoconductor 20 are sequentially fed into the space (the opposed position) by the rotation of the photoconductor 20. In the meantime, images are sequentially erased from the portion of the electronic paper 100 (that is, the controller 80 erases images sequentially from the portion fed into the nip portion).

  The electronic paper 100 on which image erasure has been completed is discharged from the image recording apparatus 1 by a paper discharge roller.

=== Other Embodiments ===
Although the present embodiment is mainly described with respect to an image recording apparatus for electronic paper, disclosure of an image recording method for electronic paper and the like is also included. Further, the present embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<Electronic paper>
In the above embodiment, the positively charged white particles and the negatively charged black particles are described as examples of the colored charged particles. However, the present invention is not limited to this.

  For example, the white particles may be negatively charged and the black particles may be positively charged. Further, the color is not limited to white and black, and any color may be used as long as both colors are different. For example, it can be appropriately selected from chromatic colors such as red, blue and green, and metallic luster colors such as gold and silver according to the purpose. Further, when only one of the two color particles is charged and the other is not charged (uncharged) (for example, the white particles are uncharged, the colored charged particles are negatively charged black particles. In such a case, the present invention can be applied.

  In the above embodiment, the upper insulating layer 141 of the electronic paper 100 is light transmissive (substantially transparent), while the lower insulating layer 142 is not light transmissive (substantially transparent). However, the present invention is not limited to this. For example, both the upper insulating layer 141 and the lower insulating layer 142 may be light transmissive (substantially transparent). In this case, any of the upper insulating layer 141 and the lower insulating layer 142 may be used. Can also be made the display surface 121.

<Image recording device>
The image recording apparatus of the above embodiment is configured to include one photoconductor 20, one charging unit 30, one exposure unit 40, and one electric field generation unit 50, but is not limited thereto.

  For example, as shown in FIG. 7, you may make it the structure provided with two each units, respectively. That is, an image is displayed using the first photoconductor 20a, the first charging unit 30a, the first exposure unit 40a, and the first electric field generation unit 50a (the image to be erased is displayed). The electronic paper 100 is erased. Thereafter, the transport unit 60 transports the electronic paper 100 after image erasure between the second photoconductor 20b and the second opposing roller 52b, and the second photoconductor 20b, the second charging unit 30b, You may make it record a new image about the electronic paper 100 after image deletion using the 2nd exposure unit 40b and the 2nd electric field generation unit 50b. Thereby, the image erasing and image recording processes can be performed continuously.

  Moreover, as shown in FIG. 8, you may comprise so that the electronic paper 100 may circulate. That is, for the first time, image erasure is performed on the electronic paper 100 displaying an image (the image to be erased is displayed). Thereafter, the electronic paper 100 after image erasure is conveyed in the direction of the arrow Q by the conveyance unit 60 and moved again between the photoconductor 20 and the second counter roller 52. Then, for the second time, a new image may be recorded on the electronic paper 100 after erasing the image, and the electronic paper after the image recording may be discharged in the direction of arrow P.

  Furthermore, when used as an image recording and erasing apparatus having both an image recording function and an image erasing function on the electronic paper 100, a liquid crystal panel is provided as an example of an operation unit, and according to an operation input by an operator. The image recording mode and the image erasing mode may be switched.

<Voltage waveform applied to opposing roller 52>
In the image recording apparatus 1 according to the above embodiment, the rectangular wave voltage shown in FIG. 6 is applied to the facing roller 52, but the present invention is not limited to this. For example, a sine wave as shown in FIGS. 9A, 9B, and 9C may be applied instead of each of FIGS. 6A, 6B, and 6C. Further, a triangular wave as shown in FIGS. 10A, 10B, and 10C may be applied. Alternatively, a staircase voltage as shown in FIG. 11 may be applied. For convenience, in FIG. 6A in FIG. 6, a first example of an alternative staircase wave is shown in FIG. 11A, and a second example is shown in FIG. 11B.

1 image recording device, 20 photoconductor,
30 charging unit, 30a charging roller, 40 exposure unit,
50 electric field generation unit, 52 opposing roller, 54 voltage application unit,
60 transport units, 62 paper cassettes, 64 paper feed rollers,
66 transport roller, 80 controller (voltage control unit),
81 interface unit, 82 CPU, 83 memory,
84 unit control circuit,
100 electronic paper, 103 display layer, 107 sealing portion,
121 display surface, 131 microcapsule, 132 binder,
133 Capsule body, 141 Upper insulating layer, 142 Lower insulating layer

Claims (5)

An image carrier for carrying a latent image;
A facing member facing the image carrier,
An electronic paper having colored charged particles and displaying the image by moving the colored charged particles in the thickness direction, and a supply unit for supplying the paper between the image carrier and the opposing member;
By applying a voltage to the facing member, an electric field is generated along the thickness direction therebetween, and the colored charged particles are moved in the thickness direction to display an image corresponding to the latent image on the electronic paper. A voltage applying unit to be
A voltage controller that controls the voltage applied to the opposing member such that the value of the voltage varies with time;
An image recording apparatus for electronic paper, comprising: The image recording apparatus for electronic paper according to claim 1,
Of the potential in the image portion of the latent image and the potential in the non-image portion, the smaller one is V1, and the larger one is V2,
The image recording apparatus for electronic paper, wherein the voltage control unit controls the voltage so that a value of the voltage fluctuates within a range of V1 or more and V2 or less. The image recording apparatus for electronic paper according to claim 2,
The image control apparatus for electronic paper, wherein the voltage control unit controls the voltage so that the voltage value is V1 or V2. The image recording apparatus for electronic paper according to claim 1,
The supply unit supplies the electronic paper on which an image is displayed in the middle,
The voltage application unit includes:
The electrons that generate an electric field along the thickness direction by applying a voltage to the counter member, move the colored charged particles in the thickness direction, and are supplied between the electrons by the supply unit to display an image. Erase the image on the paper,
The voltage controller is
Of the potential in the image portion of the latent image and the potential in the non-image portion, the smaller one is V1, and the larger one is V2,
To the electronic paper, wherein the voltage is controlled so that the voltage value fluctuates including at least one of a value greater than V2 and a value less than V1 and a value greater than or equal to V1 and less than or equal to V2. Image recording device. An electronic paper having colored charged particles and displaying an image by moving the colored charged particles in the thickness direction is supplied between an image carrier that carries a latent image and an opposing member that faces the image carrier. And
Applying a voltage to the opposing member, and controlling the voltage applied to the opposing member so that the value of the voltage varies with time,
By generating an electric field along the thickness direction during the period, and moving the colored charged particles in the thickness direction,
Displaying an image corresponding to the latent image on the electronic paper;
A method for recording an image on electronic paper.

Images