JP6362354B2 - Image display device, image display control device, and image display program - Google Patents

Description

  The present invention relates to an image display device, an image display control device, and an image display program.

  2. Description of the Related Art An image display device that moves a plurality of types of particles colored in different colors enclosed between substrates by applying a voltage according to an image between a pair of substrates, and displays the image of the colors of the particles as contrast is known. It has been.

  For example, in the technique described in Patent Document 1, a dispersion medium sealed between a pair of substrates and a substrate that moves between the substrates according to an electric field that is dispersed in the dispersion medium and formed between the substrates. The driving device drives a display medium having first and second migrating particles having different colors and charged polarities. When the drive device displays the color of the first migrating particles in gradation, the voltage is equal to or higher than a threshold voltage necessary for peeling at least some of the first migrating particles from the display substrate or the back substrate. And applying a first voltage corresponding to the gradation of the color of the first migrating particles between the substrates, and then applying a second voltage having the same polarity as the first voltage and smaller than the threshold voltage. It has been proposed to provide.

JP 2012-133310 A

  An object of the present invention is to provide an image display device, an image display control device, and an image display program capable of suppressing color mixing.

  The image display device of the image display medium according to claim 1, wherein a plurality of types of particles having different threshold voltages that are sealed between a pair of substrates and are sealed between the pair of substrates and are each separated from the substrate by voltage application. And a voltage of an application time corresponding to the gradation of the particle having the larger threshold voltage after the particles having the smaller threshold voltage of the adjacent pixel have moved to one substrate. And an application unit for applying.

  According to a second aspect of the present invention, in the first aspect of the present invention, the application unit may be configured such that the particles having a smaller threshold voltage are separated from the substrate, and the particles having the larger threshold voltage are separated from the substrate. A voltage that does not peel is applied in advance.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the application unit has a large threshold voltage when a voltage at which each of the particles moves is applied by the application unit. A voltage having a magnitude or a time at which the movement of the particle having the smaller threshold voltage ends before the particle starts to peel from the substrate is further applied at the time of resetting.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects of the present invention, the application section has a size for separating the particles from the substrate and an application time corresponding to a gradation. Applying a driving pulse having a first step of applying a voltage, and a second step of applying a voltage that is smaller than the voltage applied in the first step and that causes the particles detached from the substrate to adhere to the substrate. .

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the application unit applies the drive pulse in which the voltage application timings of the second step of each pixel are aligned.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the two kinds of particles are applied when the larger threshold voltage is applied between the pair of substrates. The particles having the characteristic that the time until the particles having the larger threshold voltage are separated from the substrate is longer than the time until the particles having the smaller threshold voltage are separated from the substrate and the movement is finished. is there.

  The image display control apparatus according to claim 7, wherein a plurality of types of particles are sealed between a pair of substrates, are separated from the substrate by a voltage applied between the pair of substrates, and have different threshold voltages for starting the separation. Among the plurality of pixels including adjacent pixels, the voltage of the application time corresponding to the gradation of the particles having the larger threshold voltage after the particles having the smaller threshold voltage of the adjacent pixels finish moving to one substrate. The control part which controls a voltage so that may be applied is provided.

  An image display program according to an eighth aspect causes a computer to function as the application unit of the image display apparatus according to any one of the first to sixth aspects.

  According to the first aspect of the present invention, the voltage of the application time corresponding to the gradation of the particle having the larger threshold voltage before the particle having the smaller threshold voltage of the adjacent pixel finishes moving to the one substrate. As compared with the case of applying, there is an effect that it is possible to provide an image display device capable of suppressing color mixing.

  According to the second aspect of the present invention, there is an effect that color mixing can be further suppressed as compared with a case where a voltage having such a magnitude that particles having a smaller threshold voltage are peeled from the substrate is not applied in advance.

  According to the third aspect of the present invention, when the particle having the larger threshold voltage starts to move, the voltage of the magnitude or time at which the movement of the smaller threshold voltage ends is not applied at the time of resetting. In comparison, there is an effect that the time until the movement of the particles having a smaller threshold voltage is completed can be shortened.

  According to the fourth aspect of the present invention, it is possible to display a stable image by reducing suspended particles after voltage application, as compared with the case where the driving pulse having the first step and the second step is not used. There is an effect that can be done.

  According to the fifth aspect of the present invention, there is an effect that an inexpensive device can be obtained as compared with the case where the application timing of the voltage in the second step is different for each pixel.

  According to the invention described in claim 6, the time until the particles having the larger threshold voltage are separated from the substrate is longer than the time until the particles having the smaller threshold voltage are separated from the substrate and the movement is finished. There is an effect that color mixing can be suppressed as compared with the case where particles having long characteristics are not employed.

According to the seventh aspect of the present invention, the voltage of the application time corresponding to the gradation of the particle having the larger threshold voltage before the particle having the smaller threshold voltage of the adjacent pixel finishes moving to one substrate. As compared with the case of applying, there is an effect that it is possible to provide an image display control device capable of suppressing color mixing.

  According to the eighth aspect of the present invention, the voltage of the application time corresponding to the gradation of the particle having the larger threshold voltage before the particle having the smaller threshold voltage of the adjacent pixel finishes moving to one substrate. As compared with the case of applying, there is an effect that an image display program capable of suppressing color mixing can be provided.

(A) is a schematic diagram showing an outline of an image display apparatus according to the present embodiment, and (B) is a block diagram showing a configuration of a control unit of the image display apparatus according to the present embodiment. It is a figure for demonstrating the example which color mixing generate | occur | produces. It is a figure for demonstrating the example of control of the voltage application part by the control part of the image display apparatus which concerns on this Embodiment. It is a figure for demonstrating the example which applies previously the pulse voltage which moves the 1st migrating particle with a smaller threshold voltage first. It is a figure for demonstrating the example which controls the peeling start time of an electrophoretic particle with the magnitude | size of a voltage at the time of reset, and application time. It is a figure for demonstrating an example of the drive pulse which applies a voltage in two steps. It is a figure for demonstrating an example of the drive pulse which aligned the application timing of a voltage so that the voltage of the same magnitude | size may be applied at the same timing in each pixel.

  Hereinafter, the present embodiment will be described with reference to the drawings. Members having the same functions and functions may be given the same reference numerals throughout the drawings, and redundant descriptions may be omitted. In addition, in order to simplify the description, the present embodiment will be described with reference to a diagram that focuses on one cell as appropriate.

  FIG. 1A schematically shows an image display apparatus according to this embodiment. The image display device 50 includes an image display medium 10 and a drive device 20 that drives the image display medium 10. The driving device 20 includes a voltage application unit 30 that applies a voltage between the display-side electrode 3 and the back-side electrode 4 of the image display medium 10, and a voltage application unit 30 according to image information of an image displayed on the image display medium 10. And a control unit 40 to be controlled.

  The image display medium 10 includes a pair of substrates in which a translucent display substrate 1 serving as an image display surface and a rear substrate 2 serving as a non-display surface are disposed to face each other with a gap therebetween. .

  A gap member 5 is provided that holds the substrates 1 and 2 at a predetermined interval and partitions the substrates into a plurality of cells.

  The cell indicates a region surrounded by the back substrate 2 provided with the back side electrode 4, the display substrate 1 provided with the display side electrode 3, and the gap member 5. Note that one cell includes a plurality of pixels. In this embodiment, an example having the gap member 5 is described. However, the gap member 5 may be omitted as long as the gap between the substrates can be held.

In the cell, for example, a dispersion medium 6 made of an insulating liquid, a first migrating particle 11 dispersed in the dispersion medium 6, and a second migrating particle 12 are sealed as a particle group. The first migrating particles 11 and the second migrating particles 12 are colored in different colors and have different charging characteristics, and the migrating particles are controlled by controlling the voltage applied between the pair of electrodes 3 and 4. 11 and 12 migrate between the substrates. In addition, the migrating particles 11 and 12 each have a threshold voltage at which separation starts from the substrate. When a threshold voltage is applied between the substrates, the migrating particles 11 and 12 are separated from the substrate and migrate according to the polarity.

  The first migrating particles 11 and the second migrating particles 12 are colored in different colors, and have different adhesion forces to maintain the state of adhering to the substrate, and are adhering to the substrate due to the electric field between the substrates. Different voltages are required to detach the substrate from the substrate. That is, by controlling the voltage applied between the pair of electrodes 3 and 4, the first migrating particles 11 and the second migrating particles 12 each have a characteristic of migrating alone. More specifically, when the force in the direction in which the particles leave the substrate exceeds the adhesion force by the electric field generated by applying a voltage, the particles leave the substrate and go to the other substrate. The voltage at which the force generated by the electric field is balanced with the adhesive force and the particles start to move is called a threshold voltage. In the present embodiment, even after the first migrating particles 11 and the second migrating particles 12 are moved and the image is displayed and the application of voltage is stopped, the particles are caused by van der Waals force, mirror image force, electrostatic attraction, etc. It remains attached to the substrate and the image display is maintained. In order to control the adhesion force of the particles, it is only necessary to adjust the mirror image force, electrostatic attraction force, van der Waals force, and the like. For example, the charge amount of the particles, the particle size, the charge density, the dielectric constant, The surface shape, the surface energy, the composition and density of the dispersing agent, etc. can be appropriately adjusted. In addition to the first migrating particles 11 and the second migrating particles 12, white particles colored white may be included as a particle group. In this case, the white particles are less charged than the first migrating particles 11 and the second migrating particles 12, and the voltage at which the first migrating particles 11 and the second migrating particles 12 move to either one of the electrodes is between the electrodes. Even if it is applied to, suspended particles that do not move to any electrode side may be used. Or it is good also as a structure which displays white different from the color of electrophoretic particle by mixing a coloring agent with a dispersion medium.

  The drive device 20 (the voltage application unit 30 and the control unit 40) controls the voltage applied between the display-side electrode 3 and the back-side electrode 4 of the image display medium 10 according to the color for displaying the first electrophoretic particles. 11 and the second migrating particles 12 are migrated and attracted to either the display substrate 1 or the back substrate 2 according to their respective charging polarities.

  The voltage application unit 30 is electrically connected to the display side electrode 3 and the back side electrode 4, respectively. Further, the voltage application unit 30 is connected to the control unit 40 so as to exchange signals.

  FIG. 1B is a block diagram illustrating a configuration of the control unit 40 of the image display device 50 according to the present embodiment.

  As shown in FIG. 1B, the control unit 40 is configured as a computer 40, for example. The computer 40 includes a CPU (Central Processing Unit) 40A, a ROM (Read Only Memory) 40B, a RAM (Random Access Memory) 40C, a nonvolatile memory 40D, and an input / output interface (I / O) 40E via a bus 40F. It is connected. A voltage application unit 30 is connected to the I / O 40E. In this case, a program for causing the computer 40 to execute processing for instructing the voltage application unit 30 to apply a voltage necessary for displaying each color is written in, for example, the nonvolatile memory 40D, and this is read and executed by the CPU 40A. The program may be provided by a recording medium such as a CD-ROM.

  The voltage application unit 30 is a voltage application device for applying a voltage to the display side electrode 3 and the back side electrode 4, and applies a voltage according to the control of the control unit 40 to the display side electrode 3 and the back side electrode 4. . The voltage application unit 30 may apply an active matrix method or a passive matrix method. Alternatively, a segment method may be applied.

By the way, in the image display device 50 configured as described above, a voltage equal to or higher than a threshold voltage at which particles start to peel from the substrate is applied, and the movement of the two kinds of particles is controlled by the application time of the voltages, thereby displaying gradation. Is possible. Hereinafter, two types of particles having the same charging polarity will be described, but the effect remains the same even if the charging polarity is different. Two types of particles having different threshold voltages are moved by determining the gradation of particles having a large threshold voltage for each pixel based on a gradation signal corresponding to the particles having a large threshold. Thereafter, the gradation of particles having a small threshold voltage is determined and moved for each pixel by a gradation signal corresponding to the particles having a small threshold voltage. At this time, by applying a voltage that determines the gradation of particles having a large threshold voltage, particles having a small threshold voltage have a low adhesion force, and therefore start moving from one substrate before particles having a large threshold voltage, and move to the other substrate. To reach. Particles having a large threshold voltage also start to move to the other substrate, but the amount of particles that move by the gradation is adjusted by the length of the voltage application time. When the amount of moving particles is large, a long time voltage is applied, and when the amount of moving particles is small, a short time voltage is applied. If only particles with a small threshold voltage are moved without moving particles with a large threshold voltage, all particles with a small threshold voltage are moved first. The voltage application is terminated before the particles having a large threshold voltage start moving, and then only the voltage corresponding to the gradation of the particles having the small threshold voltage is moved. Applied to move particles with a small threshold voltage. Further, when neither particles having a large threshold voltage nor particles having a small threshold voltage are moved, no voltage is applied.

  However, if a voltage having an application time corresponding to the gradation of the migrating particle having the larger threshold voltage is applied before the migrating particle having the smaller threshold voltage finishes moving to one substrate in the adjacent pixel, the color mixture ( So-called crosstalk occurs.

  For example, when the first migrating particles 11 move with a threshold voltage smaller than that of the second migrating particles 12, it takes time for the first migrating particles 11 to peel off from one substrate and finish moving to the other substrate. . Here, before the movement of the first migrating particle 11 is finished, a voltage for moving the second migrating particle 12 is applied to the adjacent pixel, so that the first migrating particle 11 before the movement is finished is applied to the adjacent pixel. Color mixing occurs due to the influence of voltage.

  More specifically, the threshold voltage of the first migrating particle 11 is | Vt1 |, the threshold voltage of the second migrating particle 12 is | Vt2 | (| Vt1 | <| Vt2 |), and a voltage | V2 larger than | Vt2 | When | is applied, it has characteristics as shown in FIG. The reflectivity shown in FIG. 2A indicates a value measured from the display substrate side. When the number of particles arranged on the display substrate side is large, the reflectance is small. When the amount of particles arranged on the display substrate side is small, the reflectance is large. . By measuring the reflectance, the amount of movement of the particles can be measured. The solid line in FIG. 2A indicates the start of peeling of the first migrating particles 11 when the voltage −V2 is applied, and the dotted line indicates the end of movement of the first migrating particles 11. The dotted line represents the amount of particles arranged on the rear substrate side calculated from the velocity of the particles and the distance between the substrates. The dotted line also coincides with the value obtained by measuring the reflectance with the rear substrate being transparent. In addition, the alternate long and short dash line in FIG. 2A indicates the start of peeling of the second migrating particles 12. In the example of FIG. 2A, both the first migrating particles 11 and the second migrating particles 12 have positive charging characteristics, the display-side electrode 3 is a ground as a common electrode, and the back-side electrode 4 is an electrode AC. A voltage is applied as follows.

Here, for example, the voltages applied to the adjacent electrodes A to C are applied as shown in FIG. Note that resetting is performed in advance to move the first migrating particles 11 and the second migrating particles 12 to the display substrate 1 side. In this case, in each pixel, by first applying a voltage of −V2, the first migrating particles 11 are moved from the display substrate 1 side to the back surface as shown in FIG. 2D from the state of FIG. The movement to the substrate 2 side is started. Then, at time t1 in FIG. 2B, as shown in FIG. 2E, the first migrating particles 11 are in the process of being separated from the substrate and moving. When the application is finished, the movement of the first migrating particles 11 toward the back substrate 2 is finished as shown in FIG. 2 (F) at time t2 in FIG. 2 (B). However, the second migrating particles 12 also start to move before the end of the movement of the first migrating particles 11. Furthermore, a voltage for moving the second migrating particles 12 corresponding to the gradation is continuously applied to the electrode B. As a result, when the second electrophoretic particles 12 are moved to the back substrate 2 side of the electrode B, the second electrophoretic particles 12 separated from the display substrate 1 side of the electrodes A and C are as indicated by the arrows in FIG. The movement of the second migrating particles 12 is completed as shown in FIG.

  Therefore, in the present embodiment, the control unit 40 controls the voltage application unit 30 to increase the threshold voltage after the movement of the first migrating particle 11 having the smaller threshold voltage of the adjacent pixel to one substrate. A voltage having an application time corresponding to the gradation of the second migrating particles 12 is applied.

  For example, when the larger threshold voltage is applied between the substrates, the second migration having the larger threshold voltage than the time until the first migrating particles 11 having the smaller threshold voltage are separated from the substrate and the movement is finished. By adopting particles having a longer time until the particles 12 are peeled from the substrate, the second migrating particles 12 are peeled after the first migrating particles 11 are peeled off from one substrate and moved. Select startable particles. Thereby, after the movement of the first migrating particle 11 having the smaller threshold voltage of the adjacent pixel to one substrate, the voltage of the application time corresponding to the gradation of the second migrating particle 12 having the larger threshold voltage is applied. It becomes possible to do.

  Here, a specific control example of the voltage application unit 30 by the control unit 40 of the image display device 50 according to the embodiment of the present invention will be described. FIG. 3 is a diagram for explaining a control example of the voltage application unit 30 by the control unit 40 of the image display device 50 according to the present embodiment.

  As the first migrating particles 11 and the second migrating particles 12, particles having characteristics as shown in FIG. 3A are selected. The threshold voltage of the first migrating particles 11 is | V1 |, and the threshold voltage of the second migrating particles 12 is | V2 |. As in FIG. 2, the solid line in FIG. 3A indicates the start of separation of the first migrating particles 11 when the voltage −V2 is applied, and the dotted line indicates the end of movement of the first migrating particles 11. Moreover, the alternate long and short dash line in FIG. 3A indicates the start of peeling of the second migrating particles 12. In the example of FIG. 3A, both the first migrating particles 11 and the second migrating particles 12 have positive charge characteristics, the display side electrode 3 is a common electrode and the ground, and the back side electrode 4 is an electrode AB. A voltage is applied as follows. The two types of particles have the same effect even if they have both negative electrode charging characteristics and different charging polarities.

  In the present embodiment, as shown in FIG. 3A, a sufficiently large threshold voltage difference between the first migrating particles 11 and the second migrating particles is selected. The difference between the threshold voltages is sufficiently large when the voltage −V2 corresponding to the threshold voltage of the second migrating particles 12 is applied until the movement of the first migrating particles 11 is completed after the substrate is peeled off. It shows that the time until the second migrating particles 12 start to peel from the substrate is longer than the time.

Here, it is assumed that the control unit 40 controls the voltage application unit 30 to apply the voltages applied to the adjacent electrodes A to C as shown in FIG. Note that resetting is performed in advance to move the first migrating particles 11 and the second migrating particles 12 to the display substrate 1 side. In this case, in each pixel, by first applying a voltage of −V2, the first migrating particles 11 start moving from the state of FIG. 3C and move from the display substrate 1 side to the rear substrate 2 side. To do. Then, the movement of the first migrating particles 11 is finished. Subsequently, in the electrode B, voltage application according to the gradation of the second migrating particles 12 is continued, and as shown in FIG. 3E, the display substrate 1 side of the second migrating particles 12 to the rear substrate 2 side. Start moving to. Then, at time tx in FIG. 3B, as shown in FIG. 3F, the voltage application to the electrodes A and C is completed, and the voltage corresponding to the gradation of the second migrating particles 12 is applied to the electrode B. The application is continued, the second migrating particles 12 move to the back substrate 2 side, and the voltage application of the electrode B is terminated when the voltage application time corresponding to the gradation has elapsed. In the present embodiment, since the voltage is applied in accordance with the gradation of the second migrating particle 12 after the movement of the first migrating particle 11 is completed, color mixture does not occur and FIG. As shown in FIG. 4, the movement of the second migrating particles 12 according to the gradation is finished.

  In the above embodiment, when the threshold voltage of the second migrating particles 12 is applied, the first migrating particles 11 can be separated from the one substrate, and after the movement, the second migrating particles 12 can be separated. As a configuration example, when a larger threshold voltage is applied between the substrates, the first threshold voltage having a larger threshold voltage than the time until the first migrating particles 11 having the smaller threshold voltage peel off from the substrate and finish moving. Although the example which selected the particle | grains with the characteristic that the time until the 2 electrophoretic particle 12 peels from a board | substrate is longer was demonstrated, it does not restrict to this.

  For example, the control unit 40 may control the voltage application unit 30 to apply in advance a pulse voltage that moves the first migrating particles 11 having the smaller threshold voltage first. Or you may make it control the peeling start time of the electrophoretic particle by the magnitude | size of the voltage at the time of reset, and application time. Or you may make it combine at least one of these and selection of particle | grains.

  An example in which a pulse voltage for moving the first migrating particles 11 having the smaller threshold voltage first is applied in advance is shown in FIG.

  As shown in FIG. 4A, a voltage −V1 corresponding to the threshold voltage of the first migrating particles 11 is applied in advance to each pixel. That is, a voltage is applied in advance so that only the first migrating particles are separated from the substrate and the second migrating particles 12 are not separated from the substrate.

  Thus, in FIG. 4B, from the time from the start of applying the voltage −V1 to the time when the first migrating particles 11 are peeled off from the substrate and finish, the second migrating particles from the start of applying the voltage −V1. The time until 12 starts to peel from the substrate becomes longer.

  That is, the resetting is performed in advance and the first migrating particles 11 and the second migrating particles 12 are moved to the display substrate 1 side (the state shown in FIG. 4C). When a voltage is applied between the substrates as in FIG. 4A, in each pixel, only the first migrating particles 11 move to the back substrate 2 side by the voltage −V1 applied between the substrates, and FIG. It will be in the state shown in Subsequently, the voltage −V2 is applied between the substrates for each pixel, and the movement of the first migrating particles 11 toward the back substrate 2 is completed. At this time, as shown in FIG. 4E, the second migrating particles 12 start moving from the display substrate 1 to the rear substrate 2 side. Subsequently, the application of the voltages of the electrodes A and C is stopped at the time tx in FIG. 4A, and the application of the voltage of the electrode B is continued according to the gradation. In the electrode B, the application of the voltage −V2 is continued according to the gradation, and as shown in FIG. 4F, the second migrating particles 12 move to the back substrate 2 side, and the time corresponding to the gradation is obtained. When the time has elapsed, the application of voltage is stopped and the state shown in FIG.

  As described above, even if the pulse voltage for moving the first particle 11 having the smaller threshold voltage first is applied in advance, the second migration is performed after the first migration particle 11 is separated from the one substrate and the movement is completed. Since peeling of the particles 12 starts, color mixing is suppressed.

On the other hand, the case where the peeling start time of electrophoretic particles is controlled by the magnitude of voltage at reset and the application time will be described. For example, when the threshold voltage of the second electrophoretic particle 12 is applied between the substrates, the first electrophoretic particle 11 having the smaller threshold voltage is required until the second electrophoretic particle 12 having the larger threshold voltage starts to peel from the substrate. A voltage having a magnitude or a time at which the movement of the motor ends is applied at the time of resetting. As the voltage application time TR at reset (see FIG. 5A) is longer or the voltage VR at reset (see FIG. 5A) is larger, the particles moved by the reset are aligned closer to the substrate surface. Be placed. Therefore, the electrostatic adhesive force acting between the particles and the substrate is uniform, and the distribution of the electrostatic adhesive force is reduced.

  Therefore, after applying the reset voltage, when the voltage for moving the particles toward the opposite substrate is applied between the substrates, the time for the particles to start peeling from the substrate is the longer the reset time or the reset voltage The larger the value, the larger. As a result, as shown in FIG. 5B, the distribution of the separation time of the first migrating particles 11 having the smaller threshold voltage that moves first becomes smaller, the time from the start of separation to the end of the movement becomes smaller, and the next movement By the time the second migrating particles 12 having a large threshold voltage start to move, most of the first migrating particles 11 having a small threshold voltage reach the opposite substrate, and the second migrating particles 12 having a large threshold voltage are driven by gradation. Thus, even if a potential difference occurs between adjacent electrodes, the occurrence of inadvertent particle movement can be suppressed by color mixing. After applying the reset voltage for aligning the particles on one side of the substrate, a voltage for moving each particle according to the gradation is applied, but it may have time to apply a 0 V potential before applying each voltage. In this case, since the current of the power source does not flow at the same time when the voltage polarity is switched between the electrodes, there is an effect of saving power.

  Note that the voltage applied between the electrodes by the voltage application unit 30 of the image display device 50 according to the above embodiment may be applied to a voltage other than the drive pulse described above. For example, as shown in FIG. 6A, a driving pulse for applying a voltage in two steps may be applied. The drive pulse is smaller than the voltage applied in the first step, the first step of applying the voltage −V2 of the application time corresponding to the magnitude and gradation for separating the electrophoretic particles from the substrate, and the separated electrophoretic particles are removed from the substrate. The driving pulse is combined with the second step of applying the voltage −V1 having a magnitude to be attached to the electrode.

  For example, when a driving pulse consisting of two steps is applied to each of the electrodes A to C as shown in FIG. 6 (A), the particles move as shown in FIGS. 6 (B) to (E). That is, in a state where the resetting is performed in advance and the first migrating particles 11 and the second migrating particles 12 are moved to the display substrate 1 side (the state shown in FIG. 6B), the pixels shown in FIG. Thus, when the voltage of the first step is applied between the substrates, in each pixel, the first migrating particles 11 start to move by the voltage −V2 applied between the substrates and move to the opposite substrate. Then, at the time tx in FIG. 6A, the movement of the first migrating particles 11 is completed and the state shown in FIG. 6C is obtained. Subsequently, the application of the voltages of the electrodes A and C is stopped, and the application of the voltage of the electrode B is continued according to the gradation. Thereby, as shown in FIG. 6D, the second migrating particles 12 move to the electrode B. Then, by applying the voltage of the second step to the electrodes A to C of each pixel, the second migrating particles 12 that have peeled off and floated before the application of the voltages of the electrodes A and C to the back substrate 2 side are removed. It will adhere and will be in the stable state as shown in FIG.6 (E).

  By the way, as shown in FIG. 6A, in the case of applying a drive pulse consisting of two steps, for example, after time tx in FIG. It is necessary to apply a voltage. In order to apply different voltages for each pixel at the same timing, complicated control or an expensive power supply circuit is required.

  Therefore, the voltage application timings may be aligned so that the same voltage is applied at the same timing in each pixel.

  For example, as shown in FIG. 7A, the application time of a voltage (first step voltage) that is equal to or higher than the threshold voltage for peeling particles having a larger threshold voltage from the substrate between electrodes of different gradations If the value differs between pixels, the potential is once set to 0 potential after the pulse ends. In the example of FIG. 7A, the potentials of the electrodes A and C are once set to zero. A voltage lower than the threshold voltage (second step voltage) for moving the separated particles is applied after the application of the first step voltage of all the pixels is completed. That is, when the first step voltage is applied and the application time corresponding to the gradation has elapsed, the voltage application is temporarily stopped, and the voltage application timing of the second step is made uniform for each pixel. As a result, the same voltage (or 0 potential) is applied to each pixel at the same timing.

  Alternatively, as shown in FIG. 7B, the timing for ending the application of the voltage in the first step may be aligned. In this case, as shown in FIG. 7B, by aligning the end timing of the voltage application in the first step, unnecessary movement of particles between pixels is suppressed, and color mixing is suppressed.

  In the above-described embodiment, an example in which two types of migrating particles are sealed between substrates has been described. However, the present invention is not limited to this. For example, the present invention may be applied when enclosing three or more types of electrophoretic particles. In this case, when switching the respective threshold voltages, after the migrating particles having the smaller threshold voltage of the adjacent pixels move to one substrate, the application is performed in accordance with the gradation of the migrating particles having the larger threshold voltage. The control unit 40 may control the voltage application unit 30 so as to apply the voltage of time. In addition, two or three types of migrating particles having different charging polarities may be encapsulated, and the particles having different charging polarities have different migratory directions when an electric field is applied, but the smaller migrating particles having a lower threshold voltage. After the movement to the opposite substrate, the particles having a large threshold voltage may be controlled so as to move in the direction opposite to the particles having the small threshold voltage previously migrated.

  In addition, the control of the voltage application unit 30 by the control unit 40 in the above-described embodiment may be realized by hardware or may be realized by executing a software program. The program may be stored in various storage media and distributed.

DESCRIPTION OF SYMBOLS 1 Display substrate 2 Back substrate 3 Display side electrode 4 Back side electrode 10 Image display apparatus 11 1st electrophoretic particle 12 2nd electrophoretic particle 20 Drive apparatus 30 Voltage application part 40 Control part 50 Image display apparatus

Claims (6)

A pair of substrates;
A plurality of pixels encapsulated between the pair of substrates, each peeled off from the substrate by voltage application, each including a plurality of types of particles having different threshold voltages for starting peeling; and
An application unit that applies a voltage of an application time according to the gradation of the particle having the larger threshold voltage after the particles having the smaller threshold voltage of the adjacent pixel have finished moving to one substrate;
With
The application unit is an image display device that further applies in advance a voltage with such a magnitude that the particles having a smaller threshold voltage are separated from the substrate, and the particles having a larger threshold voltage are not separated from the substrate . A pair of substrates;
A plurality of pixels encapsulated between the pair of substrates, each peeled off from the substrate by voltage application, each including a plurality of types of particles having different threshold voltages for starting peeling; and
An application unit that applies a voltage of an application time according to the gradation of the particle having the larger threshold voltage after the particles having the smaller threshold voltage of the adjacent pixel have finished moving to one substrate;
With
The application unit moves the particles having a smaller threshold voltage before the particles having the larger threshold voltage start to peel from the substrate when a voltage at which each of the particles moves is applied by the application unit. An image display device that further applies a voltage having a magnitude or time for resetting at the time of resetting. A pair of substrates;
A plurality of pixels encapsulated between the pair of substrates, each peeled off from the substrate by voltage application, each including a plurality of types of particles having different threshold voltages for starting peeling; and
An application unit that applies a voltage of an application time according to the gradation of the particle having the larger threshold voltage after the particles having the smaller threshold voltage of the adjacent pixel have finished moving to one substrate;
With
The application unit has a first step of applying a voltage having an application time corresponding to a gradation, and a voltage applied in the first step. A second step of applying a voltage that is small and has a magnitude that causes the particles peeled off the substrate to adhere to the substrate, and the drive pulse applies the voltage application timing of the second step of each pixel. Is an image display device. The particles having the smaller threshold voltage and the particles having the larger threshold voltage are applied when the threshold voltage having the larger threshold voltage is applied between the pair of substrates. than the time until the end peeling to move from the substrate, any one of the preceding claims 1-3 wherein the particles of the upper threshold voltage is large particles having a long characteristic towards the time until separated from the substrate The image display device described in 1. The image display control apparatus provided with the control part which controls the voltage which the said application part of the image display apparatus of any one of Claims 1-4 applies . The image display program for functioning a computer as the said application part of the image display apparatus of any one of Claims 1-4 .

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