JP2016014851A - Method for driving reflective display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for driving a reflective display device by which a response speed can be improved and a rewiring life can be elongated.SOLUTION: The method for driving a reflective display device is applied to a device in which each display region can display a first color when a potential of a display electrode is in negative polarity and can display a second color when the potential is in positive polarity. At a time of rewriting display, a common electrode is connected to a third potential; a display electrode in a display region where a display color is to be switched from the second color to the first color is connected to a first potential that is in negative polarity with respect to the third potential for a first writing time duration, then connected to a second potential that is in positive polarity with respect to the third potential for a first adsorption prevention time duration shorter than the first writing time duration, and then connected to the third potential; and a display electrode in a display region where a display color is to be switched from the first color to the second color is connected to the second potential for a second writing time duration, then connected to the first potential for a second adsorption prevention time duration shorter than the second writing time duration, and then connected to the third potential.

Description

  The present invention relates to a driving method of a reflective display device applied to electronic paper or the like.

  Recently, as a reflective display device, an electrophoretic display device using an electrophoretic material as an electroresponsive material contained in a display medium has been widely used. An electrophoretic display device is a device that displays information by using electrophoretic migration, that is, particle movement, of an electrophoretic body (usually electrophoretic particles) in air or in a solvent. In general, an electrophoretic state is controlled by applying an electric field between two substrates, thereby realizing a desired display. As the electrophoretic body, charged powder as well as charged particles can be used. In that case, the charged powder electrophoreses in the gas.

  In recent years, the electrophoretic display device has attracted attention especially as an electronic paper. When applied as an electronic paper, it is possible to enjoy advantages such as visibility at the printed matter level (easy for eyes), ease of information rewriting, low power consumption, and light weight.

  The structure of one type of electrophoretic display device will be described in more detail. Between one substrate and the other substrate, a common electrode that covers a plurality of display areas and a display medium including an electrophoretic body are arranged. A display medium layer and a plurality of display electrodes corresponding to each of the plurality of display regions are provided in this order from one substrate side to the other substrate side, and the common electrode connects the GND potential. Each of the plurality of display areas has a display electrode of one of the first color and the second color according to the polarity of the voltage applied to the display electrode corresponding to the display area. Can be selectively displayed on the side (viewing side).

  Specifically, for example, when the display medium includes positively charged black electrophoretic particles and negatively charged white electrophoretic particles, when a positive voltage is applied to the display electrode, Electric force acts on each of the electrophoretic particles and the white electrophoretic particles, so that the white electrophoretic particles move to the display electrode side, and the black electrophoretic particles move to the common electrode side. As a result, black is displayed on the common electrode side of the display area. On the other hand, when a negative voltage is applied to the display electrode, the white electrophoretic particles move to the common electrode side, and the black electrophoretic particles move to the display electrode side. Thereby, white is displayed on the common electrode side of the display area. When the GND potential is connected to the display electrode, that is, when the voltage application to the display electrode is stopped, the electric force acting on the black electrophoretic particles and the white electrophoretic particles disappears. Therefore, the black electrophoretic particles and the white electrophoretic particles are each stopped in place. As a result, the display color of the display area is maintained.

  In Patent Document 1 (Japanese Patent Laid-Open No. 2002-82361), by applying a voltage having a polarity opposite to the write voltage immediately before the write voltage is applied to the display electrode, potential fluctuations when the write voltage is applied are described. A method for obtaining a high-contrast display by double the drive voltage is disclosed.

JP 2005-82361 A

  By the way, when such a reflective display device is actually mass-produced in a factory, the minimum voltage required to switch the display color due to differences in environmental conditions during panel manufacture and individual differences in panel materials. The application time length is different for each panel. That is, there are individual differences for each panel. Since it is difficult to sufficiently optimize the writing time length set in the drive circuit for each panel in the limited time during mass production, the minimum voltage is usually required as the writing time length set in the drive circuit. A time length longer than the application time length is employed.

  However, in this case, there are the following problems. That is, when the display is rewritten, the voltage application is performed for a longer time than the necessary minimum voltage application time, so that the electroresponsive material in the display medium is excessively adsorbed to the electrode. Thereby, at the time of the next display rewriting, the electrically responsive material is not smoothly separated from the electrode, and the response speed is lowered. In addition, in a reflective display device, the number of electrically responsive materials that are attracted to an electrode and not separated each time display rewriting is repeated generally increases the rewrite life as a product, that is, the maximum number of rewritable times. Although it is one of the reasons for defining, when rewriting the display, applying voltage for a longer time length than the minimum necessary voltage application time length and excessively adsorbing the electroresponsive material to the electrode, The number of electrically responsive materials that are attracted to the electrode and cannot be separated from each other is increased, thereby shortening the rewriting life as a product.

  The present invention has been made paying attention to such problems, and an object of the present invention is to provide a driving method of a reflective display device that can improve the response speed and extend the rewrite life. Another object of the present invention is to provide a reflective display device that can cope with such a driving method.

  In the present invention, a display medium including at least one kind of electrically responsive material is sealed between two opposing substrates on which at least one has translucency and each has electrodes formed thereon, A reflective display device that performs a desired display when a predetermined electric field is applied between two substrates, wherein a common electrode that covers a plurality of display regions is provided between one substrate and the other substrate. The display medium layer in which the display medium is arranged and a plurality of display electrodes corresponding to each of the plurality of display areas are provided in this order from the one substrate side to the other substrate side. Each of the plurality of display areas can display a first color when the potential connected to the display electrode corresponding to the display area is negative with respect to the potential connected to the common electrode. Yes, second color can be displayed when the polarity is positive A method of driving a reflective display device, which corresponds to a display region in which a third potential is connected to the common electrode and a display color is switched from a second color to a first color at a display rewrite timing. A first potential having a negative polarity with respect to the third potential is connected to the display electrode for a first writing time length, and then a second potential having a positive polarity with respect to the third potential is connected to the first electrode. The display electrode corresponding to the display region that is connected for the first anti-adsorption time length shorter than the writing time length and then connected to the third potential and switches the display color from the first color to the second color is connected to the display electrode. Connecting a second potential for a second writing time length, then connecting the first potential for a second anti-adsorption time length shorter than the second writing time length, and then connecting the third potential. This is a feature of a driving method of a reflective display device.

  Preferably, when the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color, the second potential is continuously applied. And the step of continuously connecting the third potential are alternately repeated, and the first potential is applied to the display electrode corresponding to the display region for switching the display color from the first color to the second color. When connecting during the second adsorption prevention time length, the step of continuously connecting the first potential and the step of continuously connecting the third potential are alternately repeated.

  In this case, more preferably, when the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first anti-adsorption time length, The continuous connection time length of the potential is 1 ms or more, the continuous connection time length of the third potential is 500 μs or more, and the display electrode corresponding to the display region for switching the display color from the first color to the second color is used. When the first potential is connected for the second adsorption prevention time length, the continuous connection time length of the first potential is 1 ms or more, and the continuous connection time length of the third potential is 500 μs or more.

  Preferably, the first adsorption prevention time length is a reflectance of the display area before and after connecting the second potential to the display electrode corresponding to the display area for switching the display color from the second color to the first color. The second adsorption prevention time length connects the first potential to the display electrode corresponding to the display area for switching the display color from the first color to the second color. This is the length of time during which the change rate of the reflectance of the display area before and after is within 5%.

  Specifically, for example, the first adsorption prevention time length is 0.1% to 5% of the first writing time length, and the second adsorption prevention time length is the second writing time. The time length is 0.1% to 5% of the length.

  Further, the present invention is a reflective display device that can cope with the driving method as described above. That is, a display medium containing at least one or more kinds of electrically responsive materials is sealed between two opposing substrates on which at least one has translucency and each has electrodes formed thereon. A reflective display device that performs a desired display when a predetermined electric field is applied between the substrates, and is provided between one substrate and the other substrate, and the display medium layer on which the display medium is disposed A common electrode provided on the one substrate and covering a plurality of display areas, a plurality of display electrodes provided on the other substrate and corresponding to each of the plurality of display areas, and each display A voltage application control unit that applies a voltage to each of the electrodes, and each of the plurality of display regions has a potential connected to the display electrode corresponding to the display region with respect to a potential connected to the common electrode Display first color when polarity is negative The second color can be displayed when the polarity is positive, the third potential is connected to the common electrode, and the voltage application control unit is configured to display the second color at the display rewrite timing. A first potential having a negative polarity with respect to the third potential is connected to a display electrode corresponding to a display region for switching the display color from the color to the first color, and then the third potential is applied. A second potential having a positive polarity with respect to the potential is connected for a first anti-adsorption time length shorter than the first writing time length, and then the third potential is connected to display from the first color to the second color. The display electrode corresponding to the display area for switching colors is connected to the second potential for a second writing time length, and then the first potential is set to a second adsorption prevention time length shorter than the second writing time length. And then connect the third potential. A reflective display device, characterized in that there.

  Preferably, when the voltage application control unit connects the second potential to the display electrode corresponding to the display region for switching the display color from the second color to the first color during the first adsorption prevention time length, For the display corresponding to the display area for switching the display color from the first color to the second color by alternately repeating the operation of continuously connecting the second potential and the operation of continuously connecting the third potential. When the first potential is connected to the electrode during the second adsorption prevention time length, the operation of continuously connecting the first potential and the operation of continuously connecting the third potential are alternately performed. It is supposed to repeat.

  In this case, more preferably, when the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first anti-adsorption time length, The continuous connection time length of the potential is 1 ms or more, the continuous connection time length of the third potential is 500 μs or more, and the display electrode corresponding to the display region for switching the display color from the first color to the second color is used. When the first potential is connected during the second anti-adsorption time length, the continuous connection time length of the first potential is 1 ms or more, and the continuous connection time length of the third potential is 500 μs or more. .

  Preferably, the first adsorption prevention time length is a reflectance of the display area before and after connecting the second potential to the display electrode corresponding to the display area for switching the display color from the second color to the first color. The second adsorption prevention time length connects the first potential to the display electrode corresponding to the display area for switching the display color from the first color to the second color. This is the length of time during which the change rate of the reflectance of the display area before and after is within 5%.

  Specifically, for example, the first adsorption prevention time length is 0.1% to 5% of the first writing time length, and the second adsorption prevention time length is the second writing time. The time length is 0.1% to 5% of the length.

  According to the present invention, in a reflective display device, the response speed can be improved and the rewriting life can be extended.

FIG. 1 is a schematic configuration diagram showing a reflective display device according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the reflective display device shown in FIG. FIGS. 3A to 3D are schematic diagrams illustrating examples of display images displayed on the reflective display device illustrated in FIG. 1. FIG. 4 is a schematic diagram showing a waveform of a voltage applied to each display electrode when the display images shown in FIGS. 3A to 3D are rewritten in this order. FIG. 5 is a schematic diagram showing a modification of the waveform of the voltage applied to each display electrode when the display images shown in FIGS. 3A to 3D are rewritten in this order. FIG. 6 is a schematic diagram showing an enlarged waveform of a portion surrounded by a one-dot chain line denoted by reference symbol A in FIG. FIG. 7 is an enlarged schematic diagram showing the waveform of the portion surrounded by the alternate long and short dash line with the symbol B in FIG.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram showing a reflective display device according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the reflective display device shown in FIG.

  As shown in FIGS. 1 and 2, the reflective display device 10 according to the present embodiment has at least one of light-transmitting properties and two electrodes 12 or 15 a, 15 b, 15 c are formed facing each other. When a display medium 13 containing at least one kind of electrically responsive material is enclosed between the two substrates 11 and 16, and a predetermined electric field is applied between the two substrates 11 and 16, a desired display is performed. It is supposed to be. Here, in the specification and claims of the present application, “translucent” means a property of transmitting light. In this embodiment mode, the substrate disposed on the viewing side has a light-transmitting property such that the total light transmittance is 50% or more, preferably 80% or more, and more preferably 90% or more.

  In the present embodiment, as shown in FIG. 1, a plurality of (three in the illustrated example) display areas 18a, 18b, and 18c are covered between one substrate 11 and the other substrate 16. Two or more (one in the illustrated example) common electrode 12, a display medium layer in which the display medium 13 is disposed, and a plurality (not shown) corresponding to each of the plurality of display regions 18a, 18b, 18c. In this example, three display electrodes 15a, 15b, and 15c are provided in this order from one substrate 11 side to the other substrate 16 side. Here, the “display area” means an area used for a desired display in the reflective display device 10.

  In the present embodiment, as shown in FIG. 1, one substrate 11 is disposed on the viewing side, and the other substrate 16 is disposed on the non-viewing side.

  As one substrate 11, a transparent electrode such as polyethylene (PE), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), or transparent glass, and the common electrode 12 as A material with a translucent electrode such as indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO) is typically used. The common electrode 12 of the present embodiment is formed as a common electrode for segment driving.

  The common electrode 12 is formed so as to cover the plurality of display regions 18a, 18b, and 18d of at least one substrate 11 by a coating method, a sputtering method, a vacuum deposition method, a CVD method, or the like. The common electrode 12 is not necessarily formed with a pattern, and the entire surface of the substrate may be an electrode.

  The thickness of one substrate 11 is preferably 10 μm to 1 mm. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  One substrate 11 can be applied in either a roll shape or a sheet shape.

  As the other substrate 16, display electrodes 15 a, 15 b, and 15 c are formed of a conductive material such as a metal on the surface of the substrate such as a resin film, a resin plate, glass, or epoxy glass (glass epoxy) on the display medium 13 side. Can be used. The display electrodes 15a, 15b, and 15c of the present embodiment are formed as segmented pattern pattern electrodes (segment electrodes). As shown in FIGS. 1 and 2, the display areas 18a, 18b, 18c in the reflective display device 10 are defined by individual display electrodes 15a, 15b, 15c.

  For the other substrate 16, a base material having translucency may be used. Furthermore, it may be an opaque base material that is translucent, but an opaque glass base material, resin film, resin plate, glass, epoxy glass with the other surface different from the electrode surface roughened. (Garaepo) or the like can be used. In the present embodiment, as shown in FIG. 1, the other substrate 16 is disposed at a position opposite to the viewing side, and thus does not necessarily have translucency. However, when the same physical properties as the one substrate 11 such as thermal expansion characteristics are required, a light-transmitting member similar to the one substrate 11 can be used.

  The thickness of the other substrate 16 is preferably 10 μm to 1 mm, similarly to the thickness of the one substrate 11. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

The other substrate 16 can be applied in either a roll shape or a sheet shape. The display medium layer of this embodiment includes a partition wall 14 that partitions a plurality of cells between one substrate 11 and the other substrate 16. The display medium 13 is arranged in each cell. Here, the “cell” refers to a minute electrophoretic body divided between the two substrates 11 and 16 in order to prevent poor display due to sedimentation or uneven distribution of the electrophoretic body, particularly a decrease in contrast. It means migration space, that is, movement space. In addition, the said movement space may be divided | segmented by other structures, such as a microcapsule. Further, when the risk of sedimentation or uneven distribution of the electrophoretic body is low, the space between the two substrates 11 and 16 may not be divided by such a structure.

  The partition wall 14 can be composed of an ultraviolet curable resin, a thermosetting resin, a room temperature curable resin, or the like. As a method for forming the partition wall 14, a mold transfer method such as embossing can be adopted in addition to a photolithography method. Further, a method of manufacturing a structure having a desired pattern as a partition and sticking the structure to one substrate 11 may be employed. The aperture ratio is preferably 70% or more, and particularly preferably 90% or more. The higher the aperture ratio, the wider the displayable area, so that high contrast can be obtained.

  The shape of the unit pattern of the partition 14 is basically arbitrary such as a circle, a lattice, a hexagon, and other polygons. The cell size (pitch) is 0.05 mm to 1 mm, preferably 0.1 mm to 0.5 mm, although it depends on the size of the display panel. Here, the pitch means the distance between the center points of adjacent cells.

  The height of the partition wall 14 is 5 μm to 50 μm, preferably 10 μm to 50 μm. If the thickness is 5 μm or less, the amount of ink to be filled is small, and sufficient display characteristics, in particular, contrast cannot be obtained. On the other hand, if the thickness is 50 μm or more, the panel is too thick and the drive voltage increases excessively. From the viewpoint of obtaining good display characteristics at a low driving voltage, a height in the range of 10 μm to 50 μm is preferable.

  Between the top surface of the partition wall 14 and the display electrodes 15a, 15b, 15c on the other substrate 16 or other elements on the other substrate 16 or the other substrate 16, the top surface of the partition wall 14; An adhesive layer (not shown) for adhering the display electrodes 15 a, 15 b, 15 c on the other substrate 16 to other elements on the other substrate 16 or the other substrate 16 may be provided.

  The adhesive layer is formed of a thermoplastic resin such as a polyester-based thermoplastic adhesive with a thickness of 1 μm to 100 μm by, for example, a transfer method or a printing method. Preferably, it is formed with a thickness of 1 μm to 50 μm, particularly preferably with a thickness of 1 μm to 20 μm.

  As an adhesive for forming the adhesive layer, an adhesive using a thermoplastic material is preferable. It has a property of softening by heating and solidifying when cooled, and the composition is reversible when cooling and heating are repeated. It is a material that is kept in a safe manner.

  Specific examples of the adhesive layer include thermoplastic base polymers such as ethylene-vinyl acetate copolymer, polyester, polyamide, polyolefin, and polyurethane, natural rubber, styrene-butadiene block copolymer, and styrene-isoprene block copolymer. Resins mainly composed of thermoplastic elastomers such as polymers, styrene-ethylene-butylene-styrene block copolymers, styrene-ethylene-propylene-styrene copolymers and blended with tackifier resins and plasticizers. Is done.

  In order to improve the adhesion between the partition wall 14 and the adhesive layer, the partition wall 14 may be subjected to surface treatment by ultraviolet irradiation, plasma treatment, or the like, or a primer may be formed. Alternatively, a silane coupling agent may be added to the adhesive layer.

  The display medium 13 includes at least one kind of electrically responsive material. As the electroresponsive material, so-called electrophoretic particles in which colored charged particles such as white, black, and color move in response to an electric field, or nanoparticle materials that move by an electric field are used.

  In the present embodiment, the display medium 13 includes a dispersion medium, and white electrophoretic particles and black electrophoretic particles dispersed in the dispersion medium. The black electrophoretic particles are positively charged, and the white electrophoretic particles are negatively charged. As a result, when the potentials of the display electrodes 15a, 15b, and 15c are made lower than the potential of the common electrode 12, the positively charged black electrophoretic particles are moved in the dispersion medium toward the display electrodes 15a, 15b, and 15c. The white electrophoretic particles, which are electrophoresed so as to be attracted to the negative electrode and are negatively charged, migrate so as to be attracted toward the common electrode 12 in the dispersion medium. Further, when the potentials of the display electrodes 15a, 15b, and 15c are made higher than the potential of the common electrode 12, the positively charged black electrophoretic particles migrate so that the dispersion medium is attracted to the common electrode 12 side. The negatively charged white electrophoretic particles migrate so as to be attracted to the display electrodes 15a, 15b, and 15c in the dispersion medium. Then, by controlling the migration of such white electrophoretic particles and black electrophoretic particles, one of the white and black display colors is changed to the common electrode 12 side in each display region 18a, 18b, 18c. (That is, it can be selectively displayed on the viewing side).

  In the present embodiment, as shown in FIGS. 1 and 2, the display medium 13 is surrounded by an outer peripheral seal 17. In the illustrated example, the reflective display device 10 has a rectangular shape, and the outer peripheral seal 17 is disposed in a rectangular shape correspondingly.

  The outer peripheral seal 17 is formed by applying an adhesive such as an ultraviolet curable resin on one substrate 11 or the other substrate 16 in a rectangular shape using a dispenser, and then being cured by ultraviolet rays. Is formed. In addition to the ultraviolet curable resin, it can be constituted by a thermosetting resin, a room temperature curable resin, a heat seal resin, or the like. In addition to the dispenser, the outer peripheral seal 17 can be arranged by various printing methods or by thermocompression bonding.

  As shown in FIG. 1, the reflective display device 10 further includes a voltage application control unit 19 that applies a voltage to each of the display electrodes 15a, 15b, and 15c.

  In the present embodiment, the voltage application control unit 19 is electrically connected to the common electrode 12 and the display electrodes 15a, 15b, and 15c, and is at least a third potential (for example, + 15V) and negative with respect to the third potential. Driver IC 20 capable of selectively outputting a first potential (for example, 0V) having a positive polarity and a second potential (for example, + 30V) having a positive polarity with respect to the third potential, the driver IC 20 to the common electrode 12 and each And an IC controller 22 that controls voltage application to the display electrodes 15a, 15b, and 15c.

  The driver IC 20 has at least four output terminals and a power supply voltage input terminal. Each output terminal is electrically connected to the common electrode 12 or each display electrode 15a, 15b, 15c separately. The power supply voltage input terminal is electrically connected to the external power supply 21. The IC controller 22 is communicatively connected to the driver IC 20 and individually controls the potential output from each output terminal of the driver IC 20 for each output terminal.

  In the present embodiment, the voltage application control unit 19 connects the third potential (that is, + 15V) to the common electrode 12 at the display rewrite timing, and also displays a display region (for example, a reference numeral 18a) whose display color should be switched from black to white. The first potential (that is, 0 V) is connected to the display electrode 15a in the display area) for the first writing time length (for example, 300 ms). As a result, the polarity of the potential of the display electrode 15a with respect to the potential of the common electrode 12 becomes negative, the negatively charged white electrophoretic particles are adsorbed to the common electrode 12, and the positively charged black electrophoretic particles are As a result, white is displayed on the common electrode 12 side (viewing side) of the display region 18a. Next, the voltage application control unit 19 applies a second potential (that is, +30 V) to the display electrode 15a during the first adsorption prevention time length shorter than the first writing time length, for example, during the first adsorption prevention time length. It is designed to connect continuously. As a result, the polarity of the potential of the display electrode 15a with respect to the potential of the common electrode 12 becomes positive, negatively charged white electrophoretic particles are repelled from the common electrode 12, and positively charged black electrophoretic particles are As a result, the electrophoretic particles are repelled from the display electrode 15a, and excessive adsorption of the electrophoretic particles to the common electrode 12 or the display electrode 15b is suppressed. Thereafter, the voltage application control unit 19 connects the third potential (that is, + 15V) to the display electrode 15a. As a result, the potential of the common electrode 12 and the potential of the display electrode 15a become the same potential, and the black electrophoretic particles and the white electrophoretic particles are stopped in place, and as a result, the white electrophoretic particles in the display region 18a The display color is maintained as it is.

  Here, the longer the length of time during which the second potential (ie, +30 V) is connected to the display electrode 15a, the more negative the white electricity charged negatively by the electric field formed between the common electrode 12 and the display electrode 15a. As the electrophoretic particles gradually move away from the common electrode 12, the positively charged black electrophoretic particles gradually move away from the display electrode 15a, and as a result, the white display color of the display region 18a changes with time. Deteriorating, that is, grayish. In general, if the change rate of the visible light reflectance (hereinafter simply referred to as “reflectance”) in the display region is within 5%, the observer cannot perceive the deterioration of the display color, but if it exceeds 5%. The observer can perceive the deterioration of the display color. Therefore, in order to prevent the display color from deteriorating to a level that can be perceived by the observer, the first adsorption prevention time length is the display area before and after the second potential (that is, +30 V) is connected to the display electrode 15a. It is preferable that the time length is such that the change rate of the reflectance of 18a is within 5%. Here, “the reflectance change rate is within 5%” means that the reflectance after the change is in the range of reflectance before change × (95% to 105%). For example, when the reflectance of the display region 18a before connecting the second potential (+ 30V) to the display electrode 15a is 40%, the display region after connecting the second potential (that is, + 30V) to the display electrode 15a. It means that the reflectance of 18a is in the range of 40% × (95% to 105%) = 38% to 42%. The present inventor uses a spectrocolorimeter “CM-700d” manufactured by Konica Minolta before and after applying a reverse pulse for preventing adsorption, and uses an SCE (regular reflected light removal) mode, a Yxy color system. When the value of Y obtained in the above is measured as a reflectance and the rate of change is calculated, the first adsorption prevention time length is set to 0.1% to 5% of the first writing time length. It was confirmed that the reflectance change rate of the display region 18a before and after the second potential (that is, + 30V) is connected to the display electrode 15a of the display region 18a can be within 5%. Therefore, the first adsorption prevention time length is preferably 0.1% to 5% of the first writing time length. Specifically, for example, when the first writing time length is 300 ms, the first adsorption prevention time length is preferably 300 ms × (0.1% to 5%) = 0.3 ms to 15 ms.

  In addition, the voltage application control unit 19 connects the third potential (that is, + 15V) to the common electrode 12 at the display rewriting timing, and also displays a display area (for example, a display area indicated by reference numeral 18b) whose display color should be switched from white to black. A second potential (that is, +30 V) is connected to the display electrode 15b for a second writing time length (for example, 300 ms). As a result, the polarity of the potential of the display electrode 15b with respect to the potential of the common electrode 12 becomes positive, the positively charged black electrophoretic particles are adsorbed to the common electrode 12, and the negatively charged white electrophoretic particles are As a result, black is displayed on the common electrode 12 side (viewing side) of the display region 18b. Next, the voltage application control unit 19 applies a first potential (that is, 0 V) to the display electrode 15b during a second adsorption prevention time length shorter than the second writing time length, for example, during the second adsorption prevention time length. It is designed to connect continuously. As a result, the polarity of the potential of the display electrode 15b with respect to the potential of the common electrode 12 becomes negative, positively charged black electrophoretic particles are repelled from the common electrode 12, and negatively charged white electrophoretic particles are As a result, the electrophoretic particles are repelled from the display electrode 15b, and excessive adsorption of the electrophoretic particles to the common electrode 12 or the display electrode 15b is suppressed. Thereafter, the voltage application control unit 19 connects the third potential (that is, +15 V) to the display electrode 15b. Thereby, the electric potential of the common electrode 12 and the electric potential of the display electrode 15b become the same electric potential, and the black electrophoretic particles and the white electrophoretic particles are stopped in place, and as a result, the black electrophoretic particles in the display region 18b The display color is maintained as it is.

  Here, the longer the length of time for which the first potential (ie, 0 V) is connected to the display electrode 15b, the more positively charged black electricity is generated by the electric field formed between the common electrode 12 and the display electrode 15b. As the electrophoretic particles gradually move away from the common electrode 12, the negatively charged white electrophoretic particles gradually move away from the display electrode 15b. As a result, the black display color of the display region 18b changes with time. Deteriorating, that is, grayish. Therefore, in order to prevent the display color from greatly deteriorating, the second anti-adsorption time length is the rate of change in the reflectance of the display region 18b before and after the first potential (that is, 0V) is connected to the display electrode 15b. It is preferable that the time length is such that is within 5%.

  According to the actual verification by the present inventors, the second adsorption prevention time length is set to 0.1% to 5% of the second writing time length, so that the display electrode 15b in the display region 18b has the second length. It was confirmed that the change rate of the reflectance of the display region 18b before and after the connection of one potential (that is, 0 V) can be within 5%. Therefore, it is preferable that the second adsorption prevention time length is 0.1% to 5% of the second writing time length. Specifically, for example, when the second writing time length is 300 ms, the second adsorption prevention time length is preferably 300 ms × (0.1% to 5%) = 0.3 ms to 15 ms.

  In addition, the voltage application control unit 19 connects the third potential (that is, +15 V) to the common electrode 12 at the display rewriting timing, and displays the display area (for example, the display area indicated by reference numeral 18c) that should keep the display color as it is. A third potential (that is, + 15V) is also connected to the electrode 15c. By connecting the common electrode 12 and the display electrode 15c to the same potential (that is, + 15V), the black electrophoretic particles and the white electrophoretic particles are stopped in place, and as a result, the display region 18c. Is displayed as it is.

  In the present specification, the “display rewriting timing” means a timing at which a desired display image is displayed again to the observer on the reflective display device 10, for example, a predetermined cycle such as a digital display clock. The timing may be repeated at (for example, 1 s), or may be a timing that is manually given irregularly like a calculator.

  The voltage application control unit 19 may apply the voltage of magnitude V continuously for the writing time length T when applying the voltage of magnitude V for the writing time length T. A pulsed voltage having a magnitude V and a time length (pulse width) W may be repeatedly applied T / W times. In other words, it is only necessary that the sum of the voltage V voltage application times is equal to the writing time length T.

  Next, an example of a driving method of the reflective display device 10 having such a configuration will be described with reference to FIGS. 3 (a) to 3 (d) and FIG. Hereinafter, the display areas 18a, 18b, and 18c are also referred to as a first display area 18a, a second display area 18b, and a third display area 18c, respectively. The display electrodes 15a, 15b, and 15c are also referred to as a first display electrode 15a, a second display electrode 15b, and a third display electrode 15c, respectively.

  FIG. 3A to FIG. 3D are schematic views illustrating examples of display images displayed on the reflective display device 10 according to the present embodiment, respectively. FIG. 4 is a schematic diagram illustrating waveforms of voltages applied to the display electrodes 15a, 15b, and 15c when the display images illustrated in FIGS. 3A to 3D are switched in this order. In the present embodiment, the first writing time length is the same as the second writing time length, and in FIG. 4, “writing time” is displayed in both the first writing time length and the second writing time length. It is attached. In the present embodiment, the first adsorption prevention time length is the same as the second adsorption prevention time length, and in FIG. 4, both the first adsorption prevention time length and the second adsorption prevention time length are “adsorption prevention”. “Time” is displayed. Further, in FIG. 4, “same potential holding step” is displayed in a period from immediately after the “adsorption prevention time” ends to immediately before the next “writing time” starts.

  In the present embodiment, an initial image as shown in FIG. 3A is displayed in the initial state. That is, the first display area 18a and the third display area 18b are displayed in white, and the second display area 18b is displayed in black. In the initial state, the voltage application control unit 19 connects the third potential (ie, +15 V) as the same potential to the common electrode 12 and the display electrodes 15a, 15b, and 15c.

  First, the step of rewriting the initial image shown in FIG. 3A to the first image shown in FIG. 3B, that is, the display color of the first display area 18a and the third display area 18c is changed from white to black. A process of switching and switching the display color of the second display area 18b from black to white will be described.

  In this case, as shown in FIG. 4, the voltage application control unit 19 connects the third potential (that is, +15 V) to the common electrode 12 at the display rewrite timing. In addition, the voltage application control unit 19 connects the second potential (that is, +30 V) to the first display electrode 15a and the third display electrode 15c for the second writing time length (that is, 300 ms), and then the first potential ( That is, 0V) is continuously connected during the second adsorption prevention time length (that is, 0.3 ms to 15 ms), here, for the second adsorption prevention time length, and then the third potential (that is, +15 V) is connected thereafter. . Thereby, the display color of the 1st display area 18a and the 3rd display area 18c switches from white to black. On the other hand, the voltage application control unit 19 connects the first potential (that is, 0V) to the second display electrode 15b for the first writing time length (that is, 300 ms), and then the second potential (that is, + 30V) is first absorbed. During the prevention time length (that is, 0.3 ms to 15 ms), here, continuous connection is made during the first adsorption prevention time length, and then the third potential (that is, +15 V) is connected. As a result, the display color of the second display area 18b is switched from black to white.

  Here, after the second potential (that is, +30 V) is connected to the first display electrode 15 a and the third display electrode 15 c for the second writing time length (that is, 300 ms), the first potential (that is, 0 V) is second adsorbed. By connecting during the prevention time length (that is, 0.3 ms to 15 ms), the electrophoretic particles are excessively applied to the common electrode 12 or the display electrodes 15a and 15c in the first display region 18a and the third display region 18c. Adsorption is suppressed. Further, after the first potential (that is, 0 V) is connected to the second display electrode 15b for the first writing time length (that is, 300 ms), the second potential (that is, +30 V) is connected to the first adsorption prevention time length (that is, 0.3 ms). ˜15 ms), the electrophoretic particles are suppressed from being excessively adsorbed to the common electrode 12 or the second display electrode 15b in the second display region 18b.

  In the present embodiment, the first adsorption prevention time length is 0.1% to 5% of the first writing time length, that is, when writing to the first display electrode 15a and the third display electrode 15c. The first display area 15a and the third display area 18c have a time length within which the reflectance change rate of the first display area 18a and the third display area 18c before and after connecting a potential of the opposite polarity is within 5%. When a potential having a polarity opposite to that at the time of writing is connected to the display electrode 15c, the display color (that is, black) in the first display region 18a and the third display region 18c may deteriorate to a level that can be perceived by an observer. Is prevented. Further, the second adsorption prevention time length is 0.1% to 5% of the second writing time length, that is, the second time before and after connecting the second display electrode 15b with a potential having a polarity opposite to that at the time of writing. Since the change rate of the reflectance of the display area 18b is within 5%, the display in the second display area 18b is connected to the second display electrode 15b when a potential having a polarity opposite to that at the time of writing is connected. The color (i.e. white) is prevented from degrading to a level that can be perceived by the viewer.

  Next, the step of rewriting the first image shown in FIG. 3B to the second image shown in FIG. 3C, that is, the display color of the first display area 18a is switched from black to white, and the second A process of switching the display color of the display area 18b from white to black and maintaining the display color of the third display area 18d as it is will be described.

  In this case, as shown in FIG. 4, at the next display rewrite timing, the voltage application control unit 19 continues to connect the third potential (ie, +15 V) to the common electrode 12 and the third display electrode 15c. Thereby, the display color (namely, black) of the 3rd display area 18c is maintained as it is. On the other hand, the voltage application control unit 19 connects the first potential (that is, 0V) to the first display electrode 15a for the first writing time length (that is, 300 ms), and then the second potential (that is, + 30V) is first absorbed. During the prevention time length (that is, 0.3 ms to 15 ms), here, continuous connection is made during the first adsorption prevention time length, and then the third potential (that is, +15 V) is connected. As a result, the display color of the first display area 18a is switched from black to white. Further, the voltage application control unit 19 connects the second potential (ie, + 30V) to the second display electrode 15b for the second writing time length (ie, 300 ms), and then applies the first potential (ie, + 0V) to the second adsorption. During the prevention time length (that is, 0.3 ms to 15 ms), here, the second adsorption prevention time length is continuously connected, and then the third potential (that is, +15 V) is connected. As a result, the display color of the second display area 18b is switched from white to black.

  Here, after the first potential (that is, 0V) is connected to the first display electrode 15a for the first writing time length, the second potential (that is, + 30V) is connected during the first adsorption prevention time length, In the first display region 18a, excessive adsorption of the electrophoretic particles to the common electrode 12 or the first display electrode 15a is suppressed. In addition, after the second potential (that is, + 30V) is connected to the second display electrode 15b for the second writing time length, the first potential (that is, 0V) is connected for the second adsorption prevention time length, thereby In the 2 display area 18b, excessive adsorption of the electrophoretic particles to the common electrode 12 or the second display electrode 15b is suppressed.

  In the present embodiment, the first adsorption prevention time length is 0.1% to 5% of the first writing time length, that is, the first display electrode 15a is applied with a potential having a polarity opposite to that at the time of writing. Since the change rate of the reflectance of the first display area 18a before and after the connection is within 5%, the first display electrode 15a is connected with a potential having a polarity opposite to that at the time of writing. It is possible to prevent the display color (that is, white) in the one display area 18a from deteriorating to a level that can be perceived by the observer. Further, the second adsorption prevention time length is 0.1% to 5% of the second writing time length, that is, the second time before and after connecting the second display electrode 15b with a potential having a polarity opposite to that at the time of writing. Since the change rate of the reflectance of the display area 18b is within 5%, the display in the second display area 18b is connected to the second display electrode 15b when a potential having a polarity opposite to that at the time of writing is connected. The color (ie, black) is prevented from degrading to a level that can be perceived by the viewer.

  Next, the step of rewriting the second image shown in FIG. 3C to the third image shown in FIG. 3D, that is, the display color of the second display area 18b is switched from black to white, and the first A process of maintaining the display colors of the display area 18a and the third display area 18c as they are will be described.

  In this case, as shown in FIG. 4, at the next display rewrite timing, the voltage application control unit 19 applies a third potential (for example, +15 V) to the common electrode 12, the first display electrode 15a, and the third display electrode 15c. Continue to connect. Thereby, the display colors of the first display area 18a and the third display area 18c are maintained as they are. On the other hand, the voltage application control unit 19 connects the first potential (that is, 0V) to the second display electrode 15b for the first writing time length (that is, 300 ms), and then the second potential (that is, + 30V) is first absorbed. During the prevention time length (that is, 0.3 ms to 15 ms), here, continuous connection is made during the first adsorption prevention time length, and then the third potential (that is, +15 V) is connected. As a result, the display color of the second display area 18b is switched from black to white.

  Here, after the first potential (that is, 0V) is connected to the second display electrode 15a for the first writing time length, the second potential (that is, + 30V) is connected during the first adsorption prevention time length, In the second display region 18b, excessive adsorption of the electrophoretic particles to the common electrode 12 or the second display electrode 15b is suppressed.

  In the present embodiment, the first adsorption prevention time length is 0.1% to 5% of the first writing time length, that is, the second display electrode 15b is applied with a potential having a polarity opposite to that at the time of writing. Since the change rate of the reflectance of the second display region 18b before and after the connection is within 5%, the second display electrode 15b is connected with a potential having a polarity opposite to that at the time of writing. It is possible to prevent the display color (that is, white) in the two display area 18b from deteriorating to a level that can be perceived by the observer.

  According to the present embodiment as described above, at the display rewrite timing, the third potential is connected to the common electrode 12 and the first potential or the second potential is applied to the display electrodes 15a, 15b, and 15c for a predetermined writing time. By connecting only the length, the electrophoretic body in the display medium is attracted to the common electrode 12 or the display electrodes 15a, 15b, and 15c, and the display regions 18a, 18b, and 18c have the first color (for example, white) or the first color. Two colors (for example, black) are displayed. Next, the common electrode 12 or the display electrode 15a, 15b, 15c is connected to the third electrode by a potential having a polarity opposite to that at the time of writing during the adsorption preventing time length shorter than the writing time length. The electrophores adsorbed on the electrodes 15a, 15b, 15c are repelled from the electrodes 12 or 15a, 15b, 15c. As a result, excessive adsorption of the electrophoretic body to the electrode 12 or 15a, 15b, 15c is suppressed, and the electrophoretic body is smoothly separated from the common electrode 12 or the display electrodes 15a, 15b, 15c during the next rewriting. Can do. Therefore, the response speed of the reflective display device 10 is improved. Further, since the electrophoretic body is suppressed from being excessively adsorbed to the electrode 12 or 15a, 15b, 15c, the electricity that is adsorbed to the electrode 12 or 15a, 15b, 15c and does not leave is generated per one rewriting. The number of migrating particles is reduced. Thereby, the rewrite life as a product, that is, the maximum number of rewrites can be extended.

  In addition, according to the present embodiment, the change in reflectance of the display area before and after connecting a potential having a polarity opposite to that at the time of writing to the display electrode corresponding to the display area where the display color is switched. Since the rate is 5% or less, the display state deteriorates to a level that can be perceived by the observer when a potential of the opposite polarity to that at the time of writing is connected to the display electrode for the length of the anti-adsorption time. Can be prevented. Specifically, for example, the first suction prevention time length is 0.1% to 5% of the first writing time length, and the second suction prevention time length is 0. 2 of the second writing time length. The time length is 1% to 5%. According to the actual verification by the present inventors, within such a numerical range, the reflectance change rate of the display area before and after connecting a potential having a polarity opposite to that at the time of writing to the display electrode is within 5%. It can be.

  In the present embodiment, the first write time length is the same as the second write time length. However, the first write time length is not limited to this, and the first write time length is different from the second write time length. Also good.

  In the present embodiment, the third potential (for example, +15 V) is connected to the common electrode 12 from the voltage application control unit 19, but the present invention is not limited to this. For example, the third potential is set to GND. The GND potential may be directly connected to the common electrode 12 at the potential (0 V). In this case, the voltage application control unit 19 sets the display electrodes 15a, 15b, and 15c to the third potential (0V), the first potential having a negative polarity with respect to the third potential (for example, −15V), and the third potential. On the other hand, it is only necessary that a second potential of positive polarity (for example, +15 V) can be selectively connected.

  Various modifications can be made to the above-described embodiment.

  For example, as shown in FIGS. 5 to 7, the voltage application control unit 19 applies a first potential (for example, the display electrode 15a corresponding to a display region (for example, a display region denoted by reference numeral 18a) that switches the display color from white to black. 0V) during the second anti-adsorption time period, an operation of continuously connecting the first potential (ie, 0V) and an operation of continuously connecting the third potential (eg, + 15V). It may be repeated alternately. Here, as shown in FIG. 6, the sum of the connection times of the first potential and the connection times of the third potential therebetween is equal to the second adsorption prevention time length.

  In this case, the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15a can be more effectively peeled off from each electrode. According to the actual verification by the present inventors, when the first potential is connected to the display electrode 15a during the second adsorption prevention time length, the operation of continuously connecting the first potential and the third potential are By alternately repeating the operation of continuous connection, it is possible to obtain an adsorption prevention effect in a shorter time than when the first potential is continuously connected for the second adsorption prevention time length. Was confirmed.

  This is considered to be due to the following actions. That is, by connecting the first potential to the display electrode 15a, negatively charged white electrophoretic particles are repelled from the display electrode 15a, and positively charged black electrophoretic particles are transferred from the common electrode 12. By repelling and moving each electrophoretic particle, a pressure gradient is generated in the display medium 13, that is, the pressure of the display medium 13 in the vicinity of the display electrode 15a and in the vicinity of the common electrode 12 is reduced. Next, by connecting the third potential to the display electrode 15a, the electrical force acting on each electrophoretic particle disappears, and the pressure gradient of the display medium 13 is relaxed, that is, the display electrode 15a. And the pressure of the display medium 13 in the vicinity of the common electrode 12 increases. Then, the connection of the first potential to the display electrode 15a and the connection of the third potential are alternately repeated, thereby increasing the number of times pressure is applied from the display medium 13 to the common electrode 12 and the display electrode 15a. Therefore, the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15a are effectively peeled off from the electrodes.

  In the example shown in FIGS. 5 to 7, when the first potential (that is, 0V) is connected to the display electrode 15a during the second adsorption prevention time length, the continuous connection time length T11 of the first potential (that is, 0V). Is preferably 1 ms or more. When the continuous connection time length T11 of the first potential is less than 1 ms, the effect of peeling the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15a from the electrode is reduced. This is considered to be because the continuous connection time length T11 of the first potential is too short to form a sufficient pressure gradient in the display medium 13. In addition, the continuous connection time length T12 of the third potential (that is, + 15V) is preferably 500 μs or more. If the continuous connection time length T12 of the third potential is less than 500 μs, the anti-adsorption effect is the same as when the first potential is continuously connected for the second anti-adsorption time length. This is considered to be because the continuous connection time length T12 of the third potential is too short to sufficiently relax the pressure gradient of the display medium 13.

  Further, as shown in FIGS. 5 to 7, the voltage application control unit 19 applies the second potential (to the display electrode 15b corresponding to a display area (for example, a display area indicated by reference numeral 18b)) that switches the display color from black to white. For example, when connecting +30 V) during the first adsorption prevention time length, an operation of continuously connecting the second potential (that is, +30 V), and an operation of continuously connecting the third potential (that is, +15 V), May be repeated alternately. Here, as shown in FIG. 7, the sum of the connection times of the second potential and the connection times of the third potential therebetween is equal to the first adsorption prevention time length.

  In this case, the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15b can be effectively peeled off from each electrode. According to the actual verification by the present inventors, when the second potential is connected to the display electrode 15b for the first adsorption prevention time length, the operation of continuously connecting the second potential and the third potential are continuously performed. It is confirmed that the anti-adsorption effect can be obtained in a shorter time by alternately repeating the operation of connecting to the second potential than when connecting the second potential continuously for the first anti-adsorption time length. It was done.

  This is considered to be due to the following actions. That is, by connecting the second potential to the display electrode 15b, positively charged black electrophoretic particles are repelled from the display electrode 15b, and negatively charged white electrophoretic particles are removed from the common electrode 12. By repelling and moving each electrophoretic particle, a pressure gradient is generated in the display medium 13, that is, the pressure of the display medium 13 in the vicinity of the display electrode 15b and in the vicinity of the common electrode 12 is reduced. Next, by connecting the third potential to the display electrode 15b, the electric force acting on each electrophoretic particle disappears, and the pressure gradient of the display medium 13 is relaxed, that is, the display electrode 15b. And the pressure of the display medium 13 in the vicinity of the common electrode 12 increases. Then, by connecting the second potential to the display electrode 15b and connecting the third potential alternately, the number of times pressure is applied from the display medium 13 to the common electrode 12 and the display electrode 15b increases. Therefore, the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15b are effectively peeled off from the electrodes.

  In the example shown in FIGS. 5 to 7, when the second potential (that is, + 30V) is connected to the display electrode 15b during the first adsorption prevention time length, the continuous connection time length T21 of the second potential (that is, + 30V). Is preferably 1 ms or more. When the continuous connection time length T21 of the second potential is less than 1 ms, the effect of peeling the electrophoretic particles adsorbed on the common electrode 12 and the display electrode 15b from the electrode is reduced. This is considered to be because the continuous connection time length T21 of the second potential is too short to form a sufficient pressure gradient in the display medium 13. The continuous connection time length T22 of the third potential (ie + 15V) is preferably 500 μs or more. When the continuous connection time length T22 of the third potential is less than 500 μs, the adsorption prevention effect is the same as when the second potential is continuously connected for the first adsorption prevention time length. This is considered because the continuous connection time length T22 of the third potential is too short to sufficiently relax the pressure gradient of the display medium 13.

DESCRIPTION OF SYMBOLS 10 Reflective type display apparatus 11 One board | substrate 12 Common electrode 13 Display medium 14 Partition 15a Display electrode 15b Display electrode 15c Display electrode 16 The other board | substrate 17 Perimeter seal 18a Display area 18b Display area 18c Display area 19 Voltage application control part 20 Driver IC
21 External power supply 22 IC controller

Claims (10)

A display medium containing at least one or more kinds of electrically responsive materials is sealed between two opposing substrates, at least one of which has a light-transmitting property and on which electrodes are respectively formed, and the two substrates A reflective display device that performs a desired display when a predetermined electric field is applied therebetween,
Between one substrate and the other substrate, a common electrode covering a plurality of display areas, a display medium layer in which the display medium is arranged, and a plurality of display electrodes corresponding to each of the plurality of display areas Are provided in this order from the one substrate side to the other substrate side,
Each of the plurality of display areas can display the first color when the polarity of the potential connected to the display electrode corresponding to the display area is negative with respect to the potential connected to the common electrode, A method of driving a reflective display device that can display a second color when the polarity is positive,
At the display rewrite timing,
A third potential is connected to the common electrode,
The display electrode corresponding to the display region for switching the display color from the second color to the first color is connected to the first potential having a negative polarity with respect to the third potential for the first writing time length, and then A second potential having a positive polarity with respect to the third potential is connected for a first adsorption prevention time length shorter than the first writing time length, and then the third potential is connected;
The display electrode corresponding to the display area for switching the display color from the first color to the second color is connected to the second potential for the second writing time length, and then the first potential is set to the second writing time length. A method for driving a reflective display device, comprising: connecting for a shorter second anti-adsorption time, and then connecting the third potential. When the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first adsorption prevention time length, the second potential is continuously connected. Alternately repeating the step and the step of continuously connecting the third potential,
When the first potential is connected to the display electrode corresponding to the display region for switching the display color from the first color to the second color, the first potential is continuously connected. The method of driving a reflective display device according to claim 1, wherein the step and the step of continuously connecting the third potential are alternately repeated. When the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first adsorption prevention time length, the continuous connection time length of the second potential is 1 ms or more, and the continuous connection time length of the third potential is 500 μs or more,
When the first potential is connected to the display electrode corresponding to the display area for switching the display color from the first color to the second color during the second adsorption prevention time length, the continuous connection time length of the first potential is 3. The driving method of the reflective display device according to claim 2, wherein the time is 1 ms or longer, and the continuous connection time length of the third potential is 500 μs or longer. The first adsorption prevention time length is such that the change rate of the reflectance of the display area before and after connecting the second potential to the display electrode corresponding to the display area for switching the display color from the second color to the first color is 5. % Of the time,
The second adsorption prevention time length is such that the change rate of the reflectance of the display area before and after connecting the first potential to the display electrode corresponding to the display area for switching the display color from the first color to the second color is 5. 4. The method for driving a reflection type display device according to claim 1, wherein the time length is within%. The first adsorption prevention time length is a time length of 0.1% to 5% of the first writing time length,
5. The driving of a reflective display device according to claim 1, wherein the second adsorption prevention time length is 0.1% to 5% of the second writing time length. 6. Method. A display medium containing at least one or more kinds of electrically responsive materials is sealed between two opposing substrates, at least one of which has a light-transmitting property and on which electrodes are respectively formed, and the two substrates A reflective display device that performs a desired display when a predetermined electric field is applied therebetween,
A display medium layer provided between one substrate and the other substrate on which the display medium is disposed;
A common electrode provided on the one substrate and covering a plurality of display areas;
A plurality of display electrodes provided on the other substrate and corresponding to each of the plurality of display regions;
A voltage application controller for applying a voltage to each display electrode;
With
Each of the plurality of display areas can display the first color when the polarity of the potential connected to the display electrode corresponding to the display area is negative with respect to the potential connected to the common electrode, The second color can be displayed when the polarity is positive,
The third electrode is connected to the common electrode;
The voltage application control unit, at the display rewrite timing,
The display electrode corresponding to the display region for switching the display color from the second color to the first color is connected to the first potential having a negative polarity with respect to the third potential for the first writing time length, and then A second potential having a positive polarity with respect to the third potential is connected for a first adsorption prevention time length shorter than the first writing time length, and then the third potential is connected;
The display electrode corresponding to the display area for switching the display color from the first color to the second color is connected to the second potential for the second writing time length, and then the first potential is set to the second writing time length. A reflective display device, wherein the third potential is connected after a shorter second anti-adsorption time length, and then the third potential is connected. The voltage application controller is
When the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first adsorption prevention time length, the second potential is continuously connected. Alternately repeating the operation and the operation of continuously connecting the third potential,
When the first potential is connected to the display electrode corresponding to the display region for switching the display color from the first color to the second color, the first potential is continuously connected. The reflective display device according to claim 6, wherein an operation and an operation of continuously connecting the third potential are alternately repeated. When the second potential is connected to the display electrode corresponding to the display area for switching the display color from the second color to the first color during the first adsorption prevention time length, the continuous connection time length of the second potential is 1 ms or more, and the continuous connection time length of the third potential is 500 μs or more,
When the first potential is connected to the display electrode corresponding to the display area for switching the display color from the first color to the second color during the second adsorption prevention time length, the continuous connection time length of the first potential is The reflective display device according to claim 7, wherein the reflection type display device is 1 ms or longer, and a continuous connection time length of the third potential is 500 μs or longer. The first adsorption prevention time length is such that the change rate of the reflectance of the display area before and after connecting the second potential to the display electrode corresponding to the display area for switching the display color from the second color to the first color is 5. % Of the time length,
The second anti-adsorption time length is such that the reflectance change rate of the display area before and after connecting the first potential to the display electrode corresponding to the display area for switching the display color from the first color to the second color is 5. The reflective display device according to claim 6, wherein the time length is within%. The first adsorption prevention time length is a time length of 0.1% to 5% of the first writing time length,
The reflective display device according to claim 6, wherein the second adsorption prevention time length is 0.1% to 5% of the second writing time length.

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