JP2006330528A - Electrodeposition type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeposition display device wherein display viewing easiness is improved. <P>SOLUTION: In the electrodeposition display device wherein a chromophoric material is colored or decolored by applying electricity between a transparent electrode and a counter electrode to perform display, one frame to be a display selection period forming one screen is divided into a plurality of sub frames, each driving voltage is applied in each sub frame, each sub frame is generated at an interval and the sub frames are superposed to perform display of one screen. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a driving method of an electrodeposition type display device in which a coloring state changes due to metal deposition on a transparent electrode and dissolution of the metal from the transparent electrode.

  2. Description of the Related Art Conventionally, a display device called an electronic paper, a paper-like display, a digital paper, or the like has been proposed that displays an image by changing optical absorption or reflection by an electric field.

  As an element whose optical absorption and reflection change due to an electric field, a microcapsule containing rotating particles combined with hemispheres with different colors and electrical characteristics together with an insulating liquid, and a solvent in which electrophoretic particles are dispersed are used. There are microcapsules that are colored and encapsulate this solvent (see, for example, Patent Document 1), and a liquid crystal / polymer composite film containing a dichroic dye and a smectic liquid crystal. A display device using these technologies has a memory property, can hold image information even without a power source, and is a reflective display device, and thus is expected as a substitute for paper. As a substrate with electrodes, for example, a PET (polyethylene terephthalate) film or the like can be used. Therefore, the display device is thin, light, and can be bent.

  In recent years, among electrochromic display devices using a color change of a substance due to a change in voltage, an electrodeposition type display device capable of realizing a paper-like contrast and whiteness has been proposed. High reflectivity can be obtained in an electrodeposition type display device in which a metal is deposited and dissolved on a transparent electrode. In this electrodeposition type display device, silver halide is dissolved in a display composition together with a supporting electrolyte containing halogen, and color develops when silver is deposited on a transparent electrode by a predetermined potential (patent). See references 2 and 3.) In addition, the metal on the transparent electrode is re-dissolved by the reverse potential, and the color is erased.

Further, when a polymer solid electrolyte in which titanium dioxide is dispersed (see Non-Patent Document 1) is used in an electrodeposition type display device, it is possible to realize a paper-like reflectance and a contrast such as printing.
Japanese Patent Laid-Open No. 01-086116 (Claims) US Pat. No. 4,240,716 (claims) US Pat. No. 4,240,717 (claims) “Rate News Paper: Electrodeposition Device for Paper-Like Display”, SID 02 Digest, p. 39-41

  In an electrodeposition type display device, display of an image can be realized by using a deposition overvoltage at which metal starts to deposit on an electrode as a threshold voltage. In this case, (1) in order to realize a display with a high contrast, it is necessary to apply a voltage 1.5 to 2 times the deposition overvoltage, and (2) in order to realize a display with a high reflectance in the background portion, It is necessary to set the distance between the transparent electrode and the counter electrode to 50 to 100 μm. When the thickness is less than 50 μm, the reflection effect of titanium dioxide or the like is insufficient.

  Regarding the display in the electrodeposition type display device, there is a problem of bleeding due to metal deposition around the display pixel due to the above (1) and (2). This will be described with reference to FIG. 2, which is a partial view of an electrodeposition type display device when facing the display screen. FIG. 2 shows a state in which a drive voltage is applied between the predetermined signal electrode line 21 and the scan electrode line 22. In this case, metal is deposited on the selected pixel 23. Under the conditions (1) and (2), metal is deposited on the outer side of the selected pixel 23, and a bleeding portion 24 is formed. In particular, it was confirmed that electric field concentration occurred at the edge portion of the transparent electrode (scanning electrode in FIG. 2), and the bleeding became stronger.

  In addition, it has been found that, in a display pixel where metal is once deposited, the electrode resistance is reduced, and a small amount of metal is also deposited in a non-display pixel surrounded by the display pixel. It is a problem to reduce the thickness.

  Such a problem is particularly remarkable when a passive matrix drive image display in which a voltage is applied to the entire signal electrode during scanning is employed. An object of the present invention is to solve these problems and to provide easy-to-see display in an electrodeposition type display device. Still other objects and advantages of the present invention will become apparent from the following description.

  According to one aspect of the present invention, coloring and decoloring are repeatedly performed between a transparent electrode and a counter electrode by depositing a metal on the transparent electrode and dissolving the metal from the transparent electrode. In an electrodeposition type display device in which a display composition containing a chromogenic material capable of forming is disposed, and the chromogenic material is colored or decolored by energization between the transparent electrode and the counter electrode. One frame, which is a display selection period for forming one screen, is divided into a plurality of subframes, each drive voltage is applied in each subframe, and each subframe is generated at intervals to display one screen. There is provided an electrodeposition type display device adapted to superimpose.

  It is preferable that the present electrodeposition type display device displays an image by passive matrix driving because a clearer effect can be obtained.

  From the viewpoint of suppressing bleeding and metal deposition on adjacent pixels, each of the drive voltages is preferably less than 1.5 times the metal deposition overvoltage.

  In this electrodeposition type display device, it may be preferable to change the amount of metal deposited in one frame. This makes it possible to perform gradation display by changing the display density in the same pixel.

  In order to smoothly deposit the metal on the transparent electrode and dissolve the metal from the transparent electrode, the counter electrode is preferably made of the same type of metal as the metal to be deposited / dissolved. Moreover, it is preferable that the metal which precipitates / dissolves is silver.

  As equipment, it is preferable that a display IC (integrated circuit: integrated circuit) is mounted in view of simplification and miniaturization of the apparatus.

  According to the present invention, an electrodeposition type display device with improved display visibility can be realized.

  Embodiments of the present invention will be described below with reference to the drawings, examples and the like. In addition, these figures, Examples, etc. and description illustrate the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention. In the drawings, the same reference numeral represents the same element.

  The electrodeposition type display device according to the present invention provides color development and decoloration between the transparent electrode and the counter electrode by the deposition of metal on the transparent electrode and the dissolution of metal from the transparent electrode. A display composition containing a chromogenic material that can be repeatedly applied is provided, and the chromogenic material is colored or decolored by energization between the transparent electrode and the counter electrode to perform display. Usually, a battery, a power supply, a drive circuit, and the like are appropriately disposed around and on the back of the display unit of the electrodeposition type display device.

  The display drive may be either constant voltage drive or constant current drive, and the shape of the voltage pulse is not particularly limited. A rectangular wave, a triangular wave, a sine wave, or the like can be employed.

<Driving system according to the present invention>
In the driving method according to the present invention, one frame is divided into a plurality of sub-frames, each driving voltage is applied to each sub-frame, and each sub-frame is generated continuously or at an interval to generate one screen. Overlay the display. That is, when displaying one screen, the application for color development to each pixel is performed in a plurality of times. Then, the respective colored displays are superimposed by the respective applications (applications by subframes), and control is performed so as to finally form one screen. Here, one frame means a period (display selection period) in which individual pixels are selected to form one screen. For example, in the case of a passive matrix system having a signal electrode line and a scan electrode line, the drive voltage is applied to each pixel where the selected signal electrode line and the scan electrode line intersect when forming one screen. Means the period during which is applied.

  The manner in which one frame is divided into a plurality of subframes will be described with reference to FIGS. 3 and 4, the vertical axis represents the drive voltage, and the horizontal axis represents time. FIG. 3 illustrates a conventional driving method in which a frame is not divided into subframes, and FIG. 4 illustrates a driving method in which a frame is divided into a plurality of subframes.

  If the subframe is generated as shown in FIG. 4, the metal is further deposited on the previously deposited metal in the next frame. In this way, superimposition of display on one screen is realized. In FIG. 4, each subframe occurs at equal intervals, and each subframe has the same length. However, these are not essential conditions, and the intervals between the subframes are different or the subframes have different lengths. It may be.

  By providing a time during which no voltage is applied between the subframes, bleeding and deposition on non-display pixels in the above-described electrodeposition display device can be prevented or reduced. As a result, the visibility of display can be improved. This is because the amount of precipitation on the non-display pixels is much smaller than the amount of precipitation on the selected pixels. Therefore, if no voltage is applied at an appropriate frequency, the precipitate dissolves in the display composition in the meantime. It is because it will be cut off.

  In the selected pixel, even under such conditions, the amount of deposited metal is large, and dissolution of the metal when no voltage is applied does not cause a problem. Then, during the next subframe, more metal is deposited on the previously deposited metal. As a result, the contrast increases like an overwriting card, and the visibility of the display can be improved.

  This state will be schematically described with reference to FIG. FIG. 5A shows a state where a drive voltage of the first subframe is applied to the selected pixel 23 (scanned), and the selected pixel 23, the bleeding portion 24, and the adjacent pixel 51 on which metal is deposited appear. Is schematically shown. When examined by the CV method (cyclic voltammetry method), metal deposition does not occur when the driving voltage is lower than the deposition overvoltage. On the other hand, once the metal is deposited, metal deposition occurs even at a voltage lower than the deposition overvoltage. A phenomenon unique to electrodeposition that occurs is observed. This is considered to be the reason for bleeding and metal deposition on adjacent pixels.

  When the state of FIG. 5A shifts to the non-scanning state, the metal on the bleeding portion 24 and the adjacent pixel 51 disappears due to the dissolution of the metal as shown in FIG. 5B. Next, when the driving voltage of the second subframe is applied (scanned) to the selected pixel 23, metal is further deposited on the deposited metal on the selected pixel 23 as shown in FIG. Metal again deposits on the exposed portion 24 and the adjacent pixel 51. When the state is shifted to the non-scanning state again in this state, the metal on the bleeding portion 24 and the adjacent pixel 51 disappears again due to the dissolution of the metal as shown in FIG.

  In this way, by forming one screen with a plurality of sub-frames, bleeding or metal deposition on adjacent pixels is prevented or reduced, and overwriting of display is realized. FIG.5 (e) is XX sectional drawing of FIG.5 (b), FIG.5 (f) is XX sectional drawing of FIG.5 (d). Comparing these figures, it can be understood that the thickness of the deposited metal 52 on the selected pixel 23 is increased and the display is overwritten.

  The electrodeposition type display device according to the present invention can be applied to both a method of displaying an image by passive matrix driving and a method of displaying an image by active matrix driving. Since a voltage is applied to the whole, bleeding and metal deposition are likely to occur in adjacent pixels, so that the effect of applying the present invention is greater.

  The above is the effect due to metal dissolution between subframes, but when multiple subframes are used, the drive voltage is lowered to further prevent bleeding and metal deposition on adjacent pixels. Or it can be reduced.

  That is, when one frame is not divided into a plurality of subframes as in the prior art, a predetermined drive voltage is required to ensure the deposition of metal on the selected pixel. Also, bleeding and metal deposition on adjacent pixels are likely to occur. In contrast, if one frame is divided into a plurality of sub-frames as in the present invention, the display contrast can be kept sufficiently high due to the overwriting effect even when a driving voltage lower than the conventional one is adopted, By reducing the drive voltage, it is possible to reduce the spread of the electric field at the transparent electrode and the counter electrode and the leakage of current to the adjacent pixels, so that bleeding and metal deposition on the adjacent pixels can be made difficult to occur. is there.

  The drive voltage in this case is preferably less than 1.5 times the metal deposition overvoltage, and more preferably less than 1.3 times the metal deposition overvoltage. The drive voltage in the present invention means an effective voltage, that is, a potential difference between a signal electrode line and a scan electrode line in a pixel where a signal electrode line and a scan electrode line described later intersect.

  The drive voltage may not be the same for each subframe. In general, when the deposited metal already exists, the deposition of the metal tends to be easier, so that the drive voltage after the second subframe can be lowered below the drive voltage of the first subframe.

  Note that the display density in a certain pixel is determined by the amount of metal deposited on that pixel in one frame. Therefore, if the amount of deposited metal is changed, gradation display by changing the display density becomes possible. The amount of metal deposited on a pixel in one frame is determined by the drive voltage applied in each subframe, the drive time (or the time between subframes), and so on. Gradation can be displayed by changing the display density.

<Components of an electrodeposition type display device>
FIG. 1 shows a schematic cross-sectional view of a display panel of an electrodeposition type display device. In the electrodeposition type display device, the metal is deposited on the transparent electrode and the metal from the transparent electrode is placed between the transparent electrode 2 and the counter electrode 4 provided on the substrates 1 and 5, respectively. A display composition 6 containing a chromogenic material capable of repeatedly performing color development and decoloring by dissolution is disposed, and the chromogenic material is colored or developed by energization between the transparent electrode and the counter electrode. This is done by decoloring. The person's line of sight is directed in the direction of the arrow. The display composition 6 is sealed by the substrates 1 and 5 and the sealing wall 3.

The transparent electrode according to the present invention needs to have high transmittance for visible light in order to perform display. For example, ITO (indium tin oxide), FTO (fluorine-doped tin oxide), SnO ₂ is formed on the transparent electrode side substrate surface. Such a conductive material is deposited or applied. Further, an inorganic material layer such as silicon oxide or aluminum oxide, or an organic material film such as polyamide may be formed between the conductive material layer and the transparent electrode side substrate. Thereby, the effect of improving the adhesiveness of the conductive material layer and improving the barrier property against gas or solvent can be obtained. The display of the image is performed by causing a color developing substance in the vicinity of the transparent electrode to be colored by electrochemical oxidation or reduction reaction by energization between the electrodes.

The material used for the counter electrode is not particularly limited as long as it is a conductive substance. For example, a highly conductive metal such as silver, gold, platinum, aluminum, or copper, or a conductive material such as carbon, polyaniline, or polypyrrole. Select from thin films of metal oxides such as polymers, ITO, FTO, SnO ₂ , vapor-deposited films, sputtered films, and, if possible, coated films using these powder pastes and sintered bodies thereof. Can do.

  The counter electrode is preferably made of the same metal as the metal deposited on the transparent electrode. In this way, metal ions are supplied from the counter electrode to the display composition when metal is deposited on the transparent electrode, thereby reducing the remelting of the metal deposited on the transparent electrode and improving the memory performance. Can be made. This metal may be an alloy with another metal. Moreover, the thing laminated | stacked on a different kind of material may be sufficient.

  The transparent electrode and the counter electrode are usually arranged directly on the substrate or through a layer provided for the purpose of improving the adhesion between the transparent electrode and the counter electrode. The material of the transparent electrode side substrate needs to be transparent, and transparent glass such as quartz glass, soda glass, borosilicate glass, etc. can be used, but is not limited thereto, polyethylene naphthalate, polyethylene Thermoplastic polyester resins such as terephthalate, cellulose esters such as polyamide, polycarbonate and cellulose acetate, fluoropolymers such as polyvinylidene fluoride, polytetrafluoroethylene and hexafluoropropylene, polyethers such as polyoxymethylene, polyacetal, Polyolefins such as polystyrene, polyethylene, polypropylene, methylpentene polymer, cycloolefin resins represented by product brands such as ZEONOR, ZEONEX (manufactured by Nippon Zeon) and ARTON (manufactured by JSR) Polyimides such as fine polyimide amide and polyetherimide may be mentioned as examples.

  In particular, when considering light transmittance and resistance to polar solvents, it is preferable to use a glass substrate, a thermoplastic polyester resin, or a substrate made of a cycloolefin resin.

  The material of the counter electrode side substrate does not necessarily need to be transparent. In addition to transparent glass such as quartz glass, soda glass, and borosilicate glass, metal and ceramic, thermoplastic polyester resins such as polyethylene naphthalate and polyethylene terephthalate, polyamide , Cellulose esters such as polycarbonate and cellulose acetate, fluoropolymers such as polyvinylidene fluoride and tetrafluoroethylene-hexafluoropropylene copolymer, polyethers such as polyoxymethylene, polyacetal, polystyrene, polyethylene, polypropylene, methylpentene Polyolefins such as polymers, cycloolefin resins represented by product brands such as ZEONOR, ZEONEX (manufactured by ZEON CORPORATION), ARTON (manufactured by JSR), and polyimide-amino Polyimides such or polyetherimide and the like.

  Especially, when the tolerance with respect to a polar solvent is considered, it is preferable to use the board | substrate made from a glass substrate, a thermoplastic polyester resin, or a cycloolefin resin.

  In any case, the substrate may be a highly rigid substrate that does not bend easily, or in order to utilize the excellent mechanical strength according to the present invention, a flexible film-like structure and It is also possible to do.

  The display composition according to the present invention includes a chromogenic material capable of repeatedly performing color development and decoloration by the deposition of metal on the electrode and the dissolution of metal from the electrode.

  As this color-forming substance, it is preferable that the metal to be deposited is silver because of its high display speed and high contrast. For example, silver halides such as silver fluoride, silver chloride, silver bromide and silver iodide can be used, and it is particularly preferable to use silver iodide having high solubility. The concentration of silver iodide is preferably 0.05 to 2.5 mol / L, more preferably 1.5 to 2.0 mol / L.

  Examples of the supporting electrolyte containing iodine for dissolving silver iodide in the display composition include ammonium iodide, tetramethylammonium iodide, tetra-n-pentylammonium iodide, tetraethylammonium iodide, tetraiodide iodide, and the like. Iodides such as n-hexylammonium, potassium iodide and sodium iodide, and bromides such as tetramethylammonium bromide and tetra-n-hexylammonium bromide can be used. From the viewpoint of the display speed of the electrodeposition type display device and the solubility of silver iodide, it is preferable to use iodide, particularly ammonium iodide. Ammonium iodide is preferably in the range of 0.5 to 2 times the silver halide concentration, and more preferably at a molar concentration comparable to that of silver iodide.

  Examples of other supporting electrolytes include known materials such as perchlorate, thiocyanate, and sulfate such as tetrabutylammonium perchlorate, tetraethylammonium perchlorate, isocyanate thiocyanate, and sodium sulfide.

  As other additives, mercaptobenzimidazole, coumarin, oxalic acid, fumaric acid, maleic acid, lactic acid, malonic acid, ammonium thiocyanate, potassium thiocyanate, triethanolamine, and the like may be appropriately added.

  Solvents for dissolving the above-described silver halide, supporting electrolyte, and additives include dimethylformamide (DMF), dimethylsulfoxide (DMSO), diethylformamide (DEF), N, N-dimethylacetamide (DMAA), N-methyl. Pyrrolidone (NMP), propylene carbonate (PC), ethylene carbonate (EC), hexamethylphosphoric triamide, sulfolane, acetonitrile (AN), 2-ethoxyethanol (EEOH), 2-methoxyethanol (MEOH), dioxolane (DOL) , Ethyl acetate (EA), tetrahydrofuran (THF), methyltetrahydrofuran (MeTHF), dimethoxyethane (DME), γ-butyrolactone (GBL), and the like may be used.

  In the display composition, a polymer can be added to form a skeleton that mechanically retains the solvent in which the above-described silver halide, supporting electrolyte, and additives are dissolved. The polymer is not particularly limited as long as it does not contradict the gist of the present invention, and known materials such as polyvinyl pyrrolidone, polyvinylidene fluoride, polyacrylonitrile, polyethylene oxide and the like can be used. Further, the polymer may be formed by polymerizing and crosslinking the monomer. The monomer is not particularly limited as long as it is not contrary to the gist of the present invention. (1) Monofunctional monomer such as methoxydiethylene glycol methacrylate, methoxytriethylene glycol acrylate, phenoxyethyl acrylate, etc. (2) Bifunctional monomer as ethylene Glycol di (meth) acrylate, propylene glycol di (meth) acrylate, etc. (3) As trifunctional monomer, Trimethylolpropane tri (meth) acrylate, Tetramethylol methane tri (meth) acrylate, etc. (4) As tetrafunctional monomer , Tetramethylolmethane tetraacrylate, pentaerythritol tetraacrylate, etc. (5) As hexafunctional monomers, known materials such as dipentaerythritol hexaacrylate are listed. It is. The alkyl chain length in the monomer may be arbitrary.

  When a polymerization initiator is required, it can be selected from known materials such as an azo polymerization initiator and a peroxide. The monomer is preferably added to the display composition in an amount of 5 to 20% by weight. The polymerization initiator is preferably added in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the monomer. As a polymerization method, it can be carried out by any method such as heat, light and electron beam.

  It is preferable to add a pigment to the display composition according to the present invention in order to improve contrast. Examples of the pigment include titanium dioxide, silicon dioxide, calcium carbonate, and aluminum oxide. From the viewpoint of the concealment rate, it is preferable to use titanium dioxide. The pigment is added in an amount of 5 to 100 parts by weight based on 100 parts by weight of the display composition. In addition, in order to improve the dispersibility of titanium dioxide, you may use well-known polymers, such as polyvinylpyrrolidone, as a dispersing agent. Alternatively, the surface treatment of titanium dioxide with a silane coupling agent can be performed so as not to affect the repeated stability of display of the display device.

<Assembly of matrix drive electrodeposition type display device>
The matrix drive electrodeposition type display device according to the present invention is assembled as follows, for example. First, a substrate provided with a transparent electrode etched in a stripe shape and a substrate provided with a counter electrode made of a stripe-shaped metal are bonded together with the electrodes facing each other. As the adhesive to be bonded, photocuring, thermosetting, hot melt type, epoxy two-component mixed type, or the like can be used. This adhesive needs to have low solubility in the display composition according to the present invention, and it is preferable to use a hot-melt adhesive made of an olefin resin. At the time of bonding, a spacer is disposed between the substrates in order to keep the distance between the two electrodes constant and prevent a short circuit between the two electrodes. As this spacer, a known material or shape such as a spherical spacer such as a polymer or glass or a columnar spacer formed of a resist or the like can be used.

  The display composition according to the present invention is injected into the gap between the panels thus obtained, and if necessary, the monomer is polymerized and cured. The inlet is sealed with an epoxy resin or the like after deaeration between both electrodes, thereby blocking the outside air from the display composition.

  A battery, a power supply, a drive circuit, and the like are appropriately arranged around and behind the display unit thus manufactured. In this case, by mounting a display IC, it is possible to reduce the number of elements to be mounted on the panel by realizing a driving function related to the above driving method and a one-chip driving program. This is preferable because an electrodeposition type display device can be obtained.

  Next, examples and comparative examples of the present invention will be described in detail. For measurement of the reflection density, Spectrodensitometer 938 (manufactured by X-Rite, measurement condition: D65 light source, 2 ° visual field) was used.

[Comparative Example 1]
A silver electrode (counter electrode) having a stripe shape (80 lines, line width 270 m, space 50 μm, substrate size 45 × 35 mm) was produced on a glass substrate. On the other hand, an ITO electrode (transparent electrode) having a stripe shape (thickness 0.7 μm, number of lines 60, line width 290 μm, space 30 μm, surface resistance: 10Ω / □) is etched on a glass substrate (Corning, 7059) by etching. It was prepared.

  The two electrodes were bonded with Bondine TX8030 (manufactured by Sumitomo Chemical Co., Ltd.) with a spacer, SP-250L100 (manufactured by Sekisui Chemical Co., Ltd., particle size of 100 μm) interposed therebetween to produce a panel with a distance of 100 μm between the electrodes.

  Silver iodide (1.6 mol / L), ammonium iodide (1.6 mol / L), and mercaptobenzimidazole (0.02 mol / L) were dissolved in N-methylformamide to prepare an electrolytic solution. To 3.85 g of this electrolytic solution, 0.5 g of monomer (2-hydroxy-1,3-dimethacryloxypropane (701), manufactured by Shin-Nakamura Chemical), oligomer (1,6-hexanediol diglycidyl ether acrylate (EA) -5521), Shin-Nakamura Chemical Co., Ltd.) 0.5 g and cyanoresin (CR-S, Shin-Etsu Chemical Co., Ltd.) 0.15 g were dissolved. This mixture was further mixed with 500 μL of a solution obtained by dissolving 2.5% by weight of a polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) in N-methylformamide, and titanium dioxide: CR-58 (manufactured by Ishihara Sangyo) was used. A display composition was prepared by dispersing in weight%. The display composition was injected between the electrodes of the panel, heated at a temperature of 80 ° C. for 40 minutes, and the injection port was closed with Araldide Standard (manufactured by Nichiban) to produce a test display device.

  When a voltage of −1.2 V is applied for 150 ms (corresponding to one frame) to display four stripes using 15 lines, the selected pixel has a reflection density of 1.04, while the non-selected pixel also crosses. The reflection resulted in a reflection density of 0.65, and the contrast was insufficient.

[Example 1]
When a test display device manufactured in the same manner as in Comparative Example 1 was overwritten with a voltage of −0.8 V eight times in a subframe of 50 ms in time, the selected pixel had a reflection density of 1.0 and was not selected. The reflection density at the pixel was 0.28, indicating that there is little bleeding and metal deposition at the non-display pixel, and display with high contrast is possible.

  In addition, the invention shown to the following additional remarks can be derived from the content disclosed above.

(Appendix 1)
For a display containing a chromogenic substance capable of repeatedly performing color development and decoloration by depositing a metal on the transparent electrode and dissolving the metal from the transparent electrode between the transparent electrode and the counter electrode In an electrodeposition type display device in which a composition is arranged, and a current is generated between the transparent electrode and the counter electrode, and the color-developing substance is colored or decolored and displayed.
One frame, which is a display selection period for forming one screen, is divided into a plurality of subframes,
Apply each drive voltage in each subframe,
An electrodeposition type display device in which each sub-frame is generated at intervals and the display on one screen is superimposed.

(Appendix 2)
For a display containing a chromogenic substance capable of repeatedly performing color development and decoloration by depositing a metal on the transparent electrode and dissolving the metal from the transparent electrode between the transparent electrode and the counter electrode In an electrodeposition type display device in which a composition is arranged, and a current is generated between the transparent electrode and the counter electrode, and the color-developing substance is colored or decolored and displayed.
An electrodeposition type display device in which when a screen is formed, a driving voltage for color development in one pixel is applied in a plurality of times to superimpose the display on one screen.

(Appendix 3)
The electrodeposition type display device according to appendix 1 or 2, wherein an image is displayed by passive matrix driving.

(Appendix 4)
The electrodeposition type display device according to any one of appendices 1 to 3, wherein each of the drive voltages is less than 1.5 times the metal deposition overvoltage.

(Appendix 5)
The electrodeposition type display device according to any one of appendices 1 to 4, wherein the amount of metal deposited in the one frame is changed to enable gradation display by display density change in the same pixel.

(Appendix 6)
The electrodeposition type display device according to any one of appendices 1 to 5, wherein the counter electrode is made of the same metal as the metal.

(Appendix 7)
The electrodeposition type display device according to any one of appendices 1 to 6, wherein the metal is silver.

(Appendix 8)
The electrodeposition type display device according to any one of appendices 1 to 7, wherein a display IC is mounted.

It is a typical cross-sectional view of the display panel of an electrodeposition type display device. FIG. 3 is a schematic partial view of an electrodeposition type display device when facing a display screen. It is a figure which illustrates application of the drive voltage in the conventional drive system which does not divide | segment a flame | frame into a sub-frame. It is a figure which illustrates application of the drive voltage in the drive system which divided | segmented the flame | frame into several sub-frames. FIG. 3 is a schematic partial view of an electrodeposition type display device when facing a display screen.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent electrode side board | substrate 2 Transparent electrode 3 Seal wall 4 Counter electrode 5 Counter electrode side board | substrate 6 Composition for a display 21 Signal electrode line 22 Scan electrode line 23 Selection pixel 24 Exudation part 51 Adjacent pixel 52 Deposited metal

Claims (5)

For a display containing a chromogenic substance capable of repeatedly performing color development and decoloration by depositing a metal on the transparent electrode and dissolving the metal from the transparent electrode between the transparent electrode and the counter electrode In an electrodeposition type display device in which a composition is arranged, and a current is generated between the transparent electrode and the counter electrode, and the color-developing substance is colored or decolored and displayed.
One frame, which is a display selection period for forming one screen, is divided into a plurality of subframes,
Apply each drive voltage in each subframe,
An electrodeposition type display device in which each sub-frame is generated at intervals and the display on one screen is superimposed. For a display containing a chromogenic substance capable of repeatedly performing color development and decoloration by depositing a metal on the transparent electrode and dissolving the metal from the transparent electrode between the transparent electrode and the counter electrode In an electrodeposition type display device in which a composition is arranged, and a current is generated between the transparent electrode and the counter electrode, and the color-developing substance is colored or decolored and displayed.
An electrodeposition type display device in which when a screen is formed, a driving voltage for color development in one pixel is applied in a plurality of times to superimpose the display on one screen.   The electrodeposition type display device according to claim 1, wherein an image is displayed by passive matrix driving.   The electrodeposition type display device according to any one of claims 1 to 3, wherein each of the drive voltages is less than 1.5 times the metal deposition overvoltage.   The electrodeposition type display device according to any one of claims 1 to 4, wherein the amount of metal deposited in the one frame is changed to enable gradation display by display density change in the same pixel.

Images