JP5879752B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  With the spread of electronic information networks, publishing in the form of electronic books, that is, electronic publishing, has been actively performed in place of books by conventional printing technology. For example, a CRT (Cathode Ray Tube) display or a backlight type liquid crystal display is used as a device for displaying electronic information distributed through such a network. However, the display using these displays has a limited reading place and is inferior in terms of handling, weight, size, shape, and portability as compared with a conventional display printed on paper. In addition, since these displays consume a large amount of power, the display time is limited if driven by a battery. Further, these displays are all light-emitting displays, and there is a problem that high-level fatigue may be caused when staring for a long time.

  Therefore, a display device that can solve the above-described problems and a rewritable display device are desired. As such a display device, a so-called paper-like display or electronic paper has been proposed. Specifically, for example, reflective liquid crystal display devices, electrophoretic display devices, display devices that rotate dichroic particles with an electric field, and electrochromic display devices have been proposed. ing.

  By the way, in an electrochromic display device (electrochromic display device), an image is displayed by energization for developing a selected pixel (selected pixel) (specifically, a line electrode that forms the selected pixel (opposing) Electrode) is applied with a negative voltage, and a positive voltage is applied to the data electrode (display electrode) forming the selected pixel), and the displayed image is erased in the direction opposite to the energization for coloring the selected pixel. This is performed by energization (specifically, applying a positive voltage to the counter electrode and a negative voltage to the display electrode).

  However, since the space between the electrodes is filled with the electrolyte solution, the electrodes for forming the selected pixel are polarized by the energization for coloring the selected pixel, resulting in a state like an electrolytic capacitor or a battery. That is, after energization for causing the selected pixel to develop color, electric charge remains between the electrodes forming the selected pixel. This electric charge moves to the periphery via the electrolyte solution and also moves between the electrodes forming the non-selected pixels. Therefore, for example, when one image is repeatedly displayed by performing a high-speed scan, the next energization is performed before the remaining charge disappears, so that charge is accumulated between the electrodes forming the non-selected pixels, There is a problem that a non-selected pixel is colored and an unclear image in which the selected pixel is blurred is displayed. Therefore, in order to prevent the movement of the remaining charge, it is conceivable to form a partition for separating the pixels between the pixels. For the formation of the partition, the accuracy and precision of alignment and the like are considered. Is required, and the burden on production is large.

Therefore, for example, as shown in FIG. 11A, the counter electrode forming the selected pixel is a negative electrode, the display electrode forming the selected pixel is a positive electrode, and a voltage of the first potential difference is applied between the electrodes. Immediately thereafter, a method has been proposed in which the counter electrode is a positive electrode and the display electrode is a negative electrode, and an application process is performed to apply a voltage of a second potential difference equal to or greater than the first potential difference between the electrodes (for example, , See Patent Document 1).
That is, immediately after the energization for coloring the selected pixel, the energization is performed in the opposite direction to the energization, and the charge generated between the electrodes forming the selected pixel is eliminated (removed), so that no charge remains. I am doing so. Therefore, the non-selected pixels are not colored due to the remaining charge, and a high-quality image can be displayed even when a high-speed scan of about 8 msec / line is performed.

JP 2010-261983 A

However, in Patent Document 1, since the potentials of the counter electrode and the display electrode that form the non-selected pixel are not controlled, the potentials of the counter electrode and the display electrode that form the non-selected pixel change according to the image to be displayed. To do. A voltage is applied between the electrode forming the selected pixel and the electrode forming the non-selected pixel in accordance with the voltage application of the first potential difference between the counter electrode forming the selected pixel and the display electrode ( 11B shows a voltage applied between the display electrode forming the selected pixel and the counter electrode forming the non-selected pixel.), The counter electrode forming the non-selected pixel If the potential of the display electrode changes depending on the displayed image or the like, the charge generated between the electrode forming the selected pixel and the electrode forming the non-selected pixel may not be sufficiently removed.
In particular, since the counter electrode is selected in the order of the first row → second row → third row →..., The same counter electrode is not continuously selected. On the other hand, for example, when the counter electrode in the first row is selected, the display electrode that forms the pixel to be colored in the first row is selected and the counter electrode in the second row is selected. Since the display electrodes that form the pixels to be colored in the second row are selected, the same display electrodes may be selected continuously. For this reason, charges are likely to remain between the display electrode forming the selected pixel and the counter electrode forming the non-selected pixel, and a high-speed scan of about 1 msec / line can be performed even using the method described in Patent Document 1. When it did, it turned out that the low quality image with which the linear blur along a display electrode is conspicuous may be displayed.

  An object of the present invention is to realize high-speed display of high-quality images in a display device including a passive matrix drive electrochromic display device.

In order to solve the above-mentioned problem, the invention described in claim 1
A plurality of first electrodes arranged in a line in parallel ;
A plurality of second electrodes disposed opposite to the first electrode, in a three-dimensional crossing at an angle of approximately 90 degrees with the first electrode, and arranged in a line in parallel ;
A controller that controls the potential of the first electrode and the second electrode ;
The first electrode and the second electrode and a electrochromic composition layer overpass region crossing,
The controller is
In case of color detection a predetermined crossing area,
The predetermined period is divided into two periods, the first first period and the next second period,
The first electrode corresponding to the predetermined three-dimensional intersection region is changed from the potential V3 to the potential V4 (V4 <V3) for the predetermined period,
From the potential V2, the second electrode corresponding to the predetermined three-dimensional intersection region is set to potential V1 (V1> V2, V1> V3) in the first period, and potential V5 (V5 <V3) in the second period. ,
If the first electrodes adjacent to the first electrode corresponding to the predetermined crossing region is not carried out the control for the color development, the to the potential V3 to the predetermined period,
In the first period, charges accumulated between the second electrode corresponding to the predetermined three-dimensional intersection region and the first electrode not corresponding to the predetermined three-dimensional intersection region are It is controlled so as to be removed in time, characterized in Rukoto.

The invention described in claim 2
The display device according to claim 1,
Before Symbol control section is,
Controlling the length of the first period and the length of the second period to be substantially the same;
Control is performed such that a difference | V1−V3 | between the potential V1 and the potential V3 and a difference | V3−V5 | between the potential V3 and the potential V5 are substantially the same.

The invention according to claim 3
The display device according to claim 1 or 2,
Before Symbol control section is,
The potential V5 is controlled to satisfy V5 ≧ V4.

The invention according to claim 4
The display device according to any one of claims 1 to 3,
The controller is
The potential V2 is controlled so that V2 <0,
The potential V3 is controlled so that V3> 0.
The invention described in claim 5
In the display device according to any one of claims 1 to 4,
When the first not by color let the overpass area corresponding to the electrode adjacent to the first electrode corresponding to the predetermined crossing region to be by color, a first electrode of the adjacent electrical potential V3 it characterized in that but is maintained.

  According to the present invention, the charge generated in the first period between the display electrode forming the selected pixel and the counter electrode forming the non-selected pixel can be substantially removed by energization in the second period. Blurring can be accurately suppressed, and high-quality images can be displayed at high speed.

It is a block diagram which shows the functional structure of the display apparatus of one Embodiment to which this invention is applied. It is a figure which shows typically an example of the electrochromic display device with which the display apparatus of FIG. 1 is provided, (a) is a top view, (b) is sectional drawing. It is sectional drawing which shows typically another example of the electrochromic display device with which the display apparatus of FIG. 1 is provided. (A) is a figure which shows an example of the circuit structure of the 1st voltage switch part with which the display apparatus of FIG. 1 is equipped, (b) shows an example of the circuit structure of the 2nd voltage switch part with which the display apparatus of FIG. 1 is equipped. FIG. It is a figure for demonstrating an example of the method of the voltage application with respect to the electrochromic display device with which the display apparatus of FIG. 1 is equipped, (a) is between the display electrode which forms a selection pixel, and the counter electrode which forms a selection pixel. The applied voltage, (b), indicates the voltage applied between the display electrode forming the selected pixel and the counter electrode forming the non-selected pixel. It is a figure for demonstrating the non-selection pixel formed between the display electrode which forms a selection pixel, and the counter electrode which forms a non-selection pixel. It is a figure for demonstrating the method of the voltage application in an Example, (a) is the voltage applied between the display electrode which forms a selection pixel, and the counter electrode which forms a selection pixel, (b) is a selection pixel. The voltage applied between the display electrode forming the pixel and the counter electrode forming the non-selected pixel is shown. It is a figure for demonstrating the method of the voltage application in a comparative example, (a) is the voltage applied between the display electrode which forms a selection pixel, and the counter electrode which forms a selection pixel, (b) is a selection pixel. The voltage applied between the display electrode forming the pixel and the counter electrode forming the non-selected pixel is shown. It is a figure which shows the result of an Example. It is a figure which shows the result of a comparative example. It is a figure for demonstrating the method of the voltage application with respect to the conventional electrochromic display device.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

(Display device)
The display apparatus 1000 includes the electrochromic display device 100 and performs a given display process according to image data input from the outside.
Specifically, for example, as shown in FIG. 1, the display device 1000 includes an electrochromic display device 100, a first voltage switching unit 200, a counter electrode selection unit 300, a second voltage switching unit 400, and the like. The display electrode selection unit 500 and the control unit 600 are provided.

(Electrochromic display device)
For example, as shown in FIG. 2, the electrochromic display device 100 includes a first substrate 10, a counter electrode 20 provided on the upper surface of the first substrate 10, and a first substrate 10 above the first substrate 10. The second substrate 30 provided oppositely, the display electrodes 40 provided on the lower surface of the second substrate 30, and the electrochromic composition layer 50 provided between the first substrate 10 and the second substrate 30. And a passive matrix driving display element.
The electrochromic display device 100 performs display by energization between the counter electrodes 20 and the display electrodes 40 and is opposite to the energization for the display between the counter electrodes 20 and the display electrodes 40. The display is erased by energizing the direction.
The counter electrodes 20 are, for example, a plurality of electrodes extending in parallel with each other. The display electrodes 40 are, for example, transparent display electrodes made up of a plurality of transparent electrodes extending in parallel with each other in a direction orthogonal to the counter electrodes 20. Pixels 60 are formed in a region where the counter electrodes 20 and the display electrodes 40 intersect three-dimensionally.

  The first substrate 10 is formed in a planar shape, for example, and has a function as a base of the electrochromic display device 100.

  The material of the first substrate 10 is not particularly limited as long as it is electrically insulating, and for example, glass or plastic can be used. Examples of the glass include soda lime glass, low alkali / borosilicate glass, alkali-free / borosilicate glass, alkali-free / aluminosilicate glass, and quartz glass. Examples of the plastic include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyamides, polycarbonates, fluoropolymers such as polyvinylidene fluoride, polyethers, polyolefins such as polystyrene and polyethylene, and polyimides. Can be mentioned.

  The first substrate 10 preferably appears white. Therefore, when the material of the first substrate 10 is glass or plastic, for example, the first substrate 10 that looks white can be formed by blending a white pigment such as titanium dioxide, barium sulfate, or kaolin. Moreover, the 1st board | substrate 10 which looks white can be formed by apply | coating the said white pigment on the lower surface of a transparent substrate, or arrange | positioning white sheets, such as white paper and a white PET sheet.

The counter electrodes 20 are formed in, for example, a line shape having a width, and are provided in stripes at equal intervals parallel to each other.
The counter electrodes 20 are provided on the upper surface of the first substrate 10 so as to be in contact with the electrochromic composition layer 50 and to sandwich the electrochromic composition layer 50 so as to face the display electrodes 40.
The counter electrodes 20 are paired with the display electrodes 40 and have a function of energizing the electrochromic composition layer 50.
The counter electrodes 20 ... are three-dimensionally crossed with the display electrodes 40, i.e., have an interval, and form a pixel 60 in the area of the intersection.

The counter electrode 20 may be a transparent electrode or an opaque electrode as long as the surface is oxidized, or a conductor and is electrochemically stable such as corrosion resistance. There is no particular limitation. Specifically, as the counter electrode 20, for example, an ITO thin film, a thin film coated with an oxide film such as SnO ₂ or InO ₂ , an ITO thin film doped with Sn or Sb, an oxide film such as SnO ₂ or InO ₂ Examples of the thin film coated with Sn or Sb, zinc oxide thin film, magnesium oxide thin film, aluminum oxide thin film, chromium oxide thin film, nickel oxide thin film, titanium oxide thin film, gold thin film, platinum thin film, carbon thin film, etc. it can. Further, a surface oxide thin film and the corrosion-resistant conductor may be used in combination, such as coating an ITO thin film on an electrochemically stable conductive thin film such as a gold thin film.

  The second substrate 30 is a transparent substrate formed in a planar shape, for example, and has a function as a support for the display electrodes 40.

  The material of the second substrate 30 is not particularly limited as long as it is an electrically insulating transparent substrate. For example, glass or plastic can be used. Examples of the glass include soda lime glass, low alkali / borosilicate glass, alkali-free / borosilicate glass, alkali-free / aluminosilicate glass, and quartz glass. Examples of the plastic include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyamides, polycarbonates, fluoropolymers such as polyvinylidene fluoride, polyethers, polyolefins such as polystyrene and polyethylene, and polyimides. Can be mentioned.

The display electrodes 40 are, for example, transparent electrodes formed in a line shape having a width, and are provided in stripes at equal intervals parallel to each other.
The display electrodes 40 are provided on the lower surface of the second substrate 30 so as to be in contact with the electrochromic composition layer 50 and so as to sandwich the electrochromic composition layer 50 facing the counter electrode 20.
The display electrodes 40 are paired with the counter electrodes 20 and have a function of energizing the electrochromic composition layer 50.
The display electrodes 40 intersect with the counter electrodes 20 three-dimensionally, that is, with an interval, and form a pixel 60 in the area of the intersection.

The display electrode 40 is not particularly limited as long as it is a transparent electrode having at least a surface oxidized. Specifically, as the display electrode 40, for example, an ITO thin film, a thin film coated with an oxide film such as SnO ₂ or InO ₂ , an ITO thin film doped with Sn or Sb, an oxide film such as SnO ₂ or InO ₂ Examples thereof include a thin film coated with Sn and Sb, a zinc oxide thin film, and a magnesium oxide thin film. Further, it may be a thin film coated with an oxide film such as ITO, zinc oxide, magnesium oxide, aluminum oxide, chromium oxide, nickel oxide, and titanium oxide.

The electrochromic composition layer 50 includes, for example, a spacer 51, an electrochromic composition 52 held by the spacer 51, and the like.
The thickness of the electrochromic composition layer 50 is not particularly limited, but the display function of the electrochromic composition 52 is effectively expressed by setting the thickness to preferably 10 μm to 500 μm, more preferably 30 μm to 200 μm. Can be made.

  The spacer 51 has a role of holding the electrochromic composition 52 with a constant volume between the first substrate 10 and the second substrate 30. That is, the spacer 51 includes the electrochromic composition 52 to support the electrochromic composition 52 between the first substrate 10 and the second substrate 30, and the electrochromic composition 52 has a thickness depending on the thickness of the spacer 51. It has a role to control the amount uniformly.

  The spacer 51 is arbitrary as long as it plays the above-described role, and for example, a porous plate-like body, a sheet-like body, a granular body (which may be porous or non-porous), etc. Is mentioned.

When the spacer 51 is a porous plate-like body or sheet-like body, for example, the electrochromic composition layer 50 is formed by introducing the electrochromic composition 52 into the pores of the spacer 51. In this case, after the spacer 51 is sandwiched between the counter electrode 20 (the first substrate 10 on which the counter electrode 20 is disposed) and the display electrode 40 (the second substrate 30 on which the display electrode 40 is disposed), The electrochromic composition 52 may be formed by introducing the electrochromic composition 52 into the pores of the spacer 51, or the electrochromic composition 52 may be introduced into the pores of the spacer 51. After the layer 50 is formed, the electrochromic composition layer 50 may be sandwiched between the counter electrodes 20 and the display electrodes 40.
Here, as a porous plate-like body or sheet-like body, pores penetrating in a substantially vertical direction with respect to the first substrate 10 and the second substrate 30 from the viewpoint of improving the display performance of the electrochromic display device 100 and the like. Specifically, for example, anodized alumina, a mesh (net) -like sheet material, and the like are exemplified, but the invention is not limited thereto.

  Further, when the spacer 51 is a granular body, for example, the paste obtained by mixing the spacer 51 and the electrochromic composition 52 is sandwiched between the counter electrode 20 and the display electrode 40, thereby forming an electrochromic composition. The physical layer 50 is formed.

The electrochromic composition 52 includes a supporting electrolyte, a polar solvent, and a leuco dye.
The electrochromic composition 52 includes a display quality degradation inhibitor (hydroquinone derivative and / or catechol derivative, ferrocene derivative and compound having a carbonyl group) for suppressing degradation of display quality of the electrochromic display device 100, and An adsorbent 53 that adsorbs a leuco dye when energized for erasing between the counter electrodes 20 and the display electrodes 40 is added.
Moreover, as a component which can be added to the electrochromic composition 52, the polymer compound etc. for adjusting the physical property (for example, thickening etc.) of the electrochromic composition 52 are mentioned, for example.

The electrochromic composition 52 has a function of coloring and decoloring related to the display of the electrochromic display device 100.
Specifically, the electrochromic composition 52 is colored by energization between the counter electrode 20 and the display electrode 40, and is energized in the direction opposite to the energization for color development or energization for color development. Decoloring by blocking.
The electrochromic composition 52 only needs to have fluidity, and may be, for example, a low-viscosity liquid, a high-viscosity paste, or a gel with a low fluidity. good.

The supporting electrolyte which is a constituent component of the electrochromic composition 52 has a function for facilitating the flow of current through the electrochromic composition 52. The supporting electrolyte contains a compound generally called a molten salt. As the supporting electrolyte, each compound may be used alone, or a plurality thereof may be mixed and used.
The supporting electrolyte is preferably added in an amount of 0.01 to 20% by weight with respect to the total weight of the electrochromic composition 52, and 0.1 to 20% by weight for sufficient expression of the function. It is more preferable to add so that it may become%.

Specifically, the supporting electrolyte is not particularly limited as long as it is a compound having the above function, and examples thereof include a first supporting electrolytic compound and / or a second supporting electrolytic compound.
Examples of the first supporting electrolytic compound include, but are not limited to, NaClO ₄ , LiClO ₄ , KClO ₄ , RbClO ₄ , CsClO ₄ , NH ₄ ClO ₄ , LiBF ₄ , LiPF _{6, and the} like. .
Examples of the second supporting electrolytic compound include (CH ₃ ) ₄ NClO ₄ , (C ₂ H ₅ ) ₄ NClO ₄ , (nC ₄ H ₉ ) ₄ NClO ₄ , and (CH ₃ ) ₄ NBF _4. , (C ₂ H ₅ ) ₄ NBF ₄ , (n-C ₄ H ₉ ) ₄ NBF ₄ , (CH ₃ ) ₄ NCl, (C ₂ H ₅ ) ₄ NCl, (CH ₃ ) ₄ NBr, (C ₂ H ₅ ) ₄ NBr, (n-C ₄ H ₉ ) ₄ NBr, (n-C ₄ H ₉ ) ₄ NI, C ₆ H ₅ (CH ₃ ) ₃ NClO ₄ , C ₆ H ₅ (C ₂ H ₅ ) ₃ NClO ₄ , C ₈ H ₁₇ (CH ₃ ) ₃ NClO ₄ , (C ₂ H ₅ ) ₄ NPF ₆ , (n-C ₄ H ₉ ) ₄ NPF ₆ , (CH ₃ ) ₄ NCF ₃ SO ₃ , (C ₂ H _{5) 4} NCF ₃ is SO ₃ and the like, is limited to Not shall.

  The polar solvent, which is a constituent component of the electrochromic composition 52, is at least one organic solvent that exhibits electrical conductivity using a supporting electrolyte, and has a function of promoting decolorization of the leuco dye by blocking voltage and / or current. . The polar solvent also serves as a solvent for the polymer compound when the polymer compound is added to the electrochromic composition 52. Various polar solvents may be used alone, or two or more polar solvents may be appropriately used in combination.

Although the example of a suitable polar solvent is shown below, these are illustrations and do not limit a polar solvent.
Specific examples of the polar solvent include, for example, N-methylpyrrolidone, dimethylformamide, diethylformamide, N, N-dimethylacetamide, propylene carbonate, dimethyl sulfoxide, γ-butyrolactone, acetonitrile, propionitrile, butyronitrile and the like. It is done. Any of the exemplified polar solvents is preferable as a polar solvent used as a component of the electrochromic composition 52, and particularly preferable examples include N, N-dimethylacetamide, propylene carbonate, and dimethyl sulfoxide.

The leuco dye that is a constituent component of the electrochromic composition 52 is a colorless or light-colored electron-donating dye precursor, and is a compound that develops color by a developer such as a phenolic compound, an acidic substance, or an electron-accepting substance.
Examples of leuco dyes include compounds that have a lactone, lactam, sultone, spiropyran, ester, or amide structure in the partial skeleton and can be practically colorless. Specific examples include triallylmethane compounds, bisphenylmethane compounds, xanthene compounds, fluorane compounds, thiazine compounds, spiropyran compounds and the like, but are not limited thereto.

  The leuco dye can be colored in various colors by appropriately selecting from the above compounds. Therefore, the display color of the electrochromic display device 100 using a leuco dye can be appropriately selected depending on the leuco dye. Specifically, for example, when a leuco dye that develops black is used, black and white and gray display are possible.

  Since the blending amount of the leuco dye depends on the solubility of the leuco dye, it is difficult to express it generally. However, the leuco dye needs to be blended in a sufficient amount for color development. In the case of a leuco dye having a low solubility, the volume of the electrochromic composition layer 50 (the thickness of the spacer 51) corresponding to each pixel 60 is increased, for example, so as to include a necessary amount. It is good to adjust the amount.

The display quality degradation inhibitor added to the electrochromic composition 52 is a compound having a function of suppressing degradation of display quality of the electrochromic display device 100 due to repeated operations of coloring and decoloring of the leuco dye.
The addition amount of the display quality deterioration inhibitor is preferably 1 to 20% by weight based on the content of the leuco dye, and 5 to 20% by weight for sufficient expression of the function. It is preferable to add so that it becomes.

  The display quality degradation inhibitor includes a first display quality degradation inhibiting compound (hydroquinone derivative and / or catechol derivative), a second display quality degradation inhibiting compound (ferrocene derivative), and a third display quality degradation inhibiting compound (carbonyl). And a compound having a group (acetophenone derivative and / or dibenzoyl derivative)).

The adsorbent 53 added to the electrochromic composition 52 is, for example, aluminum oxide and / or aluminum hydroxide.
The mode of addition of the adsorbent 53 (aluminum oxide and / or aluminum hydroxide) is not particularly limited, but it is added as a powder to the electrochromic composition 52, and a homogenizer such as an ultrasonic wave, a ball mill, or a homomixer. Is preferably dispersed as a dispersion of the electrochromic composition 52 solution. Moreover, the said dispersion liquid is apply | coated on counter electrode 20 ..., for example, as shown in FIG. 3, it can also be used as a layer (adsorption layer) of the adsorption agent 53. FIG.

The amount of adsorbent 53 added varies depending on the activity, particle size, etc. of the aluminum oxide and / or aluminum hydroxide used.
Aluminum oxide with a small surface area such as α-alumina, large aluminum oxide with a particle size of 10 μm or more, aluminum hydroxide with a small surface area, and aluminum hydroxide with a particle size of 10 μm or more have a small leuco dye adsorption effect and are sufficient In order to develop a proper adsorption action, 0.5 gram to 5 grams, preferably 1 gram to 3 grams, is preferably added to 1 gram of leuco dye.
In addition, aluminum oxide having a large surface area, such as γ-alumina, small aluminum oxide having a particle size of 1 μm or less, aluminum hydroxide having a large surface area, and small aluminum oxide having a particle size of 1 μm or less have a large leuco dye adsorption effect. Therefore, a sufficient adsorption operation is exhibited with addition of 0.1 gram to 0.5 gram per gram of leuco dye.
In addition, activated alumina used for thin layer chromatography and the like can be added in an amount of 0.1 to 0.5 gram per gram of leuco dye, even if it is a large particle having a particle size of several tens of micrometers. , Express sufficient adsorption operation.

The adsorbent 53 that adsorbs the leuco dye can be easily obtained as a chemical product.
Although the example of the suitable commercially available adsorption agent 53 is shown below, these are illustrations and do not limit adsorbent 53.
Specific examples of the commercially available adsorbent 53 include, for example, aluminum oxide 60GN neutral for thin layer chromatography (particle size: 4 μm to 50 μm) manufactured by Merck & Co., Ltd., Nippon Light Metal's low soda alumina LS235 (particle size: 0.47 μm), activated alumina C200 ( Particle diameter 4.4 μm), aluminum hydroxide B1403 (particle diameter 1.5 μm), γ-alumina KC501 (particle diameter 1 μm) manufactured by Sumitomo Chemical, aluminum sol-A2 manufactured by Kawaken Fine Chemical Co., Ltd., and the like.

The polymer compound added to the electrochromic composition 52 has a function of increasing the viscosity of the electrochromic composition 52 and facilitating the handling thereof. Various polymer compounds may be used alone, or two or more polymer compounds may be appropriately used in combination.
The polymer compound is used to increase the viscosity of the electrochromic composition 52. In this case, the properties of the electrochromic composition 52 include a low-viscosity liquid, a high-viscosity paste, and a low fluidity gel. can do.
It is preferable that the compounding quantity of a polymer compound shall be 0.1 to 80 weight% with respect to the weight of the electrochromic composition 52 whole.

Although the example of a suitable polymer compound is shown below, these are illustrations and do not limit a polymer compound.
Specific examples of the polymer compound include, for example, polyalkylene oxides such as polyvinylidene fluoride, polyvinylidene chloride, and polyethylene oxide, or polymers having a repeating unit of polyalkyleneimine and polyalkylene sulfide, polymethyl methacrylate, polyacrylonitrile, Examples thereof include polyvinyl formal such as polycarbonate and polyvinyl butyral. Particularly preferred are polyvinyl butyral and polyvinylidene fluoride.

  The electrochromic composition 52 described above is an example. If the composition is capable of electrochemical color development, the electrochromic composition layer 50 that is held by the spacer 51 is used. Is possible.

(First voltage switching unit)
For example, as shown in FIG. 1, the display device 1000 includes a plurality of (for example, the same number of counter electrodes 20 included in the electrochromic display device 100) first voltage switching units 200.
For example, the first voltage switching unit 200 switches the voltage applied to the counter electrode 20 connected to the first voltage switching unit 200.
Specifically, the first voltage switching unit 200 includes, for example, a first positive voltage power supply 201 that outputs a positive voltage, a first P-channel transistor 202 that functions as a switch, and a negative voltage as illustrated in FIG. A first negative voltage power supply 203 that outputs a voltage and a first N-channel transistor 204 that functions as a switch are configured.

The first positive voltage power supply 201 is configured to be turned ON / OFF by the counter electrode selection unit 300, for example. When the first positive voltage power supply 201 is turned on, a positive voltage is applied to one end (source) of the first P-channel transistor 202.
For example, the first P-channel transistor 202 has a gate connected to the gate terminal 200 a, one end (source) connected to the first positive voltage power supply 201, and the other end (drain) connected to the counter electrode 20 of the electrochromic display device 100. Connected to the output terminal 200b.

The first negative voltage power supply 203 is configured to be turned on / off by the counter electrode selection unit 300, for example. When the first negative voltage power supply 203 is turned on, a negative voltage at one end (source) of the first N-channel transistor 204 is applied.
For example, the first N-channel transistor 204 has a gate connected to the gate terminal 200 a, one end (source) connected to the first negative voltage power supply 203, and the other end (drain) connected to the counter electrode 20 of the electrochromic display device 100. Connected to the output terminal 200b.

(Counter electrode selection part)
The counter electrode selection unit 300 applies a positive voltage or a negative voltage to the counter electrode 20 (line electrode) by controlling the first voltage switching unit 200 according to a control signal from the control unit 600, for example.

Specifically, the counter electrode selection unit 300 applies, for example, a predetermined positive voltage to the gate terminal 200a of the first voltage switching unit 200, and turns on the first positive voltage power supply 201. As a result, the predetermined positive voltage is applied to the gate of the first P-channel transistor 202, and the positive voltage from the first positive voltage power supply 201 is applied to one end (source) of the first P-channel transistor 202. The 1P channel transistor 202 is turned on, and a positive voltage is applied to the counter electrode 20 via the output terminal 200b. As a result, the potential of the counter electrode 20 becomes a predetermined positive potential (for example, the potential V3).
On the other hand, the counter electrode selection unit 300 applies, for example, a predetermined negative voltage to the gate terminal 200a of the first voltage switching unit 200, and turns on the first negative voltage power source 203. As a result, the predetermined negative voltage is applied to the gate of the first N-channel transistor 204, and the negative voltage from the first negative-voltage power supply 203 is applied to one end (source) of the first N-channel transistor 204. The 1N channel transistor 204 is turned on, and a negative voltage is applied to the counter electrode 20 via the output terminal 200b. Thereby, the potential of the counter electrode 20 becomes a predetermined negative potential (for example, the potential V4).

(Second voltage switching unit)
For example, as shown in FIG. 1, the display device 1000 includes a plurality (for example, the same number as the number of display electrodes 40 included in the electrochromic display device 100) of second voltage switching units 400.
For example, the second voltage switching unit 400 switches a voltage applied to the display electrode 40 connected to the second voltage switching unit 400.
Specifically, the second voltage switching unit 400 includes, for example, as shown in FIG. 4B, a second positive voltage power supply 401 that outputs a positive voltage, a second P-channel transistor 402 that functions as a switch, A second negative voltage power source 403 that outputs a voltage and a second N-channel transistor 404 that functions as a switch are configured.

The second positive voltage power supply 401 is configured to be turned ON / OFF by the display electrode selection unit 500, for example. When the second positive voltage power supply 401 is turned on, a positive voltage is applied to one end (source) of the second P-channel transistor 402.
For example, the second P-channel transistor 402 has a gate connected to the gate terminal 400 a, one end (source) connected to the second positive voltage power supply 401, and the other end (drain) connected to the display electrode 40 of the electrochromic display device 100. Connected to the output terminal 400b.

The second negative voltage power supply 403 is configured to be turned on / off by the display electrode selection unit 500, for example. When the second negative voltage power supply 403 is turned on, a negative voltage at one end (source) of the second N-channel transistor 404 is applied.
For example, the second N-channel transistor 404 has a gate connected to the gate terminal 400 a, one end (source) connected to the second negative voltage power supply 403, and the other end (drain) connected to the display electrode 40 of the electrochromic display device 100. Connected to the output terminal 400b.

(Display electrode selection part)
The display electrode selection unit 500 applies a positive voltage or a negative voltage to the display electrode 40 (data electrode) by controlling the second voltage switching unit 400 according to a control signal from the control unit 600, for example.

Specifically, for example, the display electrode selection unit 500 applies a predetermined positive voltage to the gate terminal 400a of the second voltage switching unit 400 and turns on the second positive voltage power supply 401. As a result, the predetermined positive voltage is applied to the gate of the second P channel transistor 402, and the positive voltage from the second positive voltage power supply 401 is applied to one end (source) of the second P channel transistor 402. The 2P channel transistor 402 is turned on, and a positive voltage is applied to the display electrode 40 via the output terminal 400b. Thereby, the potential of the display electrode 40 becomes a predetermined positive potential (for example, the potential V1).
On the other hand, the display electrode selection unit 500 applies, for example, a predetermined negative voltage to the gate terminal 400a of the second voltage switching unit 400 and turns on the second negative voltage power source 403. As a result, the predetermined negative voltage is applied to the gate of the second N-channel transistor 404 and the negative voltage from the second negative voltage power supply 403 is applied to one end (source) of the second N-channel transistor 404. The 2N channel transistor 404 is turned on, and a negative voltage is applied to the display electrode 40 via the output terminal 400b. Thereby, the potential of the display electrode 40 becomes a predetermined negative potential (for example, the potential V2 or the potential V5).

(Control part)
The control unit 600 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and centrally controls the operation of each unit constituting the display device 1000.
The control unit 600 functions as a display control unit that causes the electrochromic display device 100 to display a predetermined image.

(Display operation)
For example, the control unit 600 controls the counter electrode selection unit 300 and the display electrode selection unit 500 on the basis of image data input from the outside, via the first voltage switching unit 200 and the second voltage switching unit 400. Then, an image based on the image data is displayed on the electrochromic display device 100 by passive matrix driving.
A method of applying a voltage to the electrochromic display device 100 by the control unit 600 of the present embodiment will be described with reference to FIGS.
FIG. 5A shows a voltage applied between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a.
FIG. 5B shows a voltage applied between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b.

Specifically, the control unit 600 first controls the potential of each display electrode 40 to be the potential V2 and the potential of each counter electrode 20 to be the potential V3.
Next, when performing display, the control unit 600 selects the pixel 60 to be colored, and between the counter electrode 20 that forms the selected pixel 60 (selected pixel 60a) and the display electrode 40 that forms the selected pixel 60a. A voltage is applied to the display to energize for display (energization for coloring the pixel 60). At this time, for example, as shown in FIGS. 5A and 5B, the control unit 600 divides a period for energization for the display into two periods. For example, as shown in FIG. 5A, the control unit 600 determines that the potential of the display electrode 40 forming the selected pixel 60a is the potential V1 (V1> V2, V1> V3) in the first first period P1. And the potential of the counter electrode 20 forming the selected pixel 60a is controlled to be the potential V4 (V4 <V3), and the potential of the counter electrode 20 is maintained at the potential V4 in the next second period P2. In addition, the potential of the display electrode 40 is controlled to be the potential V5 (V5 <V3). Further, in the first period P1 and the second period P2, the control unit 600 maintains the potential of the display electrode 40 that forms the non-selected pixel 60 (non-selected pixel 60b) at the potential V2, and does not select it. Control is performed so that the potential of the counter electrode 20 forming the pixel 60b is maintained at the potential V3.

  More specifically, the counter electrode selection unit 300 follows the control signal from the control unit 600 in the first row (for example, the top counter electrode 20 in FIG. 2) → second row → third row →. For example, as illustrated in FIG. 5A, a negative voltage is applied so that the potential of the selected counter electrode 20 is switched from the potential V3 to the potential V4 in the first first period P1. In the next second period P2, the state in the first period P1 is maintained. When the second period P2 ends, the counter electrode selection unit 300 applies a positive voltage so that the potential of the selected counter electrode 20 returns from the potential V4 to the potential V3, and selects the counter electrode 20 in the next row. . The counter electrode selection unit 300 is configured not to select a plurality of counter electrodes 20 at the same time.

  On the other hand, the display electrode selection unit 500 selects the display electrode 40 in synchronization with the selection of the counter electrode 20 by the counter electrode selection unit 300 according to the control signal from the control unit 600. That is, for example, the display electrode selection unit 500 includes the display electrode 40 that forms the pixel 60 to be colored in the first row at substantially the same timing as the counter electrode selection unit 300 selects the counter electrode 20 in the first row. select. Then, for example, as shown in FIG. 5A, the display electrode selection unit 500 applies a positive voltage so that the potential of the selected display electrode 40 is switched from the potential V2 to the potential V1 in the first first period P1. In the next second period P2, a negative voltage is applied so that the potential of the selected display electrode 40 is switched from the potential V1 to the potential V5. When the second period P2 ends, the display electrode selection unit 500 applies a negative voltage so that the potential of the selected display electrode 40 returns from the potential V5 to the potential V2, and the counter electrode selection unit 300 performs the second row. The display electrode 40 that forms the pixel 60 to be colored in the second row is selected at substantially the same timing as the timing of selecting the counter electrode 20.

Here, between the display electrode 40 forming the selection pixel 60a and the counter electrode 20 forming the selection pixel 60a, for example, as shown in FIG. 5A, the potential difference “1” in the first first period P1. A voltage of “V1−V4” (> 0) is applied, and a voltage of a potential difference “V5−V4” is applied in the next second period P2.
Further, between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the non-selected pixel 60b, for example, as shown in FIG. 5B, the potential difference “V1” in the first first period P1. The voltage of −V3 ”(> 0) is applied, and the voltage of the potential difference“ V5−V3 ”(<0) is applied in the next second period P2. Therefore, among the non-selected pixels 60b, the non-selected pixel 60b1 (see FIG. 6) formed by the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b includes the first period P1. Thus, a current in the same direction as the energization for coloring the pixel 60 (the energization in the first period P1 between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a). Flowing. Therefore, if the charge accumulated in the first period P1 is not removed between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b, the charge remains and blurring of the image occurs. It becomes a cause.

Therefore, the control unit 600 sets the length of the first period P1 and the length of the second period P2, the potential V1, the potential V3, and the potential V5 to the non-display electrode 40 that forms the selection pixel 60a in the first period P1. It is configured to control so that the charge accumulated between the counter electrode 20 forming the selection pixel 60b becomes a value that is substantially eliminated in the second period P2.
Specifically, for example, the control unit 600 controls the length of the first period P1 and the length of the second period P2 to be substantially the same, and the difference | V1-V3 | between the potential V1 and the potential V3 | And the difference | V3−V5 | between the potential V3 and the potential V5 is controlled to be substantially the same.
Thereby, the electric charge accumulated in the first period P1 between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the non-selected pixel 60b can be almost removed by energization in the second period P2. Therefore, it is possible to prevent the charge from remaining.
In particular, the potential of the counter electrode 20 that forms the non-selected pixel 60b is controlled to accumulate between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b in the first period P1. By surely grasping the amount of charge that is generated, the potential of the display electrode 40 that forms the selected pixel 60a and the length of the first period P1 are ensured so that the charge accumulated between these electrodes is reliably removed. The length of the second period P2 can be controlled. Therefore, it is possible to surely prevent electric charge from remaining between these electrodes as compared with the case where the potential of the counter electrode 20 forming the non-selected pixel 60b is not controlled. As a result, blurring of the image can be accurately suppressed, and a high-quality image can be displayed.
In addition, the dashed-dotted line shown in FIG.5 (b) and FIG.7 (b) mentioned later is a line displayed for convenience, in order to clarify the relationship between potential difference "V1-V3" and potential difference "V5-V3", This is not a line indicating that the potential of the display electrode 40 forming the selected pixel 60a may be V3.

The control unit 600 is configured to control the potential V5 so that V5 ≧ V4.
As a result, a current in the same direction as the energization for coloring the pixel 60 flows between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the selected pixel 60a in the second period P2. Compared with the case where energization in the direction opposite to that for energizing the pixels 60 is performed in the second period P2, the contrast ratio is maintained, and a higher quality image can be displayed.
Note that the potential V5 can be arbitrarily changed as long as V5 ≧ V4. When the first period P1 and the second period P2 are substantially the same, preferably −V1 × 0.7 ≦ V5 <0 (however, V1> 0), and more preferably −V1 × 0.8 ≦ V5 <0 (where V1> 0).

The control unit 600 is configured to control the potential V2 so that V2 <0 and to control the potential V3 so that V3> 0.
As a result, a current in the direction opposite to that for energizing the pixel 60 flows between the display electrode 40 forming the non-selected pixel 60b and the counter electrode 20 forming the non-selected pixel 60b, and therefore remains. Charges can be reliably removed. Therefore, bleeding of the image can be suppressed more accurately, and a higher quality image can be displayed.

An example of a display operation for displaying an image on the electrochromic display device 100 will be described more specifically.
First, the control unit 600 selects the first line (the counter electrode 20 in the first line), and the potential of the counter electrode 20 in the selected first line is changed from the potential V3 to the potential in the first first period P1. A negative voltage is applied so as to switch to V4, and the potential of the display electrode 40 forming the selected pixel 60a among the pixels 60 on the first row line is changed from the potential V2 (for example, V2 = −V3) to the potential V1 (for example, , V1 = −V4), a positive voltage is applied, and a voltage of potential difference “V1−V4” (> 0) is applied between these electrodes.
Next, in the next second period P2, the control unit 600 applies a negative voltage so that the potential of the counter electrode 20 is maintained at the potential V4, and the potential of the display electrode 40 is changed from the potential V1 to the potential V5 ( For example, a negative voltage is applied so as to switch to V4 <V5 <V2), and a voltage having a potential difference “V5−V4” (> 0) is applied between these electrodes.
Next, when the second period P2 ends, the controller 600 applies a positive voltage so that the potential of the counter electrode 20 returns from the potential V4 to the potential V3, and the potential of the display electrode 40 changes from the potential V5 to the potential V2. A negative voltage is applied to return.

In the pixel 60 to which the voltage of the potential difference “V1−V4” is applied (that is, the selected pixel 60a), current flows from the display electrode 40 to the counter electrode 20 through the electrochromic composition 52, and the electrochromic composition layer Since the electrochromic composition 52 undergoes an electrochemical change at the interface between the display electrode 40 and the display electrode 40 (the surface of the display electrode 40), the selected pixel 60a on the first line is colored.
Further, among the non-selected pixels 60b, the non-selected pixel 60b1 formed between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b has a potential difference in the first period P1. Since a voltage of “V1−V3” is applied, a current flows from the display electrode 40 to the counter electrode 20 via the electrochromic composition 52, and in the second period P2, the potential difference “V5−V3” (≈− ( Since a voltage of V1-V3)) is applied, a current flows from the counter electrode 20 to the display electrode 40 via the electrochromic composition 52. Further, the length of the first period P1 and the length of the second period P2 are controlled to be substantially the same. Therefore, charges are generated and accumulated between the electrodes forming the non-selected pixel 60b1 as the potential difference “V1−V3” is applied. Immediately thereafter, the potential difference “V5−V3” is applied. As a result, almost all of the charge is removed.

Next, the control unit 600 selects the second line (counter electrode 20 in the second row), and the potential of the selected counter electrode 20 in the second row is changed from the potential V3 to the potential in the first first period P1. A negative voltage is applied so as to switch to V4, and a positive voltage is applied so that the potential of the display electrode 40 forming the selected pixel 60a among the pixels 60 on the second row line is switched from the potential V2 to the potential V1, By applying a voltage having a potential difference “V1−V4” between these electrodes, the selected pixel 60a on the second line is colored.
Next, in the next second period P2, the controller 600 applies a negative voltage so that the potential of the counter electrode 20 remains at the potential V4, and the potential of the display electrode 40 changes from the potential V1 to the potential V5. By applying a negative voltage so as to switch, and applying a voltage of a potential difference “V5−V4” between these electrodes, almost all the charges generated between the electrodes forming the non-selected pixel 60b1 in the first period P1 are removed. To do.
Next, when the second period P2 ends, the controller 600 applies a positive voltage so that the potential of the counter electrode 20 returns from the potential V4 to the potential V3, and the potential of the display electrode 40 changes from the potential V5 to the potential V2. A negative voltage is applied to return.

  Then, the control unit 600 performs an electrochromic display of an image for one frame (one page) by performing the same processing as described above for the third line, the fourth line, the fifth line,. It is displayed on the device 100.

<Example>
Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.

(Production of electrochromic display devices)
A 0.7 mm thick rectangular non-alkali glass substrate was used as the second substrate 30, and ITO was sputtered on one surface (lower surface). The sputtered ITO had a film thickness of 200 nm and a surface resistance of 10Ω / □. The sputter-formed ITO was formed into a stripe pattern with a stripe width of 0.42 mm and a pitch of 0.45 mm using a photolithography method, and display electrodes 40 were produced.
Similarly, a rectangular non-alkali glass substrate is used as the first substrate 10, and gold having a film thickness of 300 nm is formed on one surface (upper surface) by sputtering, and a stripe width of 0.40 mm using a photolithography method, A pattern was formed in a stripe shape with a pitch of 0.45 mm. Subsequently, an ITO film having a thickness of 200 nm was formed by sputtering on the gold stripe pattern. Thereafter, an ITO stripe pattern having a width of 0.42 mm and a pitch of 0.45 mm is formed on the gold stripe pattern by photolithography so that the ITO space portion overlaps the gold pattern space portion, and the counter electrode 20 ... were produced.

Next, Dispersion A having the following composition was adjusted by ball mill dispersion, and an adsorbent 53 layer (adsorption layer) was formed on the counter electrode 20 to have a film thickness of 10 μm.
The composition of Dispersion A is
Adsorbent 53 (aluminum oxide; Nippon Light Metal, activated alumina C200) 2 g,
2g of titanium dioxide (Ishihara Sangyo, titanium dioxide CR-93),
0.2 g of partially saponified polyvinyl alcohol (reagent, manufactured by Kanto Chemical)
20 g of distilled water
It is.

Next, an electrochromic composition 52 (hereinafter, referred to as a granule (Sekisui Chemical Co., Ltd. micropearl (particle size 50 μm))) and a predetermined additive (display quality degradation inhibitor, polymer compound, etc.) are added. The first substrate 10 having the adsorption layer formed on the counter electrodes 20 and the second substrate on which the display electrodes 40 are formed are prepared by mixing and dissolving the "electrochromic composition A"). 30. Then, the electrochromic display device 100 (hereinafter referred to as “display device A”) was manufactured by adjusting so that the counter electrodes 20 and the display electrodes 40 were orthogonal to each other and the orthogonal portions thereof were the pixels 60.
Electrochromic composition of the electrochromic composition A supporting electrolyte: tetra-n-butylammonium tetrafluoroborate _{((n-C 4 H 9} ) 4 NBF 4) 200mg,
Polar solvent: propylene carbonate 1.0 g, dimethyl sulfoxide 1.0 g,
Leuco dye: 300 mg of leuco dye that develops black color as shown in the following formula (1),
188 mg of hydroquinone derivative (2,5-ditertiary amyl hydroquinone),
122 mg of a compound having a carbonyl group (benzoylacetone),
50 mg of a polymer compound (polyvinyl butyral; Sekisui Chemical's ESREC BH3),
It is.

(Display operation)
The first voltage switching unit 200 and the second voltage switching unit 400 are connected to the line electrode (counter electrode 20) and the data electrode (display electrode 40) included in the display device A, respectively, and the display device is displayed as the electrochromic display device 100. A display device 1000 having A was manufactured.

Next, energization for display was performed using a passive matrix driving method.
FIG. 7A shows a voltage applied between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a.
FIG. 7B shows a voltage applied between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b.

Specifically, as shown in FIGS. 7A and 7B, in the first first period P1, the potential of the display electrode 40 forming the selected pixel 60a is changed from the potential V2 (= −0.2 V) to the potential. A positive voltage is applied so as to switch to V1 (= + 1.9 V), and the potential of the counter electrode 20 forming the selected pixel 60a switches from the potential V3 (= + 0.2 V) to the potential V4 (= -1.9 V). A negative voltage was applied. As a result, a voltage of a potential difference of +3.8 V (voltage at which a color development reaction occurs) is applied between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a. A voltage of a potential difference of +1.7 V (voltage at which a color development reaction occurs) was applied between the display electrode 40 to be formed and the counter electrode 20 forming the non-selected pixel 60b.
In the next second period P2, a negative voltage is applied so that the potential of the display electrode 40 forming the selected pixel 60a is switched from the potential V1 to the potential V5 (= −1.52V = −V1 × 0.8). A negative voltage was applied so that the potential of the counter electrode 20 forming the selected pixel 60a was maintained at the potential V4. As a result, a voltage of a potential difference +0.38 V (a voltage that does not cause a coloring reaction or a decoloring reaction) is applied between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a. A voltage having a potential difference of −1.72 V (a voltage causing a decoloring reaction) was applied between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the non-selected pixel 60b. The ratio of the length of the first period P1 to the length of the second period P2 was set to the length of the first period P1: the length of the second period P2 = 1: 1.
Next, when the second period P2 ends, a negative voltage is applied so that the potential of the display electrode 40 that forms the selected pixel 60a returns from the potential V5 to the potential V2, and the potential of the counter electrode 20 that forms the selected pixel 60a. A positive voltage was applied so as to return from V4 to the potential V3.

  Then, by performing this voltage application process for each line at a speed of 1 msec per line, scanning was performed to display an image, and the scanning was repeated to repeatedly display the image.

As a comparative example, an image is obtained by applying a voltage to each electrode by a conventional voltage application method (that is, a voltage application method that does not control the potential or the like of the counter electrode 20 that forms the non-selected pixel 60b (see FIG. 11)). Is displayed.
FIG. 8A shows the voltage applied between the display electrode 40 that forms the selection pixel 60a and the counter electrode 20 that forms the selection pixel 60a in the comparative example.
FIG. 8B shows a voltage applied between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b in the comparative example.

  Specifically, using the display device 1000 having the display device A, as shown in FIG. 8A, in the first first period P1, application of a voltage to the display electrode 40 forming the selected pixel 60a is started. Then, a positive voltage is applied so that the potential of the display electrode 40 becomes +1.9 V, and voltage application to the counter electrode 20 forming the selected pixel 60a is started, so that the potential of the counter electrode 20 is −1. By applying a negative voltage so as to be .9 V, a voltage having a potential difference of +3.8 V between the display electrode 40 that forms the selected pixel 60 a and the counter electrode 20 that forms the selected pixel 60 a (voltage that causes a color reaction) ) Was applied. In the next second period P2, a negative voltage is applied so that the potential of the display electrode 40 that forms the selected pixel 60a is switched from + 1.9V to -1.9V, and the counter electrode 20 that forms the selected pixel 60a is also applied. By applying a positive voltage so that the potential is switched from −1.9 V to +1.9 V, a potential difference of −3. 3 between the display electrode 40 that forms the selected pixel 60 a and the counter electrode 20 that forms the selected pixel 60 a. A voltage of 8 V (voltage causing a decoloring reaction) was applied. The ratio of the length of the first period P1 to the length of the second period P2 was set to the length of the first period P1: the length of the second period P2 = 7: 3.

Next, when the second period P2 ends, the application of the voltage to the display electrode 40 that forms the selected pixel 60a is ended, and the application of the voltage to the counter electrode 20 that forms the selected pixel 60a is ended.
Here, in FIGS. 8A and 8B, a period in which no voltage is applied is indicated by a virtual line (two-dot chain line). This is because the potential of the counter electrode 20 and the display electrode 40 during a period in which no voltage is applied is an indeterminate potential (depending on the display image), and is not actually “0 (zero)”. Show.

  Then, by performing this voltage application process for each line at a rate of 1 second per line, scanning was performed to display an image, and the scanning was repeated to display the image repeatedly.

(result)
FIG. 9 shows a part of an image displayed by the voltage application method of the example, and FIG. 10 shows a part of an image displayed by the voltage application method of the comparative example.
It was found that the image displayed by the voltage application method of the example was clearer than the image displayed by the voltage application method of the comparative example, and the image blur was suppressed.
That is, the potential of the counter electrode 20 that forms the non-selected pixel 60b is controlled to accumulate between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b in the first period P1. It was found that a high-quality image can be displayed even if a high-speed scan of 1 msec / line is performed by substantially removing the generated charges in the second period P2.

According to the display device 1000 of the present invention described above, the first substrate 10, the counter electrode 20 provided on the upper surface of the first substrate 10, and the first substrate 10 facing the first substrate 10. A second substrate 30 formed of a transparent material, a display electrode 40 provided on the lower surface of the second substrate 30 and formed at least partly of a transparent electrode material, the first substrate 10 and the second substrate. An electrochromic composition layer 50 provided between the counter electrode 20 and the display electrode 40. The electrochromic composition layer 50 is provided between the counter electrode 20 and the display electrode 40. In the display device 1000 including the passive matrix drive electrochromic display device 100 that erases the display by energization in the direction opposite to the energization for the display, the counter electrode 20 The display electrode 40 is a plurality of electrodes extending in parallel in a direction orthogonal to the counter electrode 20, and the pixel 60 is formed in a region where the counter electrode 20 and the display electrode 40 intersect three-dimensionally. Is formed, and the control unit 600 displays a predetermined image on the electrochromic display device 100. The control unit 600 is not selected while the potential of the display electrode 40 forming the non-selected pixel 60b becomes the potential V2. Control is performed so that the potential of the counter electrode 20 forming the pixel 60b becomes the potential V3, and energization for display is performed between the counter electrode 20 forming the selection pixel 60a and the display electrode 40 forming the selection pixel 60a. The period is divided into two periods. In the first first period P1, the potential of the display electrode 40 becomes the potential V1 (V1> V2, V1> V3), and the pair Controlled to the potential of the electrode 20 becomes the potential V4 (V4 <V3), the next second period P2, and controls so that the potential of the display electrode 40 is a potential V5 (V5 <V3). At that time, the control unit 600 sets the length of the first period P1 and the length of the second period P2, the potential V1, the potential V3, and the potential V5 to the display electrode 40 that forms the selection pixel 60a in the first period P1. It is configured to control so that the charge accumulated between the counter electrode 20 forming the non-selected pixel 60b becomes a value that is substantially removed in the second period P2.
Specifically, the control unit 600 controls the length of the first period P1 and the length of the second period P2 to be substantially the same, and the difference | V1−V3 | between the potential V1 and the potential V3 and the potential It is configured to control so that the difference | V3−V5 | between V3 and potential V5 is substantially the same.

Therefore, the charge accumulated in the first period P1 between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the non-selected pixel 60b can be substantially removed by energization in the second period P2. Therefore, it is possible to prevent the charge from remaining. Therefore, high-quality images can be displayed at high speed.
In particular, the potential of the counter electrode 20 that forms the non-selected pixel 60b is controlled to accumulate between the display electrode 40 that forms the selected pixel 60a and the counter electrode 20 that forms the non-selected pixel 60b in the first period P1. By surely grasping the amount of charge that is generated, the potential of the display electrode 40 that forms the selected pixel 60a and the length of the first period P1 are ensured so that the charge accumulated between these electrodes is reliably removed. The length of the second period P2 can be controlled. Therefore, it is possible to surely prevent electric charge from remaining between these electrodes as compared with the case where the potential of the counter electrode 20 forming the non-selected pixel 60b is not controlled. As a result, blurring of the image can be accurately suppressed, and a high-quality image can be displayed.

  Further, according to the display device 1000 of the present invention described above, the control unit 600 is configured to control the potential V5 so that V5 ≧ V4.

  Accordingly, a current in the same direction as the energization for coloring the pixel 60 flows between the display electrode 40 forming the selected pixel 60a and the counter electrode 20 forming the selected pixel 60a even in the second period P2. Compared with the case where the energization in the direction opposite to that for energizing the pixels 60 is performed in the second period P2, the contrast ratio is maintained, and a higher quality image can be displayed.

  Further, according to the display device 1000 of the present invention described above, the control unit 600 is configured to control the potential V2 to be V2 <0 and to control the potential V3 to be V3> 0. Yes.

  Therefore, a current in the direction opposite to the energization for coloring the pixel 60 flows between the display electrode 40 that forms the non-selected pixel 60b and the counter electrode 20 that forms the non-selected pixel 60b. Can be reliably removed. Therefore, bleeding of the image can be suppressed more accurately, and a higher quality image can be displayed.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof.

  In the embodiment, the control unit 600 controls the length of the first period P1 and the length of the second period P2 to be substantially the same, and the difference | V1−V3 | between the potential V1 and the potential V3 and the potential Although the control is made so that the difference | V3−V5 | between the V3 and the potential V5 is substantially the same, it is not limited to this. The length of the first period P1 and the length of the second period P2, and the potential V1, the potential V3, and the potential V5 are the counter electrode that forms the display electrode 40 that forms the selection pixel 60a and the non-selection pixel 60b in the first period P1. As long as the charge accumulated between 20 and 20 has a value that is substantially eliminated in the second period P2, it can be arbitrarily changed as appropriate.

DESCRIPTION OF SYMBOLS 10 1st board | substrate 20 Counter electrode 30 2nd board | substrate 40 Display electrode 50 Electrochromic composition layer 60 Pixel 60a Selection pixel 60b Non-selection pixel 100 Electrochromic display device 600 Control part (display control means)
1000 Display device P1 First period P2 Second period

Claims (5)

A plurality of first electrodes arranged in a line in parallel ;
A plurality of second electrodes disposed opposite to the first electrode, in a three-dimensional crossing at an angle of approximately 90 degrees with the first electrode, and arranged in a line in parallel ;
A controller that controls the potential of the first electrode and the second electrode ;
The first electrode and the second electrode and a electrochromic composition layer overpass region crossing,
The controller is
In case of color detection a predetermined crossing area,
The predetermined period is divided into two periods, the first first period and the next second period,
The first electrode corresponding to the predetermined three-dimensional intersection region is changed from the potential V3 to the potential V4 (V4 <V3) for the predetermined period,
From the potential V2, the second electrode corresponding to the predetermined three-dimensional intersection region is set to potential V1 (V1> V2, V1> V3) in the first period, and potential V5 (V5 <V3) in the second period. ,
If the first electrodes adjacent to the first electrode corresponding to the predetermined crossing region is not carried out the control for the color development, the to the potential V3 to the predetermined period,
In the first period, charges accumulated between the second electrode corresponding to the predetermined three-dimensional intersection region and the first electrode not corresponding to the predetermined three-dimensional intersection region are display device comprising that you control to be removed in time. The display device according to claim 1,
The controller is
Controlling the length of the first period and the length of the second period to be substantially the same;
A display device, wherein a difference | V1−V3 | between the potential V1 and the potential V3 and a difference | V3−V5 | between the potential V3 and the potential V5 are controlled to be substantially the same. The display device according to claim 1 or 2,
The controller is
The display device is characterized in that the potential V5 is controlled to satisfy V5 ≧ V4. The display device according to any one of claims 1 to 3,
The controller is
The potential V2 is controlled so that V2 <0,
A display device wherein the potential V3 is controlled so that V3> 0. In the display device according to any one of claims 1 to 4,
When the first not by color let the overpass area corresponding to the electrode adjacent to the first electrode corresponding to the predetermined crossing region to be by color, a first electrode of the adjacent electrical potential V3 Is maintained.