JPS6061727A - Electrochromic display device - Google Patents

Abstract

PURPOSE:To obtain a three-color display electrochromic display device having a high variety of display by using mixedly oxidation coloring type (O type) and reduction coloring type (R type) EC materials having coloring hues differing from each other for an EC material and providing a colored light reflecting body between two base plates. CONSTITUTION:An electrolyte contg. an O type EC material which is colored by oxidation and an R type EC material which is colored by reduction is used. A white or colored surface mask 5 is formed on the surface of a display base plate 1 in contact with the electrolyte except the display part. A light reflecting body colored to the color different from the hue to be colored by both EC materials or the hue of the surface mask is provided between both electrodes 3 and 4. When a positive voltage is impressed to the transparent electrode 3 with respect to the counter electrode 4, the mixed colors of the hue developed by the O type EC material and the colored reflecting body is a display color and when a negative voltage is impressed thereto, the mixed colors of the hue colored by the R type EC material and the light reflecting body is the display color. The O type and R type EC materials react with each other and restore the neutral state when the impressed voltage is made OV. Namely, the display is put out and the color of the light reflecting body is displayed. A variety of three-color display is thus made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an electrochromic display device (EOD).
It is related to. Among these, it particularly relates to a variable color EOD that can display multiple colors in one segment.

The EOD according to the present invention is a dissolution-diffusion type EOD that applies a phenomenon in which an electrochromic material (EC material) contained in an electrolytic solution reversibly colors and fades due to an oxidation-reduction reaction based on an electrode reaction. Recently, EOD has been attracting attention because it can operate at low voltage and low power and can provide bright and clear display.

The structure of a typical conventional dissolving type EOD is shown in the figure.

General (EOD like this one has one display substrate and two opposing substrates)
The two substrates are assembled with a spacer 7 in between, and the electrolytic solution 6 is injected into the cell formed by sealing with a sealing material 8#. In such EO'D, in order to obtain a white background, a light reflecting plate is placed between both substrates, or an electrolytic solution is mixed with white powder to form a paste. For the light reflecting plate, a ceramic such as alumina or a polymer R-containing white powder is used, such as titanium oxide or alumina powder. Hereinafter, in this specification, these reflectors, powders, etc. will be collectively referred to as the original reflector.

The display substrate 1 is generally a transparent substrate made of glass, plastic, or the like. Transparent 1 on top of this! Pole 3 is provided. This is a tin oxide (SnO) film, an indium oxide-tin oxide (ITO) film, etc., and is usually formed by a vacuum evaporation method, but chemical methods such as a spray method can also be used. There are various structures for the counter substrate 2 and the counter electrode 4. Typical examples include those in which a transparent electrode is formed on a glass substrate, those in which a metal film is formed on a glass substrate, and those in which a metal film is formed on a glass substrate. There are products such as those made by pressing a mixture of carbon and carbon and placed on a glass substrate, and metal plates.

Various methods can be considered for displaying numbers, letters, etc., but one method is to cover the insulating film 5 so that the transparent electrode 3 is exposed to the electrolyte only in the patterned segments 11 to be displayed. (hereinafter referred to as a surface mask). The material for the surface mask is mainly white ink in which white powder is dispersed in a resin, and it is formed by screen printing. Also, when displaying each segment as C separately, display 1! with those segments. We need to split the poles accordingly. Note that although the surface mask 5 is depicted in the figure, stiffness is not essential.
,(stomach.

As already mentioned, the electrolytic solution 4 contains a solvent, a supporting electrolyte, and an E
It is composed of three components: C material. Any highly polar and stable solvent can be used.In addition to water, non-aqueous solvents such as propylene carbonate and dimethylformamide are used.Example 1 using a non-aqueous solvent of 6 or less
I will mainly talk about this. For support 1'4, ordinary inorganic salts are used for water, but for non-aqueous solvents, alkali metals or tetraalkylammonium and halogen 14
f to elementary acid C! Salts with No. AO, fluoroborate BF4, and fluorophosphate PFj are used.

Transition metal compound salts such as Ea material tl, Na2WO, 0aWO4, BaWO4゜Na, MoO4, etc., inorganic materials,
Examples include organic materials such as aromatic or heterocyclic compounds such as viologen, tetrathiafulvalene, pyrazoline, fluorene, anthraquinone, biryllium, pyridium, and methylene blue, and derivatives thereof, and organometallic materials such as ferroin and ferrocene.

A conventional dissolving type EOD having such a structure displays only one color. For example, using butyl anthraquinone as the Be material7. The initial state of EOD is white, and when a negative voltage is applied to the transparent electrode, the color develops into red, and when a reverse voltage is applied, the color disappears and returns to white. This white color is the color of the light-reflecting rays.

Not only dissolving type EOD has been announced so far.

Most EODs display only one color. As an EOD that produces multiple colors, one is known that has a structure in which a vapor-deposited film of a complex of a lanthanoid thread metal and shiftalodianine is formed on a transparent electrode. This type can display three colors (red, green, and blue) by changing the applied voltage, but it is difficult to manufacture, the materials are expensive, and the characteristics obtained are not reproducible. have shortcomings.

SUMMARY OF THE INVENTION An object of the present invention is to provide a three-color electrochromic display device that is easy to manufacture and has a high variety of displays.

The electrochromic display device of the present invention is an electrochromic display device in which an electrolytic solution in which an electrochromic material and a supporting electrolyte are dissolved is filled between a pair of substrates consisting of a display substrate having a transparent electrode and a counter substrate having a counter electrode. In this apparatus, the white or colored surface mask is formed on the surface of the display substrate other than the pattern segment to be displayed that is in contact with the electrolyte, and the electrochromic material is formed of a surface mask having different coloring hues. The reflector is characterized in that it uses a mixture of an oxidative color-forming electrochromic material and is provided with an original reflector that is colored in a color different from the coloring hue of both electrochromic materials and the hue of the surface mask.

The structure of the present invention is the same as that of the conventional dissolving type FiOD shown in the figure, except that a surface mask 5 and a colored original reflection stop (not shown) are essential, and the features of the present invention are as follows. For the EC material, an oxidation coloring type (0 type) EC material and a reduction coloring type plate (T (type) EC material, which have different coloring hues from each other) were mixed and used, and 7 and 71 pieces were colored between both substrates. This is due to the provision of a light reflector.O type E
C material is an EC material that is in a state close to 2) l (color) and develops color due to oxidation in a neutral state.R type EC material/-
is also an EC material that is nearly colorless in a neutral state, and develops color by abatement.

In this way, an ROD according to the present invention using an electrolytic solution containing a lj O%QEO material and an n-type EC material has a transparent electrode 3 and a facing type. When a voltage of I''11 is applied, the 0 type EC material develops color at the pole, and the Cban/sugar EC material develops color at the electrode to which a negative voltage is applied.A light scatterer is included. Therefore, from the display substrate side, only the coloring of the poles is visible, and the coloring of the opposing type (the coloring on the furnace is hidden by the light scattering material). When a negative voltage is applied, the mixed color of the colored light reflector and the colored color of the type 0 EO material becomes the display color, and when a negative voltage is applied, the color hue of the type EC material and the colored light reflector become the displayed color. The mixed color becomes the display color.The applied voltage is ・θ■
When this happens, the colored O-type and R-type EC materials react with each other and return to a neutral state. That is, the display disappears, the state in the electrolyte returns to its initial state, and the color of the colored light reflector becomes the display color.

Melting type gOD using both O-type EC material and R-type EC material as EC material is disclosed in Japanese Patent Application No. 1983 1. ．． No. 45767, Japanese Unexamined Patent Publication No. 5
4-31297, but these known examples are not provided with a light reflector. As already mentioned, O
When the type EC material develops color, the B and type EC materials develop color using other electrodes. ζ is based on Faraday's law, which states that each time a current flows between a pair of electrodes in an electrolyte, the same amount of electrode reaction must occur on each electrode.

Therefore, in an EOD without a light reflector, 0
It is not possible to see the color development of each of the type EC material and the R type EC material independently; in other words, a mixed color of each color appears as a display, so only a negative color can be displayed. This means that
The polarity of the applied voltage does not matter.

The O-type EC material and R-type EC material used in the present invention are not limited to one type each, but a plurality of types of EC materials can be used for the O-type, R-type, or 0-type R-type. By such mixing, a mixed color of the coloring hue of each BO material alone can be used for display.
．． It is an abbreviation for 5-tri(p-methoxyphenyl)-Δ-pyrazoline, and pyrazoline-B is an abbreviation for 1-p-methoxyphenyl-3-p-dipropylaminostyryl-5-dipropylaminophenyl-Δ-pyrazoline. , BQ is benzo[α]anthracene-7,12dione, and PBPB is an abbreviation for 4-(4'=pyridyl)-N-benzyl pyridium bromide.

Various colored light reflectors can be used. - Examples include anodized alumina particles, paste-like mixtures of electrochemically inert organic or inorganic pigment particles and titanium oxide, and porous reflector plates such as ceramic plates coated with paint, etc. can be used.

The present invention will be described in detail below based on examples.

The figure is an example of a general cross-sectional view for implementing the present invention.

The display substrate 1 and the counter substrate 2 are both made of glass, and the transparent electrode 3 and the opposing electrode 4 are both made of indium oxide/tin oxide (IT).
O) Electrode, formed by vacuum evaporation. Both boards1.
The distance between the two was 0.1 m and sealed with epoxy thread adhesive. A light reflector made of a porous alumina plate with a thickness of 90 μm and spray-coated with a water-soluble yellow paint (manufactured by Asahi Pen) was placed between the two substrates.

The surface mask 5 is prepared by injecting ink (NAZDARBE-) made of titanium oxide and epoxy thread resin onto the display substrate in advance.
112) and baked Jlilj (18(1
℃, 2 powders). The color of the surface mask at this time is white. Electrolyte 6' contains pyrazoline-B (0.2 mol/l) as type 0 EO material and 2-tJ-butylanthraquinone (0.2 mon/l) as type R EO material.
, supporting electrolyte containing tetrabutylammonium fluoroborate (0.05-0.2 mol/l) and tetrabutylammonium iodide (0.05-0.2 m
ol/l), N-methyl-2-pyrodinone was used as the solution.

The initial state of this EOD is displayed in yellow.

When a negative voltage of -2.0■ is applied to the transparent electrode with respect to the counter electrode, a red display color with a contrast of 2:1 is obtained with a response time of 0.5 seconds, and by setting the contrast to θV,
The color disappeared in a response time of 1 second and returned to yellow. Plus +2.
By applying a positive voltage of 0 ■, a green display color with a contrast of 3:1 can be obtained with a response time of 0.5 seconds, and by setting it to θV, the color disappears with a response time of 1 second, and the display color returns to - )Ta.

As described above, the EOD according to this embodiment is a three-color display EOD of red, green, and yellow.

As described above, the EOD according to the present invention provides three-color display of green, yellow, and red. The O-type EO material and R-type EO material used in the present invention are not limited to the EC materials already described in Table ζ.
Various EC materials that develop color upon oxidation or reduction can be used.

Further, the color of the light reflector can be arbitrarily selected by selecting various colors of the paint. By using the light reflectors colored in various colors, the O-type EO material, and the R-type EC material in the present invention, various three-color displays can be realized.

[Brief explanation of drawings]

The figure generally shows a side cross-sectional view of the KOD. In the figure, 1...display substrate, 2...counter substrate,
3...Transparent electrode, 4°...opposed 1!
pole, 5...surface mask, 6...ff
fJ'[,7...Spacer, 8...,...
It's a sealant. Mayuzumi

Claims (1)

[Claims] In an electrochromic display device comprising a display substrate having a transparent electrode and a counter electrode, a white or colored insulating film is provided on a surface of the display substrate in contact with the electrolyte in a portion other than the pattern segment to be displayed. and using a mixture of an oxidation color-forming electrochromic material and a reduction color-forming electrochromic material having mutually different coloring hues as the electrochromic material,
Also, a light reflector colored in a color different from the coloring hue of the electrochromic materials and the hue of the insulating film is installed between the electrode substrates. electrochromic display device.