JPS59219723A - Electrochromic display element - Google Patents

Abstract

PURPOSE:To improve diversity of display by providing >=2 display regions to a titled device and sealing electrolytes into the display regions in such a way that the coloring hue of at least one of the oxidation coloring and reduction coloring electrorhomic materials incorporated in said electrolytes differs in the respective display regions. CONSTITUTION:The display region between both base plates 9 and 10 is divided to at least >=2 by means of a separating wall 16, and an oxidatin coloring electrochromic (O type EC) material and reduction coloring electrochromic (R type EC) material having respectively different coloring hues are incorporated into the electrlytes to be sealed in the respective divided display regions, for example, A and B. Said materials are so formed that the colored hue of at least one of the O type EC material and the R type EC material to be incorporated into the electrolytes sealed in said display regions A, B is the same in the respective display region but the other one is different. Then if the R type EC material having the same coloring hue and the O type EC material having different coloring hues are used for the EC materials to be incorporated into the electrolytes sealed in the display regions A, B, the display of the same hue is obtd. in both of the regions A and B when a negative voltage is impressed thereon but the display of the hues different in the regions A and B is obtd. when a positive voltage is impressed thereon. The diversity of the display is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrochromic light display device (hereinafter referred to as EC).
(abbreviated as D). Among them, variable color ECD that can display multiple colors in one segment
It is related to.

The ECD according to the present invention is a dissolution-diffusion type ECD 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, ECDs have been attracting attention because they can operate at low voltages and low power and provide bright and clear displays.

The structure of a typical conventional dissolving type ECD is shown in FIG. Generally, such an ECD includes a display substrate l and a counter substrate 202.
The two substrates are assembled via a spacer 7, and a sealing material 8
It is produced by injecting electrolyte 6 into a cell that has been sealed.

In a typical EeD, in order to obtain a white background, a light reflecting plate is placed between the two differential plates, or an electrolytic solution is mixed with white powder to form a paste. The light reflecting plate is made of ceramic such as alumina or polymer, and the white powder is titanium oxide, alumina, etc. powder. These objects will be collectively referred to as light reflectors.

The display substrate 1 is generally a transparent substrate made of glass, plastic, or the like. A transparent electrode 3 is provided on this. This is a tin oxide (Snow) film, an indium tin oxide (ITO) film, etc., and is usually formed by a vacuum deposition method, but a chemical method such as a spray method may also be used. Counter board 2
There are various structures for the counter electrode 4, but 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 mixture of iron complex and carbon is formed. There are those that are pressed and placed on a glass substrate, metal plates, etc.

There are various methods that can be considered for displaying single digits, but method (-) is a method in which the transparent electrode 3 is exposed to the electrolyte only in the part of the turn-shaped segment to be displayed. This is a method of providing a surface mask 5 on the surface.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, the valley segments are displayed separately. In this case, it is necessary to divide the display electrodes to which these segments are attached accordingly.Although a surface mask 5 is shown in the figure, this is not essential.

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 solvent can be used as long as it is highly polar and stable, and in addition to water, non-aqueous solvents such as propylene carbonate and dimethylformamide are used.

The case where a non-aqueous solvent is used will be mainly described below.

As the supporting electrolyte, ordinary inorganic salts are used for water, but for non-aqueous solvents, alkali metals or tetraalkylammonium and halogens, perchlorate ClO4, fluoroborate BF4. A salt with fluorophosphate PF is used. EC material contains Na, 'NO, Ca
WO4, HaW04. Inorganic materials such as transition metal compound salts such as Na and MoO4, aromatic or heterocyclic compounds such as viologen, tetrathiafulvalene, pyrazoline, fluorene, anthraquinone, pyrylium, pyridium, methylene blue, and organic materials such as inscriptions thereof, There are ferroin, ferrocene, and other materials.

A conventional dissolvable ECU with such a structure has only one display color. For example, the initial state of ECD using butyl anthraquinone in the EC system is white, and when a negative voltage is applied to the transparent electrode, the color develops red, and when a reverse voltage is applied, the color disappears and returns to white. This white color is the color of the light scatterer.

ECLs announced so far, limited to dissolving type ECDs
), most display only one color. As an ECD that produces multiple colors, one is known that has a structure in which a vapor-deposited film of a chain of lanthanoids and shiftalodianine is formed on a transparent electrode. This type can display three colors (red, green, and back) by changing the applied voltage, but there is no state where it becomes colorless and transparent or white, and the display colors are limited, making it possible to diversify. It has disadvantages such as lack of sex.

The object of the present invention is to provide a high display diversity, that is, to be able to obtain two different display colors in addition to a colorless state in one segment, and to be able to display the same display color at spatially different locations within the display section. An object of the present invention is to provide an electrochromic display device that can obtain different display colors.

A display device according to the present invention includes a pair of transparent substrates each having a display electrode, at least one of which is a transparent electrode, in which a display area is divided into at least two or more side substrates by a separation wall formed between the side substrates. The electrolytic solution to be sealed in each of the divided display areas contains an oxidation coloring electrochromic material and a reduction coloring electrochromic material having different coloring hues, and the electrolyte solution to be sealed in each of the display areas is The coloring hue of at least one of the oxidation coloring and reduction coloring electrochromic materials contained in the electrolytic solution is the same in each display area, and the coloring hue of the other is different.

A personal cross-sectional view showing an embodiment of the display device according to the present invention is shown in FIG. FIG. 2 is an example where the display area is divided into two. The structure is the same as the conventional structure except that a light reflector is essential and a separation wall is formed to divide the six display areas. That is, a display electrode 11 made of a transparent electrode is formed on the display substrate 9. A surface mask 13 made of a transparent or white insulating film is formed on the display electrodes other than the pattern to be displayed. Alternatively, a white insulating film may be formed on the display substrate 9 in advance in an area other than the pattern to be displayed, and then the display electrodes 11 may be formed.
Any structure may be used.

On the other hand, a counter electrode 12 is formed on the counter substrate 10. Separation wall 1 to divide the display area into (5) and (B)
6 is formed, and a light reflector 15 is installed between the side substrates. Each display area (5), (B) is filled with an electrolytic solution 14 containing an oxidation coloring type (0 type) EC material, a reduction coloring type (R type) EC material and a supporting salt, which have different coloring hues. , and the area (4).

Among the EC materials contained in each electrolytic solution to be sealed in the EC materials, one of them is used that has the same coloring hue.

Here, type 0 EC material is an EC material that is nearly indestructible in a neutral state and develops color due to oxidation.

The display substrate, counter substrate, display electrode, counter electrode, surface mask, etc. used in this device can be formed using the same materials and manufacturing methods as those used in conventional devices.

The ECD according to the present invention has a display electrode 11 and a counter electrode 12.
When a voltage is applied from the outside, the O-type EC material develops color at the electrode to which a positive voltage is applied, and the R-type EC material develops color to the electrode to which a negative voltage is applied.

Since a light reflector 15 is installed between the opposing pole 12 and the display electrode 9, the coloring on the opposing electrode is not visible.

Therefore, when a positive voltage is applied to the display electrode with respect to the counter electrode, the coloring hue of the 0-type EC material becomes the displayed color, and when a negative voltage is applied, the coloring hue of the R-type EC material changes to the display color. Become.

When the applied voltage is set to Ov, color develops and 7' (0 type and R type E
The CCM comrades react, return to a neutral, colorless state, and the display disappears.

Therefore, among the EC materials contained in the electrolytic solution sealed in each display area (2) and (B) of mJ, for example, the R-type EC material is the same, and the 0-type EC material is a material with a different coloring hue. If a negative voltage is applied to the display electrode with respect to the counter electrode, each display area (2) and (out) can display the same hue of the R-type EC material, and when a positive voltage is applied, each In the display area (β), display colors of different hues can be obtained using the Tani-0 type EC material.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the display device according to the present invention. The difference from the embodiment shown in FIG. 2 is that the light reflector 15 is not included and the position where the counter electrode 12 is installed is different. In the structure shown in FIG. 3, the counter electrode 12 is placed in a region of the display electrode other than the pattern to be displayed. In this structure, the counter electrode 1
Since the color development and fading shown in Fig. 2 is not visible, it is easy to understand that the same effect as explained in the embodiment of Fig. 2 can be expected. In the structure of FIG. 3, the counter electrode 12 is formed in an area other than the pattern to be displayed by the display electrodes on the counter substrate 10, but it may be formed anywhere as long as it is in an area other than the pattern to be displayed by the display electrodes. Needless to say.

In known examples in which both a 0-type EC material and an R-type EC material are used as the EC material, the counter electrode is formed in a region of the display electrode that faces the pattern to be displayed. As already mentioned, the display electrode'
When the O-type EC material develops color with either electrode 1 or counter electrode 12, the R-type EC material develops color with the other electrode. This is because in order for current to flow between the pair of electrodes in the electrolytic solution, the display electrode is formed on each electrode in the area facing the pattern to be displayed.In conventional devices, O-type EC material and R-type EC material It is not possible to see each color independently, only a mixture of both colors is displayed, and only a negative color can be displayed. This has nothing to do with the polarity of the applied voltage. Unfortunately, it is impossible to change the display color by changing the polarity of the applied voltage in the same segment as in the present invention, and the superiority of the present invention can be understood.

Furthermore, it goes without saying that in the cited example, it is impossible to change the display color between spatially different hues.

The O-type EC material and RfiEC material used in the present invention are not limited to one type each, and multiple types of EC materials can be used for both the O-type, R-type, or 0-type and R-type. By such a mixture, a mixture of the color hues of each EC material alone can be used for display, and the variety of displays is significantly increased.

The present invention will be described below based on examples.

Embodiment 1 In FIG. 2, the display substrate 9 and the counter substrate 10 are both glass plates, and the display electrode 11 and the counter electrode 12 are both tin oxide and indium oxide (ITO) electrodes, which are made by true wall evaporation. and processed into the desired pattern by chemical etching. Next, a surface mass 13 made of epoxy II resin containing titanium oxide was formed by screen printing an epoxy adhesive and baking under pressure to form a separation wall 16 and a peripheral seal other than the pattern to be formed on the display electrode. . Both differential plates were densely filled with titanium oxide powder to form a light reflector 15. As the electrolytic solution 14, 1-P-methoxyphenyl-3-
P-diethylaminostyryl-5-diethylaminophenyl-Δ2-pyrazoline (0.1-0.3 mol/J
), 2-butylanthraquinone (01 to 0.3 mol/#) as the R-type EC material, and tetrabutylammonium fluoroborate (0,05 mol/#) as the supporting electrolyte.
~0.2 mol/l) and tetrabutylammonium iodide (005~0.2 moA!/7?), N-2-methyl-pyrrolidinone was used as the solvent. On the other hand, type 0 E
1.3゜5-tri(P-methoxyphenyl) as C material
-he2-pyrazoline (0.05-0.3 mal/11
) was used, but the same electrolytic solution as the one sealed in the display area was used. The initial state of this ECD is yellowish white or colorless. −2 for the display electrode with respect to the counter electrode;
By applying a negative voltage of +2.OV, the display area (5) becomes blue and the display area (B) becomes blue. A yellow-green color developed. Also, by changing to Ov, each display color disappeared and returned to the initial state.

Example 2 Benzo[α]anthracene-7°12 as R-type EC material
- Same materials and structure as Example 1 except for using dione
ECD turns green when a negative voltage of -1.2 V or less is applied, +1.2
When a positive voltage of V or more was applied, the display area (2) was colored blue, and the display area (B) was colored yellow-green.

Example 3゜Same material and structure as Example 1 except that chloronaphthoquinone was used as the R-type EC material @ECD is displayed in yellow when a negative voltage of -1.2V or less is applied, and when a positive voltage of +1.2V or more is applied The area prisoner turned blue, and the display area turned yellow-green.

Example 4 1-P-methoxyphenyl-3-P- as a 0 type EC material
-diethylaminostyryl-5-diethylaminophenyl-△2-°pyrazoly;y (0.1-0.3 mol/
1, 2-1-butylanthraquinone and benzo[α]anthracene-7,12- were used as R-type EC materials contained in the electrolyte sealed in each display area (5) and (B), respectively.
Same materials and structure as Example 1 except for using dione
D was colored blue when a positive voltage of +1.2 V or more was applied, and the display area (5) was colored red and the display area CB) was colored green when a negative voltage of -1.2 V or less was applied.

As in the above embodiments, two-color display ECDs having various display color pairs could be obtained by the present invention. By using multiple EC materials instead of using -at type EC materials for either or both of the type 0 EC materials and Rfi EC materials, the mixed color of those EC materials is used as the display color. By doing so, it is also possible to diversify the display colors.

The O-type EC material and the R-type EC material used in the present invention are not limited to the EC materials described in the examples, but various two-color displays can be realized by using them for the surface that develops color through oxidation or reduction. Ru.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a conventional ECD. In FIG. 1, 1. Display substrate 2. Counter substrate 3 transparent electrode 4, counter electrode 59 surface mask 6. Electrolyte 7 Spacer
8 Sealing Material FIGS. 2 and 3 are schematic cross-sectional views showing the configuration of an embodiment of the present invention. 9 in FIGS. 2 and 3, display substrate 10. Counter substrate 111 display electrode 1
2. Opposite electrode & 131 surface mask 14. [Go to Rust Liquid 15, Light Reflector 169 Separation Wall 1 Diagram

Claims (1)

[Claims] (1) In 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, at least one of which is transparent, a display area is formed between at least two inner panels. The display area is divided by a partition wall, and the electrolytic solution to be sealed in each of the divided display areas contains an oxidation coloring electrochromic material and a reduction coloring electrochromic material having different coloring hues. , and an electrochromic display device characterized in that the coloring hue of at least one of the oxidation coloring and reduction coloring electrochromic materials contained in the electrolyte sealed in each display region is different in each display region. .