JPS62163021A - Electrochromic display element - Google Patents

Abstract

PURPOSE:To obtain the element capable of effecting a patterning display having no ooze, without deterioration of the display quality by crystallizing surroundings of the display part of the reductive coloring layer. CONSTITUTION:The surroundings of the display part of the reductive coloring layer is crystallized. The crystallization range comprises the whole range except the display part 17 and the trimming part in the surroundings of the display part, for example, the surroundings of the display part 27. The EC layer is necessary to be an amorphous in order to color it. The crystallization of the EC layer does not bring a coloring, as the EC layer does not produce a proton whereby a reaction does not occur. Thus, when the surroundings of the display part (at least a part of occuring the ooze) crystallizes, the display having no ooze is obtained. And, the ooze of the oxidative coloring layer is prevented by patterning the oxidative coloring layers 13 and 23, and the lower display electrodes 12 and 22. The method of the crystallization is not specified, if the crystallization is effected with accuracy. For example, the prescribed method is preferably the laser-annealing method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrochromic (hereinafter referred to as EC) display element. More specifically, the present invention relates to prevention of bleeding in all-solid-state EC display elements.

[Summary of the Disclosure] This specification and drawings disclose a technique for providing an EC display element that provides a bleed-free display by crystallizing the periphery of the display portion of the reduction coloring layer in the EC display element. be.

[Prior Art] Such EC display elements include, for example, numeric display elements, x-
It can be applied to Y matrix displays, optical shutters, aperture mechanisms, etc.

The first general configuration example of a bipolar coloring type all-solid-state EC display element
As shown in the figure. This device has a structure in which a lower display electrode 2) an EC layer 3 made of a transparent conductive film and an upper counter electrode 4 are sequentially laminated on a transparent substrate 1, and the EC layer 3 is made of an oxidized color-forming substance. The second EC layer 7 is composed of a second LEC layer 5 made of a dielectric film, an intermediate insulating layer 6 made of a dielectric film, and a second EC layer 7 made of a reduction coloring material.

The substrate l is generally formed of a glass plate, but it is not limited to a glass plate, and may be any colorless and transparent plate such as a plastic plate or an acrylic plate, and its position is limited to below the lower display electrode 2. It may be provided on top of the upper opposing electrode 4, or may be provided on both sides depending on the purpose (for example, for the purpose of serving as a protective cover).

The lower display electrode 2 is an ITO film (5n02 in In203).
) and NESA film (SnO2)
It is composed of transparent conductive films such as. If the upper counter electrode 4 is also a transparent electrode, a transparent element can be obtained.

The material forming the first EC layer 5 having oxidative coloring property is as follows.

V2O3, WO2, CL120. Nip, SnO,
PbO, Ce2O3, Tie.

Ga2O, Ag2O, Hg20. Tb2O3,Sin
, ↑ao, Fed, Os'.

Au203. MoO4, Cry, CdO, IrO2
, MnO, VO2, Cab.

Examples include Cr2O3.

The material forming the intermediate insulating layer 6 is TiO2+ZrO+
, HfO2, Ta205.5i02. GeO2) chalcogenide glass, NaCR, KCR, MgF2. C
aF2. Many materials can be used, such as polyvinyl chloride, polystyrene, polyvinyl alcohol, polyester, cellulose, etc.

The material forming the second EC layer 7 with reduction coloring property is WO3.
, V2O5, Gap, MnO3, S+102.
Ir0z, Nb2O5°VO:l, Ten2. Gd
O, Cr2O3, Mn0z, Ta205. Ca2O3°Real, A11203. Fe2O3,5b2
0s, TiO2, CeO2゜5b203. AgO
Examples include.

In the EC element having such a configuration, an electrochemical reaction is induced by applying a voltage between the electrodes 2 and 4, and coloring and decoloring are performed.

For example, the oxidation coloring layer 5 is TrOx, and the reduction coloring layer 7 is WC.
Consisting of h, oxidized coloring layer 5 side is positive (+), iH
When a negative (-) voltage is applied to the original color forming layer 7 side, frog
and VO3 are respectively IrOx + yH20aa − + Ir0x(OH)
y + IH1+ ye-WCh÷yH' + ye-
−+HyW03 reaction produces colored species 1rOx(O
H), It is thought that HyW03 is generated and colored, and by reversing the electric field, a reaction opposite to the above equation occurs and the color disappears.

to In the color development/decolorization reaction, the intermediate insulating layer 3 is.

It functions as a source of H20a d and at the same time prevents reverse reactions due to recombination of colored species, in other words conduction of ions and blocking of electrons.

[Problems to be Solved by the Invention] Conventionally, in order to display a pattern using such an EC display element, the electrode layer only needs to be composed of a plurality of segment electrodes. However, in this method, the coloring formed in the EC layer There is a problem in that the seeds spread around the display pattern, causing blurring on the display. In order to prevent such bleeding, both EC layers can be patterned, but since the reduction coloring layer has a thickness of approximately 0.4 #Lra, the difference in film thickness between the coloring area and the non-coloring area may cause There is a problem in that differences in reflectance and transmittance occur, resulting in a decrease in display quality.

An object of the present invention is to provide an EC display element that can perform patterned display without bleeding without causing deterioration in display quality as described above.

[Means and effects for solving the problems] In order to achieve the above object, the present invention includes a reduction coloring layer and an oxidation coloring layer,
The present invention provides an electrochromic display element of a bipolar coloring type all-solid-state electrochromic display element having an intermediate insulating layer between these two layers, characterized in that the periphery of the display portion of the reduction coloring layer is crystallized.

The EC display element of the present invention will be explained with reference to FIG. i2 and FIG. 3, which correspond to embodiments. Respective reduction coloring layers 15 and 2
The shaded area in 5 is the crystallized area. The area to be crystallized includes cases where the entire area other than the display portion 17 is covered as shown in FIG. 2, and cases where only the periphery of one display portion is formed, for example, the area around the display portion 27 is bordered as shown in FIG. In order for the EC layer to develop color, it must be amorphous, and since it is not protonated in a crystalline state, the reaction described above does not occur and no color develops. Therefore, if the periphery of the display area (at least the area where bleeding occurs) is crystallized, a display without bleeding can be obtained. Further, as in the examples shown in FIGS. 2 and 3, the oxidized color forming layer 13.23 and the lower display electrode 12.22 may be patterned to prevent bleeding in the oxidized color forming layer.

The crystallization method is not particularly limited as long as it can crystallize with high precision, but laser annealing is suitable, for example. In this case, it is preferable to use a high-power laser such as a CO2 laser or N2 laser.
When crystallizing the amorphous EC layer by once melting it as in this method, the EC layer material must have a melting point, and among the substances forming the reduction coloring layer mentioned above, WO3 is used.

T i02 etc. are suitable.

Furthermore, the conventional materials mentioned above are used for the oxidized coloring layer, intermediate insulating layer, transparent electrode, and substrate.

[Example] Example 1 FIG. 2 shows a schematic cross-sectional view of the EC element of the present invention.

The range indicated by 17 is the display part, and the range indicated by 1st is the non-display part. The transparent electrode 12 is patterned, and a patterned iridium oxide film +3 (IrO
x) is formed. The intermediate insulating layer 14 is made of tantalum pentoxide (Ta20s), the reduction coloring layer 15 is made of tungsten trioxide (W(h)), and 16 is an upper transparent electrode.

The shaded area of the reduced color forming layer 15 is the area crystallized by laser annealing, and the area without the area is in an amorphous state.

In the EC element with the above structure, if the electrode 12 is biased positively and the electrode 16 is biased negatively, it will be colored, but the shaded area is crystallized, so no color develops and no bleeding occurs. Since the display area and the non-display area are almost the same and the constituent materials are the same, the reflectance and transmittance of the display area and the non-display area are almost the same optically, and the display quality is not degraded.

Example 2 Another example according to the present invention is shown in FIG. 3, which is the same as the example shown in FIG. 2 except for the crystallized portion of the reduced coloring layer 25. That is, in Example 1, the entire non-display area was crystallized, but in this example, only the periphery of the display area was edged by laser annealing to prevent bleeding during coloring.
In this example, as in Example 1, the film thicknesses of the display area and the non-display area are almost the same, and the display quality is not degraded.

Further, FIG. 4 shows a perspective view of this element.

[Effects of the Invention] As explained above, according to the EC display element of the present invention,
It is possible to eliminate display blurring and to suppress deterioration in display quality due to patterning or the like.

[Brief explanation of drawings]

Figure 1 is a schematic cross-sectional view of a general all-solid-state EC device, Figure 2 is a schematic cross-sectional view of an example in which the entire non-display area is crystallized, and Figure 3 is a schematic cross-sectional view of an example in which only the periphery of the display area is crystallized. It is. Further, FIG. 4 is a perspective view of FIG. 3. 1.11, 21: Substrate 2.12, 22: Lower display electrode 3: Electrochromic layer 4.18, 2Ei: Upper counter electrode 5, 13.23: Oxidized coloring layer 6.14, 247 Intermediate insulating layer 7, 15 .25: Reduction coloring layer 27: Display area 28: Non-display area

Claims (2)

[Claims] (1) In a bipolar coloring type all-solid-state electrochromic display element having a reduction coloring layer, an oxidation coloring layer, and an intermediate insulating layer between these layers, it is confirmed that the area around the display portion of the reduction coloring layer is crystallized. Characteristic electrochromic display elements. (2) An all-solid-state electrochromic display element according to claim 1, wherein the oxidized coloring layer and the oxidized coloring layer side electrode are patterned.