JPH0222622A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To prevent an electrode from being seen at the time of voltage non- application to improve the visual recognizability by packing a non-patterning area on a glass substrate with a transparent insulating material having the same refractive index as an ITO. CONSTITUTION:The non-patterning area where a transparent electrode 4 is not formed on a glass substrate 2 is packed with a transparent insulating material 7 which essentially consists of ZrO2 and SiO2 and has the same refractive index as the transparent electrode, and this transparent insulating material and the transparent electrode as a patterning area are coated with an orienting film 5. That is, the transparent electrode consisting of the ITO and the transparent insulating material having the same refractive index as the ITO are formed on the same surface without gaps, and therefore, the reflectivity difference between them is resolved and the transparent electrode is prevented from being seen at the time of voltage non-application.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a liquid crystal display element (hereinafter referred to as LCD) in which transparent electrodes made of ITO are formed in correspondence with a display pattern.

[Conventional technology]

FIG. 2 is a sectional view of a main part of a conventional general LCD. In the figure, upper and lower electrode substrates 1.1 each have a transparent electrode 4 made of ITO and having a predetermined shape corresponding to a display pattern formed on a glass substrate 2 through an undercoat 3 made of SiO□. , the transparent electrode 4 of each electrode substrate l is covered with an alignment film 5 made of polyimide or the like. After rubbing the surfaces of the alignment films 5.5 in a specific direction, the picture electrode substrates 1, 1 are bonded together via a sealing material (not shown), and the liquid crystal 6 is placed between the opposing alignment films 5.5. By encapsulating it, an LCD as shown in FIG. 2 is obtained.

In such an LCD, liquid crystal molecules are oriented in a direction parallel to the rubbing direction, and by applying a voltage between desired transparent electrodes 4, 4 located at opposing positions, the shape of the transparent electrodes 4 can be adjusted according to the shape of the transparent electrodes 4. Patterns can be displayed as negative or positive.

Note that the undercoat 3 is a ψ film for preventing the Na component of the glass from melting into the liquid crystal 6.

[Problem to be solved by the invention]

However, in the above LCD, the transparent electrode 4 has a refractive index of 1.81, while the undercoat 3 has a refractive index of 1.65 and the alignment film 5 has a refractive index of 1.68. There was a problem in that the transparent electrode 4 was visible when no voltage was applied.

Such visibility of the electrodes when no voltage is applied not only impairs the design, but also causes deterioration in the visibility of the display pattern.

Therefore, it is an object of the present invention to provide an LCD that prevents electrodes from being visible when no voltage is applied.

[Means to solve the problem]

In order to achieve the above object, the present invention provides Z
It was filled with a transparent insulating material containing rO□ and Sin as main components and having the same refractive index as the transparent electrode, and the transparent insulating material and the transparent electrode serving as the patterning region were covered with an alignment film.

[Operation] According to the above means, the transparent electrode made of ITO and the ITO
Since the transparent insulating material having the same refractive index as the transparent electrode is formed on the same surface with a gap, the difference in reflectance between the two is eliminated, and there is no possibility that the transparent electrode will be visible when no voltage is applied.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view of a main part of an electrode substrate of an LCD according to an embodiment of the present invention, and parts corresponding to those in FIG. 2 are given the same reference numerals.

In FIG. 1, in the non-patterned area on the upper surface of the undercoat 3 where the transparent electrode 4 made of ITo is not formed, ZrO and Sin are formed to the same thickness as the transparent electrode 4.
It is filled with a transparent insulating material 7 made of . This transparent insulating material 7 is formed by offset printing a solution containing an organometallic compound in an organic solvent and firing the result.The organic solvent used in this example was Phenyl Cellsolve 2
8.2% by weight, 2-ethylhexanol 18.8% by weight,
Secondary butyl alcohol is 23.0% by weight, and the organometallic compounds are 22.5% by weight of zirconium tetraacetylacetonate and 7.5% by weight of silicone tetraacetylacetonate. Transparent insulating material 7 thus obtained
The component ratio is ZrO2:5iOz=3:1, and its refractive index is 1.81, which is the same as ITO. Therefore, there is no difference in reflectance between the transparent electrode 4 covering the undercoat 3 and the transparent insulating material 7, and there is no possibility that the transparent electrode 4 will be visible when no voltage is applied.

Further, in this embodiment, an insulating film 8 of 300 to 400 layers is interposed between the above-described transparent electrode 4 and transparent insulating material 7 and the alignment film 5, and this insulating film 8 prevents static electricity generated during rubbing. Breakage of the alignment film caused by this and short circuits between the upper and lower electrodes caused by the incorporation of conductive particles are prevented. The insulating film 8 is formed by offset printing a solution containing 18.0% by weight of zirconium tetraacetylacetonate and 12.0% by weight of silicone tetraacetylacetonate in the above-mentioned organic solvent, and then firing the resulting solution. The component ratio is Zr0z:SiO,=3:2, and the refractive index is 1.68, which is the same as the alignment film 5.

〔Effect of the invention〕

As explained above, according to the present invention, the non-patterned area on the glass substrate, that is, the area where the transparent electrode made of ITO is not formed, is filled with a transparent insulating material having the same refractive index as ITO. Therefore, there is no difference in reflectance between these transparent electrodes and the transparent insulating material, so that the electrodes can be prevented from being visible when no voltage is applied, and visibility is significantly improved and the design is also good.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part showing an electrode substrate of an LCD according to an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of an LCD according to a conventional example. 1... Electrode substrate, 2... Glass substrate,
3...Undercoat, 4...Transparent electrode, 5...Alignment film, 7...Transparent insulating material.

Claims (1)

[Claims] In a liquid crystal display element in which a transparent electrode patterned on a glass substrate is covered with an alignment film, a non-patterned area on the glass substrate where the transparent electrode is not formed is treated with a transparent electrode mainly composed of ZrO_2 and SiO_2. 1. A liquid crystal display element, characterized in that the transparent insulating film and the transparent electrode serving as the patterning area are covered with the alignment film, which is filled with a transparent insulating material having an equivalent refractive index.