JPH04221931A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To provide the liquid crystal display element which lessens the display unequalness arising from spacers by having the spacers provided with the characteristics of the spacers consisting of glass and spacers consisting of plastic in combination in the structure of the spacers for maintaining a spacing by being interposed between two sheets of panels. CONSTITUTION:The spherical or bar-shaped spacers 6 of the liquid crystal display element constituted by interposing the many spacers 6 between two sheets of the panels 2 are constituted of core materials 61 consisting of transparent non-alkaline glass without contg. alkaline components and clad materials 62 which is consisting of plastic and is coating the surfaces of the core materials 61.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to two types of liquid crystal display devices.
The present invention relates to the structure of a spacer that maintains a gap between two panels.

From a practical standpoint, liquid crystal display elements are required to have high-speed response, high contrast, wide viewing angle, high reliability, and the like. Among these performances, response speed, contrast, viewing angle, etc. are closely related to the thickness of the liquid crystal layer, and in liquid crystal display elements that use certain display modes, the thickness of the liquid crystal layer must be adjusted according to the optical characteristics of the liquid crystal material. High contrast cannot be obtained unless it is set precisely. Furthermore, in liquid crystal display elements using some display modes, display unevenness occurs due to uneven thickness of the liquid crystal layer, resulting in a significant decrease in visibility.

In the case of relatively small liquid crystal display elements, the thickness of the liquid crystal layer can be controlled with high precision by using a sealant provided at the periphery of the panel, but as liquid crystal display elements become larger, the thickness of the liquid crystal layer is Therefore, it becomes difficult to control the thickness of the liquid crystal layer. Therefore, in large liquid crystal display elements, transparent spacers are interposed between panels to control the thickness of the liquid crystal layer.

[0004] Spacers made of glass or plastic have already been put into practical use as spacers interposed between panels, but spacers made of glass that can be molded with high precision may damage the alignment film on the panel surface and damage the alignment film. Spacers made of non-scratch plastic are extremely difficult to control in size. Therefore, it is desired to realize a spacer that has only the features of both.

[0005]

2. Description of the Related Art FIG. 2 is a side sectional view showing a conventional liquid crystal display element. In the figure, a conventional liquid crystal display element has two panels 2 facing each other with a liquid crystal layer 1 in between, a sealing material 3 provided along the periphery of the panel 2, and a sealing member 4 for preventing leakage of liquid crystal. However, panel 2 is made of glass plate 21 and ITO.
It is composed of a transparent electrode 22 and an alignment film 23. Furthermore, in order to control the thickness of the liquid crystal layer 1 with high precision, a large number of transparent spacers 5 are sandwiched between the two panels 2 and are appropriately dispersed so as not to concentrate in a specific position.

In a liquid crystal display element, spacers that are interposed between panels and that control the thickness of the liquid crystal layer with high precision include rod-shaped spacers made of alkali-free glass that does not contain alkali components, and spacers that have a coefficient of thermal expansion close to that of the liquid crystal material. There is a spherical spacer made of plastic. A rod-shaped spacer made of transparent alkali-free glass allows highly accurate dimensional control and is suitable for highly accurate control of the thickness of a liquid crystal layer interposed between panels.

However, spacers made of glass have a thermal expansion coefficient different from that of the liquid crystal material, so even if they are fixed between panels at room temperature, they tend to move when the entire liquid crystal display element becomes hot, and when they move, the alignment film and transparent There is a problem with damaging the electrodes. Therefore, conventional liquid crystal display elements generally use spherical spacers made of plastic.

That is, a spacer having a diameter of several μm to 10-odd μm is selected that is compatible with the optical characteristics of the liquid crystal material.
In the assembly process of the liquid crystal display element, the components are dispersed as appropriate so as not to be concentrated in a specific location. Spacers made of such plastic have a coefficient of thermal expansion close to that of liquid crystal materials and appropriate elasticity, and are firmly fixed regardless of temperature when sandwiched between panels without damaging alignment films or the like.

[0009]

[Problems to be Solved by the Invention] As described above, spacers made of plastic have many excellent features. However, it is difficult to make plastic spheres with a diameter of several μm to 10-odd μm with high precision, and even if they are dispersed appropriately so that they do not concentrate in a specific place during the assembly process of liquid crystal display elements, such spacers are placed between panels. If they are interposed, there is a problem in that objects with a relatively small diameter move and accumulate at positions along the transparent electrode over time, causing display unevenness.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display element that has a spacer that has both the features of a spacer made of glass and a spacer made of plastic, and that exhibits less display unevenness caused by the spacer.

[0011]

Means for Solving the Problems FIG. 1 is a side sectional view showing a liquid crystal display element according to the present invention. The same objects are represented by the same symbols throughout the figures.

The above-mentioned problem is a liquid crystal display element formed by interposing a large number of spacers 6 between two panels 2, in which a core material 61 is made of transparent alkali-free glass that does not contain an alkali component, and a core material is made of plastic. This is achieved by the liquid crystal display element of the present invention in which the spherical or rod-shaped spacer 6 is constituted by a cladding material 62 covering the surface of the material 61.

[0013]

[Operation] In Fig. 1, a core material and a cladding material constitute a double-structured spherical or rod-shaped spacer, and by forming the core material, which occupies most of the volume, from alkali-free glass, it can be used in the same way as a spacer made of glass. Highly accurate dimensional control of spacers becomes possible. Moreover, by covering the surface of the core material with a cladding material made of plastic, the spacer can be firmly fixed between the panels without damaging the alignment film or the like, regardless of the temperature. That is, it is possible to realize a liquid crystal display element that has a spacer that has both the features of a spacer made of glass and a spacer made of plastic, and has less display unevenness caused by the spacer.

[0014]

[Embodiment] An embodiment of the present invention will be explained in detail below with reference to FIG. In the figure, the liquid crystal display element according to the present invention includes two panels 2 facing each other with a liquid crystal layer 1 in between, a sealing material 3 provided along the peripheral edge of the panel 2, and a sealing member 4 for preventing liquid crystal leakage. The panel 2 has a glass plate 21
, a transparent electrode 22 made of ITO, and an alignment film 23. In addition, in order to control the thickness of the liquid crystal layer 1 with high precision, a large number of transparent spacers 6 are sandwiched between the two panels 2 and are appropriately dispersed so as not to concentrate in a specific position.

The spherical or rod-shaped spacer 6 is made of a core material 61.
The core material 61 is made of alkali-free glass that does not contain an alkali component and has a diameter of 5 to 6 μm. By forming the core material, which occupies most of the volume, from alkali-free glass,
As with spacers made of glass, the dimensions of the spacer can be controlled with high precision. Note that in the spacer 6, the surface of a core material 61 is covered with a cladding material 62, and the core material 61 can also be formed of glass containing an alkali component.

The cladding material 62 is made of plastic having a coefficient of thermal expansion close to that of the liquid crystal material and appropriate elasticity.
A cladding material 62 having a thickness of 0.5 to 1 μm covers the surface of the core material 61. In this way, the core material 61
By covering the surface with a cladding material 62 made of plastic, a spacer is formed that is firmly fixed between the panels regardless of temperature without damaging the alignment film or the like. Moreover, unlike spacers made of plastic, the size variation is small, and the problem of relatively small diameter ones being accumulated at positions along the transparent electrode, which causes display unevenness, can be solved.

In this way, the core material and the cladding material constitute a double-structured spherical or rod-shaped spacer, and by forming the core material, which occupies most of the volume, from alkali-free glass, it can be used in the same way as a spacer made of glass. Highly accurate dimensional control of spacers becomes possible. Moreover, by covering the surface of the core material with a cladding material made of plastic, the spacer can be firmly fixed between the panels without damaging the alignment film or the like, regardless of the temperature. That is, it is possible to realize a liquid crystal display element that has a spacer that has both the features of a spacer made of glass and a spacer made of plastic, and has less display unevenness caused by the spacer.

[0018]

As described above, according to the present invention, it is possible to provide a liquid crystal display element that has a spacer that has both the features of a spacer made of glass and a spacer made of plastic, and has less display unevenness caused by the spacer. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing a liquid crystal display element according to the present invention.

FIG. 2 is a side sectional view showing a conventional liquid crystal display element.

[Explanation of symbols]

Claims (2)

[Claims] [Claim 1] A liquid crystal display element consisting of two panels (2) with a number of spacers (6) interposed between them, comprising a core material (61) made of transparent alkali-free glass containing no alkaline components; , a cladding material (62) made of plastic and covering the surface of the core material (61),
A liquid crystal display element characterized in that said spacer (6) is spherical. [Claim 2] A liquid crystal display element comprising two panels (2) with a number of spacers (6) interposed between them, comprising a core material (61) made of transparent alkali-free glass containing no alkaline components; , a cladding material (62) made of plastic and covering the surface of the core material (61),
A liquid crystal display element characterized in that the spacer (6) has a rod shape.