JPS59224826A - Liquid crystal display cell - Google Patents

Abstract

PURPOSE:To prevent deformation of liquid crystal display cell by arranging a base formed by applying uniaxially stretched films to a polarizer so as to direct the absorption axis of the polarizer in parallel to the stretching axes, and another base formed by applying other uniaxially stretched films to another polarizer so as to direct the absorption axis at right angles to the stretching axes so that the films of both bases may have the stretching axes in parallel to each other. CONSTITUTION:A base 1 is formed by applying uniaxially stretched films 12, 12' to both sides of a polarizer 11, such as iodine and/or dichroic dye type polarizer or polyene type polarizer. The absorption axis, as shown with a dotted line, is directed in parallel to the stretching axes of the films 12, 12', as shown with a full line. Another base 2 is formed like the base 1, except in the respect that the absorption axis of another polarizer 21 is directed at right angles to the stretching axes of other films 22, 22'. The stretching axes of the uniaxially stretched films 12, 12' of the base 1 are arranged in parallel to those of the films 22, 22' of the base 2. As the uniaxially stretched film, the ones of a plastic, such as polycarbonate, polyacrylate, and polyester, of 50-200mum thickness are used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display cell, and more specifically, it provides a liquid crystal display cell that maintains a constant gap between upper and lower electrodes and polarizing substrates.

In recent years, display devices using liquid crystal display cells as display bodies (1) have been widely used in desktop electronic computers, electronic clocks, office equipment, toys, instruments, etc., but with the diversification of display applications, Currently, there is a growing demand for devices to be lighter in weight, have better visibility, and be lower in cost.

In response to such demands, various attempts have been made to use plastic films instead of conventional glass plates as upper and lower electrode substrates constituting liquid crystal display cells.

In general, electrode substrates are required to have chemical resistance, mechanical properties, etc. in addition to optical properties, and from this viewpoint, uniaxially stretched films have been used in various experiments as electrode substrate materials.

However, since the -axis stretched film has anisotropy in shrinkage and thermal expansion coefficients, a liquid crystal display in which the stretching axis of the film is orthogonal to the upper and lower electrode polarizing substrate using the film as the surface material of a polarizer is proposed. The cell deforms into a substantially arched shape due to shrinkage of the film and anisotropy of the coefficient of thermal expansion due to changes in outside temperature.

(2) Such cell deformation causes the thickness of the liquid crystal layer sealed between the substrates to become uneven, resulting in drawbacks such as rainbows appearing on the display surface and variations in display response speed. It is something.

In view of this situation, the inventors of the present invention have conducted extensive research, and as a result,
It was discovered that deformation of a liquid crystal display cell can be prevented by skillfully combining two different types of electrode polarizing substrates in which the absorption axis of a polarizer and the stretching axis of a uniaxially stretched film are laminated in parallel and perpendicularly, and the present invention has been developed. This is what led to this.

That is, the present invention provides a liquid crystal display cell in which a liquid crystal is sealed between upper and lower electrodes and polarizing substrates, wherein the upper substrate is formed by laminating the absorption axis of a polarizer and the stretching axis of a uniaxially stretched film in parallel; The substrate is laminated with the absorption axis of the polarizer and the stretching axis of the uniaxially stretched film perpendicular to each other, and the upper and lower substrates are arranged with the stretching axis of the film constituting the substrate parallel to each other. The present invention provides a liquid crystal display cell.

According to the present invention, since the stretching axes of the electrode and polarizing substrate are uniaxially stretched (3) in parallel to each other, the directions of shrinkage and thermal expansion are the same, and the coefficients of shrinkage and thermal expansion are also the same. It does not deform due to changes in the

Examples of the present invention will be specifically described below using the drawings.

The drawing is a partial schematic explanatory diagram of a liquid crystal display cell A of the present invention, in which the surfaces of an upper electrode polarizing substrate 1 and a lower electrode polarizing substrate 2 on which electrode backs (not shown) are formed face each other, and the peripheral The portion is sealed with a sealing material 3, and a liquid crystal 4 is sealed.

The substrate 1 is made by pasting -axis stretched films 12 and 12' on both sides of a polarizer 11 such as an iodine and/or dichroic dye-based polarizer or a polyene-based polarizer. The axis (dotted line) and the stretching axis (solid line) of the film 12.12' are parallel. Further, the substrate 2 has the same structure as the substrate 1, but the absorption axis of the polarizer 21 and the film 22
．． They are bonded so as to be perpendicular to the 22° stretching axis. The substrates 1 and 2 are the uniaxially stretched film 1 which is the constituent material.
The stretching axes of 2.12'' and 22.22' (4) are arranged in parallel.

As the -axially stretched film, a uniaxially stretched film (thickness: 50 to 200 μm) made of plastic such as polycarbonate, polyacrylic, polyester, etc. is used, preferably having a retardation value of 0.
A uniaxially stretched polyester film having a thickness in the range of 5 to 200 μm is desirable because it has uniform color and has excellent heat resistance.

Since the liquid crystal display cell A of the present invention is constructed as described above, it provides a display device that is not deformed due to changes in outside temperature and is free from color unevenness.

It is practically preferable to add the following configuration to the liquid crystal display cell A.

One of them is a film (pencil hardness 2 to 5 (5) H) made of a curable resin such as an ultraviolet curable acrylic urethane resin or an ultraviolet curable polyester acrylate resin on the surface of the upper electrode polarizing substrate 1 (the surface of the film 12). It is to establish. The film effectively prevents scratches and the like on the surface of the substrate 1 from deteriorating the display performance. Further, by providing a coating containing a light-diffusing fine powder such as silica gel or silica sol in the resin, it is possible to prevent glare on the display surface in addition to preventing scratches.

The second method is to provide in advance a cured film made of the above-mentioned resin or the like on the electrode pattern forming surfaces of the substrates 1 and 2 (the surfaces of the films 12' and 22'). The film effectively prevents the electrode pattern formed thereon from being disconnected due to scratches or the like.

The third method is to provide a protective film made of the above-mentioned curable resin or adhesive on the line connected to the electrode pattern. This effectively prevents the lead wire from breaking due to distortion due to the difference in physical properties between the sealing material 3 and the film 12' (or 221).

Fourth, a light reflecting layer made of a metal film is formed on the surface of the substrate 20 (the surface of the film 22) by a vapor deposition method. The formation of such a light-reflecting layer is easier than the case of fixing the light-reflecting plate up to (6) with an adhesive or the like.
The forming operation can be simplified, and the entire display device can be made lighter and less bulky.

[Brief explanation of the drawing]

The drawing is a partially schematic explanatory diagram showing an example of the liquid crystal display cell of the present invention. 1 and 2 are electrode polarizing substrates, 11 and 21 are polarizers 12,
12', 22 and 22' Uniaxially Stretched Film Patent Applicant Nitto Electric Industry Co., Ltd. Representative Kamigata Sanbe (7)

Claims (1)

[Claims] (11) A liquid crystal display cell comprising a liquid crystal sealed between upper and lower electrodes and polarizing substrates, wherein the upper substrate has an absorption axis of a polarizer and a stretching axis of a uniaxially stretched film laminated in parallel. The lower substrate is made by laminating the absorption axis of the polarizer and the stretching axis of the uniaxially stretched film at right angles, and the upper and lower substrates are arranged with the stretching axes of the films constituting the substrate parallel to each other. (2) The liquid crystal display cell according to claim 1, wherein the axially stretched film is a uniaxially stretched polyester film.