JPS6261125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid crystal display panel having novel electrode substrates.

A liquid crystal display panel has a structure in which a gap between a pair of electrode substrates is filled with a liquid crystal material, and it is desirable to maintain the gap between the electrode substrates in parallel with a constant gap. A schematic cross-sectional view of a conventional liquid crystal display panel is shown in FIG.
As shown in the figure, transparent electrodes 2a, 2b and alignment films 3a, 3b are coated on glass substrates 1a, 1b, and these pair of glass substrates are coated with spacers 4.
A, 4b maintain a constant spacing, and are fixed by sealing materials 5a, 5b. Inlet 6
A liquid crystal material 8 is filled in the gap between the pair of electrode substrates, and the injection port is sealed with a sealing material 7 after the liquid crystal material is filled. The parallelism of the electrode substrate gap largely depends on the flatness of the glass substrate used. ±0.5 even for relatively flat float glass substrates.
There is a waviness of μm/cm, and therefore the flatness of the glass substrate is required for large-sized liquid crystal display panels, liquid crystal display panels using cholesteric-nematic phase transition electro-optic effects, or time-divisionally driven liquid crystal display panels. If the properties are severe, the glass substrate must be polished to obtain the desired flatness. Polishing the glass substrate makes the liquid crystal display panel expensive and also increases the thickness of the glass substrate.

An object of the present invention is to provide an inexpensive liquid crystal display panel in which the gap between a pair of electrode substrates has good parallelism.

The liquid crystal display panel of the present invention includes a pair of electrode substrates,
the liquid crystal material filled between the pair of electrode substrates;
and an alignment film coated on the pair of electrode substrates in contact with the liquid crystal material, and in particular,
One of the pair of electrode substrates is a glass substrate coated with a transparent electrode, and the other electrode substrate is
A material or adhesive that is deformed by an external force and solidified by physical or chemical treatment is sandwiched between a substrate and a conductive film, and is brought into close contact with the glass substrate under pressure. It is characterized by the fact that

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention in the case of a transmissive liquid crystal panel will be described in detail below with reference to the drawings.

In Figure 2, a glass substrate 12 and a transparent conductive film 10 (TM4S100 manufactured by Teijin) are bonded together using a light-transmitting resin adhesive 11 (for example, Cemedine CS-2340-5).
This is a schematic diagram showing how the parallelism of the electrode substrate is corrected by curing the adhesive using the adhesive. As shown in the figure, the glass substrate 9 coated with a transparent electrode is brought into close contact with the glass substrate 12 to which the film 10 is adhered, and the adhesive 11 is cured.
The film 10 can be adhered to the glass substrate 12 according to the shape of the contact surface, and the parallelism of the electrode substrate can be corrected. Actually, the glass substrate 9 and film 10 are coated with a transparent electrode in a predetermined pattern with a thickness of about 500 Å, but the influence of unevenness due to the presence or absence of the transparent electrode on the glass substrate 9 and film 10 can be ignored. Although the electrode pattern is omitted in FIG. 2, the glass substrate 9 and the film 10 are brought into close contact with each other in the same alignment as the electrode pattern alignment when actually assembling a liquid crystal display panel.

The structure of a cholesteric-nematic phase transition type liquid crystal display panel as an embodiment of the present invention will be described using the pair of electrode substrates described using FIG. 2 and using the schematic cross-sectional view of FIG. 3. A transparent electrode 13a is coated on the glass substrate 9, and a thin film of FS150 (manufactured by Dainippon Ink Co., Ltd.) is coated thereon as a vertical alignment film. Further, a film coated with a transparent electrode 14b is adhered to the glass substrate 12 using the manufacturing method described in FIG. 2, and a thin film of FS150 (manufactured by Dainippon Ink Co., Ltd.) is coated thereon as a vertical alignment film. . The FS150 thin film is formed by impregnating a pair of transparent electrode substrates made by the method shown in Figure 2 with an aqueous solution of 0.03% by weight of FS150, and then baking at 120°C for 1 hour. Next, panel assembly begins, with a pair of transparent electrode substrates placed between mylar spacers (~
10 μm thick) 16a and 16b with a gap of about 10 μm, and seal the periphery with a sealing material (Tall Seal, manufactured by Varian). From the injection port 17,
After injecting a liquid crystal material 19 containing a mixture of 68, 20, and 12 weight percent of methoxybenzylidene butylaniline, butoxybenzylidene cyanoaniline, and cholesteryl chloride, respectively, in a vacuum, the injection port is sealed with a sealing material 18 (e.g., Aron Alpha, Toagosei, etc.). (Chemical).

The liquid crystal molecules of the cholesteric-nematic phase transition type liquid crystal display panel described above have a spiral domain orientation (cholesteric phase) when no voltage is applied, but when a voltage higher than the threshold voltage is applied, the cholesteric liquid crystal spirals. The structure is dissolved and vertical alignment occurs (transition to nematic phase due to electric field). At a low voltage below the threshold voltage, a light scattering state called focal conic alignment (cholesteric phase) is exhibited. Since the voltages for creating vertical alignment and focal conic alignment are proportional to the thickness of the liquid crystal layer, the distance between the pair of transparent electrode substrates is ±
Parallelism of 1.5 μm is required. As is clear from FIG. 3, the undulations of the glass substrate 12 are corrected by the film 10 and the adhesive 11 to correspond to the undulations of the glass substrate 9, so the distance between the pair of transparent electrode substrates is determined by the parallelism. You can get something good.

As is clear from the above, according to the present invention, it is possible to achieve parallelism between a pair of transparent electrodes in a very easy way, and it has the advantage that it can be done at a very low cost. , and according to the present invention,
Even if there is waviness in the glass substrate, it can be easily corrected, so a thin glass substrate can be used, which has the advantage of providing a lightweight liquid crystal display panel.

The present invention has been described above, and although a transmissive cholesteric-nematic phase change type liquid crystal display panel was used in the embodiment, liquid crystal display panels using other electro-optical effects, such as a dynamic scattering type, an electric field-twisting type, etc. For nematic type and guest-host type,
By using the electrode substrate according to the present invention, a liquid crystal display panel with good parallelism between a pair of electrode substrates can be obtained. Further, in the present invention, a film coated with a transparent electrode is used, but in the case of a reflective liquid crystal display panel, a film coated with a reflective metal electrode may be used. In addition, in the case of reflective liquid crystal display panels,
The substrate to which the films are bonded does not have to be a glass substrate, but may be a plate-shaped material such as a metal plate or a resin plate. Further, in the case of a reflective liquid crystal display panel, the effects of the present invention are not impaired even if an adhesive other than a light-transmitting adhesive is used. In the above embodiment, a liquid crystal display panel using an electrode substrate having a structure in which a conductive film is bonded to a glass substrate with an adhesive is described, but other materials such as plastic may be used instead of the adhesive. That is, in this case, a structure in which plastic or the like is molded by the method shown in FIG. 2 and then bonded to a glass substrate, and the above-mentioned conductive film is fixed on this molded plastic, or a metal electrode is used instead of the conductive film. The electrode substrate has a structure that is directly formed on the molded plastic by a method such as vapor deposition. Furthermore, the same effect as in the embodiment can be obtained by using the molded plastic itself as a substrate without adhering the molded plastic to a glass substrate, and forming an electrode substrate on which a metal electrode or a conductive film is formed.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view for showing the structure of a conventional liquid crystal display panel, and FIG. 2 is for explaining a method for producing an electrode substrate used in an embodiment of the liquid crystal display panel for explaining the present invention. FIG. 3 is a schematic cross-sectional view of the structure of a transmissive liquid crystal display panel according to an embodiment. In the figure, 1a, 1b, 9, 12 are glass substrates, 2a, 2b, 13a, 13b are transparent electrodes, 3a, 3b, 14a, 14b are alignment films, 4
a, 4b, 16a, 16b are spacers, 5a, 5
b, 15a, 15b are sealing materials, 6, 17 are injection ports, 7, 18 are sealing materials, 8, 19 are liquid crystal materials, 10
is film, 11 is adhesive.

Claims (1)

[Claims] 1. A liquid crystal display panel comprising a pair of electrode substrates, a liquid crystal material filled between the pair of electrode substrates, and an alignment film coated on the pair of electrode substrates in contact with the liquid crystal material. One of the pair of electrode substrates is a glass substrate coated with a transparent electrode, and the other electrode substrate is coated with a material or adhesive that is deformed by external force and solidified by physical or chemical treatment. A liquid crystal display panel characterized in that the electrode substrate is formed to match the undulations of the glass substrate by sandwiching the electrode substrate between conductive films and pressuring the glass substrate into close contact with the glass substrate.