JPS61179419A - Orienting method for ferroelectric liquid-crystal - Google Patents

Abstract

PURPOSE:To perform homogeneous orientation treatment and to uniform the temperature gradient between substrates by sealing ferromagnetic liquid-crystal between a couple of electrodes which have a transparent conductive film, providing an oriented film,and rubbing it or carrying out slanting vapor deposition. CONSTITUTION:Transparent conductive films 2 and 2' are formed out of indium oxide, etc., on glass substrates 1 and 1', one conductive film 2 is rubbed, and an inorganic or organic oriented film 3 after homogeneous orientation treatment is arranged. The space between the substrates 1 and 1' is sealed hermetically with a seal material 5, and the liquid-crystal layer 4 of smetic liquid-crystal having ferroelectricity is sealed between the oriented film 3 and conductive film 2'. When this liquid-crystal layer 4 is oriented, the temperature is raised previously to place the liquid-crystal layer 4 in an isotropic state and then the temperature is so controlled that the substrate 1 is lower in temperature then the substrate 1' to give a temperature gradient; and then the temperature is lowered gradually and homogeneous orientation is carried out.

Description

[Detailed description of the invention] lgosako The present invention relates to a method for aligning ferroelectric liquid crystals.

Conventionally, as a method for homogeneous alignment of a liquid crystal cell using a ferroelectric liquid crystal, for example, an alignment film is provided on a substrate of a liquid crystal cell, and the substrate is rubbed.
In addition to the alignment film/rubbing method that homogeneously aligns the liquid crystal molecules by binging, there are other methods such as the shearing method, spacer edge, and temperature gradient method.

However, when actually manufacturing a liquid crystal cell using these methods, the alignment film/rubbing method can achieve homogeneous alignment in a small area, but the memory effect decreases, and the sharing method, spacer edge/temperature gradient method, etc. Although the memory effect can be ensured, there are disadvantages such as not being able to achieve homogeneous alignment over a large area and being limited to a small area. The reality is that it is difficult to obtain homogeneous orientation over the area.

Purpose: In view of the above circumstances, the present invention provides a method for aligning ferroelectric liquid crystals that achieves homogeneous alignment over a large area and does not impair the memory effect.

Summary According to the present invention, the above object is to seal a ferroelectric liquid crystal between a pair of substrates having a transparent conductive film, and to provide an alignment film on one of the substrates by rubbing or subjecting it to oblique evaporation. By applying homogeneous alignment treatment,
This is achieved by creating a temperature gradient between both substrates.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment. In the figure, indium oxide, etc. is deposited on the glass substrate at 1 and 1 degrees, and on the substrate at 1.1 degrees at 2.2". or a transparent conductive film formed by sputtering or the like; 3 is an inorganic or organic alignment film formed on the transparent conductive film 2 toward the glass substrate 1 side and subjected to homogeneous alignment treatment by rubbing; 4 is a strong a liquid crystal layer made of, for example, Smectisok liquid crystal having dielectric properties, 5 a sealing material for sealing the liquid crystal display device between the glass substrates vi2.2°; 6;
6゛ is a polarizing plate, respectively. The alignment treatment of the liquid crystal layer 4 is performed by raising the temperature in advance to make the liquid crystal layer 4 isotropic, and then using an appropriate temperature controller between the glass substrates 1 and 1° so that the temperature on the glass substrate 1 side is lower than the glass substrate 1°. gives a temperature gradient by
This is done by gradually lowering the temperature.

Since the method of the present invention is configured as described above, it is possible to homogeneously align the liquid crystal layer 4 over a relatively large area using the rubbed alignment film 3, and in particular, it is possible to homogeneously align the liquid crystal layer 4 over a relatively large area.
Since a temperature gradient is provided within 1°, the alignment becomes more uniform, and the memory effect can be ensured without impairing the properties of the liquid crystal layer 4.

Therefore, when an electric field is applied to the liquid crystal layer 4, the tilt direction of the liquid crystal molecules is determined by the parallel alignment direction, and a display with relatively high brightness and little color unevenness can be performed over a large area.

In the above-mentioned embodiments, the glass substrate 1 was homogeneously aligned using an alignment film and rubbing process, but an oblique evaporation process may also be used. The alignment state can be improved by cleaning the glass substrate 1'' with acetone cleaning or the like.

-As mentioned above, the method for aligning ferroelectric liquid crystal according to the present invention is as follows:
Although the orientation area is relatively large, it has a memory effect, so it is extremely useful as a display device, and has the advantage that it can be applied not only to electric field birefringence type liquid crystals but also to guest-host type liquid crystals.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing an embodiment of a liquid crystal display device for carrying out the method of the present invention. 1.1°108. Glass substrate, 2.2°000. Transparent conductive film, 3. Alignment film, 4. ,,,liquid crystal layer,5,
,,, sealing material, 6,6°980. Polarizer.

Claims (1)

[Claims] A ferroelectric liquid crystal is sealed between a pair of glass substrates having a transparent conductive film, and one of the substrates is provided with an alignment film and homogeneously aligned by rubbing or oblique evaporation. A method for aligning ferroelectric liquid crystal characterized by creating a temperature gradient between