JPH02198420A - Production of electrooptical element - Google Patents

Abstract

PURPOSE:To produce the electrooptical element which is free from orientation defects and unequal display by reducing the size of the fibers of a rubbing cloth in a rubbing treatment. CONSTITUTION:Electrodes 2, 8 of prescribed shapes are formed on the surfaces of substrates 1, 9 consisting of transparent glass and plastic and insulating layers 3, 7 are formed thereon; further, oriented films 4, 6 consisting of an orientation treating agent, such as silane coupling agent, are formed thereon. The surfaces of the oriented layers 4, 6 are rubbed by the rubbing cloth to orient the liquid crystal molecules in a prescribed direction before the electrooptical element is completed by sealing a liquid crystal layer 5 between a pair of such substrates. The size of the fibers constituting the rubbing cloth is reduced to as small as 0.1mum to 15mum. The electrooptical element which is substantially free from the orientation defects and the unequal display is obtd. in this way.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing an electro-optical element.

[Prior Art] Conventionally, electro-optical elements using liquid crystals have been developed as thin and lightweight displays. As a simple liquid crystal alignment method for an electro-optical element using liquid crystal, a method of rubbing at least one of the opposing surfaces of two substrates constituting the electro-optical element with a cloth (rubbing method) has been used.

[The problem that the invention tries to solve! ] However, in the conventional technology, two-pinning is performed using a cloth using fibers with a thickness of 15 μm or more, so there are problems such as the fact that the fibers are thick and cannot be rubbed uniformly, and alignment defects are likely to occur when liquid crystal is encapsulated. In the mode (abbreviated as STN or 5BFj) in which the liquid crystal molecules are tilted with respect to the substrate, the tilt angle of the liquid crystal molecules changes with a slight difference in rubbing strength, making it difficult to obtain a uniform element over the entire screen.

[Means for Solving the Problems] The method for manufacturing an electro-optical element of the present invention includes the following steps: (1) As a liquid crystal alignment treatment method, at least one of the facing surfaces of two substrates constituting an electro-optical element is rubbed with a cloth. (Rubbing) method is characterized in that the thickness of the fibers constituting the rubbing cloth is from 0.1 μm to 15 μm.

(2) The liquid crystal is a nematic liquid crystal.

(3) The liquid crystal is a ferroelectric liquid crystal.

[Example] Hereinafter, the details of the present invention will be shown by examples.

(Example 1) An electro-optical element having a basic configuration as shown in FIG. 1 was manufactured. As shown in FIG. 1, electrodes 2, 8 of a predetermined shape are formed on the surface of a substrate 1, 90 made of transparent glass or plastic.
was formed, an insulating layer 5.7 was formed thereon, and alignment layers 4 and 6 made of an alignment treatment agent such as a silane coupling agent were further formed thereon. A liquid crystal layer 5 is placed between these pair of substrates.
Before completing the electro-optical device by encapsulating the liquid crystal molecules, the surface of the alignment layer 4.60 is rubbed with a rubbing cloth to orient the liquid crystal molecules in a predetermined direction. According to the above, since the fibers of the rubbing cloth are thin, rubbing is performed uniformly over the entire surface of the substrate, and almost no orientation defects occur. Furthermore, in the STN or 5BFi mode, uniform tilt alignment can be easily obtained over the entire surface.

The fiber thickness is 0.1 μ7 for each of the 5 substrates.
When rubbing was performed using rubbing cloths of 7L, 2 μm, 5 μm, 10 μm, and 15 μm, uniform orientation without orientation defects could be obtained.

(Example 2) In this example, a case will be described in which a ferroelectric liquid crystal is used as the liquid crystal. The liquid crystal used was Merck ZL Aero 48.
It is 8. When the liquid crystal is sealed and observed with a polarizer Pj and a mirror, it is oriented so neatly that no traces of rubbing are visible. Furthermore, there are almost no orientation defects.

(Example 6) In this example, a nematic liquid crystal was used as the liquid crystal.Both thread plates were rubbed using the method described above using ZL knee 2214 + chiral dopant, and the liquid crystal molecules were
Adjust the rubbing directions of the chiral dopant and the upper and lower substrates so that the twist is greater than 0°. An STN or SBE mode electro-optical element with uniform tilt orientation on the entire surface and no display unevenness could be manufactured.

In addition, the present invention can also be applied as an orientation means for organic nonlinear optical materials that are being developed recently.

[Effects of the Invention] As described above, according to the present invention, by reducing the thickness of the fibers of the rubbing cloth in the rubbing process, an electro-optical element without orientation defects and display unevenness can be produced.

Furthermore, if applied to organic nonlinear optical elements, the conversion efficiency of harmonic generation can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electro-optical element showing the basic configuration of the present invention. 1... Substrate 2... Electrode 6... Insulating layer 4... Alignment layer 5. ......Liquid crystal layer 6...Alignment layer 7...Insulating layer 8...Electrode 9...・・・・・・Substrate

Claims (3)

[Claims] (1) As a liquid crystal alignment treatment method, at least one of the opposing surfaces of two substrates constituting an electro-optical element is rubbed with a cloth (rubbing), in which the thickness of the fibers constituting the rubbing cloth is from 0.1 μm to A method for manufacturing an electro-optical element, characterized in that the thickness is 15 μm. (2) The method for manufacturing an electro-optical element according to claim 1, wherein the liquid crystal is a nematic liquid crystal. (3) The method for manufacturing an electro-optical element according to claim 1, wherein the liquid crystal is a ferroelectric liquid crystal.