JPS6048739B2 - Field-effect liquid crystal display element and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a field-effect liquid crystal display element in which a nematic liquid crystal compound is sealed between two substrates, at least one of which is transparent, and particularly relates to a field-effect liquid crystal display element in which a nematic liquid crystal compound is sealed between two substrates, at least one of which is transparent. The present invention relates to a field effect liquid crystal display device whose layers are composed of a combination of a horizontal alignment layer portion and a vertical alignment layer portion, and a method for manufacturing the same.

F. Conventionally, when a horizontal alignment layer portion and a vertical alignment layer portion were arranged side by side on the same substrate, they were fabricated using the following method.

That is, a first mask plate having openings having the same shape as the pattern of the horizontal alignment layer portion and a second mask plate having openings having the same shape as the pattern of the vertical alignment layer portion are prepared. First, for example, the first mask plate is mounted on a substrate on which a liquid crystal alignment layer is to be formed, and a horizontal alignment layer portion is formed by a mask vapor deposition method. Next, the first mask plate is removed, and a second mask plate is attached in its place to cover the horizontal alignment layer portion, and in this state, the vertical alignment layer portion is formed by vapor deposition. Note that the formation order of the horizontal alignment layer portion and the vertical J-direction alignment layer portion may be reversed to that described above. However, this conventional method has various drawbacks, such as requiring a large-sized evaporation device, the process being complicated and inefficient, and it being difficult to form the horizontal alignment layer portion and the vertical alignment layer portion with a good yield. ing.

An object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a field effect liquid crystal display element in which horizontal alignment layer portions and vertical alignment layer portions are formed on the same substrate with high precision without positional deviation. The purpose is to

To achieve this object, the present invention provides that a liquid crystal alignment layer formed on the same substrate having an inorganic surface includes a horizontal alignment layer portion having a predetermined pattern made of an organic polymer that hardly adsorbs a vertical alignment agent; Due to the difference in adsorption of the vertical alignment agent to the horizontal alignment layer portion and the substrate, the horizontal alignment layer portion is configured in combination with the vertical alignment layer portion formed on the base portion where the horizontal alignment layer portion is not formed. vinegar. Ru.

Still another object of the present invention is to provide an efficient and low-cost manufacturing method for a field effect liquid crystal display element having a liquid crystal alignment layer in which a horizontal alignment layer portion and a vertical alignment layer portion are combined on the same substrate. There is something to offer.

In order to achieve this objective, the present invention forms a horizontal alignment layer made of an organic polymer that does not easily adsorb a vertical alignment agent on the inorganic surface of the substrate on which the liquid crystal alignment layer is formed, and the necessary portions of the horizontal alignment layer are A horizontal alignment layer portion having a predetermined pattern is created by removing the other than the base,=,i from the body.

Thereafter, the horizontal alignment layer portion is not formed due to the difference in adsorption of the vertical alignment agent between the substrate having an inorganic surface and the horizontal alignment layer portion.The vertical alignment layer portion is formed on the substrate portion. . In the present invention, as the horizontal alignment layer that hardly adsorbs the vertical alignment agent, an organic polymer film made of, for example, polyamide or polyvinyl alcohol is suitable.

In addition, it is difficult to be adsorbed to the horizontal alignment layer, and the glass substrate,
Vertical alignment agents that are easily adsorbed to inorganic substrates such as ceramic substrates or transparent electrodes include, for example, N,
Silane coupling agents such as N-dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride (DMOAP) and octadecyltriethoxysilane (0DTES), or chromium complexes are suitable. In the field-effect liquid crystal display device of the present invention, a small amount of dichroic dye is mixed with P-type liquid crystal having positive dielectric anisotropy, no electric field is applied to the portion corresponding to the horizontal alignment layer, and the vertical alignment layer is If an electric field is applied only to the area corresponding to the horizontal alignment layer, the dye will absorb light and color display will occur in the area corresponding to the horizontal alignment layer, while there will be no absorption by the dye in the area corresponding to the vertical alignment layer. Since light passes through as is, patterns in unnecessary areas can be erased, and a guest-host type color display element with positive display can be easily created.

Conventionally, such positive color displays use liquid crystals with negative dielectric anisotropy, and either create cells that are oriented slightly tilted in one direction from the vertical, or create a reverse pattern, that is, apply voltage to all parts other than the segments. The method used was to apply an electric current and then blank out the background. However, since the former method uses an oblique evaporation method for alignment treatment, process control is difficult and the yield is poor. Furthermore, the latter method has many restrictions on pattern design and cannot make the background completely transparent.
Next, the manufacturing order of the field effect type liquid crystal display element according to the present invention will be described. First, a transparent electrode is formed on a glass or ceramic substrate, and an organic polymer film such as polyimide or polyvinyl alcohol is formed thereon by spin coating or dipping.

The portions of this organic polymer film other than those required are removed by appropriate means such as etching to form an organic polymer portion having a predetermined pattern. Next, add this to DMOAP
Alternatively, it is immersed in a solution of a silane coupling agent such as 0DTES, and the coupling agent is adsorbed onto the surface. At this time, there is a large difference in adsorption of silane coupling agents between inorganic surfaces such as substrates and transparent electrodes and organic polymer surfaces, and while silane coupling agents are well adsorbed on inorganic surfaces, organic polymer surfaces Almost no adsorption occurs. Then, by washing with water, drying, and heat treatment,
A monomolecular film of silane is formed on the surface other than the organic polymer portion.

Thereafter, the organic polymer portion is wrapped in a certain direction as necessary, and then the two substrates are laminated facing each other, and a nematic liquid crystal compound is sealed between them, so that the organic polymer portion is transferred to the horizontal alignment layer portion. The molecular film portion becomes the vertical alignment layer portion. Next, embodiments of the present invention will be described with reference to the drawings.

Example 1 As shown in FIG. 1A, first, a transparent electrode 2 made of a mixture of indium oxide and silicon oxide is formed on the surface of a glass substrate 1 by a screen printing method, a vapor deposition method, or the like.

Aminosilane (manufactured by Toray Silicone Co., Ltd., product name S)
H6O2O) solution for surface treatment, and then a polyamic acid solution (manufactured by Toray Industries, product name: Trenice).
A solution diluted 5 times with dimethylacetamide is applied using a spin coater, heated to 200°C to volatilize the solvent, and a polyamic acid coating 3 is formed on the entire surface as shown in the opening in FIG. Next, an etching resist for screen printing (manufactured by PrOtOkOte, product name 340-C) is printed on the polyamic acid coating 3 in a predetermined pattern,
After drying the resist, unnecessary portions of the polyamic acid coating 3 are removed with a 5% aqueous sodium hydroxide solution, and the resist is further washed off with trichloroethane.

After thorough washing, the polyamic acid is heated at 350° C. to react and harden the polyamic acid to form a polyimide film 3a as shown in FIG. 1C. and these as DMO
DMOAP is immersed in a 0.1% aqueous solution of AP for 10 minutes, then taken out from the solution and dried, and as shown in FIG. A monomolecular film 4 is formed.

Since the polyimide film 3a hardly adsorbs DMOAP, a monomolecular DMOAP film 4 is not formed on its surface. Separately from this, as shown in FIG.
A transparent electrode 2 made of a mixture of indium oxide and silicon oxide is formed thereon.

Then, this was immersed in a 0.1% aqueous solution of DMOAP, then taken out from the solution and dried, and the entire surface of the substrate 7 and the transparent electrode 2 was coated with DMOA.
A monomolecular P film 4 is formed. Thereafter, as shown in FIG. 2, the substrate 1 on which the polyimide film 3a and the silane monomolecular film 4 were disposed side by side, and the substrate 7 on which only the silane monomolecular film 4 was formed were placed facing each other, with a distance of about 10μ between them. The outer periphery is bonded with a sealing material made of epoxy resin so that a gap is formed.

In the cell constructed in this way, a P-type nematic liquid crystal compound (RO
RO-GH-605-15B (manufactured by Che Company) is enclosed. In the figure, 5 indicates a liquid crystal molecule, and 6 indicates a dye molecule. The portion where the polyimide film 3a is formed has a high absorbance of the dye due to the horizontal orientation, and only that portion becomes bright blue, resulting in a positive display guest-host type color display element. Furthermore, if one polarizing plate is attached with the polarization axis aligned in the wrapping direction, the contrast ratio will be increased and the pattern can be clearly recognized. Example 2 In the same manner as in Example 1, a transparent J transparent electrode 2 is formed on a glass substrate 1, and a polyimide film 3a and a monomolecular film 4 of DMOAP are provided in parallel on the surface thereof.

Two cell substrates made in this way are used facing each other as shown in FIG. Wrap it with absorbent cotton. A cell is constructed by bonding the outer periphery with a sealing material made of epoxy resin so that a gap of about 10 μ is formed between the substrates 1, 1, and inside the cell,
A P-type nematic liquid crystal compound with positive dielectric anisotropy (product name E-44, manufactured by Merkuf Co., Ltd.) and 0.5% of a dichroic dye (product name G-204, manufactured by Tamoto Photosensitive Color Co., Ltd.) was added as an optically active substance. A mixture of 1% cholesteryl propionate (manufactured by BDH, product name CB-15) was sealed. FIG. 3A shows a state in which the switch 8 is open and no electric field is applied, and a bright positive color display is obtained.

The opening in FIG. 3 shows a state in which the switch 8 is closed and an electric field is applied, and the positive color display disappears. The present invention has the above-described configuration, and allows the horizontal alignment layer portion and the vertical alignment layer portion to be formed on the same substrate with high accuracy, and furthermore, the process is simplified, improving productivity and reducing costs. be able to.

[Brief explanation of the drawing]

The figures are all for explaining the embodiments of the present invention, and FIGS. Fig. 3 is a cross-sectional view of the liquid crystal display element obtained in the first embodiment, and Fig. 3 is a cross-sectional view of the liquid crystal display element according to the second embodiment. , the opening in the figure shows the state when an electric field is applied. 1...Glass substrate, 2...Transparent electrode, 3...Polyamic acid coating, 3a...
- Polyimide coating, 4... Monomolecular coating of DMOAP, 5... Liquid crystal molecules, 6... Dye molecules, 7... Substrate.

Claims (1)

[Scope of Claims] 1. A liquid crystal alignment layer formed on the same substrate having an inorganic surface includes a horizontal alignment layer portion having a predetermined pattern made of an organic polymer that does not easily adsorb a vertical alignment agent, and the horizontal alignment layer A field effect type characterized in that the vertical alignment layer portion is formed in combination with a vertical alignment layer portion formed on a base portion where the horizontal alignment layer portion is not formed due to the difference in adsorption of the vertical alignment agent to the portion and the substrate. Liquid crystal display element. 2. In claim 1, the liquid crystal compound in contact with the liquid crystal alignment layer is a P-type liquid crystal compound with positive dielectric anisotropy, and a dichroic dye is mixed in the liquid crystal compound. A field-effect liquid crystal display device featuring: 3. In claim 1, the horizontal alignment layer portions are arranged to face each other, and the alignment direction of the horizontal alignment layer portions is twisted, and the liquid crystal compound in contact with the liquid crystal alignment layer is dielectric. 1. A field-effect liquid crystal display element comprising a P-type liquid crystal compound with positive anisotropy, in which a dichroic dye and an optically active substance are mixed. 4. A horizontal alignment layer made of an organic polymer that does not easily adsorb a vertical alignment agent is formed on the inorganic surface of the substrate on which the liquid crystal alignment layer is formed, and the parts of the horizontal alignment layer other than the necessary parts are removed from the substrate to form a predetermined area. A horizontal alignment layer portion having a pattern is created, and then a vertical alignment agent is applied onto the substrate, and due to the difference in adsorption of the vertical alignment agent to the horizontal alignment layer portion and the substrate, a substrate is formed on which no horizontal alignment layer portion is formed. 1. A method for manufacturing a field-effect liquid crystal display device, comprising forming a vertical alignment layer portion in a portion thereof.