LCD and method for producing the same in which a larger number of substrate gap control materials is larger in the polymer walls than in the liquid crystal regions

• US 5,729,312 A
• Filed: 03/15/1995
• Issued: 03/17/1998
• Est. Priority Date: 03/18/1994
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nishiguchi, Kenji, Shinomiya, Tokihiko, Yamagishi, Shinji, Fujimori, Kohichi
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): MALINOWSKI, WALTER J
• Application Number:
  US08/404,539
• Time in Patent Office: 1,098 Days
• Field of Search: 359/51, 359/52, 359/81, 349/86, 349/92, 349/93, 349/155, 349/156, 349/157
• US Class Current: 349/86
• CPC Class Codes: G02F 1/13392 spacers dispersed on the cell substrate, e.g. spherical particles, microfibres
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence

Abstract

The liquid crystal display device of the invention includes; a pair of substrates disposed so as to be opposed to each other; and a display medium interposed between the pair of substrates, the display medium having liquid crystal regions comprising one or a plurality of pixels, and the liquid crystal regions being surrounded by polymer walls, wherein a number of substrate gap control materials which are disposed in a gap between the pair of substrates is larger in the polymer walls rather than in the liquid crystal regions.

Claims

1. A liquid crystal display device comprising:

a pair of substrates disposed so as to be opposed to each other; and

a display medium interposed between the pair of substrates, the display medium having liquid crystal regions comprising one or a plurality of pixels, and the liquid crystal regions being surrounded by polymer walls,

wherein a number of substrate gap control materials which are disposed in a gap between the pair of substrates is larger in the polymer walls than in the liquid crystal regions.

2. A liquid crystal display device according to claim 1, wherein the substrate gap control materials are composed of a material tending to exist in the polymer wells rather than in the liquid crystal regions.

3. A liquid crystal display device according to claim 1 comprising an alignment film on at least one of the pair of substrates, the alignment film being composed of a material tending to make the substrate gap control materials exist in the polymer walls.

4. A liquid crystal display device according to claim 1, wherein the substrate gap control materials are spherical spacers.

5. A liquid crystal display device according to claim 4, wherein the polymer walls include a mixture of at least one kind of fine particles having a different refractive index from a refractive index of the polymer walls.

6. A liquid crystal display device according to claim, 1, wherein the substrate gap control materials are composed of a polymer resin.

7. A method for producing a liquid crystal display device comprising a pair of substrates disposed so as to be opposed to each other;

and a display medium interposed between the pair of substrates, the display medium having liquid crystal regions comprising one or a plurality of pixels, and the liquid crystal regions being surrounded by polymer walls,

the method comprising the steps of;

disposing the pair of substrates so as to be opposed to each other and interpose therebetween substrate gap control material composed of a material tending to exist in the polymer walls rather than in the liquid crystal regions,

injecting a mixture including at least a liquid crystal material and a photopolymerizable compound into a gap between the pair of substrates; and

selectively irradiating the mixture with ultraviolet rays, thereby forming a display medium comprising the liquid crystal regions surrounded by the polymer walls and making a larger number of the substrate gap control materials exist in the polymer walls than in the liquid crystal regions.

8. A method for producing a liquid crystal display device according to claim 7, wherein the step of selectively irradiating the mixture with ultraviolet rays comprises covering portions of the mixture corresponding to pixel positions with a photomask, thereby selectively differentiating intensities between the pixel portions and portions excluding the pixel portions.

9. A method for producing a liquid crystal display device according to claim 7, wherein the step of selectively irradiating the mixture with ultraviolet rays comprises forming an organic film, an inorganic film, or a metal film on at least one of the substrates facing the display medium to selectively distribute the irradiated ultraviolet rays.

10. A method for producing a liquid crystal display device according to claim 7, wherein the irradiation step comprises irradiating the mixture at a temperature equal to or higher than a nematic-isotropic phase transition temperature (T_NI) of the liquid crystal.

11. A method for producing a liquid crystal display device comprising a pair of substrates disposed so as to be opposed to each other;

and a display medium interposed between the pair of substrates, the display medium having liquid crystal regions comprising one or a plurality of pixels, and the liquid crystal regions being surrounded by polymer walls,

the method comprising the steps of;

disposing the pair of substrates so as to be opposed to each other by disposing substrate gap control materials at arbitrary positions on at least one of the pair of substrates;

injecting a mixture comprising at least a liquid crystal material and a photopolymerizable compound into a gap between the pair of substrates; and

selectively irradiating the mixture with ultraviolet rays, thereby forming a display medium comprising the liquid crystal regions surrounded by the polymer walls and making a larger number of the substrate gap control materials exist in the polymer walls rather than in the liquid crystal regions.

12. A method for producing a liquid crystal display device according to claim 11, further comprising printing the substrate gap control material at arbitrary positions.

13. A method for producing a liquid crystal display device according to claim 11, wherein the step of selectively irradiating the mixture with ultraviolet rays comprises covering portions of the mixture corresponding to pixel positions with a photomask, thereby selectively differentiating intensities between the pixel portions and portions excluding the pixel portions, rays comprises covering portions of the mixture corresponding to pixel positions with a photomask, thereby selectively differentiating intensities between the pixel portions and portions excluding the pixel portions.

14. A method for producing a liquid crystal display device according to claim 11, wherein the step of selectively irradiating the mixture with ultraviolet rays comprises forming an organic film, an inorganic film, or a metal film on at least one of the substrates facing the display medium to selectively distribute the irradiated ultraviolet rays.

15. A method for producing a liquid crystal display device according to claim 11, wherein the irradiation step comprises irradiating the mixture at a temperature equal to or higher than a nematic-isotropic phase transition temperature (T_NI) of the liquid crystal.

16. A liquid crystal display device comprising:

a pair of substrates disposed so as to be opposed to each other; and

a display medium interposed between the pair of substrates, the display medium having liquid crystal regions surrounded by polymer walls at arbitrary positions,

wherein the polymer walls are formed of a polymer material having a compressive value of 10 g/mmφ

or more in its cured state.

17. A liquid crystal display device according to claim 16, wherein the display medium includes fine particles, and wherein the fine particles have a refractive index which is different than a refractive index of the polymer walls.

18. A liquid crystal display device according to claim 16, wherein the polymer wall includes at least one of a thermosetting resin and a photocurable resin, and the polymer walls are attached to both of the pair of substrates.

19. A method for producing a liquid crystal display device comprising a pair of substrates disposed so as to be opposed to each other;

and a display medium interposed between the pair of substrates, the display medium having liquid crystal regions surrounded by polymer walls at arbitrary positions,

the method comprising the steps of;

injecting a mixture including at least a liquid crystal material and a polymerizable compound having a compressive value of 10 g/mmφ

or more in its cured state between the pair of substrates; and

applying energy of heat or light to the mixture so as to phase separate the liquid crystal material and the polymerizable compound, thereby selectively forming the liquid crystal regions and the polymer wall at arbitrary positions.

20. A method for producing a liquid crystal display device according to claim 19 further comprising applying an arbitrary vibration to at least the mixture during the application of energy of heat or light to the mixture so as to phase separate the liquid crystal material and the polymerizable compound.

21. A method for producing a liquid crystal display device according to claim 19 further comprising applying an arbitrary voltage across the mixture interposed between the pair of substrates during the application of energy of heat or light to the mixture so as to phase separate the liquid crystal material and the polymerizable compound.