Liquid crystal electro-optical device and manufacturing method for the same

• US 5,559,619 A
• Filed: 02/14/1994
• Issued: 09/24/1996
• Est. Priority Date: 11/24/1989
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Sato, Masahiko
• Primary Examiner(s): Crane, Sara W.
• Assistant Examiner(s): Bowers, Courtney A.
• Application Number:
  US08/195,451
• Time in Patent Office: 953 Days
• Field of Search: 359/72, 359/74, 359/75, 359/79, 359/76
• US Class Current: 349/123
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133711 by organic films, e.g. polymeric films

Abstract

A liquid crystal electro-optical device having gettering means therein and a method for manufacturing such a liquid crystal electro-optical device are disclosed. For example, in a liquid crystal panel disposed in the device, polyvinyl carbazole film is formed as the getting means on at least one of a pair of substrates, and the film has a function to absorb ionized impurities existing in liquid crystal disposed in the device. In virtue of the film, ionized impurities in the liquid crystal layer are decreased, and by heating the liquid crystal panel, the function of the polyvinyl carbazole film, i.e. the function to absorb ionized impurities, is enhanced. Consequently, a liquid crystal electro-optical device free from after-image which was a problem in conventional liquid crystal display devices can be obtained.

Claims

1. A liquid crystal electro-optical display device comprising:

a pair of substrates provided with electrodes thereon, to which a plurality of display pixel elements are connected;

a liquid crystal layer interposed between said substrates;

an orientation control film comprising polyimide formed adjacent to one of said substrates and contacting one surface of said liquid crystal layer; and

a film comprising polyvinyl carbazole formed adjacent to the other one of said substrates and contacting the other surface of said liquid crystal.

20. The liquid crystal electro-optical display device of claim 1 wherein said liquid crystal layer comprises a ferroelectric liquid crystal.

2. A liquid crystal device comprising:

a pair of opposed substrates, at least one of which is transparent;

an electrode arrangement formed on said substrates;

a liquid crystal layer interposed between said substrates;

an orientation control film comprising polyimide formed on one of said substrates and contiguous to said liquid crystal layer; and

an organic layer provided on the other one of said substrates and contacting said liquid crystal layer,

wherein said organic layer comprises polyvinyl carbazole and a surface of said organic layer is a rubbed surface.

3. The liquid crystal device of claim 2 wherein a surface of said orientation control film is rubbed.

6. The liquid crystal device of claim 2 wherein said liquid crystal is ferroelectric liquid crystal, twisted nematic liquid crystal, or super twisted nematic liquid crystal.

7. The liquid crystal device of claim 2 wherein a thickness of said organic layer is from 100 Å

to 1000 Å

.

8. The liquid crystal device of claim 2 wherein said liquid crystal device is passive type.

9. The liquid crystal device of claim 2 wherein said electrode arrangement includes active devices.

10. The liquid crystal device of claim 2 wherein said device is an active matrix type device and said electrode arrangement includes thin film transistors.

11. The liquid crystal device of claim 2 wherein said device is an active matrix type device and said electrode arrangement includes metal insulator metal devices.

12. The liquid crystal device of claim 2 wherein said organic layer is capable of absorbing mobile ions including sodium, potassium, or lithium ions.

22. The liquid crystal device of claim 2 wherein said orientation control film consists essentially of a polyimide film.

4. A liquid crystal device comprising:

a pair of opposed substrates, at least one of which is transparent;

an electrode arrangement formed on said substrates;

a liquid crystal layer interposed between said substrates;

a polyimide film formed on at least one of said substrates; and

an organic layer provided between said liquid crystal layer and said polyimide film,

wherein said organic layer comprises polyvinyl carbazole.

5. The device of claim 4 wherein said polyimide film has a rubbed surface in contact with said organic layer.

13. The liquid crystal device of claim 4 wherein said liquid crystal is ferroelectric liquid crystal, twisted nematic liquid crystal, or super twisted nematic liquid crystal.

14. The liquid crystal device of claim 4 wherein a thickness of said organic layer is from 100 Å

to 1000 Å

.

15. The liquid crystal device of claim 4 wherein said liquid crystal device is passive type.

16. The liquid crystal device of claim 4 wherein said electrode arrangement includes active devices.

17. The liquid crystal device of claim 4 wherein said device is an active matrix type device and said electrode arrangement includes thin film transistors.

18. The liquid crystal device of claim 4 wherein said device is an active matrix type device and said electrode arrangement includes metal insulator metal devices.

19. The liquid crystal device of claim 4 wherein said organic layer is capable of absorbing mobile ions including sodium, potassium, or lithium ions.

21. A liquid crystal electro-optical display device comprising:

a pair of substrates provided with electrodes thereon;

a ferroelectric liquid crystal layer interposed between said substrates;

an orientation control film comprising polyimide formed adjacent to one of said substrates and contacting one surface of said liquid crystal layer; and

a film comprising polyvinyl carbazole formed adjacent to the other one of said substrates and contacting the other surface of said liquid crystal.