Quantcast

Optically compensated splay mode LCD

Imported: 23 Feb '17 | Published: 22 Oct '02

Seung Ho Hong, Hyang Yul Kim, Seung Hee Lee

USPTO - Utility Patents

Abstract

Disclosed is a optically compensated splay mode liquid crystal display. The device includes: lower and upper substrates opposed with intervening a selected distance and having driving electrodes in their inner surfaces respectively and a liquid crystal layer sandwiched between the lower and the upper substrates and having a plurality of liquid crystal molecules, wherein no voltage is applied to the driving electrodes, the liquid crystal molecules are arranged in a bend state, and wherein a voltage above a critical voltage is applied to the driving electrodes, the liquid crystal molecules are arranged in a splay state which makes a symmetry of up and down with respect to a middle layer of the liquid crystal layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to IC illustrate a conventional OCB mode LCD.

FIG. 2 is a cross-sectional view for briefly illustrating a portion in which spacers are dispersed in a conventional LCD.

FIG. 3 is a cross-sectional view only showing a lower substrate of a conventional LCD.

FIGS. 4A and 4B are views for illustrating an LCD according to the present invention.

FIG. 5 is a graph showing a free energy according to pre-tilt angles of the LCD.

FIG. 6 is a graph showing a free energy according to voltages of the LCD.

FIG. 7 is a graph showing a transmittance variation with the lapse of time.

FIG. 8 shows an iso-contrast ratio according to the viewing angles of the present LCD.

FIG. 9 shows an equal contrast ratio according the angles of a conventional TN mode LCD.

FIG. 10 is a cross-sectional view for briefly illustrating a portion in which spacers are dispersed in the present LCD.

FIG. 11 is a cross-sectional view only showing a lower substrate of the present LCD.

Claims

1. An optically compensated splay (OCS) mode liquid crystal display (LCD) comprising:

2. The OCS mode LCD of claim 1, wherein the liquid crystal molecules have negative dielectric anisotropy.

3. The OCS mode LCD of claim 1, further comprising an alignment layer having a pre-tilt angle of below 90° at the respective inner surfaces of the lower and the upper substrates.

4. An OCS mode LCD comprising:

5. The OCS mode LCD of claim 4, wherein the first and the second alignment layers have the pre-tilt angle range of 45° to 70°.

6. The OCS mode LCD of claim 5, wherein the polarizing axes of the first and the second polarizing plates intersect to each other.

7. The OCS mode LCD of claim 6, wherein an angle formed by the rubbing axis and one of the polarizing axes of the first and the second polarizing plates is approximately in the range of 35°˜55°.

8. The OCS mode LCD of claim 4, wherein the phase compensation plate comprises the liquid crystal molecules of negative birefringence.

9. The OCS mode LCD of claim 8, wherein phase retardation index of the phase compensation plate is in the range of approximately −0.2˜2.0 m.

10. The OCS mode LCD of claim 4, wherein phase retardation index of the liquid crystal layer is in the range of 0.2˜2.0 m.

11. The OCS mode LCD of claim 4, wherein the dielectric anisotropy index of the liquid crystal molecules is in the range of −2˜−15.

12. An OCS mode LCD comprising:

13. The OCS mode LCD of claim 12, wherein the first and the second alignment layers have the pre-tilt angle in the range of 45°˜90°.

14. The OCS mode LCD of claim 13, wherein an angle formed by the rubbing axis and one of the polarizing axes of the first and the second polarizing plates is approximately in the range of 35°˜55°.

15. The OCS mode LCD of claim 12, wherein each phase compensation plate comprises the liquid crystal molecules of negative birefringence.

16. The OCS mode LCD of claim 15, wherein phase retardation index of the phase compensation plate is in the range of approximately −0.2˜−1.5 m.

17. The OCS mode LCD of claim 12, wherein phase retardation index of the liquid crystal layer is in the range of 0.2˜1.5 m.

18. The OCS mode LCD of claim 12, wherein dielectric anisotropy index of the liquid crystal molecules is in the range of −2˜−15.