Full symmetrical wide-viewing angle display

• US 20050270457A1
• Filed: 05/23/2005
• Published: 12/08/2005
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Kopin Corporation
• Original Assignee: Kopin Corporation
• Inventors: Ong, Hiap L.
• Granted Patent: US 7,564,522 B2
• Time in Patent Office: Days
• US Class Current: 349/117
• CPC Class Codes: G02F 1/13363 Birefringent elements, e.g. for optical compensation
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 2413/02 Number of plates being 2

Abstract

A microdisplay including a light-transmissive active circuit layer, the active circuit layer having an optical birefringence value that contributes to an asymmetrical viewing space and an optical compensator to compensate for the optical bireflingence value of the active circuit layer. The optical compensator can include a retardation film, a c-plate, and/or a passive circuit layer. The passive circuit layer can be fabricated to equivalent specifications of the active circuit layer.

Claims

1. A microdisplay, comprising:

a light-transmissive active circuit layer, the active circuit layer having an optical birefringence value that contributes to an asymmetrical viewing space; and

an optical compensator to compensate for at least a portion of the optical birefringence value of the active circuit layer.

2. The microdisplay of claim 1, wherein the optical compensator includes a retardation film.

3. The microdisplay of claim 2, wherein the optical compensator includes a c-plate.

4. The microdisplay of claim 1, wherein the optical compensator includes a passive circuit layer.

5. The microdisplay of claim 4, wherein the passive circuit layer is fabricated to equivalent specifications of the active circuit layer.

6. The microdisplay of claim 1, wherein the optical compensator is disposed in close proximity to an outer surface of the active circuit layer.

7. The microdisplay of claim 6, wherein the optical compensator is integrated with a wide viewing angle film.

8. The microdisplay of claim 1, wherein the active circuit layer includes a CMOS circuit.

9. The microdisplay of claim 8, wherein the CMOS circuit includes a plurality of thin-film-transistors.

10. The microdisplay of claim 1, wherein the active circuit layer includes an array of pixel electrodes, having a pixel dimension of less than about 50 microns.

11. The microdisplay of claim 1, further comprising a layer of one member selected from the group comprising twisted-neumatic liquid crystal material, single-domain tilted vertical alignment liquid crystal material, and multi-domain vertical alignment liquid crystal material.

12. The microdisplay of claim 1, wherein the optical birefringence value is less than 0.03 μ

m.

13. A method for compensating an asymmetrical viewing space of a microdisplay having an active circuit layer with an optical birefringence value that contributes to the asymmetrical viewing space, comprising:

adding an optical compensator to compensate for at least a portion of the optical birefringence value of the active circuit layer.

14. The method of claim 13, wherein the optical compensator is a retardation film.

15. The method of claim 13, wherein the optical compensator is a c-plate.

16. The method of claim 13, wherein the optical compensator is passive circuit layer.

17. The method of claim 16, wherein the passive circuit layer is fabricated to equivalent specifications of the active circuit layer.

18. The method of claim 13 further comprising disposing the optical compensator in close proximity to an outer surface of the active circuit layer.

19. The method of claim 13, wherein the optical compensator is integrated with a wide viewing angle film.

20. The microdisplay of claim 13, wherein the active circuit layer includes a CMOS circuit.

21. The microdisplay of claim 20, wherein the CMOS circuit includes a plurality of thin-film-transistors.

22. The microdisplay of claim 13, wherein the active circuit layer includes an array of pixel electrodes, having a pixel dimension of less than about 50 microns.

23. The microdisplay of claim 13, further comprising a layer of one member selected from the group comprising twisted-neumatic liquid crystal material, single-domain tilted vertical alignment liquid crystal material, and multi-domain vertical alignment liquid crystal material.

24. The microdisplay of claim 13 wherein the optical birefringence value is less than 0.03 μ

m.

25. A microdisplay, comprising:

means for displaying an image through an active circuit layer having an optical birefringence value that contributes to an asymmetrical viewing space; and

means for compensating for at least a portion of the optical birefringence of the active circuit layer.