Aperture frame for liquid crystal display device

• US 6,414,337 B1
• Filed: 11/10/2000
• Issued: 07/02/2002
• Est. Priority Date: 11/10/2000
• Status: Expired due to Term

• Current Assignee: Compound Photonics Limited
• Original Assignee: Three-Five Systems, Inc.
• Inventors: Day, Kevin, Slater, Andrew R.
• Primary Examiner(s): Sherry, Michael J.
• Assistant Examiner(s): SARKAR, ASOK K
• Application Number:
  US09/709,903
• Time in Patent Office: 599 Days
• Field of Search: 257/72, 438/30, 345/87, 349/58, 349/113, 349/147, 349/44, 349/110, 349/111
• US Class Current: 257/72
• CPC Class Codes: G02F 1/133388 with constructional differences between the display region and the peripheral region
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence

Abstract

Liquid crystal display devices having display screens with an improved black frame is provided. The microdisplay of the LCD is formed of a matrix of pixels disposed on the top surface of a silicon substrate, a layer of glass, and a layer of a reflective metal, preferably aluminum, which is disposed between the silicon substrate and layer of glass. The layer of reflective metal has a pattern, which forms a frame around the matrix of pixels, and is involved in generating the black frame when viewed by the user on the display screen. The reflective material functions to reflect light back to the light generating source, and thus displays a pure black image to the user. In another embodiment, a layer of reflective metal, preferably black chromium, patterned to form a frame around the matrix of pixels, is disposed on the top surface of the glass. The reflective metal layer on top of the glass may be used either in place of, or in addition to, the reflective metal layer on the bottom of the glass to generate the improved black frame.

Claims

1. A microdisplay device, comprising:

(a) a matrix of pixels disposed on the top surface of a substrate;

(b) a layer of transparent material having a top surface and a bottom surface, the bottom surface of said layer of transparent material being disposed adjacent to the top surface of said substrate;

(c) a seal disposed between the substrate and the layer of transparent material, said seal arranged to form a perimeter around the matrix of pixels;

(d) an annulus formed by a region bounded by the top surface of the substrate, the bottom surface of the layer of transparent material, and an inside of the perimeter formed by the seal, said annulus being filled with a liquid crystal; and

(e) a layer of reflective material disposed between the top surface of the substrate and the bottom surface of the layer of transparent material, said layer of reflective material patterned to form a frame around the matrix of pixels.

2. The microdisplay device according to claim 1, further comprising a layer of reflective or absorptive material disposed on the top surface of the layer of transparent material, patterned to form a frame around the matrix of pixels.

3. The microdisplay device according to claim 1, further comprising a layer of conductive material disposed over the bottom surface of the layer of transparent material.

4. The microdisplay device according to claim 3, wherein the layer of reflective material is disposed over the layer of conductive material.

5. The microdisplay device according to claim 3, wherein the layer of conductive material is disposed over the layer of reflective material.

6. The microdisplay device according to claim 5, wherein a layer of polysilicon material is disposed between the layer of conductive material and the layer of reflective material.

7. The microdisplay device according to claim 3, further comprising a plurality of transparent beads disposed in said annulus, which act as spacers to prevent the top surface of the substrate from coming in contact with the layer of conductive material.

8. The microdisplay device according to claim 3, further comprising a barrier metal layer disposed between the layer of reflective material and the layer of conductive material.

9. The microdisplay device according to claim 1, wherein the reflective material comprises a metal selected from the group consisting of aluminum, platinum, chromium, copper, and silver.

10. A microdisplay device, comprising:

(a) a matrix of pixels disposed on a substrate;

(b) a layer of transparent material disposed adjacent to said substrate; and

(c) a layer of reflective material disposed between said substrate and said layer of transparent material, said layer of reflective material patterned to form a frame around the matrix of pixels.

11. The microdisplay according to claim 10, further comprising a layer of reflective or absorptive material disposed on the top surface of transparent material, patterned to form a frame around the matrix of pixels.

12. The microdisplay device according to claim 10, further comprising a seal disposed between the layer of transparent material and the substrate, said seal arranged to form a perimeter around the matrix of pixels.

13. The microdisplay device according to claim 12, wherein an annulus is formed in a region bounded by the substrate, the layer of transparent material, and the seal.

14. The microdisplay device according to claim 13, further comprising a liquid crystal, which fills the annulus.

15. The microdisplay device according to claim 14, further comprising a layer of conductive material comprising indium tin oxide, said layer of conductive material disposed over the layer of transparent material.

16. The microdisplay device according to claim 15, further comprising a plurality of transparent beads disposed in said annulus, which act as spacers to prevent the substrate from coming in contact with the layer of conductive material.

17. The microdisplay device according to claim 10, wherein the layer of reflective material comprises a metal selected from the group consisting of aluminum, platinum, chromium, copper, and silver.

18. A microdisplay device, comprising:

(a) a matrix of pixels disposed on a substrate;

(b) a layer of transparent material disposed adjacent to said substrate;

(c) a layer of reflective or absorptive material disposed on a top surface of said layer of transparent material, said layer of reflective material patterned to form a frame around the matrix of pixels; and

(d) a layer of reflective material disposed between the layer of transparent material and the substrate, said layer of reflective material patterned to form a frame around the matrix of pixels.

19. The microdisplay device according to claim 18, further comprising a layer of conductive material disposed between a bottom surface of the layer of transparent material and the layer of reflective material.

20. The microdisplay device according to claim 19, further comprising a plurality of layers of conductive material sandwiched between a plurality of layers of polysilicon material.

21. The microdisplay device according to claim 19, wherein the layer of conductive material comprises indium tin oxide.

22. The microdisplay device according to claim 18, wherein the layer of reflective or absorptive material comprises a black chromium material and the layer of reflective material comprises a metal selected from the group consisting of aluminum, platinum, chromium, copper, and silver.