Liquid crystal display apparatus with light guide panel having light-absorbing or light-storing layer

• US 6,577,359 B2
• Filed: 04/18/2001
• Issued: 06/10/2003
• Est. Priority Date: 12/10/1999
• Status: Expired due to Fees

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Ishihara, Takayuki
• Primary Examiner(s): Dudek, James
• Assistant Examiner(s): SCHECHTER, ANDREW M
• Application Number:
  US09/731,764
• Publication Number:
  US 20010024253A1
• Time in Patent Office: 783 Days
• Field of Search: 349/62, 349/63, 349/65, 349/70, 349/71, 362/31
• US Class Current: 349/63
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G02F 1/133617 Illumination with ultraviolet light; Luminescent elements or materials associated to the cell

Abstract

A liquid crystal display apparatus includes a liquid crystal panel, a transparent light guide panel disposed in front of the liquid crystal panel and having one irregular surface for emitting light entering from a light source toward the liquid crystal panel, and a reflector disposed behind the liquid crystal panel for reflecting light passing through the light guide panel and the liquid crystal panel toward the liquid crystal panel and the light guide panel. The irregular surface of the light guide panel is partially formed with an absorbing layer for absorbing external light or a light storing layer for storing light.

Claims

1. A liquid crystal display apparatus comprising:

a liquid crystal panel;

a transparent light guide panel disposed in front of the liquid crystal panel and having at least one irregular surface for emitting light entering from a light source toward the liquid crystal panel; and

a reflector disposed behind the liquid crystal panel for reflecting light passing through the light guide panel and the liquid crystal panel toward the liquid crystal panel and the light guide panel;

wherein the irregular surface of the light guide panel is partially formed with a light storing layer for storing light.

2. The liquid crystal display apparatus according to claim 1, wherein the irregular surface of the light guide panel includes a plurality of projections each of which is triangular in cross section with two inclined surfaces differing from each other in direction and angle of inclination;

and

the light storing layer is provided at a steeper inclined surface of each projection.

3. The liquid crystal display apparatus according to claim 2, wherein the light storing layer is formed by applying a light storing coating material onto the steeper inclined surface.

4. The liquid crystal display apparatus according to claim 2, wherein the light guide panel has at least one side surface provided with a light storing layer.

5. The liquid crystal display apparatus according to claim 2, wherein the steeper inclined surface of each said projection is located farther away from the light source than the other inclined surface.

6. The liquid crystal display apparatus according to claim 2, wherein the steeper inclined surface of each said projection is located closer to the light source than the other inclined surface.

7. The liquid crystal display apparatus according to claim 1, wherein the irregular surface of the light guide panel includes a plurality cylindrical projections having a circumferential side surface on which the light storing layer is formed.

8. The liquid crystal display apparatus according to claim 1, wherein the irregular surface of the light guide panel is oriented away from the liquid crystal panel.

9. The liquid crystal display apparatus according to claim 1, wherein the irregular surface of the light guide panel faces toward the liquid crystal panel.

10. A liquid crystal display apparatus comprising:

a liquid crystal panel;

a transparent light guide panel disposed in front of the liquid crystal panel and having at least one irregular surface for emitting light entering from a light source toward the liquid crystal panel; and

a reflector disposed behind the liquid crystal panel for reflecting light passing through the light guide panel and the liquid crystal panel toward the liquid crystal panel and the light guide panel;

wherein the irregular surface of the light guide panel is partially formed with an absorbing layer for absorbing external light; and

wherein the irregular surface of the light guide panel faces toward the liquid crystal panel.

11. The liquid crystal display apparatus according to claim 10, wherein the irregular surface of the light guide panel includes a plurality of projections each of which is triangular in cross section with two inclined surfaces differing from each other in direction and angle of inclination;

and

the absorbing layer is provided on a steeper inclined surface of each projection.

12. The liquid crystal display apparatus according to claim 11, wherein the absorbing layer is formed by applying a black coating onto the steeper inclined surface.

13. The liquid crystal display apparatus according to claim 11, wherein the steeper inclined surface of each said projection is located closer to the light source than the other inclined surface.

14. A liquid crystal display apparatus comprising:

a liquid crystal panel;

a transparent light guide panel disposed in front of the liquid crystal panel and having at least one irregular surface for emitting light entering from a light source toward the liquid crystal panel; and

a reflector disposed behind the liquid crystal panel for reflecting light passing through the light guide panel and the liquid crystal panel toward the liquid crystal panel and the light guide panel;

wherein the irregular surface of the light guide panel is partially formed with an absorbing layer for absorbing external light;

wherein the irregular surface of the light guide panel includes a plurality of projections each of which is triangular in cross section with two inclined surfaces differing from each other in direction and angle of inclination;

wherein the absorbing layer is provided on a steeper inclined surface of each projection; and

wherein the steeper inclined surface of each said projection is located closer to the light source than the other inclined surface.

15. A liquid crystal display apparatus comprising:

a liquid crystal panel;

a transparent light guide panel disposed in front of the liquid crystal panel and having at least one irregular surface for emitting light entering from a light source toward the liquid crystal panel; and

a reflector disposed behind the liquid crystal panel for reflecting light passing through the light guide panel and the liquid crystal panel toward the liquid crystal panel and the light guide panel;

wherein the irregular surface of the light guide panel is partially formed with an absorbing layer for absorbing external light; and

wherein the irregular surface of the light guide panel includes a plurality of cylindrical projections each having a circumferential side surface on which the absorbing layer is formed.