Light guide plate and support unit for the same

• US 20040130912A1
• Filed: 12/19/2003
• Published: 07/08/2004
• Est. Priority Date: 12/20/2002
• Status: Active Grant

• Current Assignee: Citizen Electronics Company Limited
• Original Assignee: Citizen Electronics Company Limited
• Inventors: Miyashita, Shinichi
• Granted Patent: US 7,188,989 B2
• Time in Patent Office: Days
• US Class Current: 362/561
• CPC Class Codes: G02B 6/002 by shaping at least a portion of the light guide, e.g. with collimating, focussing or diverging surfaces
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity

Abstract

The light guide plate 32 has a light receiving portion 36 on one side thereof to receive light emitted by the LED 24 and a flexible light guide body 35 for transforming the light received by the light receiving portion 36 into planar light. The light guide body 35 is arranged along the liquid crystal panel 23 and has a plurality of light scattering portions 30 arranged on an outer surface thereof in a propagation direction of light emitted by the LED 24. Since the light guide plate 32 comprises a flexible member and thus can be arranged in a curved shape conforming to the liquid crystal panel 23 having a curved surface portion, the curved surface portion of the liquid crystal panel 23 can be illuminated uniformly. Further, the provision of the light scattering portions 30 can enhance a light reception efficiency and light emission efficiency even if the light guide plate 32 is thin.

Claims

1. A light guide plate comprising:

a light receiving portion on one side of the light guide plate to receive light emitted from a light source; and

a light guide body to transform the light received by the light receiving portion into planar light and illuminate a display body with the planar light;

wherein the light guide body comprises a flexible member and is arranged along the display body and has a plurality of light scattering portions arranged on an outer surface thereof in a propagation direction of light emitted from the light source.

2. A light guide plate according to claim 1, wherein the display body has a curved surface portion and the light guide body is arranged in a similar curved shape along the curved surface portion of the display body.

3. A light guide plate according to claim 1, wherein the light guide body has light scattering portions arranged on at least an outer surface thereof facing the display body or an outer surface thereof on a back side.

4. A light guide plate according to claim 1, wherein the light guide body is a transparent or translucent, thin sheet member comprising polyethylene terephthalate, silicone or polyimide.

5. A light guide plate according to claim 1, wherein the light scattering portions comprise a plurality of undulated surface portions or through-holes that partially refract or reflect the light introduced into the light guide body, and the light scattering portions are arranged at an increasing arrangement density as they are further away from the light source.

6. A light guide plate according to claim 1, wherein the light receiving portion has an enlarged light receiving face and a light introducing portion, the enlarged light receiving face being formed on one side surface of the light guide body by progressively increasing a thickness of the light guide body toward the one side surface, the light introducing portion being formed to progressively converge from the enlarged light receiving face toward the light guide body.

7. A light guide plate according to claim 6, wherein the enlarged light receiving face has a V-shaped notch that reflects or refracts light emitted from the light source.

8. A light guide plate according to claim 6, wherein the light introducing portion has a through-hole that reflects or refracts light entering through the enlarged light receiving face.

9. A light guide plate support unit comprising:

a light guide plate having a light receiving portion on one side thereof to receive light emitted by a light source and a light guide body comprising a flexible member to transform the light received by the light receiving portion into planar light and illuminate a display body with the planar light, the light guide body having a plurality of light scattering portions arranged on an outer surface thereof; and

a clamp portion having a substrate mounting a light source and a support portion projecting from the substrate in a light emission direction of the light source to support the one side surface of the light guide plate.

10. A light guide plate support unit according to claim 9, wherein the clamp portion comprises a transparent resin material or a transparent resin material containing a fluorescent material and has a light shielding member arranged on upper and lower surfaces thereof.