Light guiding device with two opposite light emitting surfaces and backlight module using the same

• US 20050088838A1
• Filed: 09/27/2004
• Published: 04/28/2005
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hon Hai Precision Industry Co., Ltd.
• Inventors: Tsai, Kun-Jung
• Granted Patent: US 7,226,200 B2
• Time in Patent Office: Days
• US Class Current: 362/615
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0063 for extracting light out both the major surfaces of the light guide

Abstract

A backlight module (1) has a light guiding device (2) and a light source (200). The light guiding device has a light guide plate (20), a reflection member (26), and a reflection plate (210). The light guide plate has a light incidence surface (211) and two opposite light emitting surface (22, 23), defines a space (not labeled) receiving the reflection member therein, and an opening (25) for accessing the space. The reflection member has two opposite reflection surfaces (28, 29), and a plurality of micro dots (27) provided on the reflection surfaces. A reflection film (220) is attached to the reflection plate. In assembly, the reflection member is disposed such that the reflection surfaces face the light emitting surfaces of the light guide plate, respectively, and the light source is disposed adjacent to the light incidence surface, the reflection plate is attached to the side surface.

Claims

1. A light guiding device, comprising:

a light guide plate comprising a light incidence surface and two opposite light emitting surfaces; and

a reflection member comprising two opposite reflection surfaces;

wherein the light guide plate defines a space receiving the reflection member therein, and an opening for accessing the space, and the reflection surfaces of the reflection member face the light emitting surfaces of the light guide plate respectively.

2. The light guiding device as claimed in claim 1, wherein the light guide plate comprises a side surface at the opening, and a reflection plate is attached to the side surface.

3. The light guiding device as claimed in claim 2, further comprising a reflection film attached to the reflection plate.

4. The light guiding device as claimed in claim 2, wherein a plurality of micro dots is formed on the reflection surfaces, thereby defining a top diffusing region and a bottom diffusing region respectively.

5. The light guiding device as claimed in claim 4, wherein areas of the top diffusing region and the bottom diffusing region are different from each other.

6. A backlight module, comprising:

a light guiding device comprising a light guide plate and a reflection member; and

a light source;

wherein the light guide plate comprises a light incidence surface and two opposite light emitting surfaces, the reflection member comprises two opposite reflection surfaces, the light guide plate further comprises an inner space receiving the reflection member, and a side surface with an opening for putting the reflection member into the inner space, the reflection surfaces of the reflection member face the light emitting surfaces of the light guide plate respectively, and the light source is disposed adjacent to the light incidence surface of the light guide plate.

7. The backlight module as claimed in claim 6, further comprising a reflection plate attached to the side surface.

8. The light guiding device as claimed in claim 7, further comprising a reflection film attached to the reflection plate.

9. The light guiding device as claimed in claim 7, wherein a plurality of micro dots is formed on the reflection surfaces, thereby defining a top diffusing region and a bottom diffusing region respectively.

10. The backlight module as claimed in claim 6, wherein the light source is an LED (light-emitting diode) or a CCFL (Cold Cathode Fluorescent Lamp).

11. A backlight module, comprising:

a light source; and

a light guiding device disposed adjacent to said light source, comprising an incident surface to allow light from said light source passable therethrough, and at least two light emitting surfaces facing at least two corresponding directions; and

a reflection member interferingly located in a pathway of said light from said incident surface to said at least two light emitting surfaces and splitting said light into subgroups of light so as to allow each of said light subgroups passable through each of said at least two light emitting surfaces along one of said at least two directions.

12. The backlight module as claimed in claim 11, wherein said reflection member is surrounded by said light guiding device.

13. The backlight module as claimed in claim 11, wherein one of said at least two light emitting surfaces is disposed parallel to another of said at least two light emitting surfaces.