BACKLIGHT DEVICE AND LIQUID CRYSTAL DISPLAY

• US 20090213301A1
• Filed: 05/07/2009
• Published: 08/27/2009
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: TANABE, Takayoshi
• Granted Patent: US 7,802,911 B2
• Time in Patent Office: Days
• US Class Current: 349/65
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

A backlight apparatus of a sidelight type includes a light guide plate having an incident face on a lateral face and a light source unit having a plurality of substrates. The plurality of the substrates are respectively disposed on the incident face side of the light guide plate such that each of substrate faces of the substrates is parallel with a light exit face of the light guide plate, and the substrates are adjacent to one another in a thickness direction of the light guide plate. A plurality of light emitting devices that emit light along the substrate faces are mounted in columns on each of the substrate faces of the plurality of the substrates such that emitting directions of the light emitting devices are directed to the incident face.

Claims

1. A backlight apparatus of a sidelight type comprising:

a light guide plate having an incident face on a lateral face; and

a light source unit having a plurality of substrates;

wherein

each of the plurality of substrates is respectively disposed on the incident face side of the light guide plate such that a face of each of the plurality of substrates is parallel with a main face of the light guide plate;

the plurality of substrates are arranged adjacent to one another in a thickness direction of the light guide plate;

a plurality of light emitting devices are mounted in columns on each of the substrate faces of the plurality of substrates such that light emitted from the plurality of light emitting devices is directed to the incident face; and

a heat sink plate is disposed between adjacent ones of the plurality of light emitting devices.

2. The backlight apparatus according to claim 1, wherein switching on of the plurality of light emitting devices on each of the plurality of substrates is controlled independently of any other of the plurality of substrates.

3. The backlight apparatus according to claim 1, wherein:

two adjacent substrates among the plurality of substrates are disposed such that mounting faces of the two adjacent substrates face each other; and

a first group of the plurality of light emitting devices that are mounted on one of the two adjacent substrates and a second group of the plurality of light emitting devices that are mounted on the other one of the two adjacent substrates are mounted in positions that are not overlapped with each other in the thickness direction of the light guide plate.

4. The backlight apparatus according to claim 1, wherein the thickness of a portion of the light guide plate decreases in a direction extending away from the incident face of the light guide plate.

5. The backlight apparatus according to claim 1, wherein the plurality of light emitting devices are light emitting diodes.

6. The backlight apparatus according to claim 5, wherein the light emitting diodes emit white color light.

7. The backlight apparatus according to claim 5, wherein the light emitting diodes include a red color light emitting diode, a green color light emitting diode, and a blue color light emitting diode.

8. A liquid crystal display comprising the backlight apparatus according to claim 1.