Backlight unit

• US 8,684,587 B2
• Filed: 12/29/2009
• Issued: 04/01/2014
• Est. Priority Date: 07/16/2009
• Status: Expired due to Fees

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Hee-Cheoul, Nam, Ji-Geun, Kang, Choun-Sung, Choi, Jin-Taek, Ahn, Sang-Hyun, Choi, Jong-Bum, Yang, Seung-Soo
• Primary Examiner(s): CARTER, WILLIAM JOSEPH
• Application Number:
  US12/648,904
• Publication Number:
  US 20110013376A1
• Time in Patent Office: 1,554 Days
• Field of Search: 362600-634
• US Class Current: 362/628
• 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 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays

Abstract

A backlight unit is capable of preventing generation of mura such bright lines and dark lines. The backlight unit includes a light guide panel divided into a plurality of light guide blocks for local dimming driving, a first block partitioning unit formed as a groove between respective adjacent light guide blocks on a lower surface of the light guide panel, and a point light source received in the first block partitioning unit.

Claims

1. A backlight unit comprising:

a light guide panel;

at least two first block partitioning units formed as a groove on a lower surface of the light guide panel, wherein the at least two first partitioning units have a polygonal section that includes one slanted surface and one incident part facing each other;

a plurality of light guide blocks formed by partitioning the light guide panel, wherein the light guide blocks are integrated, not separated by at least two first partitioning units,

at least two point light sources received in the at least two first block partitioning unit, and constituting one light block corresponding to one of the plurality of light guide blocks,

at least one second block partitioning unit that has a hole or groove form, wherein a length of the at least one second block partitioning unit is arranged in a perpendicular direction to a length of the at least two first block partitioning units; and

at least one second point light source received in the at least one second block partitioning unit and arranged in the perpendicular direction to the at least two first block partitioning units, wherein the second point light source is turned off during a local dimming driving and turned on except during the local dimming driving,

wherein a width of the groove surrounded with the slanted surface and the incident part is formed to be gradually narrower as it goes from the lower surface of the light guide panel to an upper surface of the light guide panel; and

wherein lights generated from the point light sources are directly incident to the incident part and are not directly incident to the slanted surface.

2. The backlight unit according to claim 1, wherein the plurality of light guide blocks are each formed with at least one of optical patterns on at least one of an upper surface and a lower surface of each of the plurality of light guide blocks.

3. The backlight unit according to claim 2, wherein the optical patterns include at least a dot pattern or a prism pattern.

4. The backlight unit according to claim 1, wherein the plurality of light guide blocks each include a surface exposed by the at least two first partitioning units , and the surface is planarized through a mirror surface processing with an improved light incident efficiency.

5. The backlight unit according to claim 1, wherein the at least one point light source is side-view light source.

6. The backlight unit according to claim 1, wherein the second point light source is a top-view light source.

7. A backlight unit comprising:

a light guide panel;

at least two first block partitioning units formed as a groove on a lower surface of the light guide panel, wherein the at least two first partitioning units have a polygonal section that includes one slanted surface and one incident part facing each other;

a plurality of light guide blocks formed by partitioning the light guide panel wherein the light guide blocks are integrated, not separated by at least two first partitioning units;

at least two point light sources received in the at least two first block partitioning units, and constituting one light block corresponding to one of the plurality of light guide blocks;

at least one second block partitioning unit that has a hole or groove form, wherein a length of the at least one second block partitioning unit is arranged in a perpendicular direction to a length of the at least two first block partitioning units; and

at least one second point light sources that are received in the at least one second block partitioning unit and are arranged in the perpendicular direction to the at least two first block partitioning units, wherein the second point light sources is turned off during a local dimming driving and turned on except during the local dimming driving,

wherein lights generated from the point light sources are directly incident to the incident part and are not directly incident to the slanted surface.

8. The backlight unit according to claim 7, wherein the second point light source is a top-view light source.

9. The backlight unit according to claim 7, wherein a width of the groove of the at least two first block partitioning units surrounded with the slanted surface and the incident part is formed to be gradually narrower as it goes from the lower surface of the light guide panel to an upper surface of the light guide panel.