Light unit and liquid crystal display device having the same

• US 8,057,057 B2
• Filed: 07/31/2007
• Issued: 11/15/2011
• Est. Priority Date: 08/11/2006
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: Park, Jun Seok
• Primary Examiner(s): Husar; Stephen F
• Assistant Examiner(s): Neils; Peggy A.
• Application Number:
  US12/067,007
• Publication Number:
  US 20080316750A1
• Time in Patent Office: 1,568 Days
• Field of Search: 362/612, 362/613, 362/630, 362/294, 362/373, 362/231, 362/97.3, 362/249.02, 362/631, 362/800, 345/102, 349/161, 361/719, 361/721
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: H05K 1/142 Arrangements of planar printed circuit boards in the same plane, e.g. auxiliary printed circuit insert mounted in a main printed circuit

Abstract

Provided are a light unit and a liquid crystal display (LCD) having the same. The light unit comprises a housing; at least one first printed circuit board (PCB) arranged in the housing in a first direction; at least one second PCB arranged in the housing in a direction opposite to the first direction; and light emitting diodes mounted on the first and second PCBs.

Claims

1. A light unit, comprising:

a housing including a first side, a second side opposite to the first side, a third side, and a fourth side opposite to the third side;

a first printed circuit board arranged in the housing in a first direction from the first side to the second side, wherein the first printed circuit board includes a first connector arranged adjacent to the first side of the housing;

a second printed circuit board arranged in the housing in the first direction and adjacent to the first printed circuit board, wherein the second printed circuit board includes a second connector arranged adjacent to the second side of the housing;

a third printed circuit board arranged in the housing in the first direction and adjacent to the second printed circuit board, wherein the third printed circuit board includes a third connector arranged adjacent to the first side of the housing; and

light emitting diodes mounted on the first, second and third printed circuit boards,

wherein, in the first printed circuit board, the first connector and the light emitting diodes on the first printed circuit board are disposed in a first line, and the light emitting diodes on the first printed circuit board are arranged between the first connector and the second side,

wherein, in the second printed circuit board, the second connector and the light emitting diodes on the second printed circuit board are disposed in a second line, and the light emitting diodes on the second printed circuit board are arranged between the second connector and the first side,

wherein, in the third printed circuit board, the third connector and the light emitting diodes on the third printed circuit board are disposed in a third line, and the light emitting diodes on the third printed circuit board are arranged between the third connector and the second side, and

wherein there is only one connector on each printed circuit board and a connector of an adjacent printed circuit board is alternately and oppositely positioned.

2. The light unit according to claim 1, wherein the first and second printed circuit boards are arranged such that they alternate each other in singularity or plurality.

3. The light unit according to claim 1, wherein the light emitting diode comprises at least one of a red light emitting diode chip, a green light emitting diode chip and a blue light emitting diode chip.

4. The light unit according to claim 1, further comprising:

a heatsink member provided on at least one of a base, a rear surface and a side surface of the housing,

wherein the heatsink member comprises at least one of a heatsink sheet, a heatsink plate and a heatsink bar.

5. The light unit according to claim 1, wherein the housing has a shape of a rectangular frame, and an outer side of the housing is inclined at a predetermined angle with respect to a base of the housing, the predetermined angle arranged to reflect leakage light.

6. The light unit according to claim 1, wherein each of the first and second printed circuit boards comprises a plurality of light emitting diode bars connected in series.

7. A light unit, comprising:

a housing including a first side, a second side opposite to the first side, a third side, and a fourth side opposite to the third side;

a plurality of printed circuit boards disposed on a front surface of the housing;

a plurality of heatsink bars disposed on a rear surface of the housing, wherein, in each of the plurality of heatsink bars, a heatsink bar area adjacent to the third side is greater than a heatsink bar area adjacent to the fourth side;

a heatsink sheet between the housing and the plurality of heatsink bars and between the housing and the plurality of printed circuit boards; and

light emitting diodes mounted on the plurality of printed circuit boards.

8. The light unit according to claim 7, wherein at least one of the printed circuit boards includes:

a first connector arranged at the first side of the housing, and

a second connector arranged at the second side of the housing.

9. The light unit according to claim 7,

wherein the plurality of printed circuit boards comprises a first printed circuit board and a second printed circuit board,

wherein the light emitting diodes include a first light emitting diode mounted on the first printed circuit board and a second light emitting diode mounted on the second printed circuit board, and

wherein the first light emitting diode has a brightness distribution different from a brightness distribution of the second light emitting diode.

10. The light unit according to claim 7, wherein each of the plurality of heatsink bars is formed separately from the housing and is coupled to the housing, each of the plurality of heatsink bars having a stripe type right-angled triangle shape.

11. The light unit according to claim 7, wherein a surface of each of the plurality of heatsink bars is anodized.

12. The light unit according to claim 7, further comprising:

a light emitting diode driver; and

a liquid crystal panel driver disposed on a portion of a rear surface of the housing.

13. A liquid crystal display, comprising:

a liquid crystal panel; and

a light unit provided under the liquid crystal panel, and configured to supply light,

wherein the light unit comprises;

a housing including a first side, a second side opposite to the first side, a third side, and a fourth side opposite to the third side;

a first printed circuit board arranged in the housing in a first direction from the first side to the second side, wherein the first printed circuit board includes a first connector arranged adjacent to the first side of the housing;

a second printed circuit board arranged in the housing in the first direction and adjacent to the first printed circuit board, wherein the second printed circuit board includes a second connector arranged adjacent to the second side of the housing;

a third printed circuit board arranged in the housing in the first direction and adjacent to the second printed circuit board, wherein the third printed circuit board includes a third connector arranged adjacent to the first side of the housing; and

light emitting diodes mounted on the first, second and third printed circuit boards,

wherein, in the first printed circuit board, the first connector and the light emitting diodes on the first printed circuit board are disposed in a first line, and the light emitting diodes on the first printed circuit board are arranged between the first connector and the second side,

wherein, in the second printed circuit board, the second connector and the light emitting diodes on the second printed circuit board are disposed in a second line, and the light emitting diodes on the second printed circuit board are arranged between the second connector and the first side,

wherein, in the third printed circuit board, the third connector and the light emitting diodes on the third printed circuit board are disposed in a third line, and the light emitting diodes on the third printed circuit board are arranged between the third connector and the second side,

wherein the light unit further comprises at least one of;

a heatsink sheet provided on the housing;

a heatsink plate provided on the housing;

a semiconductor heatsink element provided on the housing;

a heatsink fin provided on the housing; and

a heatsink bar provided on the housing,

wherein the housing includes a base and side surfaces,

wherein the base is formed in a rectangular frame and has first and second short edges and third and fourth long edges, and

wherein the heatsink bar is provided on a rear surface of the housing, and the heatsink bar has an area in a third direction adjacent to the third long edge greater than an area in a fourth direction adjacent to the fourth long edge opposite to the third direction.

14. The liquid crystal display according to claim 13, wherein the light unit further comprises:

a diffusion sheet and a prism sheet disposed on the light emitting diode.

15. A display unit, comprising:

a display panel;

a housing including a base and side surfaces;

a plurality of printed circuit boards disposed in the housing, the plurality of printed circuit boards being arranged in a first direction and parallel to each other, each of the printed circuit board comprising one connector;

a heatsink bar disposed on the housing, the heatsink bar being arranged substantially perpendicular to the first direction; and

light emitting diodes mounted on the plurality of printed circuit boards,

wherein at least one connector of the printed circuit board is positioned at a different portion where the connector of another printed circuit board is positioned, and

wherein a height of the heatsink bar varies.

16. The light display unit according to claim 15, wherein a height of the heatsink bar is highest at one end of the heatsink bar, and the height of the heatsink bar lowers continuously toward an opposite end of the heatsink bar.

17. The display unit according to claim 15, wherein the heatsink bar is disposed on a rear surface of the housing.