LIGHTING DEVICE, DISPLAY DEVICE AND TELEVISION DEVICE

• US 20130222705A1
• Filed: 11/24/2011
• Published: 08/29/2013
• Est. Priority Date: 11/30/2010
• 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: Shimizu, Takaharu, Yamamoto, Kaori
• Granted Patent: US 8,985,799 B2
• Time in Patent Office: Days
• US Class Current: 348/790
• CPC Class Codes: F21V 7/00 Reflectors for light sources characterised by cooling arrangements F21V29/505
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors

Abstract

An object is to prevent or reduce uneven brightness in a direct-type lighting device. A lighting device according to the present technology includes LEDs 28 arranged in a matrix on a bottom plate of the chassis and a reflector 26 including first and second side walls 26a, 26b each arranged between the LEDs 28 adjacent in a Y-axis direction and an X-axis direction, respectively. The LEDs 28 are configured to emit light toward an opening of the chassis. The first side wall 26a has a side surface 26a rising from a front surface 30a of an LED board 30 toward the opening of the chassis while being inclined. The first side wall 26a extends straightly along the X-axis direction and has a triangular cross-sectional shape taken along the Y-axis direction. The second side wall 26b has a prism-like shape rising from the front surface 30a toward the opening and has a rhombic outline in a plan view.

Claims

1. A lighting device comprising:

a chassis including a bottom plate having a first main surface, a side plate rising from an outer periphery of the first main surface, the chassis having an opening on a first main surface side;

a plurality of light sources arranged in a matrix on the first main surface side of the bottom plate, the light sources being configured to emit light toward the opening of the chassis; and

a reflector including;

a first side wall arranged between the light sources adjacent to each other in a first direction that is one of a vertical direction and a horizontal direction in a plan view, the first side wall having a side surface rising from a mounting surface on which the light sources are mounted toward the opening of the chassis while being inclined, the first side wall extending straightly along a second direction that is another one of the vertical direction and the horizontal direction and having a triangular cross section taken along the first direction,

second side walls each arranged between the light sources adjacent to each other in the second direction, the second side walls each having a prism-like shape rising from the mounting surface toward the opening of the chassis and each having a rhombic outline in a plan view.

2. The lighting device according to claim 1, wherein

the side surface of the first side wall extends straightly in a cross section taken along the first direction, and

the side surface forms an acute angle with the mounting surface on which the light sources are mounted, the acute angle satisfying an expression:

10°

≦

θ

1≦

80 °

where θ

1 is the acute angle formed between the side surface of the first side wall and the mounting surface.

3. The lighting device according to claim 2, wherein the side surface of the first side wall satisfies an expression:

θ

1=45°

+tan<sup>−

1</sup>(H1/L1)/2

where L1 is a distance between one of the light sources and an apex of the first side wall, and H1 is a distance between the mounting surface on which the light sources are mounted and the apex of the first side wall.

4. The lighting device according claim 1, wherein the side surface of the first side wall is rounded to have a concave surface curved toward an inner side of the first side wall in a cross section taken along the first direction.

5. The lighting device according to claim 1, wherein each of the second side walls has the side surface that forms an acute angle with the mounting surface on which the light sources are mounted, the acute angle satisfying an expression:

45°

≦

θ

2≦

90°

where θ

2 is the acute angle formed between the side surface of the second side wall and the mounting surface.

6. The lighting device according to claim 1, wherein each of the second side walls having the rhombic outline in a plan view includes four corners that are rounded.

7. The lighting device according to claim 1, wherein

the first side wall includes a plurality of first side walls, and

each of the second side walls extends from one of the first side walls to another one of the first side walls adjacent to each other in the first direction.

8. The lighting device according to claim 7, wherein each of the second side walls includes two corners each located adjacent to each of the first side walls and connected to the first side wall.

9. The lighting device according to claim 1, wherein

each of the second side walls has a top surface, and

the top surface is arranged parallel with the bottom plate of the chassis.

10. The lighting device according to claim 1, wherein the reflector further includes a bottom having a plurality of through holes through each of which each of the light sources are passed, the bottom being arranged on the mounting surface of the light sources without overlapping with the first side wall and the second side walls.

11. The lighting device according to claim 1, wherein a distance between the light sources adjacent to each other in the first direction is larger than a distance between the light sources adjacent to each other in the second direction.

12. The lighting device according to claim 1, wherein the first side wall includes a plurality of first side walls, and

distances between the first side walls adjacent to each other gradually decrease toward a middle section of the chassis and distances between the light sources adjacent to each other in the first direction gradually decrease toward the middle section of the chassis.

13. The lighting device according to claim 1, wherein distances between the second side walls gradually decrease toward a middle section of the chassis and distances between the light sources adjacent to each other in the second direction gradually decrease toward the middle section of the chassis.

14. The lighting device according to claim 1, further comprising an optical member over the opening of the chassis, the optical member through which the light from the light sources passes,

wherein the optical member and an apex of the first side wall are not in contact with each other, thereby providing a space therebetween.

15. The lighting device according to claim 14, wherein the first side wall and the second side walls are equal in height.

16. The lighting device according to claim 1, wherein each of the light sources has a light intensity distribution in which light having a peak light intensity travels in a direction inclined with respect to a front direction of each of the light sources.

17. The lighting device according to claim 16, wherein an angle formed between the side surface of the first side wall and the front direction of the light sources is smaller than an angle formed between light having a peak light intensity and the front direction of the light sources.

18. The lighting device according to claim 1, wherein the first side wall and the second side walls define spaces equal in size, each of the light sources being arranged in each of the spaces.

19. A display device comprising:

a display panel configured to provide display using light from the lighting device according to claim 1.

21. A television device comprising the display device according to claim 19.

20. (canceled)