LIGHTING DEVICE, DISPLAY DEVICE, AND TELEVISION RECEIVER

• US 20120293727A1
• Filed: 12/17/2010
• Published: 11/22/2012
• Est. Priority Date: 01/22/2010
• 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: Yoshikawa, Takahiro
• Granted Patent: US 8,870,437 B2
• Time in Patent Office: Days
• US Class Current: 348/739
• CPC Class Codes: G02B 6/0091 of the light source relative to the light guide G02B6/0021 takes precedence
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side

Abstract

A lighting device maintains an optical design and absorbs expansion of a light guide plate with a simple structure if the light guide plate expands toward a light source side. A backlight unit 24 includes an LED board 30; an LED light sources 28 arranged on the LED board 30; a light guide plate 20 having a flat plate shape and including light entrance surfaces 20a1 and 20a2 on side surfaces that are provided on opposite sides, the light entrance surfaces 20a1 and 20a2 being arranged to face the LED light sources 28 of the LED board 30; and spacer members 25a (25b) regulating a distance W1 between the LED board 30 and the light guide plate 20. Each spacer member 25a (25b) has a Young'"'"'s modulus smaller than that of the light guide plate 20. Each spacer member 25a (25b) regulates the distance W1 between the LED light sources 28 and the light guide plate 20 and absorbs the expansion of the light guide plate 20.

Claims

1. A lighting device comprising:

a light source board;

a light source arranged on a surface of the light source board;

a light guide plate formed in a flat plate shape having side surfaces that are provided on opposite sides of the light guide plate and including light entrance surfaces on the side surfaces, each of the light entrance surfaces being arranged to face the light source of the light source board; and

spacer members configured to regulate a distance between the light source board and the light guide plate, each of the spacer members having Young'"'"'s modulus smaller than Young'"'"'s modulus of the light guide plate.

2. The lighting device according to claim 1, wherein Young'"'"'s modulus of the spacer member provided close to one of the light entrance surfaces of the light guide plate is different from Young'"'"'s modulus of the spacer member provided close to another one of the light entrance surfaces of the light guide plate.

3. The lighting device according to claim 1, wherein each of the spacer members includes a plate spring that is elastically deformed in a direction vertical to the light entrance surfaces of the light guide plate.

4. The lighting device according to claim 3, wherein elastic modulus of the plate spring of the spacer member provided close to one of the light entrance surfaces of the light guide plate is different from elastic modulus of the plate spring of the spacer member provided close to another one of the light entrance surfaces.

5. The lighting device according to claim 1, further comprising a housing member housing at least the light source board and the light guide plate,

wherein the spacer members are arranged on a surface of the housing member between the light source board and the light guide plate, and the spacer members are fixed to the housing member.

6. The lighting device according to claim 5, further comprising a board holding member fixed to the surface of the housing member and configured to hold the light source board,

wherein the spacer members are arranged on the surface of the board holding member.

7. The lighting device according to claim 1, wherein the spacer members arranged close to one of the light entrance surfaces of the light guide plate and the spacer members arranged close to another one of the light entrance surfaces are arranged in a mirror symmetrical manner.

8. The lighting device according to claim 1, wherein the spacer members and the light guide plate abut each other with no load applied between the spacer members and the light guide plate under a temperature condition of 25°

C.

9. The lighting device according to claim 1, further comprising a reflection member arranged between the light source and the light guide plate, wherein each of the light entrance surfaces is formed in an elongated shape and the reflection member is arranged along a longitudinal direction of the light entrance surface.

10. A display device comprising a display panel performing display using light from the lighting device according to claim 1.

11. The display device according to claim 10, wherein the display panel is a liquid crystal panel using a liquid crystal.

12. A television receiver comprising a display device according to claim 10.