LIGHTING DEVICE, DISPLAY DEVICE AND TELEVISION RECEIVER

• US 20110205448A1
• Filed: 07/08/2009
• Published: 08/25/2011
• Est. Priority Date: 09/23/2008
• 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: Takata, Yoshiki
• Granted Patent: US 8,430,519 B2
• Time in Patent Office: Days
• US Class Current: 348/739
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

A lighting device 12 includes at least one point light source 17, an optical member 15a provided on a light output side of the lighting device 12 from the point light source 17. The optical member 15a is formed of a member having a substantially uniform light reflectance. A first light reflecting portion 31 is formed on a portion of the optical member 15a that overlaps the point light source 17, and the first light reflecting portion 31 reflects light from the point light source 17. A second light reflecting portion 30a, 23 is provided to reflect the light that is reflected by the first light reflecting portion 31 to be directed to the first light reflecting portion 31.

Claims

1. A lighting device comprising:

at least one point light source;

an optical member provided on a light output side of the lighting device from the point light source, the optical member being formed of a member having a substantially uniform light reflectance;

a first light reflecting portion formed on a portion of the optical member that overlaps the point light source, the first light reflecting portion reflecting light from the point light source; and

a second light reflecting portion provided to reflect the light that is reflected by the first light reflecting portion to be directed to the first light reflecting portion.

2. The lighting device according to claim 1, wherein:

the optical member has a first surface facing the point light source and a second surface opposite from the first surface; and

the first light reflecting portion is formed on the second surface of the optical member.

3. The lighting device according to claim 1, wherein:

the first light reflecting portion is provided on a portion of the optical member that does not overlap the point light source; and

on the surface of the optical member on which the first light reflecting portion is formed, the light reflectance of the surface of the portion of the optical member that overlaps the point light source is higher than the light reflectance of the surface of the portion of the optical member that does not overlap the point light source.

4. The lighting device according to claim 1, wherein the light reflectance of the surface of the optical member on which the first light reflecting portion is formed decreases in a direction away from the portion that overlaps the point light source.

5. The lighting device according to claim 1, wherein the first light reflecting portion is formed in a dot pattern having light reflectivity.

6. The lighting device according to claim 5, wherein the dot pattern of the first light reflecting portion is configured such that an area of each dot decreases in a direction away from the portion that overlaps the point light source.

7. The lighting device according to claim 1, further comprising a light scattering portion formed on a portion of the optical member that does not overlap the point light source, the light scattering portion scattering the light emitted from the point light source.

8. The lighting device according to claim 7, wherein the optical member has a first surface facing the point light source and a second surface opposite from the first surface;

and

the light scattering portion is formed on the second surface of the optical member.

9. The lighting device according to claim 7, wherein the light scattering portion is formed in a dot pattern having light scattering property.

10. The lighting device according to claim 9, wherein the dot pattern of the light scattering portion is configured such that an area of each dot increases in a direction away from the portion that overlaps the point light source.

11. The lighting device according to according to claim 1, further comprising a light scattering member provided on a light output side of the optical member, the light scattering member scattering the light passing through the optical member.

12. The lighting device according to claim 1, wherein:

the point light source is arranged on a light source substrate;

the light source substrate has a surface facing the optical member and including at least a first end portion, a second end portion, and a middle portion, the second end portion being located at an end away from the first end portion, and the middle portion being located between the first end portion and the second end portion;

one or two of the first end portion, the second end portion and the middle portion are configured as light source installation areas in each of which the point light source is arranged, and the rest is configured as an empty area in which no light source is arranged.

13. The lighting device according to claim 1, further comprising a chassis housing the light source and having an opening for light from the light source to pass through, wherein:

the chassis has a surface facing the optical member and including at least a first end portion, a second end portion, and a middle portion, the second end portion being located at an end away from the first end portion, and the middle portion being located between the first end portion and the second end portion;

one or two of the first end portion, the second end portion and the middle portion are configured as light source installation areas in each of which the point light source is arranged, and the rest is configured as an empty area in which no point light source is arranged.

14. The lighting device according to claim 13, wherein the light source installation area of the chassis is smaller than the empty area.

15. The lighting device according to claim 13, wherein the light source installation area is provided in the middle portion of the chassis.

16. The lighting device according to claim 13, wherein the light source installation area is provided in one of the first end portion and the second end portion.

17. The lighting device according to claim 13, wherein the light source installation area is provided in each of the first end portion and the second end portion.

18. The lighting device according to claim 13, wherein the chassis includes a light reflecting member in the empty area, the light reflecting member having a directing surface for directing light from the point light source to the optical member.

19. The lighting device according to claim 12, wherein on the surface of the optical member on which the first light reflecting portion is formed, the light reflectance of at least the surface of the portion that overlaps the empty area is higher on a side close to the portion that overlaps the light source installation area than on a side away therefrom.

20. The lighting device according to claim 12, further comprising a light source driving board configured to supply driving power to the point light source, wherein the light source driving board is disposed so as to overlap the light source installation area.

21. A display device comprising:

the lighting device according to claim 1; and

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

22. The display device according to claim 21, wherein the display panel is a liquid crystal display panel using liquid crystal.

23. A television receiver comprising the display device according to claim 21.