Backlight device and display device

• US 8,733,959 B2
• Filed: 09/12/2012
• Issued: 05/27/2014
• Est. Priority Date: 03/21/2006
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Moriya, Koji, Nishi, Takeshi
• Primary Examiner(s): SEMBER, THOMAS M
• Application Number:
  US13/611,411
• Publication Number:
  US 20130003355A1
• Time in Patent Office: 622 Days
• Field of Search: 362 971- 974, 362/231, 362/249.02, 362/249.05, 362/249.06, 362/84, 349 63- 65, 349/72, 349/155, 349/156
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: G02F 1/133628 with cooling means

Abstract

It is an object to manufacture a highly reliable backlight device with less color unevenness and less luminance unevenness, and a high-performance and highly reliable display device including the backlight device, which can display a high quality image. A light emitting diode (LED) is used as a light source of a backlight device and thermoelectric elements are provided in a chassis for holding the light emitting diode so as to surround the light emitting diode (the thermoelectric elements are provided under the light emitting diode and on the four sides thereof). A temperature in the backlight device is adjusted by cooling and heating by the thermoelectric elements.

Claims

1. A semiconductor device comprising:

a liquid crystal display panel; and

a backlight device adjacent to the liquid crystal display panel,

wherein the liquid crystal display panel comprises;

a transistor; and

a sealant,

wherein the backlight device comprises;

a board;

a reflective sheet over the board;

a first light emitting part over the board;

a second light emitting part over the board;

a third light emitting part over the board;

a diffusing plate over the reflective sheet, the first light emitting part, the second light emitting part and the third light emitting part; and

a prism sheet over the diffusing plate,

wherein the first light emitting part, the second light emitting part and the third light emitting part each comprises;

a plurality of light emitting diodes; and

a fluorescent material over the plurality of light emitting diodes,

wherein the transistor overlaps with the first light emitting part, and

wherein the sealant does not overlap with the first light emitting part, the second light emitting part and the third light emitting part.

2. A semiconductor device according to claim 1, wherein the first light emitting part, the second light emitting part and the third light emitting part emit red light, green light and blue light, respectively.

3. A semiconductor device according to claim 1, wherein the first light emitting part, the second light emitting part and the third light emitting part each emits white light.

4. A semiconductor device according to claim 1, wherein colors of the plurality of light emitting diodes of the first light emitting part are different each other.

5. A semiconductor device according to claim 1,

wherein the transistor does not overlap with the second light emitting part.

6. A semiconductor device according to claim 1,

wherein the transistor does not overlap with the third light emitting part.

7. An electric appliance comprising a semiconductor device according to claim 1, wherein the electric appliance comprises one selected from the group consisting of a portable information terminal, a camera, a mobile phone, a television device, and a computer.

8. An electric appliance comprising a semiconductor device according to claim 1, a speaker and a remote control unit.

9. A semiconductor device comprising:

a liquid crystal display panel; and

a backlight device adjacent to the liquid crystal display panel,

wherein the liquid crystal display panel comprises;

a pixel electrode layer; and

a sealant,

wherein the backlight device comprises;

a board;

a reflective sheet over the board;

a first light emitting part over the board;

a second light emitting part over the board;

a third light emitting part over the board;

a diffusing plate over the reflective sheet, the first light emitting part, the second light emitting part and the third light emitting part; and

a prism sheet over the diffusing plate,

wherein the first light emitting part and the second light emitting part each comprises;

a plurality of light emitting diodes; and

a fluorescent material over the plurality of light emitting diodes,

wherein the pixel electrode layer overlaps with the third light emitting part, and

wherein the sealant does not overlap with the first light emitting part, the second light emitting part and the third light emitting part.

10. A semiconductor device according to claim 9, wherein the first light emitting part, the second light emitting part and the third light emitting part emit red light, green light and blue light, respectively.

11. A semiconductor device according to claim 9, wherein the first light emitting part, the second light emitting part and the third light emitting part each emits white light.

12. A semiconductor device according to claim 9, wherein colors of the plurality of light emitting diodes of the first light emitting part are different each other.

13. A semiconductor device according to claim 9,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor overlaps with the first light emitting part.

14. A semiconductor device according to claim 9,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor does not overlap with the second light emitting part.

15. A semiconductor device according to claim 9,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor does not overlap with the third light emitting part.

16. A semiconductor device according to claim 9,

wherein the pixel electrode layer does not overlap with the first light emitting part.

17. A semiconductor device according to claim 9, wherein the pixel electrode layer does not overlap with the second light emitting part.

18. An electric device comprising a semiconductor device according to claim 9, wherein the electric device is one selected from the group consisting of a portable information terminal, a camera, a mobile phone, a television device, and a computer.

19. An electric appliance comprising a semiconductor device according to claim 9, a speaker and a remote control unit.

20. A semiconductor device comprising:

a liquid crystal display panel; and

a backlight device adjacent to the liquid crystal display panel,

wherein the liquid crystal display panel comprises;

a capacitor; and

a sealant,

wherein the backlight device comprises;

a board;

a reflective sheet over the board;

a first light emitting part over the board;

a second light emitting part over the board;

a third light emitting part over the board;

a diffusing plate over the reflective sheet, the first light emitting part, the second light emitting part and the third light emitting part; and

a prism sheet over the diffusing plate,

wherein the first light emitting part and the second light emitting part each comprises;

a plurality of light emitting diodes; and

a fluorescent material over the plurality of light emitting diodes,

wherein the capacitor overlaps with the third light emitting part, and

wherein the sealant does not overlap with the first light emitting part, the second light emitting part and the third light emitting part.

21. A semiconductor device according to claim 20, wherein the first light emitting part, the second light emitting part and the third light emitting part emit red light, green light and blue light, respectively.

22. A semiconductor device according to claim 20, wherein the first light emitting part, the second light emitting part and the third light emitting part each emits white light.

23. A semiconductor device according to claim 20, wherein colors of the plurality of light emitting diodes of the first light emitting part are different each other.

24. A semiconductor device according to claim 20,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor overlaps with the first light emitting part.

25. A semiconductor device according to claim 20,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor does not overlap with the second light emitting part.

26. A semiconductor device according to claim 20,

wherein the liquid crystal display panel comprises a transistor, and

wherein the transistor does not overlap with the third light emitting part.

27. A semiconductor device according to claim 20,

wherein the capacitor does not overlap with the first light emitting part.

28. A semiconductor device according to claim 20,

wherein the capacitor does not overlap with the second light emitting part.

29. An electric device comprising a semiconductor device according to claim 20, wherein the electric device is one selected from the group consisting of a portable information terminal, a camera, a mobile phone, a television device, and a computer.

30. An electric appliance comprising a semiconductor device according to claim 20, a speaker and a remote control unit.

31. A semiconductor device comprising:

a liquid crystal display panel; and

a backlight device adjacent to the liquid crystal display panel,

wherein the liquid crystal display panel comprises;

a substrate and a counter substrate;

a pixel electrode layer over the substrate;

a spacer between the substrate and the counter substrate; and

a sealant between the substrate and the counter substrate,

wherein the backlight device comprises;

a board;

a reflective sheet over the board;

a first light emitting part over the board;

a second light emitting part over the board;

a third light emitting part over the board;

a diffusing plate over the reflective sheet, the first light emitting part, the second light emitting part and the third light emitting part; and

a prism sheet over the diffusing plate,

wherein the first light emitting part and the second light emitting part each comprises;

a plurality of light emitting diodes; and

a fluorescent material over the plurality of light emitting diodes,

wherein at least a part of the spacer overlaps with the pixel electrode layer, and

wherein the sealant does not overlap with the first light emitting part, the second light emitting part and the third light emitting part.

32. A semiconductor device according to claim 31, wherein the first light emitting part, the second light emitting part and the third light emitting part emit red light, green light and blue light, respectively.

33. A semiconductor device according to claim 31, wherein the first light emitting part, the second light emitting part and the third light emitting part each emits white light.

34. A semiconductor device according to claim 31, wherein colors of the plurality of light emitting diodes of the first light emitting part are different each other.

35. An electric device comprising a semiconductor device according to claim 31, wherein the electric device is one selected from the group consisting of a portable information terminal, a camera, a mobile phone, a television device, and a computer.

36. An electric appliance comprising a semiconductor device according to claim 31, a speaker and a remote control unit.

37. A semiconductor device comprising:

a liquid crystal display panel; and

a backlight device adjacent to the liquid crystal display panel,

wherein the liquid crystal display panel comprises;

a substrate and a counter substrate;

a pixel electrode layer over the substrate;

a spacer between the substrate and the counter substrate; and

a sealant between the substrate and the counter substrate,

wherein the backlight device comprises;

a board;

a reflective sheet over the board;

a first light emitting part over the board;

a second light emitting part over the board;

a third light emitting part over the board;

a diffusing plate over the reflective sheet, the first light emitting part, the second light emitting part and the third light emitting part; and

a prism sheet over the diffusing plate,

wherein the first light emitting part and the second light emitting part each comprises;

a plurality of light emitting diodes; and

a fluorescent material over the plurality of light emitting diodes,

wherein at least a part of the spacer does not overlap with the pixel electrode layer, and

wherein the sealant does not overlap with the first light emitting part, the second light emitting part and the third light emitting part.

38. A semiconductor device according to claim 37, wherein the first light emitting part, the second light emitting part and the third light emitting part emit red light, green light and blue light, respectively.

39. A semiconductor device according to claim 37, wherein the first light emitting part, the second light emitting part and the third light emitting part each emits white light.

40. A semiconductor device according to claim 37, wherein colors of the plurality of light emitting diodes of the first light emitting part are different each other.

41. An electric device comprising a semiconductor device according to claim 37, wherein the electric device is one selected from the group consisting of a portable information terminal, a camera, a mobile phone, a television device, and a computer.

42. An electric appliance comprising a semiconductor device according to claim 37, a speaker and a remote control unit.