IP Library Granted Patent US 7,641,373
Granted Patent B2
US 7,641,373 · App. 11/516,488 · Granted Jan 5, 2010

Backlight unit

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Quick Facts
Patent No.
US 7,641,373
App. No.
11/516,488
Granted
Jan 5, 2010
Kind
B2
Abstract

Disclosed is a backlight unit which illuminates a display panel from a rear surface thereof, including at least: tubular lamps arranged in parallel to the panel; and a reflecting member which reflects light from the lamps toward the panel, wherein the reflecting member is divided into a first region opposed to an area near an electrode provided in an end portion of the lamp and a second region nearer to a middle area than the first region, the first region having a higher reflectance than the second region. In another backlight unit, a reflecting member is divided, with respect to the arrangement direction of the lamps, into an end lamp near region which is opposed to a lamp arranged in end portion and a middle region which is nearer to a middle area than the end lamp region, the end lamp region having a higher reflectance than the middle region.

Claims (66)

1. A backlight unit which illuminates a display panel from a rear surface thereof, comprising at least:

tubular lamps arranged in parallel to the display panel; and

a reflecting member which reflects light from the lamps toward the display panel,

wherein the reflecting member is divided into a first region opposed to an area near an electrode provided in an end portion of the lamp and a second region nearer to a middle area than the first region,

wherein the first region has a higher reflectance than the second region, and

wherein the first region comprises a continuous portion that extends from one side of the display panel to an other side of the display panel and being perpendicular to a direction of extension of the lamp, said continuous portion covering an entirety of end portions of the tubular lamps adjacent to an edge of the rear surface.

2. The backlight unit according to claim 1 , wherein the reflecting member includes:

a first reflector which is disposed in the first region and the second region; and

a second reflector disposed in the first region.

3. The backlight unit according to claim 1 , wherein the reflecting member includes:

a first reflector disposed in the second region; and

a second reflector which is disposed in the first region and has a higher reflectance than the first reflector.

4. The backlight unit according to claim 1 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

an absorber which is disposed in the second region and has a prescribed absorptivity.

5. The backlight unit according to claim 1 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

a reflecting film having a prescribed reflectance which is formed in the first region of the reflector.

6. The backlight unit according to claim 1 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

an absorbing film having a prescribed absorptivity which is formed in the second region of the reflector.

7. The backlight unit according to claim 1 , wherein each of the lamps comprises a U-shaped lamp.

8. The backlight unit according to claim 1 , wherein the reflecting member further comprises a third region between the first region and the second region,

the third region having a reflectance which is lower than the reflectance of the first region and higher than the reflectance of the second region.

9. The backlight unit according to claim 1 , wherein the first region further includes a region opposed to an area near a lamp arranged in an end portion with respect to an arrangement direction of the lamps.

10. The backlight unit according to claim 9 , wherein the first region has a shape which surrounds the second region.

11. The backlight unit according to claim 9 , wherein the reflecting member includes:

a first reflector disposed in the second region; and

a second reflector which is disposed in the first region and has a higher reflectance than the first reflector.

12. The backlight unit according to claim 9 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

an absorber which is disposed in the second region and has a prescribed absorptivity.

13. The backlight unit according to claim 9 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

a reflecting film having a prescribed reflectance which is formed in the first region of the reflector.

14. The backlight unit according to claim 9 , wherein the reflecting member includes:

a reflector disposed in the first region and the second region; and

an absorbing film having a prescribed absorptivity which is formed in the second region of the reflector.

15. The backlight unit according to claim 9 , wherein each of the lamps comprises a U-shaped lamp.

16. The backlight unit according to claim 15 , wherein a region opposed to an area near a bent portion of the U-shaped lamp is the same as the first region.

17. The backlight unit according to claim 1 , wherein the first region comprises the area near the electrode rather than an area which extends in a direction of said parallel lamps, and

wherein the reflecting member comprises a flat sheet.

18. The backlight unit according to claim 1 , wherein said reflecting member comprises a single-piece sheet to control an entirety of luminance distribution of all of the tubular lamps.

19. A backlight unit which illuminates a display panel from a rear surface thereof, comprising at least:

tubular lamps arranged in parallel to the display panel; and

a reflecting member which reflects light from the lamps toward the display panel,

wherein the reflecting member is divided into a first region opposed to an area near an electrode provided in an end portion of a lamp and a second region nearer to a middle area than the first region,

wherein the first region has a higher reflectance than the second region,

wherein the first region further includes a region opposed to an area near a lamp arranged in an end portion with respect to an arrangement direction of the lamps, and

wherein the reflecting member includes:

a first reflector disposed in the first region and the second region; and

a second reflector disposed in the first region.

20. A backlight unit which illuminates a display panel from a rear surface thereof, comprising at least:

tubular lamps arranged in parallel to the display panel; and

a reflecting member which reflects light from the lamps toward the display panel,

wherein the reflecting member is divided into a first region opposed to an area near an electrode provided in an end portion of a lamp and a second region nearer to a middle area than the first region,

wherein the first region has a higher reflectance than the second region,

wherein the second region is further divided, with respect to an arrangement direction of the lamps, into an end lamp region which is opposed to an area near a lamp arranged in an end portion and a middle region which is nearer to a middle area than the end lamp region, and

wherein the end lamp region has a higher reflectance than the middle region.

21. A backlight unit which illuminates a display panel from a rear surface thereof, comprising at least:

tubular lamps arranged in parallel to the display panel; and

a reflecting member which reflects light from the lamps toward the display panel,

wherein the reflecting member is divided, with respect to the arrangement direction of the lamps, into at least an end lamp region which is opposed to an area near a lamp arranged in an end portion and a middle region which is nearer to a middle area than the end lamp region,

wherein the end lamp region has a higher reflectance than the middle region, and

wherein the first region comprises a continuous portion that extends from one side of the display panel to an other side of the display panel and being perpendicular to a direction of extension of the lamp, said continuous portion covering an entirety of end portions of the tubular lamps adjacent to an edge of the rear surface.

22. The backlight unit according to claim 21 , wherein said reflecting member comprises a single-piece sheet to control an entirety of luminance distribution of all of the tubular lamps.

Assignments (2)
CHANGE OF NAME Recorded Nov 8, 2011
From: NEC LCD TECHNOLOGIES, LTD.
To: NLT TECHNOLOGIES, LTD.
Reel/Frame 027190/0252 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 7, 2006
From: SUGAWARA, HIDEAKI; ISHIDA, HIROSHI
To: NEC LCD TECHNOLOGIES, LTD.
Reel/Frame 018271/0722 →