Apparatus and methods for backlight unit with vertical interior reflectors

• US 8,651,685 B2
• Filed: 03/16/2007
• Issued: 02/18/2014
• Est. Priority Date: 03/16/2007
• Status: Active Grant

• Current Assignee: Brightplus Ventures LLC (IPValuation Partners, LLC)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Roberts, John K., You, Chenhua
• Primary Examiner(s): CARIASO, ALAN B
• Application Number:
  US11/687,165
• Publication Number:
  US 20080225512A1
• Time in Patent Office: 2,531 Days
• Field of Search: 362/97, 362/241, 362/246, 362/247, 362/299, 362/300, 362/307, 362/308, 362/555, 362/558, 362 971- 974, 362/240
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

Provided are solid state backlight devices and methods for forming the same. A solid state backlight unit according to some embodiments of the invention includes a housing having a major surface and multiple LEDs on a first surface of the major surface. The solid state backlight unit also includes a specular reflector proximate to the first surface of the major surface and oriented substantially perpendicular to the first surface of the major surface.

Claims

1. A solid state backlight unit, comprising:

a first solid state emitter and a second solid state emitter that are configured to radiate light;

a diffuse reflector arranged to reflect first portions of the light radiated from the first and second solid state emitters

a diffuser arranged to partially transmit the light directly radiated from the first and second solid state emitters and the reflected first portions;

a center wall that is positioned between the first emitter and the second emitter; and

a first vertical reflector arranged to reflect a second portion of the light directly radiated from the at least one emitter

wherein the first vertical reflector comprises a substantially specularly reflective surface.

2. The solid state backlight unit of claim 1, wherein the diffuser is substantially parallel to the diffuse reflector.

3. The solid state backlight unit of claim 1,

wherein the diffuser is arranged to partially transmit the reflected second portion.

4. The solid state backlight unit of claim 3, further comprising:

a second vertical reflector arranged to reflect a third portion of the light directly radiated from the at least one emitter,

wherein the diffuser is arranged to partially transmit the reflected third portion.

5. The solid state backlight unit of claim 4, wherein the first and second vertical reflectors are substantially perpendicular to the diffuse reflector and wherein the first vertical reflector is substantially parallel to the second vertical reflector.

6. The solid state backlight unit of claim 4, wherein the first and second vertical reflectors comprise a multilayer optical film.

7. The solid state backlight unit of claim 4, wherein the first and second vertical reflectors comprise a metallic tape.

8. The solid state backlight unit of claim 4, wherein the first vertical reflector is configured to reflect light to the second vertical reflector and wherein the second vertical reflector is configured to reflect light to the first vertical reflector.

9. A solid state backlight unit, comprising:

at least one solid state emitter configured to radiate light;

a diffuse reflector configured to reflect a first portion of the light directly radiated from the at least one emitter and that includes at least one aperture that is configured to receive the at least one solid state emitter;

a first vertical reflector including a substantially specularly reflective surface configured to reflect a second portion of the light radiated from the at least one emitter;

a second vertical reflector configured to reflect a third portion of the light radiated from the at least one emitter; and

a diffuser that is configured to be substantially parallel to a display panel and that is configured to partially transmit the light radiated from the at least one emitter, the reflected first portion, the reflected second portion and the reflected third portion to the display panel.

10. A solid state backlight unit, comprising:

a first solid state emitter and a second solid state emitter that are configured to radiate light;

a diffuse reflector arranged to reflect a first portion of the light radiated from the first and second solid state emitters;

a first vertical reflector arranged to reflect a second portion of the light directly radiated from the first solid state emitter; and

a second vertical reflector that is positioned between a first optical cavity that includes the first solid state emitter and a second optical cavity that includes the second solid state emitter,

wherein the first vertical reflector comprises a substantially specularly reflective surface.

11. The solid state backlight unit of claim 10, further comprising a diffuser arranged to partially transmit the light directly radiated from the at least one emitter, the reflected first portion, the reflected second portion and the reflected third portion.

12. The solid state backlight unit of claim 11, wherein the first and second vertical reflectors are substantially perpendicular to the diffuse reflector and wherein the first vertical reflector is substantially parallel to the second vertical reflector.

13. The solid state backlight unit of claim 11, wherein the diffuser is substantially parallel to the diffuse reflector.

14. The solid state backlight unit of claim 10, wherein the first and second vertical reflectors comprise a multilayer optical film.

15. The solid state backlight unit of claim 10, wherein the first and second vertical reflectors comprise a metallic tape.

16. The solid state backlight unit of claim 10, wherein the first vertical reflector is configured to reflect light to the second vertical reflector and wherein the second vertical reflector is configured to reflect light to the first vertical reflector.

17. A lighting panel, comprising:

a plurality of solid state emitters on a first surface;

a first vertical reflector that extends from the first surface, wherein the first vertical reflector is oriented substantially perpendicular to the first surface, and wherein the first vertical reflector is positioned adjacent a first side of the plurality of solid state emitters;

a second vertical reflector that extends from the first surface, wherein the second vertical reflector is positioned between a first emitter of the plurality of solid state emitters and a second emitter of the plurality of solid state emitters; and

a diffuse reflector arranged to reflect a portion of the light radiated from the first emitter,

wherein the first vertical reflector comprises a substantially specularly reflective surface.

18. The lighting panel of claim 17, wherein the second vertical reflector includes a first reflective surface on a first side of the second vertical reflector and a second reflective surface on a second side of the second vertical reflector that is opposite the first side.

19. The lighting panel of claim 17,

wherein the first vertical reflector is configured to reflect a first portion of light radiated from the first emitter;

wherein the second vertical reflector comprises a substantially specularly reflective first surface that is configured to reflect a second portion of light radiated from the first emitter and a substantially specularly reflective second surface that is configured to reflect a first portion of light radiated from the second emitter.

20. The lighting panel of claim 19, wherein at least one of the substantially specularly reflective surface of the first vertical reflector, the substantially specularly reflective first surface of the second vertical reflector and the substantially specularly reflective second surface of the second vertical reflector includes a specularly reflective component.

21. The lighting panel of claim 17, further comprising a third vertical reflector that extends from the first surface, wherein the third vertical reflector is oriented substantially perpendicular to the first surface, and wherein the third vertical reflector is positioned adjacent a second side of the plurality of solid state emitters that is opposite the first side of the plurality of solid state emitters.

22. The lighting panel of claim 17, further comprising:

a diffuser arranged to partially transmit the light directly radiated from the first emitter and the reflected portion from the diffuse reflector.