METHODS OF FORMING DIRECT-LIT BACKLIGHTS HAVING LIGHT RECYCLING CAVITY WITH CONCAVE TRANSFLECTOR

• US 20070047228A1
• Filed: 08/24/2006
• Published: 03/01/2007
• Est. Priority Date: 08/27/2005
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Thompson, D., Kienitz, Scott, Schardt, Craig, Ostlie, Brian, Wheatley, John
• Application Number:
  US11/466,787
• Publication Number:
  US 20070047228A1
• Time in Patent Office: Days
• US Class Current: 362/237
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0021 for housing at least a part of the light source, e.g. by forming holes or recesses
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

Direct-lit backlights and associated methods and components are disclosed In one embodiment, a method of forming a direct-lit backlight having an output area includes providing a transflector that partially transmits and partially reflects incident light. The method further includes forming one or more recycling cavities that substantially fill the output area of the backlight, where forming the one or more recycling cavities includes forming the transflector into at least one concave structure that faces a back reflector of the backlight. The method further includes positioning at least one light source behind the output area to inject light into the one or more recycling cavities.

Claims

1. A method of forming a direct-lit backlight having an output area, comprising:

providing a transflector that partially transmits and partially reflects incident light;

forming one or more recycling cavities that substantially fill the output area of the backlight, wherein forming the one or more recycling cavities comprises forming the transflector into at least one concave structure that faces a back reflector of the backlight; and

positioning at least one light source behind the output area to inject light into the one or more recycling cavities.

2. The method of claim 1, wherein forming the transflector into at least one concave structure comprises attaching a first edge and a second edge of the transflector to the back reflector.

3. The method of claim 1, wherein forming the transflector into at least one concave structure comprises attaching a first edge of the transflector to a first sidewall of the backlight and a second edge of the transflector to a second sidewall of the backlight.

4. The method of claim 1, wherein forming the transflector into at least one concave structure comprises compressing the transflector between a first and second sidewall of the backlight.

5. The method of claim 1, wherein forming the transflector into at least one concave structure comprises:

scoring the transflector along an entire length of the transflector to form a first scored portion of the transflector; and

bending the transflector along the first scored portion to form two concave structures.

6. The method of claim 5, wherein forming one or more recycling cavities further comprises attaching the transflector to the back reflector along the first scored portion such that the first scored portion is in contact with the back reflector.

7. The method of claim 6, wherein forming one or more recycling cavities further comprises attaching a first edge and a second edge of the transflector to the back reflector.

8. The method of claim 6, wherein forming one or more recycling cavities further comprises attaching a first edge of the transflector to a first sidewall of the backlight and a second edge of the transflector to a second sidewall of the backlight.

9. The method of claim 5, wherein forming the transflector into at least one concave structure further comprises:

scoring the transflector along an entire length of the transflector to form a second scored portion of the transflector; and

bending the transflector along the second scored portion of the transflector to form three concave structures.

10. The method of claim 9, wherein forming one or more recycling cavities further comprises attaching the transflector to the back reflector along the first scored portion and the second scored portion such that the first scored portion and second scored portion are in contact with the back reflector.

11. The method of claim 1, wherein forming the transflector into at least one concave structure comprises:

folding the transflector along an entire length of the transflector to form a crease in the transflector; and

bending the transflector along the crease of the transflector to form at least two concave structures.

12. The method of claim 11, wherein forming one or more recycling cavities further comprises attaching the transflector to the back reflector along the crease such that the crease is in contact with the back reflector.

13. The method of claim 12, wherein forming one or more recycling cavities further comprises attaching a first edge and a second edge of the transflector to the back reflector.

14. The method of claim 12, wherein forming one or more recycling cavities further comprises attaching a first edge of the transflector to a first sidewall of the backlight and a second edge of the transflector to a second sidewall of the backlight.

15. The method of claim 1, wherein forming the transflector into at least one concave structure comprises:

attaching a first edge and a second edge of the transflector to the back reflector; and

attaching at least a portion of the transflector between the first edge and the second edge to the back reflector to form at least two concave structures in the transflector.

16. The method of claim 15, wherein attaching the at least a portion of the transflector between the first edge and the second edge to the back reflector comprises screwing two or more pins through the transflector into the back reflector.

17. The method of claim 16, further comprising positioning a diffuser plate proximate the output area of the backlight on the two or more pins.

18. A method of forming a direct-lit display system, comprising:

providing a display panel;

forming a direct-lit backlight, wherein forming the direct-lit backlight comprises;

providing a transflector that partially transmits and partially reflects incident light;

forming one or more recycling cavities that substantially fill the output area of the backlight, wherein forming the one or more recycling cavities comprises forming the transflector into a concave structure that faces a back reflector of the backlight; and

positioning at least one light source behind the output area to inject light into the one or more recycling cavities; and

illuminating the display panel with light from the direct-lit backlight.