LED EMITTER WITH RADIAL PRISMATIC LIGHT DIVERTER

• US 20070139798A1
• Filed: 12/21/2005
• Published: 06/21/2007
• Est. Priority Date: 12/21/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Epstein, Kenneth
• Granted Patent: US 7,637,639 B2
• Time in Patent Office: Days
• US Class Current: 359/831
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 5/02 of prismatic shape F21V5/04 takes precedence
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21V 7/05 plane
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

An optical assembly includes a light emitting diode (LED) and a structured surface. The structured surface has a plurality of prismatic structures arranged radially with respect to a reference point, and is disposed relative to the LED such that the reference point is substantially aligned with a light emission axis of the LED. Arrays of such assemblies and backlights and displays including same are also disclosed.

Claims

1. An optical assembly, comprising:

a light emitting diode (LED) having a light emission axis; and

a structured surface comprising a plurality of prismatic structures arranged radially with respect to a reference point, the structured surface disposed relative to the LED such that the reference point is substantially aligned with the light emission axis.

2. The optical assembly of claim 1, wherein each of the prismatic structures has a substantially linear prism apex.

3. The optical assembly of claim 2, wherein each prism apex is parallel to a reference plane, the reference plane being perpendicular to the light emission axis.

4. The optical assembly of claim 2, wherein the prism apices are inclined in a conical arrangement relative to the light emission axis.

5. The optical assembly of claim 1, wherein each of the prismatic structures has a curved prism apex.

6. The optical assembly of claim 5, wherein the prism apices are inclined in a funnel arrangement relative to the light emission axis.

7. The optical assembly of claim 1, wherein each of the prismatic structures has a prism apex, and the prism apices substantially intersect at the reference point.

8. The optical assembly of claim 1, wherein each of the prismatic structures has a prism apex having a first end proximate the reference point, the first ends of the prism apices being spaced apart from the reference point.

9. The optical assembly of claim 8, wherein the diverting element also includes a funnel-shaped recess at the reference point, the first ends of the prism apices being arranged around the recess.

10. The optical assembly of claim 1, further comprising:

a reflective layer positioned to receive at least some LED light reflected by the a structured surface.

11. The optical assembly of claim 1, wherein the LED includes an LED die disposed within an encapsulant, and wherein the structured surface is disposed on the encapsulant.

12. The optical assembly of claim 11, wherein the structured surface is formed in an outer surface of the encapsulant.

13. The optical assembly of claim 11, wherein the structured surface is formed in a diverting element and is disposed on the encapsulant.

14. The optical assembly of claim 1, wherein the prismatic structures divert at least some light from the LED by total internal reflection.

15. The optical assembly of claim 1, wherein a given prismatic structure diverts at least some light from the LED by successive first and second reflections from adjacent first and second prismatic facets respectively.

16. The optical assembly of claim 1, wherein the structured surface includes a funnel-shaped recess having a rotationally symmetric shape about the light emission axis.

17. An array of optical assemblies according to claim 1.

18. The array of claim 17, further comprising:

a reflective layer disposed adjacent the LEDs.

19. The array of claim 17, wherein the diverting elements are formed on an optical film that extends over at least some of the LEDs.

20. A backlight comprising the optical assembly of claim 1.

21. A backlight comprising the array of claim 17.