Phosphor based light sources having a non-planar long pass reflector

• US 7,091,653 B2
• Filed: 12/02/2003
• Issued: 08/15/2006
• Est. Priority Date: 01/27/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wheatley, John A., Ouderkirk, Andrew J.
• Primary Examiner(s): Williams, Joseph
• Assistant Examiner(s): QUARTERMAN, KEVIN J
• Application Number:
  US10/727,072
• Publication Number:
  US 20040144987A1
• Time in Patent Office: 987 Days
• Field of Search: 313/502, 313/512, 313/113, 257/98, 257/99, 257/100, 362/800
• US Class Current: 313/113
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01077 Iridium [Ir]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light source includes an LED that emits excitation light, an optically transparent body, a phosphor material positioned to receive the excitation light and disposed on or in the optically transparent body, the phosphor material emitting visible light when illuminated with the excitation light, and a non-planar flexible multilayer reflector that reflects the excitation light and transmits visible light. The non-planar polymeric multilayer reflector is positioned to reflect LED light onto the phosphor material.

Claims

1. A light source, comprising:

an LED that emits excitation light;

an optically transparent body;

a phosphor material positioned to receive the excitation light and disposed on or in the optically transparent body, the phosphor material emitting visible light when illuminated with the excitation light; and

a non-planar flexible multilayer reflector that reflects the excitation light and transmits visible light, the non-planar flexible multilayer reflector being positioned to reflect LED light onto the phosphor material.

2. The light source according to claim 1, wherein the non-planar flexible multilayer reflector comprises polymeric material.

3. The light source according to claim 1, wherein the non-planar flexible multilayer reflector comprises alternating layers of a first and second thermoplastic polymer and wherein at least some of the layers are birefringent.

4. The light source according to claim 1, wherein the phosphor material is uniformly disposed on or in the optically transparent body.

5. The light source according to claim 1, wherein the phosphor material is non-uniformly disposed on or in the optically transparent body.

6. The light source according to claim 1, wherein the phosphor material is disposed within the optically transparent body adjacent the LED and the optically transparent body has a second region spaced away from the LED where phosphor material is not present.

7. The light source according to claim 1, wherein the phosphor material is disposed within the optically transparent body and spaced away from the LED.

8. The light source according to claim 1, wherein the phosphor material is disposed on the optically transparent body and the phosphor material has a first thickness or first density that is greater at a first angle normal to the excitation light than a second thickness or second density at a second angle non-normal to the excitation light.

9. The light source according to claim 1, wherein the phosphor material is disposed on the optically transparent body and the non-planar flexible multilayer reflector is disposed on the phosphor material.