High flux led assembly

• US 6,318,886 B1
• Filed: 02/11/2000
• Issued: 11/20/2001
• Est. Priority Date: 02/11/2000
• Status: Expired due to Term

• Current Assignee: Whelen Engineering Company Incorporated
• Original Assignee: Whelen Engineering Company Incorporated
• Inventors: Sousa, David J., Stopa, James L.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): WARD, JOHN A
• Application Number:
  US09/502,137
• Time in Patent Office: 648 Days
• Field of Search: 362/555, 362/545, 362/346, 362/347, 362/800, 362/241, 362/245
• US Class Current: 362/555
• CPC Class Codes: F21K 9/68 Details of reflectors forming part of the light source
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 29/85 characterised by the material liquid coolants F21V29/56
• CPC Class Codes: F21V 29/87 Organic material, e.g. filled polymer composites; Thermo-conductive additives or coatings therefor
• CPC Class Codes: F21V 31/00 Gas-tight or water-tight arrangements
• CPC Class Codes: F21V 7/0083 Array of reflectors for a cluster of light sources, e.g. arrangement of multiple light sources in one plane combination of two or more reflectors F21V7/0025
• CPC Class Codes: F21V 7/041 with conical or pyramidal surface
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 25/13 the devices being of a type provided for in group H01L33/00
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A high intensity light source employs a plurality of light emitting diodes associated with a unitary reflector subassembly. The reflector subassembly defines an array of frustoconical reflectors arranged in rows and columns with the adjacent reflectors of each row being connected by a diverging slot with reflective wall surfaces. The light emitting diodes are mounted on a printed circuit board which forms a component of heat sink subassembly.

Claims

1. A unitary reflector assembly for use with a plurality of light emitting diodes, said diodes each including an integral lens, said assembly comprising:

a plurality of generally concave reflectors, said reflectors each having an frustoconical surface which defines an axis, said reflectors being arranged in at least a first linear array, the wider diameter ends of said frustoconical surfaces defining a front face of the assembly; and

at least a first groove extending between adjacent reflectors of said linear array whereby said groove interrupts the frustoconical surfaces of adjacent of said reflectors, said groove having a base and being defined by walls which diverge from said base to said assembly front face.

2. The reflector assembly of claim 1, wherein the angle of divergence of said groove walls does not exceed 10°

.

3. The reflector assembly of claim 1, wherein said concave reflectors define a matrix comprising plural rows and plural columns, each pair of adjacent reflectors in each row being interconnected by a said groove.

4. The reflector assembly of claim 1, wherein the regions of said reflector assembly disposed between said wider diameter ends of said frustoconical surfaces comprises said front face of said assembly, said smaller diameter ends of said frustoconical surfaces in part defining apertures which extend through a back of said assembly, said assembly back being oppositely disposed from said assembly force, said apertures being sized to receive a lens of a light emitting diode.

5. The reflector assembly of claim 3, wherein the regions of said reflector assembly disposed between said wider diameter ends of said frustoconical surfaces comprises said front face of said assembly, said smaller diameter ends of said frustoconical surfaces in part defining apertures which extend through a back of said assembly, said assembly back being oppositely disposed from said assembly force, said apertures being sized to receive a lens of a light emitting diode.

6. The reflector assembly of claim 5, wherein the angle of divergence of said groove walls does not exceed 10°

.

7. The reflector assembly of claim 6, wherein the axes of said reflectors are substantially parallel.

8. The reflector assembly of claim 2, wherein the axes of said reflectors are substantially parallel.

9. A heat sink assembly for an array of light emitting diodes, said heat sink assembly comprising:

a printed circuit board, said circuit board being at least in part clad with copper on each of two opposite sides thereof, said copper cladding on at least a first side of said circuit board being etched to define passive electrical circuit components and heat absorption pads sized and shaped for affixation to individual light emitting diodes;

a plurality of copper plated holes extending through said board, said plating in said holes defining a heat transfer path between said heat absorption pads and the copper cladding on said second side of said circuit board;

a support member, said support member being comprised of a moldable thermally conductive material;

a heat conductive adhesive affixing a light emitting diode to at least some of said heat absorption pads on said printed circuit board; and

a heat conductive encapsulation material surrounding said circuit board and contacting each light emitting diode adhesively affixed thereto, said encapsulation material being in contact with said support member.

10. The assembly of claim 9, wherein said support member is comprised of a polycarbonate with a high thermal conductivity filler and wherein said adhesive comprises an epoxy.

11. An integrated, multiple emitter light assembly comprising:

a reflector subassembly comprising a plurality of generally concave reflectors, said reflectors each having an frustoconical surface which defines an axis, said reflectors being arranged in at least a first linear array, the wider diameter ends of said frustoconical surfaces defining a front face of the light assembly, the smaller diameter ends of said reflectors in part defining apertures which extend through the back of said reflector subassembly, at least a first groove extending between adjacent reflectors of said linear array whereby said grove interrupts the frustoconical surfaces of adjacent of said reflectors, said groove having a base and being defined by walls which diverge from said base to said reflector subassembly front face;

a printed circuit board, said circuit board being at least in part clad with copper on each of two opposite sides thereof, said copper cladding on at least a first side of said circuit board being etched to define passive electrical circuit components and heat absorption pads sized and shaped for affixation to individual light emitting diodes, said pads being in registration with said apertures;

a plurality of copper plated holes extending through said board, said plating in said holes defining a heat transfer path between said heat absorption pads and the copper cladding on said second side of said circuit board;

a support member, said support member being comprised of a moldable thermally conductive material;

a plurality of light emitting diodes, each of said diodes having an integral lens;

a heat conductive adhesive affixing a said individual light emitting diode to at least some of said heat absorption pads on said printed circuit board;

a heat conductive encapsulation material surrounding said circuit board and contacting each light emitting diode adhesively affixed thereto, said encapsulation material being in contact with said support member; and

means supporting said reflector subassembly with said light emitting diode lenses projecting through said apertures.

12. The reflector assembly of claim 11, wherein said concave reflectors define a matrix comprising plural rows and plural columns, each pair of adjacent reflectors in each row being interconnected by a said groove.

13. The reflector assembly of claim 12, wherein the angle of divergency of said groove walls does not exceed 10°

.

14. The reflector assembly of claim 13, wherein the axes of said reflectors are substantially parallel.