Solid state array modules for general illumination

• US 8,764,226 B2
• Filed: 08/01/2012
• Issued: 07/01/2014
• Est. Priority Date: 06/25/2008
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Roberts, John, Chaloupecky, Robert, You, Chenhua
• Primary Examiner(s): BANNAN, JULIE A
• Application Number:
  US13/564,466
• Publication Number:
  US 20120320587A1
• Time in Patent Office: 699 Days
• Field of Search: 362231-232, 362/311.01, 362/311.02, 362/249.11, 362/249.02, 362242-248, 362/235, 362/326, 362/612, 362/613, 362/616, 36221701-21705, 362/217.1, 362/227, 362/218
• US Class Current: 362/232
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 15/013 the housing being an extrusion
• CPC Class Codes: F21V 19/001 the light sources being semiconductors devices, e.g. LEDs
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 5/002 using microoptical elements for redirecting or diffusing light
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

An illumination module includes a longitudinal support member including a base portion and a pair of sidewalls extending from the base portion that together define a channel that extends in a longitudinal direction. A printed circuit board (PCB) on the base portion extends in the longitudinal direction within the channel. A plurality of light emitting diodes (LEDs) are on the PCB in a linear array. A reflective sheet is within and extends across the channel, and includes a plurality of holes that correspond with locations of the LEDs on the PCB, and the LEDs are positioned in the holes. An optical film extends across the channel above the reflective sheet and defines an optical cavity between the reflective sheet and the optical film. The optical film, the reflective sheet and the sidewalls of the support member recycle light in the optical cavity.

Claims

1. An illumination module, comprising:

a support member;

a plurality of light emitting diodes (LEDs) on the support member;

a reflective sheet on the support member, wherein the reflective sheet includes a plurality of holes therein that are arranged to correspond with locations of the LEDs on the support member, and wherein the LEDs are at least partially positioned within the holes; and

an optical film above the support member and defining an optical cavity between the reflective sheet and the optical film into which light is emitted by the LEDs, wherein the optical film and the reflective sheet are configured to recycle light in the optical cavity by reflecting some light emitted by the LEDs back into the optical cavity and transmitting some light emitted by the LEDs out of the optical cavity;

wherein the plurality of LEDs comprises LEDs having chromaticities within about a seven step Macadam ellipse about a point on a blackbody radiation curve on a 1931 CIE chromaticity space from a correlated color temperature of 2500K to 8000K, and wherein the LEDs have different optical characteristics, wherein chromaticities of the LEDs are selected so that a combined light generated by a mixture of light from the LEDs comprises light having about a target chromaticity; and

wherein each of the LEDs of the metameric pair has a luminosity that is inversely proportional to a distance of a chromaticity of the LED to the target chromaticity in a two-dimensional chromaticity space.

2. The illumination module of claim 1, wherein the optical film comprises a first optical film and the optical cavity comprises a first optical cavity, the illumination module further comprising:

a second optical film above the first optical film and defining a second optical cavity wherein the first optical film and the second optical film are configured to recycle light in the second optical cavity.

3. The illumination module of claim 2, wherein the first optical film comprises a brightness enhancement film and the second optical film comprises an optical diffuser.

4. The illumination module of claim 2, wherein the reflective sheet comprises a diffuse reflector.

5. The illumination module of claim 2, further comprising:

a third optical film in the first optical cavity between the first optical film and the reflective sheet.

6. The illumination module of claim 5, wherein the third optical film comprises an optical diffuser.

7. The illumination module of claim 1, wherein the optical film comprises a convex diffuser sheet that is bowed away from the support member.

8. The illumination module of claim 1, wherein the reflective sheet has a curved cross section.

9. The illumination module of claim 1, wherein the support member comprises a first support member, the illumination module further comprising:

a second support member, wherein the second support member is adjacent to the first support member, wherein the first support member and the second support member each comprise an electrical connector at respective adjacent ends thereof; and

a wire jumper connecting the electrical connectors.

10. The illumination module of claim 1, wherein each of the LEDs has about the same luminosity and has a chromaticity that is about the same distance from the target chromaticity in the two-dimensional chromaticity space.

11. The illumination module of claim 1, wherein the two-dimensional chromaticity space comprises a 1931 CIE chromaticity space or a 1976 CIE chromaticity space.