Illumination apparatus confining light by total internal reflection and methods of forming the same

• US 8,840,276 B2
• Filed: 10/22/2013
• Issued: 09/23/2014
• Est. Priority Date: 11/16/2011
• Status: Active Grant

• Current Assignee: Oree Advanced Illumination Solutions Ltd.
• Original Assignee: Oree, Inc.
• Inventors: Shani, Yosi, Fine, Eran, Schiffmann, Baruch, Arbiv, Dafna B., Badihi, Avner, Segal, Gadi
• Primary Examiner(s): Green, Tracie Y
• Application Number:
  US14/060,145
• Publication Number:
  US 20140119025A1
• Time in Patent Office: 336 Days
• Field of Search: 362/555, 362/269.01, 313500-512
• US Class Current: 362/296.01
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: G02B 6/0003 the light guides being doped with fluorescent agents
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• 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: G02B 6/0025 Diffusing sheet or layer; Prismatic sheet or layer
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02B 6/009 of the light source in the package G02B6/0021 takes precedence
• CPC Class Codes: G02B 6/0091 of the light source relative to the light guide G02B6/0021 takes precedence
• 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 33/483 Containers
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

In various embodiments, an illumination apparatus includes an air gap between a sub-assembly and a waveguide attached thereto at a plurality of discrete attachment points, as well as a bare-die light-emitting diode encapsulated by the waveguide.

Claims

1. An illumination device comprising:

a waveguide;

a sub-assembly attached to a first surface of the waveguide only at a plurality of discrete attachment points, an air gap separating the first surface of the waveguide and the sub-assembly between the plurality of discrete attachment points;

a light-emitting diode (LED) disposed over the sub-assembly and at least partially disposed within the waveguide, light emitted by the LED being in-coupled into the waveguide; and

a reflector disposed over at least a portion of a second surface of the waveguide to confine light within the waveguide.

2. The illumination device of claim 1, wherein at least one of the discrete attachment points comprises a substantially rigid joining element for facilitating alignment of the waveguide with the sub-assembly.

3. The illumination device of claim 1, further comprising, disposed over the LED, an in-coupling element for in-coupling light emitted by the LED into the waveguide.

4. The illumination device of claim 3, wherein the in-coupling element comprises at least one of a reflector, a prism, or one or more scattering elements.

5. The illumination device of claim 1, wherein the LED comprises a bare-die LED.

6. The illumination device of claim 1, wherein the LED consists essentially of a bare-die LED.

7. The illumination device of claim 1, further comprising a phosphor for converting a light emitted by the LED to light having a different wavelength.

8. The illumination device of claim 1, wherein the second surface is opposite the first surface.

9. The illumination device of claim 1, wherein the waveguide defines a recess in the first surface, and the LED is at least partially disposed within the recess.

10. The illumination device of claim 9, further comprising at least one index-matching material filling at least a portion of the recess.

11. The illumination device of claim 10, wherein a free surface of at least one said index-matching material in the recess is spaced away from the sub-assembly, thereby defining a second air gap between the sub-assembly and the free surface.

12. The illumination device of claim 11, wherein the free surface of the at least one index-matching material is substantially parallel to the first surface of the waveguide.

13. The illumination device of claim 1, wherein the sub-assembly comprises a metal-core printed circuit board.

14. The illumination device of claim 1, wherein the waveguide comprises, opposite the first surface, an emission surface for emitting light in-coupled into the waveguide.

15. The illumination device of claim 14, wherein the first surface and the emission surface are substantially planar.

16. The illumination device of claim 14, wherein the waveguide comprises (i) an in-coupling region in which light emitted by the LED is in-coupled into the waveguide, and (ii) an out-coupling region, discrete from the in-coupling region, from which light is out-coupled through the emission surface.

17. The illumination device of claim 16, wherein the out-coupling region is laterally spaced away from the LED.

18. The illumination device of claim 1, wherein the waveguide comprises, adjoining and not parallel to the first surface, an emission surface for emitting light in-coupled into the waveguide.

19. The illumination device of claim 18, wherein the first surface is substantially perpendicular to the emission surface.

20. The illumination device of claim 1, wherein an air gap is disposed between the second surface of the waveguide and the reflector.