Total internal reflection lens with integrated lamp cover

• US 8,303,141 B2
• Filed: 12/17/2009
• Issued: 11/06/2012
• Est. Priority Date: 12/17/2009
• Status: Expired due to Fees

• Current Assignee: Ledengin, Inc. (Ams-Osram AG)
• Original Assignee: Ledengin, Inc. (Ams-Osram AG)
• Inventors: Jiang, Wu
• Primary Examiner(s): Williams, Joseph L
• Application Number:
  US12/640,432
• Publication Number:
  US 20110149581A1
• Time in Patent Office: 1,055 Days
• Field of Search: 362/338, 362/334, 362/335, 362/336, 362/337, 126/698, 126/699, 126/692, 126/688
• US Class Current: 362/338
• CPC Class Codes: F21K 9/233 specially adapted for generating a spot light distribution, e.g. for substitution of reflector lamps
• CPC Class Codes: F21V 17/12 by screwing
• CPC Class Codes: F21V 3/04 characterised by materials, surface treatments or coatings
• CPC Class Codes: F21V 5/002 using microoptical elements for redirecting or diffusing light
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2113/17 forming a single encapsulated light source
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0066 in the form of an LED array
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source

Abstract

A total internal reflection (TIR) lens has an integrated lamp cover adapted to a lamp of a desired form factor (e.g., PAR-38). The size and shape of the TIR lens can be adapted to optimize the light output of the lamp with little regard to the desired form factor. The integrated lamp cover can extend the front surface of the TIR lens in a direction transverse from the optical axis.

Claims

1. A lens assembly comprising:

a total internal reflection (TIR) body member having a first end, a second end opposite the first end, and an outer surface, the TIR body member being substantially cylindrically symmetric with respect to an optical axis, the outer surface having a tapered shape such that the TIR body member is wider at the second end than at the first end, the tapered shape providing total internal reflection to direct light from a light source position near the first end toward the second end; and

a cover member disposed at the second end of the TIR body member and integral with the TIR body member, the cover member having a width in a direction transverse to the optical axis that is greater than a widest diameter of the TIR body member and a thickness in a direction along the optical axis that is less than a thickness of the TIR body member.

2. The lens assembly of claim 1 wherein the thickness of the cover member is not more than about 10% of a total thickness of the lens assembly.

3. The lens assembly of claim 2 wherein the thickness of the cover member is between about 5% and about 10% of a total thickness of the lens assembly.

4. The lens assembly of claim 1 wherein the widest diameter of the TIR body member is not more than about 40% of the width of the cover member.

5. The lens assembly of claim 4 wherein the widest diameter of the TIR body member is between about 25% and about 40% of the width of the cover member.

6. The lens assembly of claim 1 wherein the TIR body member further includes an inner sidewall defining a central open channel that extends longitudinally from the first end to the second end, the central open channel being centered on and substantially symmetric with respect to the optical axis.

7. The lens assembly of claim 6 wherein the central open channel extends through the cover member.

8. The lens assembly of claim 7 wherein the inner sidewall and the outer surface of the TIR body member are shaped so as to provide mixing of light from a plurality of light emitting diodes within a light source.

9. The lens assembly of claim 7 wherein the inner sidewall is tapered at an angle between about 1°

and about 5°

relative to the optical axis, such that the open channel is wider at the second end than at the first end.

10. The lens assembly of claim 1 wherein the TIR body member and the cover member are made of poly(methylmethacrylate).

11. The lens assembly of claim 1 further comprising a flange disposed near a peripheral edge of the front end face member and extending rearwardly therefrom.

12. The lens assembly of claim 11 further comprising a plurality of mounting posts extending rearwardly from the flange.

13. The lens assembly of claim 12 wherein the flange and the mounting posts are formed integrally with the cover member and the TIR body member.

14. The lens assembly of claim 1 wherein the cover member has a plurality of microlenses disposed in a front surface thereof.

15. The lens assembly of claim 1 wherein a front surface of the cover member is circular.

16. The lens assembly of claim 15 further comprising a plurality of mounting posts extending rearward from a region near a peripheral edge of the cover member.