Side emitting LED and lens

• US 6,679,621 B2
• Filed: 06/24/2002
• Issued: 01/20/2004
• Est. Priority Date: 06/24/2002
• Status: Expired due to Term

• Current Assignee: Lumileds LLC (Apollo Global Management, Inc.)
• Original Assignee: Lumileds Lighting US LLC (Apollo Global Management, Inc.)
• Inventors: West, Robert S., Sasser, Gary D., Stewart, James W.
• Primary Examiner(s): CARIASO, ALAN B
• Application Number:
  US10/179,600
• Publication Number:
  US 20030235050A1
• Time in Patent Office: 575 Days
• Field of Search: 362/308, 362/309, 362/327, 362/332, 362/336, 362/337, 362/338, 362/340, 313/512
• US Class Current: 362/327
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• 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 19/0061 the light source comprising a LED semiconductor devices with at least one potential-jump barrier or surface barrier specially adapted for light emission H01L33/00
• CPC Class Codes: G02B 19/0071 adapted to illuminate a complete hemisphere or a plane extending 360 degrees around the source
• CPC Class Codes: G02B 27/0955 Lenses lenses per se G02B3/00
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• 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 6/0033 Means for improving the coupling-out of light from the light guide
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A lens comprises a bottom surface, a reflecting surface, a first refracting surface obliquely angled with respect to a central axis of the lens, and a second refracting surface extending as a smooth curve from the bottom surface to the first refracting surface. Light entering the lens through the bottom surface and directly incident on the reflecting surface is reflected from the reflecting surface to the first refracting surface and refracted by the first refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens. Light entering the lens through the bottom surface and directly incident on the second refracting surface is refracted by the second refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens. The lens may be advantageously employed with LEDs, for example, to provide side-emitting light-emitting devices. A lens cap attachable to a lens is also provided.

Claims

1. A lens comprising:

a bottom surface;

a reflecting surface;

a first refracting surface obliquely angled with respect to a central axis of the lens; and

a second refracting surface extending as a smooth curve from the bottom surface to the first refracting surface;

wherein light entering the lens through the bottom surface and directly incident on the reflecting surface is reflected from the reflecting surface to the first refracting surface and refracted by the first refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens, and

wherein light entering the lens through the bottom surface and directly incident on the second refracting surface is refracted by the second refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens.

2. The lens of claim 1, wherein at least a portion of the bottom surface is perpendicular to the central axis.

3. The lens of claim 1, wherein the reflecting surface reflects by total internal reflection.

4. The lens of claim 1, wherein the reflecting surface is a surface of a funnel-shaped portion of the lens.

5. The lens of claim 1, wherein the reflecting surface, the first refracting surface, and the second refracting surface are each portions of surfaces having cylindrical symmetry about the central axis.

6. A light-emitting device comprising:

a light-emitting semiconductor device; and

a lens comprising;

a bottom surface;

a reflecting surface;

a first refracting surface obliquely angled with respect to a central axis of the lens; and

a second refracting surface extending as a smooth curve from the bottom surface to the first refracting surface;

wherein light emitted by the semiconductor device, entering the lens through the bottom surface, and directly incident on the reflecting surface is reflected from the reflecting surface to the first refracting surface and refracted by the first refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens, and

wherein light emitted by the semiconductor device, entering the lens through the bottom surface, and directly incident on the second refracting surface is refracted by the second refracting surface to exit the lens in a direction substantially perpendicular to the central axis of the lens.

7. The light-emitting device of claim 6, wherein at least a portion of the bottom surface of the lens is perpendicular to the central axis.

8. The light-emitting device of claim 6, wherein the reflecting surface reflects by total internal reflection.

9. The light-emitting device of claim 6, wherein the reflecting surface is a surface of a funnel-shaped portion of the lens.

10. The light-emitting device of claim 6, wherein the reflecting surface, the first refracting surface, and the second refracting surface of the lens are each portions of surfaces having cylindrical symmetry about the central axis.

11. A lens cap comprising:

a bottom surface attachable to a lens;

a reflecting surface;

a first refracting surface obliquely angled with respect to a central axis of the lens cap; and

a second refracting surface extending as a smooth curve from the bottom surface to the first refracting surface;

wherein light entering the lens cap through the bottom surface and directly incident on the reflecting surface is reflected from the reflecting surface to the first refracting surface and refracted by the first refracting surface to exit the lens cap in a direction substantially perpendicular to the central axis of the lens, and

wherein light entering the lens cap through the bottom surface and directly incident on the second refracting surface is refracted by the second refracting surface to exit the lens cap in a direction substantially perpendicular to the central axis of the lens cap.

12. The lens cap of claim 11, wherein at least a portion of the bottom surface is perpendicular to the central axis.

13. The lens cap of claim 11, wherein the reflecting surface reflects by total internal reflection.

14. The lens cap of claim 11, wherein the reflecting surface is a surface of a funnel-shaped portion of the lens cap.

15. The lens cap of claim 11, wherein the reflecting surface, the first refracting surface, and the second refracting surface are each portions of surfaces having cylindrical symmetry about the central axis.