Strip lighting apparatus and method

• US 6,637,924 B2
• Filed: 11/14/2001
• Issued: 10/28/2003
• Est. Priority Date: 11/15/2000
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Teledyne Lighting & Display Products, Inc. (Teledyne Technologies Incorporated)
• Inventors: Pelka, David G., Parkyn, William A.
• Primary Examiner(s): Husar, Stephen
• Assistant Examiner(s): PAYNE, SHARON E
• Application Number:
  US09/993,286
• Publication Number:
  US 20020114168A1
• Time in Patent Office: 713 Days
• Field of Search: 362/551, 362/555, 362/558, 362/560, 362/227, 362/235, 362/243, 362/245, 362/246, 362/327, 362/511, 385/149, 385/901, 385/123, 359/618, 359/619, 359/621
• US Class Current: 362/555
• CPC Class Codes: F21S 43/237 rod-shaped
• CPC Class Codes: F21S 43/245 emitting light from one or more of its major surfaces
• CPC Class Codes: F21S 43/247 with a single light source being coupled into the light guide
• CPC Class Codes: F21S 43/249 with two or more light sources being coupled into the light guide
• CPC Class Codes: F21Y 2103/00 Elongate light sources, e.g. fluorescent tubes
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre

Abstract

An illumination apparatus comprises an elongated waveguide having proximal and distal ends and a central longitudinal axis. The waveguide includes an elongated forward side for outputting light and an elongated rearward side having an elongated reflective surface for reflecting light towards the forward side. A light source such as a solid state light emitter may be situated on the proximal end of the waveguide introduces light into the waveguide in the form of a beam which propagates from the proximal end to the distal end. Light traveling within the waveguide is reflected from the reflective surface along the elongated rearward side towards the forward side for viewing.

Claims

1. An illumination apparatus, comprising:

an elongated waveguide having proximal and distal ends and a central longitudinal axis, said waveguide comprising an elongated forward side for outputting light and an elongated rearward side for reflecting light towards the forward side, said rearward side comprising an elongated reflective surface;

a source of light comprising a solid state light emitter on the proximal end of the waveguide; and

an optical collimating element disposed between the waveguide and the source of light, which introduces light into the waveguide in the form of a substantially collimated beam having a divergence angle a, said waveguide having a width at the distal end approximately equal to 2 L tan (α

), where L is the length of the waveguide between said ends.

2. The illumination apparatus of claim 1, wherein said waveguide has an asymmetric cross-section perpendicular to said central longitudinal axis and said width corresponds to a smallest width.

3. The illumination apparatus of claim 1, wherein said solid state light emitter comprises a light emitting diode (LED).

4. The illumination apparatus of claim 3, wherein said source of light further comprises at least one lens for coupling light from said light source into said elongate waveguide.

5. The illumination apparatus of claim 3, wherein said source of light further comprises a nonimaging optical element for coupling light from said light source into said elongate waveguide.

6. The illumination apparatus of claim 1, wherein said elongate reflective surface is diffusely reflective to scatter light propagating within said waveguide out said forward side through said elongate concave transmissive output surface.

7. The illumination apparatus of claim 6, wherein said elongate reflective surface includes a diffusely reflective layer formed thereon.

8. The illumination apparatus of claim 1, wherein said distal end has a reflective surface that reflects light back toward said proximal end.

9. The illumination apparatus of claim 8, wherein said width corresponds to said width of said reflective surface.

10. The illumination apparatus of claim 8, wherein said reflecting surface is oriented at a non-perpendicular angle with respect to said longitudinal axis.

11. The illumination apparatus of claim 1, wherein said elongate waveguide comprises material substantially optically transmissive to visible light.

12. The illumination apparatus of claim 11, wherein said elongate waveguide comprises material selected from the group consisting essentially of plastic and glass.

13. The illumination apparatus of claim 12, wherein said elongate waveguide comprises material selected from the group consisting essentially of acrylic, polycarbonate, and silicone.

14. The illumination apparatus of claim 1, wherein said elongate waveguide has a length ranging between about 4 inches to about 8 feet.

15. The illumination apparatus of claim 14, wherein said elongate waveguide has a width perpendicular to said length ranging between about ¼

inch to about 2 inches.