Back lighting device

• US 5,947,578 A
• Filed: 10/24/1995
• Issued: 09/07/1999
• Est. Priority Date: 10/24/1995
• Status: Expired due to Fees

• Current Assignee: NU-Tech & Engineering, Inc.
• Original Assignee: NU-Tech & Engineering, Inc.
• Inventors: Ayres, John A.
• Primary Examiner(s): CARIASO, ALAN B
• Application Number:
  US08/547,648
• Time in Patent Office: 1,414 Days
• Field of Search: 362/26, 362/27, 362/31, 362/255, 362/260, 362/330, 362/226, 362/267, 362/268, 362/327
• US Class Current: 362/629
• 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 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02B 6/0065 Manufacturing aspects; Material aspects
• CPC Class Codes: Y10T 156/1064 Partial cutting [e.g., grooving or incising]

Abstract

A back lighting device includes a light waveguide having generally planar upper and lower surfaces, a light module having a lamp member encapsulated between the upper and lower surfaces, a specular reflective material applied about the waveguide lower surface, and a light extracting material applied about the waveguide upper surface. The waveguide can be mounted in a user specific frame to allow high volume usage of a common waveguide element.

Claims

1. A back lighting device comprising:

a light waveguide having generally planar upper and lower surfaces and including a lamp receiving aperture through the waveguide and connecting said planar surfaces;

a light module having a lamp member, said lamp member disposed within said aperture between said upper and lower surfaces and within and closely coupled to said waveguide;

a specular reflective material applied onto said waveguide lower surface; and

a light extracting material applied onto said waveguide upper surface;

said back lighting device being devoid of any light transition area between the light waveguide and the lamp member for transmitting light between said lamp member and said light waveguide.

2. The back lighting device of claim 1 wherein said waveguide is of a plastics material.

3. The back lighting device of claim 2 wherein said plastics material comprises one of acrylic, polystyrene, and polycarbonate.

4. The back lighting device of claim 1 wherein said lamp member is encapsulated in said aperture between said upper and lower surfaces by an optical grade potting adhesive in said lamp receiving aperture.

5. The back lighting device of claim 1 wherein said light module includes an electrical lead frame electrically connected to and mounting said lamp member.

6. The back lighting device of claim 5 wherein said electrical lead frame comprises one of phosphor bronze, beryllium copper, and a plated conductor.

7. The back lighting device of claim 6 wherein said lamp member includes an incandescent surface mount lamp.

8. The back lighting device of claim 7 wherein said surface mount incandescent lamp includes a reflector portion for reflecting light generated thereby into said waveguide.

9. The back lighting device of claim 1 wherein said light extracting material includes a light scattering element.

10. The back lighting device of claim 9 wherein said light scattering element includes spaced apart light diffusing elements applied so as to form a light extracting gradient of increasing density in a direction progressing away from said lamp member.

11. The back lighting device of claim 10 wherein said light scattering element is paint.

12. The back lighting device of claim 10 wherein said light scattering element is ink.

13. The back lighting device of claim 10 wherein said light scattering element is defined by a film having a light extracting gradient.

14. The back lighting device of claim 1 comprising:

light shaping optics comprising one of concentrating lenses, dispersing lenses and ray deflectors extending between said upper and lower surfaces of said waveguide for redistributing within the waveguide light from said lamp member.

15. The back lighting device of claim 14 wherein said light shaping optics are slots cut into said waveguide through said upper and lower surfaces.

16. The back lighting device of claim 1 comprising a frame having inside edges for mounting said waveguide.

17. The back lighting device of claim 16 wherein said frame inner edges are diffusively reflective.

18. The back lighting device of claim 17 wherein said frame includes said specular reflective material.

19. A back lighting device comprising:

a light waveguide having generally planar upper and lower surfaces;

a light module having a lamp member, said lamp member disposed within said light waveguide between said upper and lower surfaces and within and closely coupled to said waveguide, said light module including an electrical lead frame electrically connected to and mounting said lamp member;

a specular reflective material applied onto said waveguide lower surface; and

a light extracting material applied onto said waveguide upper surface;

said back lighting device being devoid of any light transition area between the light waveguide and the lamp member for transmitting light between said lamp member and said light waveguide.

20. The back lighting device of claim 19 wherein said electrical lead frame comprises one of phosphor bronze, beryllium copper, and a plated conductor.

21. The back lighting device of claim 20 wherein said lamp member includes an incandescent surface mount lamp.

22. The back lighting device of claim 21 wherein said surface mount incandescent lamp includes a reflector portion for reflecting light generated thereby into said waveguide.

23. The back lighting device of claim 19 comprising:

an optical grade adhesive potting said lamp member into said waveguide.