Lighting structure having variable transmissivity internal light guide illumination

• US 5,186,530 A
• Filed: 11/22/1991
• Issued: 02/16/1993
• Est. Priority Date: 11/22/1991
• Status: Expired due to Term

• Current Assignee: CAMCAR Intellectual Properties, LLC
• Original Assignee: TIR Systems Limited (Koninklijke Philips N.V.)
• Inventors: Whitehead, Lorne A.
• Primary Examiner(s): Ostrager, Allen M.
• Application Number:
  US07/796,305
• Time in Patent Office: 452 Days
• Field of Search: 362/26, 362/31, 362/32
• US Class Current: 362/627
• CPC Class Codes: G02B 6/001 the light being emitted along at least a portion of the lateral surface of the fibre
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/032 with non solid core or cladding G02B6/02295 takes precedence
• CPC Class Codes: G02B 6/10 of the optical waveguide type G02B6/02, G02B6/24 take precedence; devices or arrangements for the control of light by electric, magnetic, electro-magnetic or acoustic means G02F1/00; transferring the modulation of modulated light G02F2/00; optical logic elements G02F3/00; optical analogue/digital converters G02F7/00
• CPC Class Codes: G09F 2013/1831 using more than one light source

Abstract

A hollow lighting structure having an optically transmissive light emitting surface. At least one light guide extends within the structure. A light source emits light into the light guide. The light guide'"'"'s light transmissivity is varied as a function of position on the surface of the light guide such that the angular and spatial distribution of light emitted from the light guide yields a predetermined distribution of light intensity as a function of position on the light emitting surface. The predetermined distribution of light intensity is preferably substantially uniform at all points on the light emitting surface.

Claims

1. A lighting device, comprising:

(a) a hollow structure having an optically transmissive light emitting surface;

(b) at least one light guide extending within said structure; and

,

(c) a light source for emitting light into said light guide;

wherein the light transmissivity of said light guide is varied as a function of position on the surface of said light guide such that the angular and spatial distribution of light emitted from said light guide results in a predetermined distribution of light intensity as a function of position on said light emitting surface.

2. A lighting device as defined in claim 1, wherein said predetermined distribution of light intensity is substantially uniform at all points on said light emitting surface.

3. A lighting device as defined in claim 2, wherein said light guide further comprises a sheet of material flexibly deformable from an initial laid-flat configuration into a curved, assembled configuration.

4. A lighting device as defined in claim 3, further comprising a patterned metallic film on said light guide for producing said transmissivity variation.

5. A lighting device as defined in claim 4, wherein said film imparts substantial longitudinal specular reflectivity to said light guide.

6. A lighting device as defined in claim 5, wherein said light source is located outside said structure.

7. A lighting device as defined in claim 6, wherein light source emits light into said light guide through a transparent window in said structure.

8. A lighting device as defined in claim 1, wherein said light guide further comprises a sheet of material flexibly deformable from an initial laid-flat configuration into a curved, assembled configuration.

9. A lighting device as defined in claim 8, further, comprising a patterned metallic film on said light guide for producing said transmissivity variation.

10. A lighting device as defined in claim 9, wherein said film imparts substantial longitudinal specular reflectivity to said light guide.

11. A lighting device as defined in claim 10, wherein said light source is located outside said structure.

12. A lighting device as defined in claim 11, wherein light source emits light into said light guide through a transparent window in said structure.

17. A lighting device as defined in claim 2, further comprising a patterned metallic film on said light guide for producing said transmissivity variation.

18. A lighting device as defined in claim 17, wherein said film imparts substantial longitudinal specular reflectivity to said light guide.

19. A lighting device as defined in claim 18, wherein said light source is located outside said structure.

20. A lighting device as defined in claim 19, wherein light source emits light into said light guide through a transparent window in said structure.

21. A lighting device as defined in claim 2, wherein said light source is located outside said structure.

22. A lighting device as defined in claim 21, wherein light source emits light into said light guide through a transparent window in said structure.

23. A lighting device as defined in claim 3, wherein said light source is located outside said structure.

24. A lighting device as defined in claim 23, wherein light source emits light into said light guide through a transparent window in said structure.

25. A lighting device as defined in claim 4, wherein said light source is located outside said structure.

26. A lighting device as defined in claim 25, wherein light source emits light into said light guide through a transparent window in said structure.

27. A lighting device as defined in claim 8, wherein said light source is located outside said structure.

28. A lighting device as defined in claim 27, wherein light source emits light into said light guide through a transparent window in said structure.

29. A lighting device as defined in claim 9, wherein said light source is located outside said structure.

30. A lighting device as defined in claim 29, wherein light source emits light into said light guide through a transparent window in said structure.

31. A lighting device as defined in claim 1, wherein said light source is located outside said structure.

32. A lighting device as defined in claim 31, wherein light source emits light into said light guide through a transparent window in said structure.

35. A lighting device as defined in claim 17, wherein said light source is located outside said structure.

36. A lighting device as defined in claim 35, wherein light source emits light into said light guide through a transparent window in said structure.

37. A lighting device as defined in claim 4, wherein said light guide has a substantially curved light emitting surface.

38. A lighting device as defined in claim 37, wherein said curved light emitting surface subtends an arc exceeding 90°

.

13. A lighting device as defined in claim further comprising a patterned metallic film on said light guide for producing said transmissivity variation.

14. A lighting device as defined in claim 13, wherein said film imparts substantial longitudinal specular reflectivity to said light guide.

15. A lighting device as defined in claim 14, wherein said light source is located outside said structure.

16. A lighting device as defined in claim 15, wherein light source emits light into said light guide through a transparent window in said structure.

33. A lighting device as defined in claim 13, wherein said light source is located outside said structure.

34. A lighting device as defined in claim 33, wherein light source emits light into said light guide through a transparent window in said structure.