Lamp

• US 20050073229A1
• Filed: 10/10/2003
• Published: 04/07/2005
• Est. Priority Date: 10/10/2002
• Status: Active Grant

• Current Assignee: REBO Lighting & Electronics GmbH (PTC Inc.)
• Original Assignee: REBO Lighting & Electronics GmbH (PTC Inc.)
• Inventors: Wimbert, Frank, Deichmuller, Horst
• Granted Patent: US 6,991,357 B2
• Time in Patent Office: Days
• US Class Current: 313/111
• CPC Class Codes: B60Q 1/302 mounted in the vicinity, e.g. in the middle, of a rear window
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/241 of complex shape
• CPC Class Codes: F21S 43/243 emitting light from one or more of its extremities
• CPC Class Codes: F21S 43/247 with a single light source being coupled into the light guide
• CPC Class Codes: F21S 43/40 characterised by the combination of reflectors and refractors
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lamp, in particular a motor vehicle lamp, comprises a light distribution device (14, 14′) into which the light of at least one light source (6) is fed in such a way as to produce a light flux which is firstly propagated through the light distribution device substantially parallel to a light exit surface defined thereby. Components are deflected out of the light flux by means of coupling-out structures (16, 16′) for delivery through the light exit surface. To achieve good illumination of the light-transmitting surface the coupling-out structures are a plurality of coupling-out layers which are arranged at spacings in succession in the direction of propagation of the light flux and which comprise a medium whose optical refractive index is different from that of the medium filling the intermediate spaces between said layers, wherein the coupling-out layers are so inclined relative to the propagation direction of the light flux at a predetermined angle that its main component passes through them without a substantial change in direction while a minor part is reflected towards the light exit surface.

Claims

1. A lamp, in particular a motor vehicle lamp, comprising a light distribution device into which the light of at least one light source is fed in such a way as to produce a light flux which is firstly propagated through the light distribution device substantially parallel to a light exit surface defined thereby and from which components are deflected by means of coupling-out structures for delivery through the light exit surface,

characterised in that

the coupling-out structures are a plurality of coupling-out layers which are arranged at spacings in succession in the direction of propagation of the light flux and which comprise a medium whose optical refractive index is different from that of the medium filling the intermediate spaces between said layers,

wherein the coupling-out layers are so inclined relative to the propagation direction of the light flux at a predetermined angle that its main component passes through them without a substantial change in direction while a minor part is reflected towards the light exit surface.

2. A lamp as set forth in claim 1 characterised in that the light distribution device is of a substantially linear and elongate configuration, wherein the propagation direction of the light flux extends in the longitudinal direction of the light distribution device.

3. A lamp as set forth in claim 2 characterised in that the light of at least one light source is fed into the elongate light distribution device from one of the ends thereof.

4. A lamp as set forth in claim 2 characterised in that the light of at least one light source is fed into the elongate light distribution device into a central region thereof.

5. A lamp as set forth in claim 1 characterised in that the light distribution device is oriented at least in a sector towards a center (Z) and that the propagation direction of the light flux extends in the radial direction with respect to the center (Z).

6. A lamp as set forth in claim 5 characterised in that the light of at least one light source is fed into the light distribution device from the center (Z).

7. A lamp as set forth in claim 5 characterised in that the light of at least one light source is fed into the light distribution device from a point spaced radially from the center (Z).

8. A lamp as set forth in claim 5 characterised in that the light distribution device is of a different configuration in various sectors around the center (Z).

9. A lamp as set forth in claim 8 characterised in that the coupling-out layers are at different radial spacings from each other in at least two different sectors.

10. A lamp as set forth in claim 8 characterised in that coupling-out layers in at least two different sectors are at different radial spacings from the center (Z).

11. A lamp as set forth in claim 1 characterised in that at least one light source is arranged in the plane of the light distribution device, that the light delivered thereby in the direction of the light exit surface passes directly therethrough and the light delivered thereby substantially parallel to the light exit surface forms the light flux through the coupling-out layers.

12. A lamp as set forth in claim 1 characterised in that at least one light source is arranged behind the light distribution device as viewed from the light exit surface and the light emanating therefrom is so deflected by a reflector arrangement that it forms the light flux through the coupling-out layers.

13. A lamp as set forth in claim 12 characterised in that there are provided a plurality of light fluxes which are propagated in different directions and associated with each of which is its own light distribution device of which each includes a plurality of coupling-out layers.

14. A lamp as set forth in claim 13 characterised in that at least two of the light fluxes are propagated towards each other.

15. A lamp as set forth in claim 14 characterised in that the at least two of the light fluxes at least partially pass through each other.

16. A lamp as set forth in claim 15 characterised in that the light distribution devices associated with the at least two light fluxes are arranged in interlocking relationship and that provided on the side of the two light distribution devices which is in opposite relationship to the light exit surface is a reflection device which reflects the parts of each light flux, which are reflected by the coupling-out layers of the light distribution device belonging to the respective other light flux towards same, towards the light exit surface.

17. A lamp as set forth in claim 13 characterised in that at least two of the light fluxes are propagated away from each other.

18. A lamp as set forth in claim 13 characterised in that at least two of the light fluxes are derived from one and the same light source.

19. A lamp as set forth in claim 13 characterised in that each of the plurality of light fluxes is derived from its own light source.

20. A lamp as set forth in claim 1 characterised in that provided for each light source is an optical imaging device which substantially parallelises the light flux before it is fed into the associated light distribution device.

21. A lamp as set forth in claim 1 characterised in that light distribution devices belonging to different light fluxes are arranged in mutually juxtaposed relationship as viewed from the light exit surface.

22. A lamp as set forth in claim 1 characterised in that light distribution devices belonging to different light fluxes are arranged in successive relationship as viewed from the light exit surface.

23. A lamp as set forth in claim 1 characterised in that the coupling-out layers of a light distribution device are combined to form groups which are arranged at a spacing from each other in the direction of propagation of the associated light flux and the number of coupling-out layers per group increases with increasing distance from the feed-in location into the light distribution device in question.

24. A lamp as set forth in claim 23 characterised in that the spacings of mutually adjacent groups of coupling-out layers decrease with increasing distance from the feed-in location into the light distribution device in question.

25. A lamp as set forth in claim 1 characterised in that the spacings of mutually adjacent coupling-out layers of a light distribution device decrease with increasing distance from the feed-in location.

26. A lamp as set forth in claim 1 characterised in that the coupling-out layers are formed by thin plates of a transparent material whose optical refractive index is different from that of the medium surrounding them.

27. A lamp as set forth in claim 26 characterised in that the coupling-out layers are integrally connected to each other.

28. A lamp as set forth in claim 27 characterised in that thin connecting legs of a transparent material which extend between the coupling-out layers transversely with respect to the propagation direction of the respective light flux are so provided that in section they give a zig-zag-shaped arrangement.

29. A lamp as set forth in claim 28 characterised in that the thin connecting legs are so inclined relative to the propagation direction of the light flux impinging thereon that the light passing through them substantially maintains its propagation direction.

30. A lamp as set forth in claim 28 characterised in that the thin connecting legs are so inclined relative to the propagation direction of the light flux impinging thereon that they couple out a part thereof in a direction opposite to the light exit surface and arranged behind the light distribution device as viewed from the light exit surface is a reflector which reflects that light towards the light exit surface.

31. A lamp as set forth in claim 28 characterised in that the thin connecting legs are narrow perpendicularly to the propagation direction of the light flux impinging thereon so that they form at least one leg extending in the propagation direction of the light flux impinging thereon.

32. A lamp as set forth in claim 27 characterised in that the coupling-out layers are connected together by connecting legs extending outside the light flux in the propagation direction thereof.

33. A lamp as set forth in claim 1 characterised in that the medium of the coupling-out layers is air and the medium filling the intermediate spaces is a transparent solid body material.

34. A lamp as set forth in claim 33 characterised in that the coupling-out layers are in the form of slots in an integral body comprising the solid body material.

35. A lamp as set forth in claim 1 characterised in that all coupling-out layers have the same optical properties.

36. A lamp as set forth in claim 1 characterised in that after passing through a plurality of coupling-out layers the light flux impinges on a mirrored surface which is so inclined relative to the longitudinal direction of the light flux at a predetermined angle that it reflects the remaining residual light impinging thereon towards the light exit surface.

37. A lamp as set forth in claim 1 characterised in that after passing through a plurality of coupling-out layers the light flux impinges on a mirrored surface which reflects it in such a way that the propagation direction of the reflected light flux is approximately opposite to that of the arriving light flux and provided on the side of the light deflection device which is opposite to the light exit surface is a reflection device which reflects the parts of the reflected light flux, which are coupled out by the coupling-out layers of the light deflection device through which the light has passed towards same, back towards the light exit surface.

38. A lamp as set forth in claim 1 characterised in that at least one of the coupling-out layers is a substantially plane-parallel layer.

39. A lamp as set forth in claim 1 characterised in that at least one of the coupling-out layers is a layer which is parallel in a curved configuration following a polygonal line in cross-section.

40. A lamp as set forth in claim 1 characterised in that at least one of the coupling-out layers is a layer which is steadily curved in cross-section and the front and rear sides of which extend substantially at a uniform spacing relative to each other.

41. A lamp as set forth in claim 1 characterised in that at least two coupling-out layers are so designed that the light flux portions coupled out thereby extend substantially parallel to each other.

42. A lamp as set forth in claim 1 characterised in that at least two coupling-out layers are so designed that the light flux portions coupled out thereby extend in mutually different directions.