Light distribution reflector for exit signs and the illuminated by LED arrays

• US 5,887,968 A
• Filed: 05/02/1997
• Issued: 03/30/1999
• Est. Priority Date: 05/02/1997
• Status: Expired due to Fees

• Current Assignee: Acuity Brands, Inc.
• Original Assignee: National Service Industries, Inc. (Alsco Incorporated)
• Inventors: Logan, Mark Campbell
• Primary Examiner(s): Sember, Thomas M.
• Assistant Examiner(s): WARD, JOHN A
• Application Number:
  US08/850,639
• Time in Patent Office: 697 Days
• Field of Search: 362/240, 362/241, 362/249, 362/800, 362/812, 40/546, 40/570
• US Class Current: 362/241
• CPC Class Codes: G09F 13/0422 Reflectors
• CPC Class Codes: G09F 13/14 Arrangements of reflectors therein
• CPC Class Codes: G09F 13/18 Edge-illuminated signs
• CPC Class Codes: G09F 2013/145 curved reflectors
• CPC Class Codes: Y10S 362/80 Light emitting diode
• CPC Class Codes: Y10S 362/812 Signs

Abstract

A reflector element intended to locate each light emitting diode of an array of light emitting diodes between outwardly angled, reflective surfaces in order to manage the distribution of light within an enclosure of an exit sign or other illuminated sign thereby illuminating a legend-bearing sign panel of the sign, the invention allows compact sign enclosure formation and provides even illumination of sign panels on all legend-bearing face walls of the exit sign even though multiple point light sources such as light emitting diodes comprise the illumination source. The reflector element of the invention is preferably embodied in a U-shaped dual wall configuration with each wall being formed substantially with a plurality of triangular tooth-like projections interspersed with substantially triangular openings, the projections angling outwardly from a reflector base, a series of apertures being formed in the reflector base for receiving the light emitting diodes of the array. The preferred reflector element of the invention is elongated in conformation and used with a linear array of light emitting diodes, each diode lying between projections forming opposing walls of the reflector element and being shaded thereby. The light emitting diode array is preferably located along at least one interior wall of the sign enclosure adjacent at least one of the legend-bearing face walls. The reflector element is particularly useful with relatively diffuse, medium-viewing angle light emitting diodes, the projections of the walls shading each diode acting to reflect light emanating from the diodes upwardly and outwardly of the reflector element and into interior portions of the sign enclosure to illuminate portions of one or more sign panels having at least edge portions disposed adjacent the LED array.

Claims

1. In an illuminated sign having at least one legend which is to be illuminated from interiorly of the sign for viewing of the legend from a location outside of the sign, the sign including a top wall, a bottom wall, side walls and planar face walls forming a sign enclosure, at least one of the face walls bearing the at least one legend, the interior of the sign enclosure being illuminated by an array of spaced apart point light sources disposed substantially along at least portions of internal wall surfaces of at least one of the top, bottom or side walls, the improvement comprising reflector means disposed adjacent to at least certain of the light sources for reflecting light incident onto surfaces thereof opposing said light sources into the interior of the sign enclosure, the reflector means having reflective surfaces spaced from and adjacent to each of the light sources, openings being provided between the reflective surfaces at locations between said light sources, the interior of the sign enclosure being thus evenly illuminated and thereby evenly illuminating the at least one legend.

2. In the illuminated sign of claim 1 wherein the point light sources comprise light emitting diodes.

3. In the illuminated sign of claim 2 wherein the light emitting diodes are relatively diffuse, medium-viewing angle diodes.

4. In the illuminated sign of claim 2 wherein the light emitting diodes are disposed in a linear array.

5. In the illuminated sign of claim 2 wherein the light emitting diodes are disposed at locations opposing nearmost portions of the at least one legend.

6. In the illuminated sign of claim 2 and further comprising means for mounting the light emitting diodes in a predetermined location within the interior of the exit sign enclosure and for maintaining the light emitting diodes in a fixed location therewithin.

7. In the illuminated sign of claim 6 wherein the mounting and maintaining means comprise a first substrate on which the light emitting diodes are mounted in an electrical circuit, a second substrate carrying circuit elements and being surmounted by the first substrate, means for interconnecting the substrates electrically, and means for interconnecting the substrates mechanically.

8. In the illuminated sign of claim 2 wherein the reflector means comprise at least one reflective wall element disposed between each light emitting diode and portions of the legend adjacent the array, the at least one wall element having open spaces between said wall element and wall elements adjacent thereto, said wall element shading said light emitting diode to prevent said diode from showing as a bright spot in the legend and reflecting at least portions of the light emanating from the diode into the interior of the sign to illuminate the legend.

9. In the illuminated sign of claim 4 wherein the reflector means comprise an elongated base having opposing walls extending therefrom along lengthwise sides of the base, the walls being formed of projections having reflective inner surfaces, the wall having openings formed therein on either side of each projection, at least certain of the light emitting diodes being disposed between opposing projections of the opposing walls, at least portions of the light emanating from each of said at least certain of the light emitting diodes being reflected by the inner surfaces of the projections into the interior of the sign to illuminate the at least one legend.

10. A reflector useful in an illuminated sign or the like which is illuminated by a plurality of point light sources disposed substantially along at least portions of internal wall surfaces of the sign, comprising a body member formed of a base and having a plurality of tooth-like projections having reflective inner surfaces formed along opposing sides of the base, the projections being interdigitated with openings between said projections, the base having a plurality of apertures formed therein, each aperture receiving at least one of the light sources to position said source between opposing projections, at least portions of the light emanating from the source reflecting from the inner surfaces of the projections and into the interior of the illuminated sign to provide more even illumination therewithin.

11. The reflector of claim 10 wherein the light sources comprise light emitting diodes mounted to a substrate, the reflector further comprising means for mounting the body member to the substrate in juxtaposition to the diodes in order that the diodes are received into and through the apertures to extend above the base and into positions between opposing tooth-like projections.

12. In an illuminated sign having at least one legend which is to be illuminated from interiorly of the sign for viewing of the legend from a location outside of the sign, the sign including a top wall, a bottom wall, side walls and planar face walls forming a sign enclosure, at least one of the face walls bearing the at least one legend, the interior of the sign enclosure being illuminated by an array of spaced apart point light sources disposed substantially along at least portions of internal wall surfaces of at least one of the top, bottom or side walls, the improvement comprising reflector means disposed adjacent to at least certain of the light sources for reflecting light incident onto surfaces thereof opposing said light sources into the interior of the sign enclosure, and means for mounting the light sources in a predetermined location within the interior of the sign enclosure and for maintaining the light sources in a fixed location therewithin, the mounting and maintaining means comprising a first substrate on which the point light sources are mounted in an electrical circuit, a second substrate carrying circuit elements and being surmounted by the first substrate, means for interconnecting the substrates electrically, and means for interconnecting the substrates mechanically, the interior of the sign enclosure being thus evenly illuminated and thereby evenly illuminating the at least one legend.

13. In the illuminated sign of claim 12 wherein the point light sources comprise light emitting diodes.

14. In the illuminated sign of claim 12 wherein the mechanical interconnecting means comprise a dielectric wrapper encompassing the second substrate and acting to protect the circuit elements on said substrate, the wrapper having means formed therewith for engaging the first substrate.

15. In the illuminated sign of claim 14 wherein the sign enclosure has mounting means disposed on an interior wall and defining a recess for receiving at least portions of the second substrate and portions of the wrapper to hold portions of the wrapper and of the second substrate in relation to the interior wall, the engaging means formed on the wrapper acting to maintain the first substrate in a location near to and spaced from the interior wall.

16. In the illuminated sign of claim 14 wherein the mechanical interconnecting means further comprise mounting posts interconnecting the first and second substrates and extending therebetween for connection to each of said substrates.

17. In the illuminated sign of claim 12 wherein the point light sources are disposed in a linear array.

18. In the illuminated sign of claim 13 wherein the mechanical interconnecting means comprise a dielectric wrapper encompassing the second substrate and acting to protect the circuit elements on said substrate, the wrapper having means formed therewith for engaging the first substrate.

19. In the illuminated sign of claim 18 wherein the sign enclosure has mounting means disposed on an interior wall and defining a recess for receiving at least portions of the second substrate and portions of the wrapper to hold portions of the wrapper and of the second substrate in relation to the interior wall, the engaging means formed on the wrapper acting to maintain the first substrate in a location near to and spaced from the interior wall.

20. In the illuminated sign of claim 18 wherein the mechanical interconnecting means further comprise mounting posts interconnecting the first and second substrates and extending therebetween for connection to each of said substrates.

21. In the illuminated sign of claim 12 wherein the reflector means comprise reflective surfaces spaced from and adjacent to each of the light emitting diodes, openings being provided between the reflective surfaces at locations between adjacent diodes.

36. In the illuminated sign of claim 13 wherein the walls diverge outwardly from the base.

22. In an illuminated sign having at least one legend which is to be illuminated from interiorly of the sign for viewing of the legend from a location outside of the sign, the sign including a top wall, a bottom wall, side walls and planar face walls forming a sign enclosure, at least one of the face walls carrying the at least one legend, the interior of the sign enclosure being illuminated by an array of spaced apart point light sources disposed substantially along at least portions of internal wall surfaces of at least one of the top, bottom or side walls, the improvement comprising reflector means disposed adjacent to at least certain of the light sources for reflecting light incident onto surfaces thereof opposing said light sources into the interior of the sign enclosure, the reflector means comprising at least one reflective wall element disposed between each point light source and portions of the legend adjacent the array, the at least one wall element having open spaces between said wall element and wall elements adjacent thereto, said wall element shading said point light source to prevent said source from showing as a bright spot in the legend and reflecting at least portions of the light emanating from the source into the interior of the sign to illuminate the legend, the interior of the sign enclosure being thus evenly illuminated and thereby evenly illuminating the at least one legend.

23. In the illuminated sign of claim 22 wherein the point light sources comprise light emitting diodes.

24. In an illuminated sign having at least one legend which is to be illuminated from interiorly of the sign for viewing of the legend from a location outside of the sign, the sign including a top wall, a bottom wall, side walls and planar face walls forming a sign enclosure, at least one of the face walls bearing the at least one legend, the interior of the sign enclosure being illuminated by an array of spaced apart point light sources disposed substantially along at least portions of internal wall surfaces of at least one of the top, bottom or side walls, the improvement comprising reflector means disposed adjacent to at least certain of the light sources for reflecting light incident onto surfaces thereof opposing said light sources into the interior of the sign enclosure, the reflector means comprising an elongated base having opposing walls extending therefrom along lengthwise sides of the base, the walls being formed of projections having reflective inner surfaces, the wall having openings formed therein on either side of said projection, at least certain of the point light sources being disposed between opposing projections of the opposing walls, at least portions of the light emanating from each of said at least certain of the point light sources being reflected by the inner surfaces of the projections into the interior of the sign to illuminate the at least one legend, the interior of the sign enclosure being thus evenly illuminated and thereby evenly illuminating the at least one legend.

25. In the illuminated sign of claim 24 wherein the point light sources comprise light emitting diodes.

26. In the illuminated sign of claim 25 wherein the light emitting diodes are disposed in a linear array.

27. In the illuminated sign of claim 24 wherein the base has a plurality of linearly aligned apertures formed therein for receiving at least one of the point light sources therethrough.

28. In the illuminated sign of claim 27 wherein the point light sources are mounted to a substrate and wherein the reflector means further comprises means for removably mounting the reflector means to the substrate.

29. In the illuminated sign of claim 28 wherein the mounting means are formed integrally with the base and the walls.

30. In the illuminated sign of claim 24 wherein the projections are substantially triangular in conformation.

31. In the illuminated sign of claim 24 wherein the walls diverge outwardly from the base.

32. In the illuminated sign of claim 25 wherein the base has a plurality of linearly aligned apertures formed therein for receiving at least one of the light emitting diodes therethrough.

33. In the illuminated sign of claim 32 wherein the light emitting diodes are mounted to a substrate and wherein the reflector means further comprises means for removably mounting the reflector means to the substrate.

34. In the illuminated sign of claim 33 wherein the mounting means are formed integrally with the base and walls.

35. In the illuminated sign of claim 25 wherein the projections are substantially triangular in conformation.