Light degradation sensing LED signal with light pipe collector

• US 6,717,526 B2
• Filed: 04/06/2001
• Issued: 04/06/2004
• Est. Priority Date: 01/10/2001
• Status: Active Grant

• Current Assignee: Current Lighting Solutions, LLC (f/k/a GE Lighting Solutions, LLC) (American Industrial Partners)
• Original Assignee: Gelcore (General Electric Company)
• Inventors: Dubuc, Eden, Martineau, Patrick, Bourgault, Jean-Simon
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US09/827,429
• Publication Number:
  US 20020089420A1
• Time in Patent Office: 1,096 Days
• Field of Search: 340/815.45, 340/907, 340/931, 340/641, 340/642, 315/119, 315/121, 315/122, 315/76, 362/800, 362/217, 362/219, 362/223, 362/225
• US Class Current: 340/815.45
• CPC Class Codes: B61L 2207/02 using light-emitting diodes [LEDs]
• CPC Class Codes: B61L 5/1827 using light sources of different colours and a common optical system
• CPC Class Codes: B61L 5/1845 Optical systems, lenses
• CPC Class Codes: B61L 5/1854 Mounting and focussing of the light source in a lamp, fixing means
• CPC Class Codes: F21V 15/04 Resilient mountings, e.g. shock absorbers shock absorbing devices of vehicle headlamp housings B60Q1/0491; in general F16F15/04
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors
• CPC Class Codes: F21V 31/00 Gas-tight or water-tight arrangements
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2103/33 annular
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: G09F 27/008 Sun shades, shades, hoods or louvres on electronic displays to minimise the effect of direct sun light on the display
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

An LED signal with an LED light pipe collector and intelligent light degradation sensor. The light pipe collector captures LED light normally lost in a generally horizontal direction and redirects it into a generally vertical direction through use of total internal reflection. The light degradation sensor monitors LED signal light output. When light output degrades to a preset level, an electrical circuit triggers a disabling short circuit to deactivate the LED signal.

Claims

1. An LED signal comprising:

a housing having an interior area and an open end,

at least one LED,

a light sensing means;

a comparator means;

said at least one LED arranged and configured within said interior area of said housing;

said light sensing means located within said interior area of said housing, having an output value relative to a light level within said housing;

said comparator means comparing said output value to a reference value;

if said output value is below said reference value said comparator initiates a disablement means.

2. The LED signal of claim 1, wherein:

said light sensing means is a phototransistor.

3. The LED signal of claim 1, wherein:

said comparator means is a voltage comparator circuit.

4. The LED signal of claim 1, wherein:

said disablement means is a transistor switch that creates a short circuit between a power supply line and a neutral or ground line which increases current through a power supply line fuse to a level where said fuse burns out.

5. The LED signal of claim 1, wherein:

said at least one LED are arranged and configured on a PCB further including LED power supply electrical components and circuitry.

6. The LED signal of claim 1, further comprising:

a cover having a light transmission surface,

said cover attached to said housing open end by a means for attachment.

7. The LED signal of claim 6, wherein:

said means for attachment is integral to said distribution cover and said housing.

8. The LED signal of claim 6, wherein:

said light transmission surface is angled with respect to a peripheral mounting surface in contact with said housing.

9. The LED signal of claim 6, wherein:

said signal is a 12″

nominal size, and said light transmission surface has a spherical shape having an arc radius greater than 24″

.

10. The LED signal of claim 6, wherein:

said signal is a 8″

nominal size, and said light transmission surface has a spherical section having an arc radius greater than 18″

.

11. The LED signal of claim 6, wherein:

said means for attachment includes means for aligning said distribution cover on said housing in a desired orientation.

12. The LED signal of claim 6, further comprising:

a sealing means to environmentally seal said LED signal.

13. The LED signal of claim 12, wherein:

said sealing means is an o-ring.

14. The LED signal of claim 6, wherein:

said means for attachment is at least one connection tab on said distribution cover arranged and configured to mate with a corresponding tab socket on said housing.

15. The LED signal of claim 14, wherein:

said tab socket includes a tab socket key arranged and configured to mate with a corresponding cavity in said connection tab.

16. The LED signal of claim 6, wherein:

said housing and said cover are arranged and configured for retro-fitting into a traffic signal having an incandescent light source, optical elements and an incandescent light source reflector,

said LED signal sized to fit within a cavity formed by said traffic signal incandescent light source reflector upon removal of said incandescent light source and said optical elements.

17. The LED signal of claim 16, wherein:

electrical power connection is made by connection to an incandescent light source socket.

18. The LED signal of claim 6, wherein:

said at least one LED are arranged and configured to emit light upon a collimating element positioned between said cover and said at least one LED.

19. The LED signal of claim 18, wherein:

said at least one LED emits light in an overlapping light pattern such that failure or diminished light output of a single LED is not discernable to a viewer of said LED signal.

20. The LED signal of claim 18, wherein:

said collimating element includes collimating zones arranged and configured with respect to the distribution of said LEDs on said PCB.

21. The LED signal of claim 20, wherein:

said collimating zones are arranged in concentric circles.

22. The LED signal of claim 20, wherein:

said collimating zones are arranged in horizontal or vertical rows.

23. The LED signal of claim 20, wherein:

said collimating zones are arranged in circles or arcs and horizontal and/or vertical rows.

24. The LED signal of claim 1, wherein:

said housing has external electrical power connectors comprising;

a cavity in an external end of each external electrical power connector, and

a connector cover having a compression element;

upon insertion of a conductor into said cavity said connector cover compression element is frictionally inserted into said cavity thereby holding said conductor securely in said cavity in electrical contact with said electrical connector.

25. The LED signal of claim 1, wherein:

said at least one LED is arranged in at least one substantially circular configuration.

26. The LED signal of claim 1, wherein:

said at least one LED is arranged in at least one substantially linear configuration.

27. An LED signal comprising:

a housing having an interior area and an open end;

at least one LED;

a light pipe collector for use with at least one LED comprising;

an optical member composed of light transmissive material,

at least one total internal reflection surface, and

a receiving chamber for receiving said at least one LED;

said at least one LED emitting light in a main direction and a non-main direction;

said at least one LED arranged and configured within said interior, of said housing;

said total internal reflection surface operating to redirect said non-main direction emitted light to said main direction through total internal reflection.

28. The LED signal of claim 27, wherein:

said at least one LED is arranged and configured on a PCB further including LED power supply electrical components and circuitry.

29. The LED signal of claim 27, further comprising:

a cover having a light transmission surface,

said cover attached to said housing open end by a means for attachment.

30. The LED signal of claim 29, wherein:

said means for attachment is integral to said distribution cover and said housing.

31. The LED signal of claim 29, wherein:

said light transmission surface is angled with respect to a peripheral mounting surface in contact with said housing.

32. The LED signal of claim 29, wherein:

said signal is a 12″

nominal size, and said light transmission surface has a spherical shape having an arc radius greater than 24″

.

33. The LED signal of claim 29, wherein:

said signal is a 8″

nominal size, and said light transmission surface has a spherical section having an arc radius greater than 18″

.

34. The LED signal of claim 29, wherein:

said means for attachment includes means for aligning said distribution cover on said housing in a desired orientation.

35. The LED signal of claim 29, further comprising:

sealing means to environmentally seal said LED signal.

36. The LED signal of claim 35, wherein:

said sealing means is an o-ring.

37. The LED signal of claim 29, wherein:

said means for attachment is at least one connection tab on said distribution cover arranged and configured to mate with a corresponding tab socket on said housing.

38. The LED signal of claim 37, wherein:

said tab socket includes a tab socket key arranged and configured to mate with a corresponding cavity in said connection tab.

39. The LED signal of claim 29, wherein:

said housing and said cover are arranged and configured for retro-fitting into a traffic signal having an incandescent light source, optical elements and an incandescent light source reflector,

said LED signal sized to fit within a cavity formed by said traffic signal incandescent light source reflector upon removal of said incandescent light source and said optical elements.

40. The LED signal of claim 39, wherein:

an electrical power connection is made by connection to an incandescent light source socket.

41. The LED signal of claim 29, wherein:

said at least one LED is arranged and configured to emit light upon a collimating element positioned between said cover and said at least one LED.

42. The LED signal of claim 41, wherein:

said at least one LED emits light in an overlapping light pattern such that failure or diminished light output of a single LED is not discernable to a viewer of said LED signal.

43. The LED signal of claim 41, wherein:

said collimating element includes collimating zones arranged and configured with respect to the distribution of said LEDs on said PCB.

44. The LED signal of claim 43, wherein:

said collimating zones are arranged in concentric circles.

45. The LED signal of claim 43, wherein:

said collimating zones are arranged in horizontal or vertical rows.

46. The LED signal of claim 43, wherein:

said collimating zones are arranged in arcs and horizontal and/or vertical rows.

47. The LED signal of claim 27, wherein:

said housing has external electrical power connectors comprising;

a cavity in an external end of each external electrical power connector, and

a connector cover having a compression element;

upon insertion of a conductor into said cavity said connector cover compression element is frictionally inserted into said cavity thereby holding said conductor securely in said cavity in electrical contact with said electrical connector.

48. The LED signal of claim 27, wherein:

said at least one LED is arranged in at least one substantially circular configuration.

49. The LED signal of claim 27, wherein:

said at least one LED is arranged in at least one substantially linear configuration.

50. The LED signal of claim 27, further comprising:

a light sensing means,

a comparator means, and

a reference value;

said light sensing means located within said housing, having an output value relative to a light level within said housing;

said comparator means comparing said output value to said reference value;

if said output value is below said reference value said comparator initiates a disablement means.