Light assembly

• US 20050094393A1
• Filed: 10/12/2004
• Published: 05/05/2005
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Federal Signal Corporation
• Original Assignee: Federal Signal Corporation
• Inventors: Czajkowski, Robert A.
• Granted Patent: US 7,578,600 B2
• Time in Patent Office: Days
• US Class Current: 362/247
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21S 41/00 Illuminating devices specially adapted for vehicle exteriors, e.g. headlamps reversing lights F21S43/00
• CPC Class Codes: F21S 41/143 the main emission direction of the LED being parallel to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/151 arranged in one or more lines
• CPC Class Codes: F21S 41/153 arranged in a matrix
• CPC Class Codes: F21S 41/321 the reflector being a surface of revolution or a planar surface, e.g. truncated
• CPC Class Codes: F21S 41/323 the reflector having two perpendicular cross sections having regular geometrical curves of a distinct nature
• CPC Class Codes: F21S 41/332 with continuity at the junction between adjacent areas
• CPC Class Codes: F21S 43/13 characterised by the type of light source
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/15 Strips of light sources
• CPC Class Codes: F21S 43/30 characterised by reflectors
• CPC Class Codes: F21S 43/31 Optical layout thereof
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 7/0008 providing for indirect lighting
• CPC Class Codes: F21V 7/005 with an elongated shape to cooperate with linear light sources
• CPC Class Codes: F21V 7/04 Optical design
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21V 7/09 : with a combination of different curvatures
• CPC Class Codes: F21Y 2103/10 : comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 : Light-emitting diodes [LED]

Abstract

A light assembly is disclosed which can include an LED array and a reflector. The LED array can include a plurality of LEDs which are disposed such that each LED is substantially aligned to define a focal axis. Each LED can emit light substantially along an optical output axis, with each optical output axis being perpendicular to the focal axis. The optical output axis of the LED array can be disposed in intersecting relationship with the reflector surface. The reflector can be defined by a curve section defined with respect to a principal axis. The principal axis and the output axis of the LED array can be in non-parallel relationship with each other. The optical output axis of the LED array can be substantially perpendicular to the principal axis of the curve section of the reflector.

Claims

1. A light assembly comprising:

an LED, the LED operable to emit light substantially along an optical output axis; and

a reflector, the reflector having a reflective surface, the reflective surface including a curve section, the curve section being disposed in predetermined relationship relative to a principal axis, the principal axis being in non-parallel relationship with the optical output axis.

2. The light assembly according to claim 1 wherein the principal axis is substantially perpendicular to the optical output axis.

3. The light assembly according to claim 1 wherein the LED has a virtual focal point, the optical output axis extending through the virtual focal point, and the principal axis extending through the virtual focal point.

4. The light assembly according to claim 1 further comprising an array of LEDs.

5. The light assembly according to claim 4 wherein each LED includes a virtual focal point, the LEDs being disposed such that the virtual focal points extend along a focal axis.

6. The light assembly according to claim 5 wherein the virtual focal points are substantially aligned with each other.

7. The light assembly according to claim 4 further comprising a power supply operably arranged with the LED array such that the LED array is selectively operable to emit light.

8. The light assembly according to claim 7 further comprising a heat sink operably arranged with the LED array.

9. The light assembly according to claim 1 wherein the curve section comprises a parabolic curve section.

10. The light assembly according to claim 9 wherein the parabolic curve section is defined by a parabolic equation, the parabolic equation being y²=nx, where x is taken along the principal axis, y is taken along a y axis perpendicular to the principal axis, and n is a predetermined coefficient.

11. The light assembly according to claim 10 wherein the y axis is substantially parallel to the optical output axis.

12. The light assembly according to claim 10 wherein the parabolic curve section has a focus, the LED has a virtual focal point, the focus being disposed substantially coincident to the virtual focal point.

13. The light assembly according to claim 9 wherein the LED includes a virtual focal point, the optical output axis extending through the focal point, the parabolic curve section includes a first end and a second end, the first and second ends disposed in relation to the LED such that substantially all of the light emitted from the LED contacts the reflective surface.

14. The light assembly according to claim 13 wherein the first end and the virtual focal point defining a first line, the first line and the optical output axis defining a first angle, the second end and the virtual focal point defining a second line, the second line and the optical output axis defining a second angle.

15. The light assembly according to claim 14 wherein the first angle is different than the second angle.

16. The light assembly according to claim 15 wherein the first angle is approximately 60°

, and the second angle is 50°

.

17. The light assembly according to claim 5 the reflective surface is defined at least in part by extending the curve section along the focal axis a predetermined amount.

18. The light assembly according to claim 1 wherein the reflective surface includes at least one reflective portion, the reflective portion defined by the curve section being rotated about the principal axis over a predetermined amount.

19. The light assembly according to claim 18 further comprising an array of LEDs and a plurality of reflective portions.

20. The light assembly according to claim 19 wherein the number of LEDs corresponds to the number of reflective portions.

21. The light assembly according to claim 20 wherein each LED includes a virtual focal point, the principal axis of each reflective portion extending through the virtual focal point of a respective LED.

22. The light assembly according to claim 1 wherein the reflective surface includes a body portion having the curve section.

23. The light assembly according to claim 22 wherein the body section is defined by extending the curve section along an axis that is perpendicular to the principal axis and to the optical output axis.

24. The light assembly according to claim 22 wherein the reflective surface includes first and second end portions, the body portion being disposed intermediate the end portions.

25. The light assembly according to claim 1 wherein the curve section includes a plurality of segments, at least one segment being defined by a mathematical equation that is different than at least one other segment.

26. The light assembly according to claim 25 wherein the segments are defined by parabolic equations.

27. The light assembly according to claim 26 wherein at least one of the segments has a principal axis that is different than at least one other segment.

28. The light assembly according to claim 26 wherein the reflective surface includes a body portion and first and second end portions, the body portion including a plurality of segments, the first end portion including a plurality of segments, and the second end portion having a plurality of segments.

29. The light assembly according to claim 28 wherein the body portion has four parabolic curve segments, each body curve segment having a different parabolic equation, the first end portion has five parabolic curve segments, each first end curve segment having a different parabolic equation, the second end portion being a mirror image of the first end portion.

30. A light assembly comprising:

an LED, the LED operable to emit light substantially along an optical output axis; and

a reflector, the reflector having a reflective surface, the reflective surface including a curve section, the curve section extended along an axis a predetermined amount;

wherein the LED is positioned such that the optical axis is in intersecting relationship with the reflective surface.

31. The light assembly according to claim 30 wherein the curve section is parabolic.

32. A light assembly comprising:

an LED, the LED operable to emit light substantially along an optical output axis, the LED having a virtual focal point, the optical output axis extending through the virtual focal point; and

a reflector, the reflector having a reflective surface, the reflective surface including a curve section, the curve section being disposed in predetermined relationship relative to a principal axis, the curve section extending substantially along the principal axis, the curve section extended a predetermined amount along an axis perpendicular to the principal axis to define at least a portion of the reflective surface, the principal axis extending through the virtual focal point of the LED, the principal axis being in intersecting relationship with the optical output axis.

33. The light assembly according to claim 32 wherein the curve section is parabolic.