Light assembly

• US 8,206,005 B2
• Filed: 08/17/2009
• Issued: 06/26/2012
• Est. Priority Date: 10/10/2003
• Status: Expired due to Fees

• Current Assignee: Federal Signal Corporation
• Original Assignee: Federal Signal Corporation
• Inventors: Czajkowski, Robert A.
• Primary Examiner(s): HAN, JASON
• Application Number:
  US12/542,392
• Publication Number:
  US 20090303716A1
• Time in Patent Office: 1,044 Days
• Field of Search: 362240-241, 362/243, 362/247, 362/249.02, 362296-298, 362301-302, 362/341, 362/346, 362516-518, 362/548, 362/800, 362/545
• US Class Current: 362/243
• 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. An emergency warning light assembly for directing light into a beam pattern that meets or exceeds a predetermined emergency warning standard, the emergency warning light assembly comprising:

one or more light emitting diodes (LEDs), each having an optical output axis;

a reflector comprising an approximate parabolic composite of parabolic curve sections, each section having a different principle axis and a common focal point so as to redirect light from each of the LEDs into the beam pattern; and

end wall portions of the reflector flanking the composite of parabolic curve sections and cooperating with the composite of parabolic curve sections to redirect light from the LEDs into the beam pattern.

2. The light assembly of claim 1 wherein a shape and size of each of the parabolic curve sections is determined by an iterative process of adjusting one or both of the size and shape of one or more of the parabolic curve sections until the beam pattern meets or exceeds a predetermined spatial pattern.

3. The light assembly of claim 1 wherein the one or more LEDs include a plurality of LEDs having their optical output axes aligned to share a common direction.

4. The light assembly of claim 3 wherein the plurality of LEDs are mounted to a common surface.

5. The light assembly of claim 3 wherein the plurality of LEDs is arranged in a substantially linear alignment.

6. The light assembly of claim 1 wherein the reflector includes a substantially linear junction between adjacent parabolic curve sections of the reflector.

7. The light assembly of claim 1 wherein at least one of the end wall portions includes one or more parabolic reflective surfaces for reflecting light from the one or more LEDs for inclusion in the beam pattern of light emanating from the one or more LEDs.

8. The light assembly of claim 1 wherein the beam pattern conforms to a predetermined specification for providing an emergency warning light.

9. An emergency warning light assembly for directing light into a beam pattern that meets or exceeds a predetermined emergency warning standard, the emergency warning light assembly comprising:

one or more light emitting diodes (LEDs), each emitting light along an output axis;

a reflector having an approximate parabolic body portion extending between first and second end walls for reflecting light emanating from the one or more LEDs into the beam pattern whose direction is substantially across the output axis of the one or more LEDs;

the body portion of the reflector including two or more parabolic sections, each having a different principal axis and a common focal point that cooperate in reflecting light from the LEDs to form the beam pattern; and

each of the first and second end walls of the reflector having a reflective geometry that contributes light to the beam pattern.

10. The light assembly of claim 9 wherein a shape and size of each of the two or more sections is determined by an iterative process of adjusting one or both of the size and shape of one or more of the sections until the beam pattern meets or exceeds a predetermined standard for emergency lighting.

11. The light assembly of claim 9 wherein the one or more LEDs include a plurality of linearly aligned LEDs having their optical output axes directed in a common direction.

12. The light assembly of claim 11 wherein the plurality of LEDs and the reflector are mounted to a common surface.

13. The light assembly of claim 9 wherein the reflective geometry of at least one of the first and second end walls of the reflector comprises a curved surface for reflecting light from the one or more LEDs to be part of the beam pattern.

14. The light assembly of claim 13 wherein the curved surface of the at least one end wall comprises two or more different reflective geometries.

15. The light assembly of claim 9 wherein the reflective geometries of the first and second end walls of the reflector are the same.

16. The light assembly of claim 9 wherein the reflective geometries of the first and second end walls of the reflector are different.

17. The light assembly of claim 9 wherein the body portion of the reflector includes a linear transition between adjacent sections of the reflector that substantially extends between the first and second ends of the reflector.

18. The light assembly of claim 9 wherein the parabola has a principle axis that is substantially perpendicular to the output axis of each of the one or more LEDs.

19. An emergency warning light assembly for directing light into a beam pattern that meets or exceeds a predetermined emergency warning standard, the emergency warning light assembly comprising:

first means for generating a plurality of discrete light beams, each having an optical output axis in a first direction;

second means for reflecting and shaping the light beams into a single far field beam traveling in a second direction and having attributes of the beam pattern, where parts of the reflected light are reflected from the first direction to directions different from the second direction such that a composite of the reflected discrete light beams form the far field beam with the beam pattern, where the second means is an approximate parabolic composite that includes parabolic surfaces having different principle axes to reflect parts of the reflected light into the different directions; and

third means flanking and cooperating with the second means to redirect parts of the discrete light from the first means to contribute to the beam pattern of the far field beam.

20. The light assembly of claim 19 wherein a shape and size of the second means is determined by an iterative process adjusting one or both of the size and shape until the beam pattern meets or exceeds a predetermined standard for emergency lighting.

21. The light assembly of claim 19 wherein the first and second means are mounted to a common surface.