LED light assembly with reflector having segmented curve section

• US 7,578,600 B2
• Filed: 10/12/2004
• Issued: 08/25/2009
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Federal Signal Corporation
• Original Assignee: Federal Signal Corporation
• Inventors: Czajkowski, Robert A.
• Primary Examiner(s): Tso; Laura
• Assistant Examiner(s): HAN, JASON
• Application Number:
  US10/962,875
• Publication Number:
  US 20050094393A1
• Time in Patent Office: 1,778 Days
• Field of Search: 362/227, 362/235, 362240-241, 362/243, 362/245, 362/247, 362296-298, 362/341, 362/347, 362516-518, 362543-545, 362301-302, 362/346, 362/249.02
• 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. 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, the curve section including;

a body portion having at least two segments, with one segment being defined by a first mathematical equation and another segment being defined by a second mathematical equation that is different than the first mathematical equation, and

first and second end portions, the first end portion including at least two first end segments with one first end segment being defined by a third mathematical equation and another first end segment being defined by a fourth mathematical equation that is different than the third mathematical equation, and the second end portion including at least two second end segments with one second end segment being defined by the third mathematical equation and another second end segment being defined by the fourth mathematical equation.

2. The light assembly according to claim 1 wherein the second end portion is a mirror image of the first end portion.

3. The light assembly according to claim 1 wherein the body portion has four segments, each segment of the body portion having a different mathematical equation, the first end portion has five first end segments, each first end segment having a different mathematical equation, and the second end portion is a mirror image of the first end portion.

4. The light assembly according to claim 1, wherein the first, second, third, and fourth mathematical equations each comprise a parabolic equation.

5. A light assembly comprising:

an LED, the LED operable to emit light substantially along an optical output axis, the LED having a focal axis that is substantially perpendicular to the optical output axis; and

a reflector, the reflector including;

a body having a reflective surface with a parabolic curve section, the parabolic curve section extending along the focal axis a predetermined amount, the parabolic curve section comprising a plurality of parabolic curve segments with one parabolic curve segment being defined by a first mathematical equation and another parabolic curve segment being defined by a second mathematical equation that is different than the first mathematical equation, the body having a first edge and a second edge, the first and second edges in opposing relationship to each other,

a first end, and a second end,

the first and second ends having a reflective surface, the first end in adjacent relationship with the first edge of the body, and the second end being in adjacent relationship with the second edge of the body, the reflective surface of the first end includes a parabolic end curve section comprising a plurality of parabolic end segments, with at least one parabolic end segment having a parabolic equation that is different than another parabolic end segment, the reflective surface of the second end includes a parabolic end curve section comprising a plurality of parabolic end segments, with at least one parabolic end segment of the second end having a parabolic equation that is different than another parabolic end segment of the second end; and

a housing defining an opening and an interior cavity, the reflective surface of the first end, the body, and the second end disposed within the interior cavity.

6. The light assembly according to claim 5 wherein the first end is defined by rotating the parabolic end segments of the first end about their respective principal axes from the first edge of the body over a predetermined arc toward the opening of the reflector.

7. The light assembly according to claim 5 wherein the second end is a mirror image of the first end.

8. A light assembly comprising:

an array of LEDs, the LEDs each operable to emit light substantially along an optical output axis, the LEDs disposed with respect to each other to define a linear focal axis; and

a reflector including a housing and a reflective surface defining an interior cavity, the LEDs being disposed within the interior cavity, the reflective surface including a parabolic curve section comprising a plurality of parabolic curve segments each of which has a principal axis, wherein at least two parabolic curve segments are different parabolic curves, the parabolic curve section of the reflective surface extending along the linear focal axis over a length defining a body portion, each principal axis being in non-parallel relationship with the optical output axis of each LED such that the light emitted by the LEDs reflects from the reflective surface to form a substantially unidirectional beam;

wherein the reflective surface includes first and second end portions disposed adjacent first and second edges of the body portion, respectively, and

wherein the first end portion includes a parabolic curve section comprising two or more parabolic curve end segments wherein at least two parabolic curve end segments are defined by different parabolic equations.

9. The light assembly according to claim 8 wherein the parabolic curve segments of the body portion abut together to define the parabolic curve section and establish discontinuities therebetween.

10. The light assembly according to claim 8 wherein the body portion includes four parabolic curve segments to define the parabolic curve section.

11. The light assembly according to claim 8 wherein at least two of the parabolic curve segments of the body portion have different principal axes.

12. The light assembly according to claim 8 wherein the curve section of the first end portion comprises five parabolic curve segments.

13. The light assembly according to claim 8 wherein the first end portion is defined by rotating the parabolic curve segments about their respective principal axes over a predetermined arc between the first edge of the body portion and the opening of the reflector.

14. The light assembly according to claim 8 wherein the second end portion is a minor image of the first end portion.