Asymmetrical Optical System

• US 20130235580A1
• Filed: 04/29/2013
• Published: 09/12/2013
• Est. Priority Date: 12/15/2009
• Status: Active Grant

• Current Assignee: Whelen Engineering Company Incorporated
• Original Assignee: Whelen Engineering Company Incorporated
• Inventors: Smith, Todd J.
• Granted Patent: US 9,388,961 B2
• Time in Patent Office: Days
• US Class Current: 362/235
• CPC Class Codes: F21S 4/28 rigid, e.g. LED bars
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 29/89 Metals
• CPC Class Codes: F21V 5/08 producing an asymmetric light distribution
• 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 7/09 with a combination of different curvatures
• CPC Class Codes: F21W 2131/1005 of working places, building sites or the like
• 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

An asymmetrical optical assembly employs reflecting surfaces and a lens to combine the light from a plurality of LED lamps into an illumination pattern useful in a floodlight or work light. The reflecting surfaces and lens optical element are not symmetrical with respect to a plane bisecting the optical assembly and including the optical axes of the LED light sources. Some light from the LED light sources is redirected from its emitted trajectory into the desired illumination pattern, while a significant portion of the light from the LED light sources is permitted to exit the optical assembly without redirection. Minimizing the number of optical elements employed and the redirection of light enhances the efficiency of the resulting light assembly.

Claims

1. A light assembly having an illumination pattern, said light assembly comprising:

an LED light source comprising a light emitting die and having an optical axis extending from said light emitting die and perpendicular to a first plane, said LED emitting light within a hemisphere centered on said optical axis, said hemisphere bisected by a second plane including said optical axis and perpendicular to said first plane;

a reflecting surface spaced from said second plane, said reflecting surface arranged to redirect light from a range of emitted angles at which said light is emitted from said LED light source into a range of reflected angles with respect to said second plane where each angle in said range of reflected angles is less than any angle in said range of emitted angles with respect to said second plane, said range of reflected angles including angles defining a first trajectory of light emission convergent with and passing through said second plane;

an optical element in the path of light emitted from said LED light source, said optical element separate from any optical element packaged with said LED light source and comprising light entry and light emission surfaces configured to refract at least a portion of light from said LED light source passing through said optical element into a range of refracted angles with respect to said second plane, said range of refracted angles including angles defining a second trajectory of light emission convergent with and passing through said second plane,

wherein said optical element is asymmetrical with respect to said second plane, with a majority of said optical element located between said first reflecting surface and said second plane, said light assembly defining a gap along one side of said optical element through which light from said LED light source exits the light assembly without redirection by either said reflecting surface or said optical element.

2. The light assembly of claim 1, wherein said LED light source comprises a plurality of LED light sources arranged along a longitudinal axis perpendicular to the optical axes of the LED light sources, said optical axes being included in said second plane.

3. The light assembly of claim 1, substantially all light emitted from said LED light source to one side of said second plane is redirected by either said reflecting surface or said optical element.

4. The light assembly of claim 1, wherein said first reflecting surface is a parabolic surface having a focal point and said light emitting die is positioned at said focal point.

5. The light assembly of claim 2, wherein said reflecting surface is parallel to said second plane and is defined by projecting a parabolic curve along said longitudinal axis.

6. The light assembly of claim 1, wherein said reflecting surface is a parabolic surface defined by a parabolic equation.

7. The light assembly of claim 1, wherein said reflecting surface projects in the direction of light emission to an outer edge, the outer edge of said reflecting surface extending past said optical element in the direction of light emission.

8. The light assembly of claim 7, wherein said reflecting surface projects in the direction of light emission to an outer edge and said optical element is positioned adjacent said second plane and intermediate said first plane and the outer edge of said reflecting surface in the direction of light emission.

9. A light assembly comprising:

a plurality of LED light sources, each LED light source comprising a light emitting die and having an optical axis extending from said light emitting die and perpendicular to a first plane and emitting light within a hemisphere centered on said optical axis, said hemisphere bisected by a second plane including said optical axes and perpendicular to said first plane, said LED light sources arranged along a longitudinal axis perpendicular to the optical axes of the LED light sources, said optical axes being included in said second plane;

a reflecting surface parallel to and spaced apart from said second plane, said reflecting surface defined by projecting a parabolic curve along said longitudinal axis, said reflecting surface arranged to redirect light from a range of emitted angles at which said light is emitted from said LED light sources into a range of reflected angles with respect to said second plane where each angle in said range of reflected angles is less than any angle in said range of emitted angles with respect to said second plane, said range of reflected angles including angles defining a first trajectory of light emission convergent with and passing through said second plane;

a longitudinally extending optical element in the path of light emitted from said LED light sources, said optical element comprising light entry and light emission surfaces configured to refract at least a portion of light from said LED light source passing through said optical element into a range of refracted angles with respect to said second plane, said range of refracted angles including angles defining a second trajectory of light emission convergent with and passing through said second plane,

wherein said optical element is asymmetrical with respect to said second plane, with a majority of said optical element located between said second plane and said reflecting surface to define a gap along one side of said optical element through which light from said LED light sources exits the light assembly without redirection by said reflecting surface or passing through said optical element.

10. The light assembly of claim 9, wherein at least one of said light entry or light emission surfaces is a planar surface.

11. The light assembly of claim 9, wherein substantially all light emitted from said LED light sources to one side of said second plane is redirected by either said reflecting surface or said optical element and at least a portion of light emitted from said LED light source to the other side of said second plane exits the light assembly without redirection by either said reflecting surface or said optical element.

12. The light assembly of claim 9, wherein said reflecting surface is a parabolic surface having a focal point and said light emitting dies are positioned at said focal point.

13. The light assembly of claim 9, wherein said reflecting surface is defined by projecting a parabolic curve along said longitudinal axis.

14. The light assembly of claim 9, wherein said reflecting surface projects in the direction of light emission to an outer edge disposed at a distance from said first plane beyond the position of said optical element.

15. The light assembly of claim 9, wherein said optical element is parallel to said longitudinal axis, positioned adjacent said second plane and a major portion of said optical element is intermediate said second plane and said reflecting surface.

16. The light assembly of claim 14, wherein said reflecting surface projects in the direction of light emission to an outer edge and said optical element is positioned adjacent said second plane and intermediate said first plane and the outer edge of said reflecting surface in the direction of light emission.