Lighting assembly having n-fold rotational symmetry

• US 9,291,340 B2
• Filed: 08/14/2014
• Issued: 03/22/2016
• Est. Priority Date: 10/23/2013
• Status: Expired due to Fees

• Current Assignee: Rambus Delaware LLC (Rambus Inc.)
• Original Assignee: Rambus Delaware LLC (Rambus Inc.)
• Inventors: Richardson, Brian Edward
• Primary Examiner(s): RALEIGH, DONALD L
• Application Number:
  US14/459,980
• Publication Number:
  US 20150109780A1
• Time in Patent Office: 586 Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/61 using light guides
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 7/0091 using total internal reflection
• CPC Class Codes: F21Y 2107/00 Light sources with three-dimensionally disposed light-generating elements
• CPC Class Codes: F21Y 2107/50 on planar substrates or supports, but arranged in different planes or with differing orientation, e.g. on plate-shaped supports with steps on which light-generating elements are mounted
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lighting assembly includes an LED light source assembly and a unitary light-transmissive solid reflector optical element. The reflector optical element has a light output surface and n light-transmissive solid optical sub-elements having n-fold rotationally symmetrical about a central axis. Boundaries between adjacent optical sub-elements extend radially outward from the central axis. Each optical sub-element has a reflective surface positioned opposite the light output surface on the optical sub-element and shaped to create an internal reflection effect. The LED light source assembly has an LED light source for each optical sub-element. The LED light sources are positioned along an outline near the light output surface to direct light from each LED light source towards the reflective surface of the respective optical sub-element such that the light is reflected by the reflective surface to form an output light that exits the reflector optical element through the light output surface.

Claims

1. A lighting assembly, comprising:

an LED light source assembly; and

a unitary light-transmissive solid reflector optical element comprising a light output surface, the reflector optical element having n light-transmissive solid optical sub-elements, n being an integer three or greater, the sub-elements being n-fold rotationally symmetrical about a central axis, boundaries between adjacent optical sub-elements extending radially outward from the central axis, each optical sub-element comprising a reflective surface positioned opposite the light output surface on the optical sub-element and shaped to create an internal reflection effect;

wherein the LED light source assembly comprises an LED light source for each optical sub-element, the LED light sources positioned along an outline near the light output surface radially outwards from the light output surface to direct light from each LED light source towards the reflective surface of the respective optical sub-element such that the light is reflected by the reflective surface to form an output light that exits the reflector optical element through the light output surface.

2. The lighting assembly of claim 1, wherein the LED light source assembly additionally comprises a thermally conductive circuit board on which the LED light sources are mounted, the circuit board having an opening to pass light from the light output surface.

3. The lighting assembly of claim 2, wherein the circuit board is substantially parallel to the light output surface except angled portions on which the LED light sources are mounted at oblique angles relative to the light output surface.

4. The lighting assembly of claim 2, wherein the LED light source assembly additionally comprises a heat sink thermally connected to the circuit board.

5. The lighting assembly of claim 1, wherein each reflective surface is curved towards the respective LED light source.

6. The lighting assembly of claim 1, wherein at least one of the reflective surfaces is parabolic.

7. The lighting assembly of claim 1, wherein at least one of the reflective surfaces is aspherical.

8. The lighting assembly of claim 1, wherein at least one of the reflective surfaces is elliptical.

9. The lighting assembly of claim 1, wherein at least one of the optical sub-elements comprises a light input surface adjacent an edge of, and non-parallel to, the light output surface;

and the respective LED light source is mounted in optical contact with the light input surface.

10. The lighting assembly of claim 1, wherein the LED light sources are positioned adjacent an edge of the light output surface.

11. The lighting assembly of claim 1, wherein each optical sub-element additionally comprises a light pipe extending at least in part radially outward from the optical sub-element adjacent an edge of the light output surface and the respective LED light source is mounted in optical contact with a distal end of the light pipe, remote from the reflector optical element.

12. A flashlight comprising the lighting assembly of claim 1.

13. A lighting assembly, comprising:

an LED light source assembly;

a unitary light-transmissive solid reflector optical element comprising a first intermediate surface, the reflector optical element having n light-transmissive solid optical sub-elements, n being an integer three or greater, the sub-elements being n-fold rotationally symmetrical about a central axis, boundaries between adjacent optical sub-elements extending radially outward from the central axis, each optical sub-element comprising a reflective surface positioned opposite the first intermediate surface on the optical sub-element and shaped to create an internal reflection effect; and

a unitary light-transmissive adjustable element comprising a light output surface and a second intermediate surface opposite the light output surface, the first intermediate surface and the second intermediate surface being juxtaposed to each other, the adjustable element being configured to be rotatable around the central axis to a first rotation position and a second rotational position relative to the reflector optical element;

wherein the LED light source assembly comprises an LED light source for each optical sub-element, the LED light sources positioned along an outline near the light output surface radially outwards from the light output surface, the light output from each LED light source entering the adjustable element at first regions on the adjustable element when the adjustable element is in the first rotational position, the light output from each LED light source entering the adjustable element at second regions on the adjustable element when the adjustable element is in the second rotational position, the light from the LED light sources propagating from each LED light source towards the reflective surface of the respective optical sub-element such that the light is reflected by the reflective surface to form an output light that exits the reflector optical element through the light output surface, the output light when the adjustable element is in the first rotational position differing from the output light when the adjustable element is in the second rotational position.

14. The lighting assembly of claim 13, additionally comprising a first light pipes for each of the sub-elements at the first regions and a second light pipe for each of the sub-elements at the second regions, wherein each of the first light pipes has a first input end receiving light from a respective one of the LED light sources when the adjustable element is in a first rotational position and a first output end in contact with the adjustable element at the first regions, and each of the second light pipes has a second input end receiving light from a respective one of the LED light sources when the adjustable element is in a second rotational position and a second output end in contact with the adjustable element at the second regions, the first light pipes being different from the second light pipes in cross-sectional dimension.

15. The lighting assembly of claim 13, wherein the output light when the adjustable element is in the first rotational position differs in degree of collimation from the output light when the adjustable element is in the second rotational position.

16. A flashlight comprising the lighting assembly of claim 13.