Lenses and methods for directing light toward a side of a luminaire

Patent metadata

Field	Value
Publication number	US-10274159-B2
Application number	US-201715644413-A
Country	US
Kind code	B2
Filing date	Jul 7, 2017
Priority date	Jul 7, 2017
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

Lenses and methods for directing light toward a side of light fixture, and methods for manufacturing the same, are disclosed. Embodiments include lenses with an optical axis and a first (e.g., upper) portion that is rotationally symmetric about the optical axis and a second (e.g., lower) portion that is rotationally asymmetric. The first/upper portion can include a cavity that receives an LED and directs light toward the second/lower portion. The asymmetric side can include a convex surface where the light exits the lens, the convex surface extending across the optical axis. Additional embodiments include a planar surface adjacent the convex surface, where the height of the lens decreases along the portion of the convex surface near the planar surface and along the planar surface as the distance from the optical axis increases. In further embodiments, the maximum height of the lens occurs between two horizontal sides of the lens.

First claim

What is claimed is:

1. A lens for an LED light fixture, comprising:
a lens defining an optical axis and configured to direct light toward a common side of the optical axis, the lens including first and second ends,
the first end of the lens defining a cavity configured to receive an LED light source, the first end portion being configured to direct light from an LED light source received within the cavity to the second end of the lens, the first end being rotationally symmetric with respect to the optical axis, and
the second end of the lens defining an exterior surface configured to emit light received from the first end, the second end being rotationally asymmetric with respect to the optical axis, and the exterior surface including a convex section and a first planar section adjacent one another, wherein the height of the lens decreases in the first planar section as the distance from the optical axis increases;

wherein the optical axis separates a taller side of the lens from a shorter side of the lens and the height of the lens is measured in a direction parallel to the optical axis, and wherein the taller side is disposed on the common side of the optical axis; and
wherein the light exiting the taller side has less radiant intensity (W/sr) than the light exiting the shorter side.

2. The lens of claim 1 , wherein the common side of the optical axis is defined by a longitudinal axis, and wherein the lens directs light at a radiant intensity that results in the light reaching a wall with constant brightness along a direction parallel to the optical axis, and wherein the wall is perpendicular to the longitudinal axis.

3. The lens of claim 1 , wherein
the first end includes an internally reflective surface;
the cavity includes
a central convex surface disposed in a generally perpendicular orientation to the optical axis and configured to refract light emanating from an LED light source positioned within the cavity in a direction more aligned with the optical axis, and
a side cylindrical surface disposed in a direction generally parallel to the optical axis and configured to refract light emanating from an LED light source positioned within the cavity toward the internally reflective surface; and

the internally reflective surface reflects light received from the side cylindrical surface in a direction more aligned with the optical axis.

4. The lens of claim 1 , wherein the convex section extends from a first side of the optical axis to a second side of the optical axis opposite the first side.

5. The lens of claim 1 , wherein the exterior surface of the second end includes a second planar section, and the convex section is positioned between the first planar section and the second planar section.

6. The lens of claim 5 , wherein the optical axis separates a taller side of the lens as measured in a direction parallel to the optical axis from a shorter side of the lens, the taller side being disposed on the common side of the optical axis and the first planar section being disposed on the other side of the optical axis, and wherein the junction between the first planar section and the convex section is angular.

7. The lens of claim 6 , wherein the second planar section is disposed on the taller side of the lens, and the junction between the second planar section and the convex section is curvilinear.

8. The lens of claim 6 , wherein
the height of the lens decreases in the convex section as the distance from the optical axis increases.

9. The lens of claim 6 , wherein convex section defines the tallest portion of the lens.

10. The lens of claim 1 , wherein portions of the convex section located nearer to the first planar section have smaller radii of curvature than portions of the convex section located farther from the first planar section.

11. The lens of claim 10 , wherein the cross-section of the convex section is linear in a plane perpendicular to the optical axis and perpendicular to the longitudinal axis.

12. A method, comprising:
receiving a first portion of LED light propagating from an LED defining an optical axis, wherein the first portion of LED light propagates within a cone of a predetermined angle centered on the LED optical axis with a vertex collocated with the LED;
directing the received first portion of LED light to align more with the optical axis;
redirecting the first portion of LED light toward a preferred side of the LED optical axis with a curved refractive surface;
receiving a second portion of LED light propagating from the LED outside the cone of a predetermined angle centered on the LED optical axis with a vertex collocated with the LED;
directing the received second portion of LED light toward a reflective surface;
reflecting the directed second portion of LED light to align more with the optical axis; and
redirecting the reflected second portion of LED light toward the preferred side of the LED optical axis with a planar refractive surface;
wherein said redirecting the reflected second portion of LED light includes refracting light exiting a lens with a planar surface.

13. The method of claim 12 , wherein said reflecting the directed second portion of LED light includes internally reflecting light propagating through a lens off an external surface of the lens.

14. The method of claim 12 , wherein said redirecting the first portion of LED light includes refracting light exiting a lens with the curved refractive surface.

15. A lens for an LED light fixture, comprising:
a lens defining an optical axis and configured to direct light toward a common side of the optical axis, the lens including first and second ends,
the first end of the lens defining a cavity configured to receive an LED light source, the first end portion being configured to direct light from an LED light source received within the cavity to the second end of the lens, the first end being rotationally symmetric with respect to the optical axis, and

the second end of the lens defining an exterior surface configured to emit light received from the first end, the second end being rotationally asymmetric with respect to the optical axis, and the exterior surface including a convex section and a first planar section adjacent one another, wherein the height of the lens decreases in the first planar section as the distance from the optical axis increases;
wherein the exterior surface of the second end includes a second planar section, and the convex section is positioned between the first planar section and the second planar section.

16. The lens of claim 15 , wherein the common side of the optical axis is defined by a longitudinal axis, and wherein the lens directs light at a radiant intensity that results in the light reaching a wall with constant brightness along a direction parallel to the optical axis, and wherein the wall is perpendicular to the longitudinal axis.

17. The lens of claim 15 , wherein
the first end includes an internally reflective surface;
the cavity includes
a central convex surface disposed in a generally perpendicular orientation to the optical axis and configured to refract light emanating from an LED light source positioned within the cavity in a direction more aligned with the optical axis, and
a side cylindrical surface disposed in a direction generally parallel to the optical axis and configured to refract light emanating from an LED light source positioned within the cavity toward the internally reflective surface; and

the internally reflective surface reflects light received from the side cylindrical surface in a direction more al

Assignees

• Rab Lighting Inc

Inventors

• Kim Brian

Classifications

• F21V29/83

  the elements having apertures, ducts or channels, e.g. heat radiation holes · CPC title

• F21V13/04

  the elements being reflectors and refractors {(for vehicle rear lights F21S43/40)} · CPC title

• F21V5/04 Primary

  of lens shape · CPC title

• F21V7/09

  with a combination of different curvatures · CPC title

• F21V7/0091

  using total internal reflection · CPC title