Linear Light Emitting Diode Luminaires

• US 20180245753A1
• Filed: 02/24/2017
• Published: 08/30/2018
• Est. Priority Date: 02/24/2017
• Status: Active Grant

• Current Assignee: ABL IP Holding LLC (Acuity Brands, Inc.)
• Original Assignee: Whiteoptics, Llc (Acuity Brands, Inc.)
• Inventors: Magno, John N., Teather, Eric W.
• Granted Patent: US 10,317,021 B2
• Time in Patent Office: Days
• CPC Class Codes: F21S 4/20 with light sources held by or within elongate supports
• CPC Class Codes: F21V 17/164 the parts being subjected to bending, e.g. snap joints
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• 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 minimally complex, low cost/economical luminaire that distributes point source light for general lighting applications, the luminaire having a substrate with a linear array of discrete light sources positioned to emit light into an air-filled cavity and a light redirecting assembly on the other side the air-filled cavity, the assembly comprising a clear, light transmissive rigid cover and a clear, light transmissive semi-rigid flexible film positioned between the cover and the substrate, wherein the film is non-adhesively secured within the luminaire and flexed to generally conform to the shape of the cover and wherein the surface of the film facing into the air-filled cavity comprises an array of optical relief structures extending into the air-filled cavity.

Claims

1. A luminaire, which may be oriented in any direction, having a relative top and bottom and short-side axis and long-side axis, comprising:

a substrate located near the top of the luminaire and having a length extending linearly along the long-side axis;

a light redirecting assembly located at the bottom of the luminaire, comprising;

a clear, light transmissive rigid cover having a length extending linearly along the long-side axis and having a width extending in a curved path along the short-side axis, where in the curve is convex relative to the substrate;

a clear, light transmissive, semi-rigid, flexible film positioned below the rigid cover having a length extending linearly along the long-side axis, wherein the film is non-adhesively secured near the outer edge of the short-side axis and is flexed in the direction of the curve of the cover;

an air-filled cavity defined by the substrate and by the light redirecting assembly;

a linear array of discrete light sources positioned so as to emit light downwardly into the cavity, wherein the array of discrete light sources is affixed to the surface of the substrate facing into the air-filled cavity and extends along the long-side axis;

an electronic control for activating and powering the discrete light sources to emit light;

an electrical connection between the discrete light sources and the electronic control for activating and powering the discrete light sources, and wherein the surface of the clear, light transmissive, semi-rigid, flexible film facing into the air-filled cavity comprises;

an array of optical relief structures projecting into the air-filled cavity.

2. The luminaire of claim 1 wherein each of the two edges of the film extending linearly along the long-side axis are non-adhesively secured within recesses positioned within the luminaire at opposite ends of the short-side axis and which securing induce a curvature in the film so that it generally conforms to the inner surface of the cover.

3. The luminaire of claim 1 wherein the optical relief structures are selected from the group consisting of:

V groove, isosceles triangular groove, right triangular groove, acute triangular groove, pyramid, square pyramid, square right pyramid, rectangular pyramid, rectangular right pyramid, rhombic pyramid, or polygonal pyramid..

4. The luminaire of claim 1 wherein the optical relief structures have at least two opposite sides and a base and the angles between the faces on two opposite sides of the structures and the base of the structures are different from each other.

5. The luminaire of claim 1 wherein the optical relief structures have at least two opposite sides and a base and the angles between the faces on two opposite sides of the structures and the base of the structures vary from structure to structure over at least a portion of the surface of the film.

6. The luminaire of claim 1 wherein the optical relief structures have rectangular bases and the dimensions of the sides of the rectangular bases vary from structure to structure over at least a portion of the surface of the film.

7. The luminaire of claim 1 wherein the heights of the optical relief structures vary from structure to structure over at least a portion of the surface of the film.

8. The luminaire of claim 1 wherein the heights of the optical relief structures are between 5 and 200 microns.

9. The luminaire of claim 1 wherein the optical relief structures have at least rectangular bases and the sides of the rectangular bases are between 5 and 200 microns in length.

10. The luminaire of claim 1 wherein the optical relief structure comprises an array of grooves separated by ridges having triangular cross-sections;

wherein the array of grooves have isosceles triangular cross-sections and the ridges have either right or acute triangular cross-sections;

where the array covers the entire surface of the film and creates a surface topology on the film that has a sawtooth cross-sectional profile; and

wherein the triangular cross-sections of the ridges have base sides opposite the apices of the triangular cross-sections, wherein the angles of the base sides with the two remaining sides of the triangular cross-sections vary across at least a portion the surface of the film.

11. The luminaire of claim 1 wherein the surface of the film facing into the air-filled cavity has a surface topology comprised of an array of grooves that are separated by ridges having triangular cross-sections, wherein in some sections of the surface topology the triangular cross-sections of the ridges have the shape of right triangles and in other sections of the surface topology the ridges have the shape of isosceles triangles.

12. The luminaire of claim 11 wherein two sections of the surface topology having ridges with cross-sections having the shape of right triangles lie adjacent to and on opposite sides of a central axis of the film that extends the length of the substrate, and wherein the vertical sides of the right triangular cross-sections are oriented towards the central axis.

13. The luminaire of claim 12 wherein the right triangular shapes of the cross-sections of the ridges vary across the sections with the angles of the triangular shapes opposite their vertical sides increasing with increasing distance from the central axis.

14. The luminaire of claim 12 wherein two additional sections of the surface topology having ridges with cross-sections having the shape of isosceles triangles lie adjacent to the two sections having ridges with cross-sections having the shape of right triangles.

15. The luminaire of claim 13 wherein the angles of the triangular shapes opposite their vertical sides increase from 30 degrees to 50 degrees.

16. The luminaire of claim 14 wherein the four sections of the surface topology are equal in area.

17. The luminaire of claim 14 wherein the cross-sections having the shape of isosceles triangles have apex angles of 98 degrees.

18. The luminaire of claim 1 in which the shape of the cover is that of half of a hollow cylinder.

19. A luminaire with a substrate and a light redirecting assembly having an inner region disposed closer to the substrate and an outer region disposed closer to the exterior of the luminaire, comprising:

a linear array of discrete light sources positioned along the substrate so as to emit light into an air-filled cavity bounded by the substrate and the light redirecting assembly, wherein the light redirecting assembly comprises;

a clear, light transmissive semi-rigid flexible inner film layer and a clear, light transmissive rigid outer cover layer;

wherein the inner film layer is separated from the outer cover layer by a discontinuous air-gap layer extending across the majority of the outer surface of the inner film layer and the majority of the inner surface of the outer cover layer;

wherein the refractive index of the inner film layer is between 1.3 and 1.6, the refractive index of the air-gap layer is 1, and the refractive index of the outer cover layer is between 1.4 and 1.7; and

wherein the inner surface of the inner film layer contains an array of optical relief structures;

wherein the geometric shapes of the optical relief structures, along with the changes in refractive indices between the layers, allow for rays of light emitted from the light sources and passing through the light redirecting assembly to be partially reflected and partially transmitted so as to disperse and distribute light into a desired region around the exterior of the light redirecting assembly portion of the luminaire.

20. A method of dispersing light from a linear array of point light sources in luminaire comprising:

emitting light from the linear array of the point light sources arrayed along a substrate having a length;

passing the light emitted from the point light sources through an air-filled cavity;

receiving the light passed through the air-filled cavity at a light redirecting assembly comprising;

a clear, light transmissive, semi-rigid, flexible film extending the length of the substrate;

a clear, light transmissive cover extending the length of the substrate;

wherein the film is non-adhesively affixed between the cover and the substrate within the luminaire such that the affixing allows the film to approximately conform to the shape of the cover;

wherein the film is proximate to the air-filled cavity and comprises;

an array of optical relief structures that run along the length of the film and extend the length of the substrate.