Light source for uniform illumination of a surface

Patent metadata

Field	Value
Publication number	US-2018347784-A1
Application number	US-201816057870-A
Country	US
Kind code	A1
Filing date	Aug 8, 2018
Priority date	Oct 2, 2014
Publication date	Dec 6, 2018
Grant date	—

Abstract

Devices and methods for uniform illumination of a target surface are disclosed. A device assembly has a light source configured to be coupled to a mounting surface, and at least one reflector. The reflector is configured to be coupled to at least one of the light source or the mounting surface, and interposed between the light source and the mounting surface, the reflector having a reflective surface area and a plurality of curved reflective segments. The reflector is shaped and arranged relative to the light source such that the reflector directly intercepts and reflects a portion of light emitted by the light source to the target surface to thereby cause substantially uniform illumination of the target surface. The target surface has a surface area that is greater than the reflective surface area of the at least one reflector.

First claim

1 . A device for uniform illumination of an irregular target surface, comprising:
an elongated light source extending along an x axis and arranged to prevent any direct impingement of light onto the irregular target surface; and at least one reflector having a length relative to the x axis and a reflective surface area, the reflective surface area comprising a profile having a plurality of curved reflective segments; wherein the irregular target surface has a target surface area that is greater than the reflective surface area; the irregular target surface has a first region and a second region, the first region comprising an intersection between the irregular target surface and a normal of the light source, the second region being further from the intersection than the first region is; a first of the curved reflective segments is configured to reflect light primarily to the second region of the irregular target surface; a second of the curved reflective segments is configured to reflect light primarily to the first region of the irregular target surface; the elongated light source and the at least one reflector are arranged such that the at least one reflector, by virtue of its shape, is configured to directly intercept and reflect a portion of light emitted by the light source to thereby cause substantially uniform illumination of the irregular target surface; and at least some of the light reflected by the first curved reflective segment, and the light reflected by the second curved reflective segment cross paths.

2 . The device of claim 1 , wherein the at least one reflector comprises a plurality of elliptical segments each having a common focus coincident with the elongated light source but second foci non-coincident with each other and distributed over the irregular target surface.

3 . The device of claim 2 , wherein the second foci of the plurality of elliptical segments are substantially evenly distributed over the irregular target surface, thereby configured to cause substantially uniform illumination of the irregular target surface.

4 . The device of claim 1 , wherein:
the first curved reflective segment is configured to receive light having a first intensity from the elongated light source, and reflect the light having the first intensity to a first spatial region, the first spatial region a first distance from the elongated light source; and wherein the second elliptical segment is configured to receive light having a second intensity from the elongated light source and reflect the light having the second intensity to a second spatial region, the second spatial region a second distance from the elongated light source, the second distance less than the first distance, and the second intensity being lower than the first intensity.

5 . The device of claim 1 , wherein
the elongated light source is arranged along an optical axis of the at least one reflector.

6 . The device of claim 1 , wherein the at least one reflector subtends an angle of approximately 45°, measured from a center of the elongated light source.

7 . The device of claim 1 , wherein the at least one reflector subtends an angle of approximately 90°, measured from a center of the elongated light source.

8 . The device of claim 1 , wherein the at least one reflector comprises two reflectors and the device further comprises an optical element placed between the two reflectors.

9 . The device of claim 1 , wherein the at least one reflector comprises a plurality of parabolic segments or a plurality of elliptical segments having a common focus coincident with the elongated light source.

10 . The device of claim 9 , wherein directing angles of the parabolic segments or elliptical segments are evenly distributed over the irregular target surface.

11 . The device of claim 1 , wherein the x axis is non-linear.

12 . The device of claim 1 , wherein the device comprises a first reflector and a second reflector, the first and second reflectors not identical to each other.

13 . The device of claim 1 , further comprising an actuator to adjust a position of at least one curved reflective segment.

15 . A method for uniform illumination of an irregular target surface, comprising:
emitting light by an elongated light source, the elongated light source extending along an x axis and being arranged to prevent any direct impingement of light onto the irregular target surface; and causing at least one reflector extending parallel to at least a portion of the elongated light source and having a plurality of curved reflective segments to directly intercept and reflect a portion of light emitted by the elongated light source, the at least one reflector having a reflective surface area; causing a first curved reflective segment to reflect light to a second region of the irregular target surface; causing a second curved reflective segment to reflect light to a first region of the irregular target surface; causing the light reflected by the first curved reflective segment and the light reflected by the second curved reflective segment to cross paths; and effecting substantially uniform illumination of the irregular target surface, the irregular target surface having an area greater than the reflective surface area of the at least one reflector.

16 . The method of claim 15 , wherein the at least one reflector comprises a plurality of elliptical segments having a common focus coincident with the light source and different second foci distributed over the irregular target surface.

17 . A device assembly for uniform illumination of an irregular target surface, comprising:
a linear light source configured to be coupled to a mounting surface and arranged to prevent any direct impingement of light onto the irregular target surface; and at least one reflector configured to be coupled to at least one of the light source or the mounting surface, and interposed between the light source and the mounting surface, the at least one reflector having a reflective surface area, the at least one reflector comprising a plurality of curved reflective segments; wherein the at least one reflector is shaped and arranged relative to the light source such that the at least one reflector intercepts and reflects a portion of light emitted by the light source to the irregular target surface to thereby cause substantially uniform illumination of the irregular target surface; and wherein the irregular target surface has a surface area that is greater than the reflective surface area of the at least one reflector.

18 . The device assembly of claim 17 , wherein the at least one reflector comprises a first elliptical segment and a second elliptical segment;
wherein the first elliptical segment is configured to receive light having a first intensity from the light source and reflect the light having the first intensity to a first spatial region of the irregular target surface, the first spatial region a first distance from the light source; and wherein the second elliptical segment is configured to receive light having a second intensity from the light source and reflect the light having the second intensity to a second spatial region of the irregular target surface, the second spatial region a second distance from the light source, the second distance less than the first distance, and the second intensity being lower than the first intensity.

19 . The device assembly of claim 17 ; wherein
the surface area of the irregular target surface is at least an order of magnitude greater than the reflective surface a

Assignees

• Ledvance Llc

Inventors

• Catalano Anthony W

Classifications

• F21S8/04

  intended only for mounting on a ceiling or the like overhead structures (F21S8/02 takes precedence; {details of ceiling bases F21V21/03}) · CPC title

• F21Y2103/10

  comprising a linear array of point-like light-generating elements · CPC title

• F21V7/005 Primary

  with an elongated shape to cooperate with linear light sources · CPC title

• F21V7/0016

  on lighting devices that also provide for direct lighting, e.g. by means of independent light sources, by splitting of the light beam, by switching between both lighting modes · CPC title

• F21V7/08

  with elliptical curvature · CPC title