Illumination device

Patent metadata

Field	Value
Publication number	US-10502392-B2
Application number	US-201615752903-A
Country	US
Kind code	B2
Filing date	Jul 1, 2016
Priority date	Aug 24, 2015
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

An illumination device is provided with an optoelectronic light source and an optical body. The optical body is divided into an inner lens part and an outer reflector part adjoining thereon outward in relation to directions perpendicular to a main direction, which body parts are formed monolithically with one another. The inner part is formed as a Fresnel lens with active flanks which acts as a collimating lens, so that a first part of the light which passes through the Fresnel lens via the active flanks is refracted toward the main direction. A second part of the light which passes through the Fresnel lens via folding flanks is refracted away from the main direction. A reflection surface is provided on the outer reflector part, on which the second part of the light is incident and is reflected thereon and deflected with the reflection toward the main direction.

First claim

The invention claimed is:

1. An illumination device comprising
an optoelectronic light source having a light emission surface for the emission of light and an optical body, through which the light passes, for light redistribution, on which optical body the light is incident with a main direction,
wherein the optical body is divided into an inner lens part and an outer reflector part adjoining thereon outward in relation to directions perpendicular to the main direction, which optical body parts are formed monolithically with one another,
wherein the inner lens part is configured as a Fresnel lens, so that a light passage surface of the inner lens part is subdivided into active flanks and folding flanks, which Fresnel lens having the active flanks acts as a collimating lens, so that a first part of the light which passes through the Fresnel lens via the active flanks is refracted toward the main direction, wherein a second part of the light which passes through the Fresnel lens via the folding flanks is refracted away from the main direction, in which the folding flanks, observed in sectional planes which each contain a center axis of the optical body, extend substantially parallel to one another, insofar as they lie on the same side of the center axis, and wherein a reflection surface is provided on the outer reflector part, on which the second part of the light is incident and is reflected thereon and deflected with the reflection toward the main direction.

2. The illumination device as claimed in claim 1 , in which the first part of the light, immediately downstream of the inner lens part, has a first luminosity distribution having a first aperture angle ω 1 and the second part of the light, immediately downstream of the outer reflector part, has a second luminosity distribution having a second aperture angle ω 2 , wherein ω 2 ≤ω 1 .

3. The illumination device as claimed in claim 1 , in which the entire first part of the light passes the reflection surface, so that the light passes thereby.

4. The illumination device as claimed in claim 1 , in which the first part of the light, immediately downstream of the inner lens part, has a first luminosity distribution, in which the luminosity decreases from a maximum value with an increasing tilt angle in relation to the main direction, wherein the second part of the light, immediately downstream of the inner lens part, has an intermediate luminosity distribution, in which the luminosity increases at least in some regions with increasing tilt angle, wherein at tilt angles below a limit tilt angle, the luminosity in the intermediate luminosity distribution is less than the luminosity in the first luminosity distribution, at which limit tilt angle the luminosity in the first luminosity distribution only still makes up at most 20% of the maximum value.

5. The illumination device as claimed in claim 1 , in which the Fresnel lens acting as a collimating lens has a light-source-side focal point, which is spaced apart by at most 5 mm from the light emission surface.

6. The illumination device as claimed in claim 1 , in which a first of the active flanks has a first light-source-side active flank focal point and a second of the active flanks has a second light-source-side active flank focal point, wherein these two active flank focal points are spaced apart by at least 1 mm in relation to one another in the main direction.

7. The illumination device as claimed in claim 1 , in which the second part of the light enters therein at an inner surface of the outer reflector part and the reflection surface is arranged on an outer surface, which is opposite to the inner surface, of the outer reflector part.

8. The illumination device as claimed in claim 7 , in which the outer surface of the outer reflector part forms a total reflection surface and is molded for this purpose having a plurality of oblong prism protrusions, each of which has two flanks, which taper toward one another outward into a respective ridge for each prism protrusion and enclose there a respective wedge angle of at least 60° and at most 120° in each case with one another, so that each of the prism protrusions forms a reflection prism, at which at least the majority of the respective part incident thereon of the second part of the light is deflected by twofold total reflection toward the main direction.

9. The illumination device as claimed in claim 8 , in which each of the prism protrusions is provided and arranged such that the ridge thereof lies completely in a respective plane containing a center axis of the optical body.

10. The illumination device as claimed in claim 7 , in which the inner surface of the outer reflector part is faceted at least in regions.

11. The illumination device as claimed in claim 1 , in which a light entry surface, at which the light enters the inner lens part, is the light passage surface subdivided into the active flanks and the folding flanks.

12. The illumination device as claimed in claim 11 , in which a light exit surface, which is opposite to the light entry surface, of the inner lens part is provided with a light mixing means.

13. The illumination device as claimed in claim 12 , in which the light mixing means is a microlens arrangement having a plurality of microlenses molded into the light exit surface.

14. A method for producing an illumination device, the method comprising:
providing an optoelectronic light source having a light emission surface for the emission of light;
producing an optical body, through which the light passes, for light redistribution, on which optical body the light is incident with a main direction, wherein the optical body is produced by injection molding, wherein the optical body is divided into an inner lens part and an outer reflector part adjoining thereon outward in relation to directions perpendicular to the main direction, which optical body parts are formed monolithically with one another, wherein the inner lens part is configured as a Fresnel lens, so that a light passage surface of the inner lens part is subdivided into active flanks and folding flanks, which Fresnel lens having the active flanks acts as a collimating lens, so that a first part of the light which passes through the Fresnel lens via the active flanks is refracted toward the main direction, wherein a second part of the light which passes through the Fresnel lens via the folding flanks is refracted away from the main direction, in which the folding flanks, observed in sectional planes which each contain a center axis of the optical body, extend substantially parallel to one another, insofar as they lie on the same side of the center axis, and wherein a reflection surface is provided on the outer reflector part, on which the second part of the light is incident and is reflected thereon and deflected with the reflection toward the main direction.

15. The illumination device as claimed in claim 1 , in which the second part of the light enters therein at an inner surface of the outer reflector part and the reflection surface is arranged on an outer surface, which is opposite to the inner surface, of the outer reflector part as a total reflection surface.

16. A method for producing an illumination device as claimed in claim 14 , wherein of the optical body is produced by the injection molding uses a two-part injection mold.

17. An illumination device comprising
an optoelectronic light source having a light emission surface for the emission of light and an optical body, through which the light passes, for light redistribution, on which optical body the light is inci

Assignees

• Osram Gmbh

Inventors

• Schwalenberg Simon

Classifications

• F21V13/04

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

• F21V5/045 Primary

  the lens having discontinuous faces, e.g. Fresnel lenses · CPC title

• G02B3/08

  with discontinuous faces, e.g. Fresnel lens {(diffractive Fresnel lenses G02B5/1876)} · CPC title

• F21Y2115/10

  Light-emitting diodes [LED] · CPC title

• F21V13/045

  for portable lighting devices · CPC title