Illumination device

Patent metadata

Field	Value
Publication number	US-12429191-B2
Application number	US-202318462861-A
Country	US
Kind code	B2
Filing date	Sep 7, 2023
Priority date	Sep 9, 2022
Publication date	Sep 30, 2025
Grant date	Sep 30, 2025

Abstract

An illumination device includes a light source, a light conversion element with a front side, an optical element, and first and second optical interfaces, wherein (a) an outer surface of the optical element includes a first surface area extending obliquely to the front side, so that secondary light can be decoupled at the second optical interface from the optical element into the surrounding medium in a direction which has a smaller angle in relation to the normal of the front side than if the first surface area extended in parallel to the front side of the light conversion element, and/or (b) the outer surface includes a second surface area extending obliquely to the front side of the light conversion element, so that secondary light can be reflected at the second optical interface into the optical element with total reflection in a direction toward the normal of the front side.

First claim

What is claimed is:

1. An illumination device, comprising:
at least one light source configured for emitting a primary light;
a light conversion element including a front side, the light conversion element being configured for being illuminated using the primary light emitted by the at least one light source and for emitting a secondary light having a different wavelength on the front side; and
an optical element, which is applied to the front side of the light conversion element such that a first optical interface is formed between the light conversion element and the optical element, such that the illumination device is configured for the secondary light being coupled from the light conversion element into the optical element at the first optical interface, the optical element including an outer surface which forms a second optical interface to a surrounding medium, the optical element being configured such that both the primary light and the secondary light pass through the optical element, wherein at least one of:
(a) the outer surface includes at least one first surface area extending obliquely to the front side of the light conversion element, such that the illumination device is configured for the secondary light being decoupled at the second optical interface from the optical element into the surrounding medium in a direction which has a smaller angle in relation to a normal of the front side of the light conversion element than if the at least one first surface area were to extend parallel to the front side of the light conversion element; and
(b) the outer surface includes at least one second surface area extending obliquely to the front side of the light conversion element, such that the illumination device is configured for the secondary light being reflected at the second optical interface into the optical element in a direction toward the normal of the front side of the light conversion element.

2. The illumination device according to claim 1 , wherein the optical element is a first optical element, wherein at least one of:
(a) the light conversion element is configured for being illuminated on the front side using the primary light emitted by the light source;
(b) the outer surface of the first optical element includes a third surface area forming the primary light;
(c) the illumination device is configured such that a part of the primary light directed onto the front side of the light conversion element extends as scattered primary light in a direction of the outer surface of the optical element;
(d) the illumination device includes a beam splitter, which is arranged both in a beam path of the primary light and in a beam path of the secondary light and is configured for deflecting the beam path of the primary light or the beam path of the secondary light by reflection; and
(e) the illumination device includes a second optical element, which is configured for at least one of focusing and collimating the secondary light decoupled from the first optical element.

3. The illumination device according to claim 1 , wherein at least one of:
(a) the at least one first surface area, at which the illumination device is configured for the secondary light being decoupled from the optical element, is formed by at least one first planar section of the outer surface of the optical element;
(b) the at least one first surface area, at which the illumination device is configured for the secondary light being decoupled from the optical element, is formed by at least one first planar section of the outer surface of the optical element, which extends over a solid angle of at least 0.45π;
(c) the at least one second surface area, at which the illumination device is configured for the secondary light being reflected into the optical element with total reflection, is formed by at least one second planar section of the outer surface of the optical element; and
(d) the at least one second surface area, at which the illumination device is configured for the secondary light being reflected into the optical element with total reflection, is formed by at least one second planar section of the outer surface of the optical element, which extends over a solid angle of at least 1π.

4. The illumination device according to claim 3 , wherein at least one of:
(a) at least one of (i) the outer surface of the optical element and (ii) the at least one first planar section of the outer surface of the optical element is at least partially spherically shaped;
(b) at least one of (i) the outer surface of the optical element and (ii) the at least one first planar section of the outer surface of the optical element is at least partially spherically shaped over a solid angle of at least 0.45π;
(c) at least one of (i) the outer surface of the optical element and (ii) the at least one second planar section of the outer surface of the optical element is at least partially parabolically shaped; and
(d) at least one of (i) the outer surface of the optical element and (ii) the at least one second planar section of the outer surface of the optical element is at least partially parabolically shaped over a solid angle of at least 1π.

5. The illumination device according to claim 3 , wherein at least one of:
(a) the illumination device, which is configured for the secondary light being decoupled at the at least one first surface area from the optical element, is configured for the secondary light being decoupled in a direction toward the normal of the front side of the light conversion element;
(b) the outer surface of the optical element is configured for at least one of focusing and collimating the secondary light;
(c) the at least one first surface area, which is configured for being that at which the secondary light is decoupled from the optical element, is configured for the secondary light being decoupled thereon and being decoupled in a center of the first optical interface into the optical element; and
(d) the at least one second surface area, which is configured for being that at which the secondary light is reflected into the optical element with total reflection, is configured for the secondary light being reflected thereon and being decoupled in a center of the first optical interface into the optical element.

6. The illumination device according to claim 1 , wherein the optical element is at least partially provided with a coating, wherein the outer surface of the optical element is provided at least partially with a coating.

7. The illumination device according to claim 1 , wherein at least one of:
(a) the light conversion element includes at least one of the following materials: a ceramic converter material; Ce:YAG; Ce:GYAG; Ce:LuAG; and Ce:GaLuAG;
(b) the light conversion element includes a polycrystalline material;
(c) the light conversion element includes an inorganic material;
(d) the light conversion element includes a monocrystalline material; and
(e) the light conversion element has an index of refraction which is greater than 1.5.

8. The illumination device according to claim 1 , wherein at least one of:
(a) the optical element includes at least one of the following materials: a glass; LaSF glass; N—LaSF9 glass; LASF35 glass; P-LASF51 glass; SF glass; and a glass equivalent thereto;
(b) the optical element has an index of refraction which is greater than 1.5;
(c) an index of refraction of the optical element is at most 0.3 less than that of the light conversion element;
(d) the optical element consists of a glass, which (i) in a range of 440 nm to 780 nm has an internal transmittance, measured on a 10-mm-thick sample, of at least 90%, and (ii) in a range of 500 nm to 780 nm has an internal transmittance, measured on a 10-mm-thick sample, of at

Assignees

• Schott Ag

Inventors

• Hagemann Volker
• Stöhr Ulrike

Classifications

• F21K9/60

  Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction · CPC title

• F21Y2115/30

  Semiconductor lasers · CPC title

• F21K9/68

  Details of reflectors forming part of the light source · CPC title

• F21V9/30 Primary

  Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) · CPC title

• F21V5/00

  Refractors for light sources (characterised by cooling arrangements F21V29/504) · CPC title