Light-emitting assembly and lamp having a light-emitting assembly

Abstract

A light-emitting assembly that has a light-radiating element for radiating light, an optical element for influencing the light, and a transparent insulating element, which is arranged in the path of the light, wherein the insulating element is made of a material that is more thermally stable than the material of the optical element. A lamp, in particular in the form of a spotlight, having such a light-emitting assembly is also disclosed.

Claims

1. A light-emitting assembly, having; a light-emitting element for emitting a light along a path, an optical element for influencing the path of the light, and a transparent insulating element, which is arranged in the path of the light between the light-emitting element and the optical element, wherein the insulating element comprises a material which is more thermally stable than that of the optical element, and a surrounding element which is arranged so as to surround both the optical element and the insulating element in dust-tight fashion, wherein the surrounding element has a hollow-cylindrical region and the optical element has a cylindrical outer surface which contacts the hollow-cylindrical region, and the insulating element has a cylindrical outer surface which contacts the hollow-cylindrical region of the surrounding element.

2. The light-emitting assembly as claimed in claim 1, wherein the optical element and the insulating element are spaced at least 2 mm apart.

3. The light-emitting assembly as claimed in claim 1, in which the surrounding element consists of plastic.

4. The light-emitting assembly as claimed in claim 1, in which the surrounding element is formed of one piece.

5. The light-emitting assembly as claimed in claim 1, in which the insulating element has a plate-shaped or disk-shaped configuration.

6. The light-emitting assembly as claimed in claim 1, in which an air-filled space is formed between the optical element and the insulating element.

7. The light-emitting assembly as claimed in claim 1, in which the insulating element is formed so as to consist of one piece.

8. The light-emitting assembly as claimed in claim 1, in which the insulating element is configured and arranged in such a way that it bounds a light entry surface for the entry of the light into the optical element.

9. The light-emitting assembly as claimed in claim 1, further having a light diffusing disk, which is arranged in the path of light between the optical element and the insulating element.

10. The light-emitting assembly as claimed in claim 9, in which the surrounding element is configured and arranged in such a way that it bounds a light entry surface for the entry of the light into the optical element.

11. The light-emitting assembly as claimed in claim 9, in which the light-emitting element is arranged so as to be held directly on the surrounding element.

12. The light-emitting assembly as claimed in claim 9, in which the surrounding element consists of a non-transparent material.

13. The light-emitting assembly as claimed in claim 9, in which the surrounding element forms a reflector element.

14. The light-emitting assembly as claimed in claim 9, in which the surrounding element is formed so as to consist of one piece.

15. A projector lamp, comprising a light-emitting assembly as claimed in claim 9.

16. The light-emitting assembly as claimed in claim 1, wherein the insulating element is formed of glass.

17. The light-emitting assembly as claimed in claim 16, wherein the optical element consists of plastic.

18. The light-emitting assembly as claimed in claim 1, wherein the optical element consists of plastic.

19. The light-emitting assembly as claimed in claim 9, wherein the light diffusing disk consists of plastic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective sketch in the form of an exploded illustration of component parts of a light-emitting assembly according to the invention,

(2) FIG. 2 shows a corresponding cross-sectional sketch, and

(3) FIGS. 3 to 5 show illustrations of the damage to known light-emitting assemblies.

DETAILED DESCRIPTION

(4) In FIG. 1, component parts of a light-emitting assembly according to the invention are sketched in the form of an exploded illustration, and FIG. 2 shows a corresponding cross-sectional illustration. The light-emitting assembly comprises a light-emitting element 1 for emitting a light. In FIG. 2, the light-emitting element 1 is indicated purely schematically. In particular, the light-emitting element 1 may be an LED light source, i.e., for example, a printed circuit board on which an LED is arranged or a plurality of LEDs are arranged.

(5) Furthermore, the light-emitting assembly comprises an optical element 2 for influencing the light emitted by the light-emitting element 1. In particular, the optical element 2 consists of a plastic. The optical element 2 may be, for example, a lens.

(6) Preferably, the optical element 2 has a light entry surface 25, which is configured to allow the entry of the light emitted by the light-emitting element 1. As is the case in the example shown, the light entry surface 25 can be formed by a surface region of the optical element 2 which faces the light-emitting element 1.

(7) Furthermore, the light-emitting assembly comprises a transparent insulating element 3. In this case, the insulating element 3 is arranged in the path of the light and consists of a material which is more thermally stable than the material of which the optical element 2 consists. In particular, the configuration is such that the insulating element 3 is arranged in such a way that the light emitted by the light-emitting element 1 first passes through the insulating element 3 and then enters the optical element 2.

(8) Preferably, the insulating element 3 consists of glass. Glass is more thermally stable than plastic.

(9) As sketched by way of example in the figures, the insulating element 3 preferably has a plate-shaped or disk-shaped configuration. In addition, it preferably consists of only one piece. In this way, the passage of light through said insulating element is impaired to a particularly low extent.

(10) By virtue of the insulating element 3, it is possible to form an “interlayer” which is comparatively thermally stable between the thermally more susceptible optical element 2, on the one hand, and a particle 9, which may be present, on the other hand. Owing to the transparency of the insulating element 3, it is in this case possible to achieve a situation whereby, as a result, the optical properties of the light-emitting assembly, in particular the lighting efficiency thereof, are not notably impaired. The interlayer or the insulating element 3 so to speak distributes the heat which forms in the case of the deposited particle 9 as light enters as a result of absorption by means of thermal conduction and represents a thermal resistance between the particle 9 and the optical element 2. As a result, the temperature of the optical element 2 is kept correspondingly low.

(11) If the thermal conductivity of the insulating element 3 is directionally independent or isotropic and is comparatively high, the heat is distributed very well, but the thermal resistance formed perpendicular to the insulating element 3 by the insulating element 3 is comparatively low. If, on the other hand, the thermal conductivity of the insulating element 3 is comparatively low, the thermal resistance between the particle 9 and the optical element 2 is comparatively high, but the heat is not distributed as well. This effect can be effectively counteracted if the light-emitting assembly is configured in such a way that an air-filled space or an air layer is formed between the insulating element 3 and the optical element 2 (not shown in the figures). In this case, the heat is distributed well within the insulating material 3, but the thermal resistance between the particle 9 and the optical element 2 is nevertheless particularly high owing to the air layer. The spacing between the optical element 2 or the light entry surface 25 of the optical element 2, on the one hand, and the insulating element 3, on the other hand, is preferably at least 1 mm, particularly preferably at least 2 mm.

(12) In the example sketched in FIGS. 2 and 3, the light-emitting assembly also comprises a diffusing disk 5, which is arranged between the optical element 2 and the insulating element 3. The diffusing disk 5 can consist of plastic. In this case, the diffusing disk 5 itself represents an optical element which is protected in an analogous manner by the insulating element 3.

(13) As is furthermore the case in the example illustrated, the light-emitting assembly preferably also has a surrounding element 4, which is formed and arranged in such a way that it surrounds both the optical element 2 and the insulating element 3, in particular in dust-tight fashion. In this way, the possibility of a particle being deposited in an undesired manner on the light entry surface 25 can be practically prevented.

(14) For example, the configuration can be such that, as indicated in FIG. 2, the surrounding element 4 has a hollow-cylindrical region B and the optical element 2 has a cylindrical outer surface, with which it makes contact with the hollow-cylindrical region B, and the insulating element 3 likewise has a cylindrical outer surface with which it makes contact with the hollow-cylindrical region B of the surrounding element 3. Preferably, the shape is in each case circular-cylindrical.

(15) In this case, the surrounding element 4 can be configured and arranged in such a way that it bounds the light entry surface 25 of the optical element 2.

(16) Preferably, the configuration is furthermore such that the light-emitting element 1 is arranged so as to be held directly or indirectly on the surrounding element 4.

(17) Preferably, the surrounding element 4 consists of a non-transparent material, for example of plastic or a metal. As is the case in the example shown, the surrounding element may be a reflector element, which is preferably furthermore configured to influence the light, in particular the light that has emerged from the optical element 2 again.

(18) The surrounding element 4 can be formed from one piece, as sketched, but it is also possible for it to consist of a plurality of pieces.

(19) In the exemplary embodiment shown, the light-emitting assembly also has a ring-shaped reflector element 8, for example in the form of a reflector film, which is arranged on that side of the insulating element 3 which is opposite the optical element 2.

(20) Particularly preferably, the light-emitting assembly forms a component part of a lamp, in particular a projector lamp. In particular, the lamp can be designed for a downward light emission.