WO2015089535A1

WO2015089535A1 - Optical element for a light source

Info

Publication number: WO2015089535A1
Application number: PCT/AT2014/000228
Authority: WO
Inventors: Martin Siegel
Original assignee: Zumtobel Lighting Gmbh
Priority date: 2013-12-20
Filing date: 2014-12-19
Publication date: 2015-06-25

Abstract

An optical element (1) in particular for influencing the light emission of an LED or OLED light source comprises a body (10) which consists of a silicone material and which has structures (20), in particular microstructures, that are produced by treating the silicone material using a laser (50).

Description

Optical element: for mm light source

The invention vorliegende- ^'heirifft an optical element for a light source, in particular the dispensing Liebt LED or oiled by means of the optical element - that is, a so-called organic LED - to be infiuenced.

In the meantime, LED-based light sources can be found in all areas of the industry

Lighting technology Use, in particular in the room lighting or in the lighting of larger buildings or building complexes. Since the lichteinitiierende Halbleiterehip an LED usually radiates the Liebt in a very large angular range, a variety of optics are used, with the help of which the light is then bundled in the desired manner or in the desired manner .ausgerichtet. Often the light output is even affected by several optical elements, on the one hand a so-called, primary optics, which is formed directly on the LED chip or associated with this, and on the other hand, a in

Light emission direction downstream secondary optics, which then

determines the actual levy of a lamp.

The primary optics directly assigned to the LED chip usually also simultaneously fulfill a protective function, since they cause light pollution

Halide element is shielded from external influences. Furthermore can be contained within the primary optics also Farbkonversionspartil el or phosphors with the ^'help of at least a part of light emitted from the LED chip light is converted into light of another wavelength, so that letztendiich ei Lsehlieht suitable color or generated with appropriate color temperature is , This represents, for example, a relatively easy way to produce with the help of an LED light source Welßiicht.

Often the primary optics applied directly to the LED chip consist of silicone material. Such optics are then either in. Injection molding or in the case of simpler optics also produced by simple dispensing methods.

Although such methods can be carried out relatively inexpensively, they at most allow the creation of macroscopic optics with the aid of which the light emission can be influenced only to a small degree. For a more precise influencing of the light output, microstructures would be needed, ie structures in the

Less micrometer required, but the above methods do not provide sufficient accuracy. Alternative materials such as glass or plastic could be compared to. Silicone are processed accordingly fine, but they have other disadvantages, which prevent meaningful use as primary optics for LEDs. For example, glass for use directly on a LED chip for both optical reasons as well as for material technical reasons - glass is too hard and could therefore be easily damaged - not usable.

The present invention is therefore based on the object - to provide a novel solution to the manufacturer: optical elements, which allows, if necessary, to be able to realize structures in the micrometer range with sufficient accuracy.

The object is achieved by an optical element having the features of claim 1 and by a method according to claim 14. Advantageous developments of the invention are the subject of the dependent claims.

The solution according to the invention is based on the idea of forming the desired optical element from a silicone material. This silicone material has at least partially structures that were created by processing the silicone material by means of a laser.

Erfindungsgernaß an optical element for influencing the light output, in particular a LED or OLED LiehtquelSe is proposed, wherein the optical element comprises a made of ^' a silicone material body having created by processing the silicone material by means of laser structures, in particular microstructures.

The solution according to the invention is based on a technology known from the prior art in which a polymerizafiom process can be controlled in a targeted manner with the aid of laser radiation in certain silicone materials. This method has been developed especially in the medical field and is used here in a number of different applications. With the present invention it is now proposed to use this method specifically for the production of Siükon-based structures in the field of lighting technology. This opens up the possibility of producing new optical elements which can benefit from the advantageous material properties of silicone, namely its mixer stability and its optical transparency. Femer can with the help of

Process structures can be created with accuracies of a few microns. wa meets the above requirements for the purposeful influencing of the light output.

According to the invention, the structures produced by means of the laser machining can be located on a surface of the optical element facing away from the light source. However, this does not necessarily have to be the case. Instead, the structures could also be embedded in the optical element in such a way that they are surrounded by a silicon material with different optical properties, in particular with a different refractive index. This configuration is achieved in a simple manner in that, with the aid of laser radiation, regions of the starting silicone material that are influenced in such a way - in fact polymerized - are such that they have a different refractive index compared to the regions not processed with the laser radiation. In this way, virtually any three-dimensional structures can be introduced into the silicone body. If the non-polymerizing material is subsequently removed therefrom, if necessary in part, it results in an optical element which consists exclusively of the material processed with the aid of the laser radiation or has the optical structures on its surface as described above. The erfindungsgen ate microstructures, for example, lens-like

Structures include "It may, however, also be concerned with light-scattering structures that are based, for example, on lattice or grid structures. Furthermore, with the aid of the procedure according to the invention, the surface of the optical element could also be provided with an anti-reflective structure, wherein it would also be conceivable to realize these different thoughts together in an optical element.

As already mentioned, the advantage of the solution according to the invention is that it makes use of the silicone materials, which have already been widely used in the past. Accordingly, it can also be provided that the silicone material of the optical element according to the invention additionally phospliore or other

Has color conversion means., By means of which the light emitted by the light source is at least partially converted into light of different wavelength. The optical element according to the invention or its silicone body can be arranged directly on the LED light source and then correspondingly form a primary optic. Alternati v to this, the silicone body could, however, also be arranged on a separate support element, which is then preferably transparent, so for example consists of glass. The invention will be explained in more detail in the attached drawing. 1 shows a schematic illustration to illustrate the procedure according to the invention for creating micro-opaque structures.

FIG. 2 is a plan view of a first embodiment of an optic according to the invention; FIG. Fig. 3 shows a second Ausrhrungsungsbeispiel a erfmdungsge ate optics in

Selinittdärsielinng and

4 shows a variant of the optics of FIG. 3, FIG. 1 shows a first exemplary embodiment of a primary optics according to the invention for influencing the light of an LED light source;

The procedure for creating the macro structures should be clarified

Shown is a Prr aroptic for a LED chip 100, wherein the optics, which is generally designated by the reference numeral 1, a silicone body 10 which is disposed on the Liehtabstrahhmg provided surface of the LED chip 100. The silicone body 0 could, for example, be applied to the surface 101 of the LED chip 100 by a correspondingly simple dispenser loss. In the following step, that is to say after the application of the silicone material to the LED chip 100, the microstructure 20 indicated schematically in FIG. 1 is to be created »; This is done by machining the silicone body 10 with the aid of a laser beam 50, wherein the laser beam 50 can be focused on a specific area of the silicone body 10. The laser beam. 50 now makes it possible to deliberately initiate a polymerization of the silicone material 1 in the area 51; a prerequisite for this is, of course, that a suitable silicone material be selected, for which purpose, for example, PDMS (polydimethylsiloxane). possibly could be used with admixture of suitable photocatalysts. The polymerization of the Silikonmateriais has the consequence that the pol merisierte

Material compared to the surrounding silicone material, which has not been polymerized, has a different refractive index. This results in structures 20, which can influence light beams by refraction or scattering accordingly. Since with the described method of Polvinerisationsprozess the As a result of the very precise control of the silicon atom, it is possible to create the structures with micrometer accuracies.

With the aid of the method shown at the bottom in FIG. 1, structures 20 could thus be introduced into the silicone dome 10, as they are shown by way of example in FIG. 2. In this case, a laser structure 50 was introduced into the silicone material 10 with the aid of the laser beam 50, by means of which the light emitted by the LED chip 100 should be influenced in a corresponding manner. The distances d between the individual lines 26 and their width can thereby be influenced be chosen in almost any way, since the process in this regard has a very high flexibility.

Another way to realize a micro-optic _. according to the present invention is shown in Fig. 3, in this. Fall is again the use as

Provided that the silicone material 10 is disposed directly on the surface of the LED chip 100 in the same way, however, would also be conceivable that as a support substrate for the silicone material 10 is a Glaspiätichen or the like is used, in which case dan the optical element is no longer necessarily used as the primary optics but then, for example, at a certain distance from the light uelle is arranged. In the illustrated Ausfuhmngsbeispiel according to FIG. 3, a lens structure 28 is now introduced into the silicone material with the aid of the laser beam. Such a structure 20 also makes it possible for the light emitted by the LED 100 to be influenced with regard to the angular range in which the light is radiated, the influence now being significantly greater than in the case of those known from the prior art primary optics. Since, in turn, there are no restrictions with regard to the design of the lens structures 28, the light-influencing property of the optical element 1 according to the invention can be varied almost as desired. Instead of the lenses 28, for example, the realization of prism structures, for example in the form of pyramid or p ramidenstumpfrbrmiger structures conceivable. These may be elongate or arranged like a mairix.

The finally obtained structures 20 can remain within the uncured silicone 10, so that they are therefore protected by this. However, it would also be conceivable to at least partially remove the non-cured silicone after completion of the laser processing. In this case, only the cured structure 20 would remain. This is true for both shown Unsen- or prism structures as well as for the lattice structure in the Ausfxihrungsbeispiel according to Figure 2.

The exemplary embodiment of FIG. 4 differs from the

Aissföhrungshei game according to FIG. 3 in that between the carrier substrate 100, so either the LED chip or a glass plate, for example, and the.

Silikonmatena! 10 additionally a phosphor layer 1 10 was introduced. With the help of this phosphor layer 1 10 occurring light beams are at least partially implemented in Lieht a different wavelength, so that in Kombinatton with the not influenced by the Phosphormalerial light a mixed light, is generated, which is emitted via the erfindungsgsgemäße optical element 1. Alternatively, however, could also be the silicone material 10, which in the

according to the invention ^' way, even the phosphorus particles include.

In particular, in case of use as a primary optic, the. With the help of

created procedure according to the invention. Macro structure does not necessarily cover the entire Kchtemittlerendert area of the LED chip. It would be conceivable, for example, that the microstructure covers only a portion of the chip and in other areas no microstructure is provided or the structure is designed differently here. This can be useful, in particular, if the optical element is used as primary optics for an LED cluster consisting of a plurality of LEDs which emit light of different colors. In this case, it would be entirely conceivable that the optics, the light of individual colors, would be used specifically to optimize, for example, the mixing of the different LED colors or to achieve a special licensing of the LED light.

The microstructures do not necessarily serve to influence the light output but can also be used to others

Properties of the optical element to influence. It would be conceivable, for example, to form anti-reflection structures, which are known as Moth-Eye structures, on the surface of the optical element, through which the

Overall appearance of the light-emitting device is optimized,

It should be noted, moreover, that the optical elements according to the invention need not necessarily be used for LEDs but, for example, also in the case of other light sources, e.g. In general, however, the effort to create the macrostructures will increase, the greater the luminous area of the assigned

Light source is. Accordingly, ^" Semi-new! Light sources certainly the optimal field of application -for the present invention.

Claims

claims

1. Optical element (!), In particular for influencing the delivery of a LED or OLED light source.

wherein the optical element (I) comprises a. comprising a silicone material existing body { ^' lo), which by machining the Silikonmateriai s by means of laser (50) created structures (20), in particular microstructures having 2, optical element according to claim 1,

characterized,,

in that the structures (20) are located on a surface of the optical element (1) facing away from the light source. 3, optical element according to claim 1,

characterized gekeniizetehset

in that the structures (20) are embedded in the body (10) made of silicone material, such that they differ from silicone materials with other optical materials

Properties, in particular with a different refractive index are surrounded.

4. Optical element according to claim 3,

by doing so,

that the silicone material with the other optical properties is material of the body (10) which has not been processed by the laser.

5. Optical element according to one of the preceding claims,

by doing so,

the structures (20) comprise lens-like structures (28) and / or prismatic structures.

6. Optical element according to one of the preceding claims,

dadu c marked,

the structure (20) comprises light-scattering structures. 7. Optical element according to one of the preceding claims,

characterized.

the structures (20) comprise grid or grid structures (.25).

8. Optical element according to one of the preceding claims, thereby. gekennsseiclMefc,

that the silicon material includes phosphors for color conversion of the light.

9. Optical element according to egg em of the preceding claims.

thereby gekenaxeichuei,

that the silicone body (10) on a support element. (1 ÖÖ) is arranged, which is preferably translucent, in particular consists of glass.

10. An optical element according to any one of claims 1 to 8,

gekesastdehnet,

that this forms a primary optic for at least one LED light source.

1 1. Arrangement consisting of an LED light source and an LED light source associated optical element. (1) according to one of the preceding: claims.

12 »arrangement according to claim 1 1,

characterized,

the structures (20) cover only a partial area of the LED light source. Spoke 12,

characterized,

the LED light source comprises at least two differently colored LED chips, wherein the optical element (1) covers both LED chips, but the structures are formed solely in the region of one of the chips, or they are differently formed in the regions assigned to the different LED chips are.

14. ^'A method for forming -one optical element according to any one of claims 1 to 10,

characterized by

a silicone core is applied to a carrier stock (100) and subsequently processed by means of laser radiation.