DE102008025013A1 - Optical element for use in illumination device for illumination of side of laminar element of vehicle number plate, has light access area with contour running from LED and another contour running away from LED, in vertical sectional plane - Google Patents

Abstract

The optical element (1) has a light conducting area (30) lying opposite to a light access area (2). The light access area provided at outside of an optical axis of an LED has a contour (6) running from the LED and emanating from a minimum distance section (5) lying in an area of the optical axis in a vertical sectional plane normal to a surface to-be illuminated. The light access area has another contour running away from the LED and emanating from the optical axis in the vertical sectional plane normal to a surface to-be illuminated. The light from the LED enters into the optical element.

Description

The The invention relates to an optical element for illuminating a page a substantially flat element, such. B. one Vehicle license plate, wherein the optical element has a light entry area has, over which light from at least one light emitting diode can enter the optical element and wherein in the assembled state the optical element at a distance above / below the illuminated Elementes and at a distance in front of the illuminated side of the Element is arranged.

Furthermore, The invention relates to a lighting device for lighting a vehicle registration with at least one light emitting diode and at least an above-mentioned optical element.

by virtue of the existing legal requirements, it is necessary, the Exterior surfaces / light exit surfaces of License plate lighting optics plan to produce. Previous license plates with a filament as a light source could due their extension with simple optics the legal requirements to meet the license plate lighting. But are LEDs (LEDs) used as a light source, then leads the quasi-point-like Radiation characteristic of the LED to problems in lighting the flag corners.

Previous Possible solutions are the optics for distribution of light and a cover plate, z. B. a lens of the license plate light to separate and / or use multiple light emitting diodes. Also the use reflective surface inside the license plate light can facilitate the illumination of the license plate corners.

An example of these solutions, but still for general bulbs, shows the document DE 11 01 983 B in which a license plate lamp for motor vehicles is described with incorporated in the cover prism-shaped grooves. The EP 0 453 887 A1 discloses a license plate light with a lens having portions of optically active elements. The lens is designed to be curved in the longitudinal direction. In the DE 20 2005 014 363 U1 an LED license plate light is described in which in the beam path of the illuminant optics and further a light exit disc are arranged. In this case, the optics has a light-collecting effect on its side facing the luminous means, the side facing away from the luminous means is configured in such a way that the light is deflected in the direction of a marking to be illuminated.

These However, solutions have several disadvantages such as B. a relatively large space requirement and a high Positioning accuracy due to the multi-part optics, and metallic or vaporized reflectors are often necessary resulting in high costs in manufacturing and assembly.

It It is an object of the invention to obviate the above problems.

• *) in ersten Schnittebenen im Wesentlichen parallel zu der zu beleuchtenden Fläche der Lichteintrittsbereich der zumindest einen Leuchtdiode gegenüber eine Vertiefung und beiderseits der optischen Achse der Leuchtdiode, ausgehend von der Vertiefung, in Richtung zu der zumindest einen Lichtdiode hin ansteigende Flanken aufweist, und
• *) in zweiten, vertikalen Schnittebenen im Wesentlichen normal auf die zu beleuchtende Fläche der Lichteintrittsbereich außerhalb der optischen Achse der Leuchtdiode ausgehend von einem in etwa im Bereich der optischen Achse liegenden Minimalabstandsabschnitt, von der zu beleuchtenden Seite weglaufend eine von der Leuchtdiode weggerichtet verlaufende erste Kontur und ausgehend von der optischen Achse zu der zu beleuchtenden Seite hingerichtet eine zweite, ebenfalls von der zumindest einen Leuchtdiode weglaufende Kontur aufweist.

This object is achieved with an optical element mentioned in the introduction, in which

• *) in first sectional planes substantially parallel to the surface to be illuminated, the light entry region of the at least one light emitting diode opposite a depression and on both sides of the optical axis of the light emitting diode, starting from the depression, towards the at least one light diode has rising edges, and
• *) in second, vertical sectional planes substantially normal to the surface to be illuminated, the light entry region outside the optical axis of the light emitting diode starting from a lying approximately in the region of the optical axis minimum distance portion, running away from the side to be illuminated away from the light emitting diode extending first contour and executed, starting from the optical axis to the side to be illuminated, a second contour which likewise runs away from the at least one light-emitting diode.

By the inventive design of the optical element with depression and flanks in one direction takes one side a fanning out of the entering into the Optikelement Light, on the other hand, by the invention Design of the optical element in a direction normal to the to be illuminated surface the light to be illuminated Directed surface.

at The presented solution can therefore with a single Optical element and with only a single or a few light-emitting diode a license plate is lit according to legal regulations become. It also turned out that such Optical element in terms of mounting accuracy particular "optical robust ", that is, that assembly inaccuracies have relatively little influence take the illumination of the license plate.

The Production and also the assembly of the presented optical element are easy to accomplish, since it is a single, one-piece Element is in the quasi cover and optics with planner Light exit surface are formed in an element.

On additional optical aids as in the prior art often used can also be waived to legal Specifications to meet the license plate lighting worldwide.

Around from the LED to the front, d. H. from the surface to be illuminated directed to redirect radiated light to the surface, it is useful if the first contour one rounded, curved away from the at least one light emitting diode History has.

Furthermore, it is favorable if the second contour is a rectilinear, from the at least one light-emitting diode directed course.

To Rear light emerging from the LED can thus better over distributed the height of the surface to be illuminated be and along with the over the first, front contour Deflected light can increase the area over its height be evenly lit.

Furthermore, it is provided that the minimum distance section step-shaped is trained.

A Such a level may be constructional or computational Reasons prove favorable, but is for optical reasons unnecessary.

It can then be provided that the second contour in the area the minimum distance portion closer to the at least a light-emitting diode lies as the first contour.

Around a uniform splitting of the incoming Light in the optical element to reach the width, it is expedient when the two flanks have a substantially symmetrical course exhibit.

A optimal width division of the light is achieved when the Deepening in first cutting planes starting from their deepest Point one towards the at least one light emitting diode curved, has rounded contour, which in substantially rectilinear or curved away from the at least one light emitting diode Flanks passes.

Around from the LED strongly to the sides radiated light "capture" and for the width illumination of the area to be able to use, is in a specific variant further provided that the flanks have a kink and then to the kink the flank contour also a substantially straight or of the at least one light-emitting diode directed course which has a lower inclination to a horizontal plane has as the rectilinear or of the at least one light emitting diode away curved edge.

By the strong refraction of this freeform optics to the side and to the mark The light is distributed homogeneously on the license plate. This look However, there is no sufficient illumination of the license plate corners guarantee that by further increasing the curvature the optics could no longer penetrate it, but on the surface would be reflected.

Around to realize a sufficient illumination of the corners of the surface Accordingly, it is further provided that the optical element laterally adjacent to the light entry region, on the flanks, outward wedge-shaped, outwardly tapering Lichtleitbereiche having.

Furthermore, it is provided that the optical element a the light entry area opposite, substantially planar light exit area having.

One Part of the light in the optical element passes through this planar Lichtleitbereich from the optical element and is on the surface to be illuminated directed. Another part is reflected on the flat surface and reflected into the light guide areas where it is due to the wedge-shaped configuration by multiple reflections in the light guide areas and by light emission at the light entry area opposite side to an illumination of the area also in the width comes.

Easy to manufacture and optimal in terms of optical properties it is, if further the light-emitting surface of the wedge-shaped Lichtleitbereiche and the light entry region opposite the light exit region to form a common level.

At the upper "top surface" of the wedge-shaped Lichtleitbereiche then no or no significant loss of light takes place and Almost all of the light reflected or radiated into the light guide areas Can be used for side and corner lighting of the area be used.

The Lichtleitbereiche have on their outer side no light entry areas on. Accordingly, the entire exiting from the LED To be able to use light are the light entry area and the wedge-shaped light guide area through a step area separated from each other.

In This step area is the light emitted laterally of the light emitting diode "captured" and directed into the optical element.

Furthermore, it is still favorable if the light entry area in Direction to the surface to be illuminated through a Total reflection optical barrier is limited.

With this optical barrier that is in the direction the light emitted to be illuminated surface captured and directed over the optical element on the surface.

Around the light from the optic barrier over a larger one Optics barrier extends to distribute angular range essentially over the entire width of the light entry area and is curved away from the surface to be illuminated, points So practically a curved shape (in a Top view of the optical element).

After all it may still be useful if subsequently to the first contour a directed away from the horizontal again third contour is provided.

With this towards the front, directed away from the surface to be illuminated upwards rising surface can be forward, d. H. from the area swept away light and over the optic element be directed to the surface.

in principle can use multiple light emitting diodes opposite a depression be arranged. It is optimal, however, if a well exactly a light emitting diode is arranged opposite. Using of two or more light-emitting diodes, it is therefore favorable if each recess exactly opposite a light emitting diode lies.

A Deepening is essentially directly opposite the light emitting diode arranged, since so the best use of emitted by the light emitting diode Light results. A second LED outside the well makes little sense visually.

Around Therefore, two or more light emitting diodes in terms of light output To be able to optimally use it is therefore advantageous how above described per light diode own well and the Provide appropriate optical structures and each depression opposite to provide a light emitting diode.

Per Light emitting diode, the optical element thus each have an optics area such as described above with depression, flanks, etc. from. The wedge-shaped On the other hand, light-guiding areas remain proportional however, unchanged and can of all LEDs "shared benefits".

Around a mixing of the LED light and a homogenization of the Color impression can also be provided be that the light entry area, at least in areas an optical Structure having about a microstructure.

A Such micro-optical structure arises z. B. by roughening the Surface, by providing a laser grating, etc. where the structure lies in the μm range.

expedient it is there, if essentially the one between the optical barrier and the minimum distance range lying areas with the optical Structure are provided.

at These areas are for those with regard to the color splitting critical areas. The other uncritical Areas do not have such a structure to avoid unnecessary ones To avoid light losses.

additionally or alternatively, essentially the area around the third Contour be provided with an optical structure, since it is also here can be a critical area.

in the The invention is closer to the drawing explained. In this shows

1 a perspective top view of an inventive optical element in a designated holding or mounting element,

2 the optical element 1 in an enlarged view,

3 a top view of the upper, the LED facing side of the optical element,

4 a section through the optical element 3 along the line AA,

5 an enlarged view of the central region of the optical element according to the section 4 .

6 a section through the optical element 3 along the line BB,

7 an enlarged view of the central region of the optical element according to the section 6 .

8th a vehicle license plate illuminated with two optical elements according to the invention,

9 the vehicle license plate 8th in the region of one of the two optical elements and schematically indicated a corresponding beam path,

10 a perspective view of another variant of an optical element according to the invention, and

11 a plan view of the optical element according to 10 ,

FIG. 1 shows an optical element according to the invention 1 , About the optic element is schematically a light source in the form of a light emitting diode 101 represented, from which light into the optical element 1 is fed. The optical element and the light-emitting diode are the essential components of a lighting device according to the invention for illuminating a license plate. The optical element 1 itself is in a mounting or holding element 90 arranged, with which a mounting above / below the surface to be illuminated, in particular a license plate of a vehicle takes place.

Schematically, the arrangement of two optical elements according to the invention 1 over a license plate 100 in the 8th respectively. 9 shown.

With the shown optical element 1 can the lighting of a page 100 ' a substantially flat element, such. B. a vehicle registration 100 , be realized according to the legal regulations.

Concretely, the invention, the optical element 1 a light entry area 2 on, over which light from the light emitting diode 101 in the optical element 1 can occur. When assembled, the optical element is located 1 doing so according to the representation at a distance above the plate 100 and at a distance in front of the side to be illuminated 100 ' of the license plate 100 ,

Like that 2 - 7 and in particular in detail 6 and 7 can be removed, now has the light entry area 2 of the optical element 1 in first sectional planes E1 (of which one in 2 is indicated), substantially parallel to the surface to be illuminated 100 the LED 101 opposite a recess 3 on.

On both sides of the optical axis OA of the LED 101 , starting from the depression 3 , has the light entrance area surface 2 towards the at least one light diode 101 rising flanks 4 on.

Appropriately, is the light emitting diode 101 centrally over the well 3 arranged such that the optical axis OA of the light emitting diode 101 pierces the depression at its lowest point.

When optical axis OA is zero-degree direction, d. H. the straight ahead direction or main emission direction of the light emitting diode.

In second, vertical cutting planes E2 substantially normal to the surface to be illuminated 100 ' indicates the light entry area 2 outside the optical axis OA of the LED 101 starting from a lying approximately in the region of the optical axis OA minimum distance portion 5 , from the side to be lit. 100 ' Running away one of the light emitting diode 101 directed first contour 6 and starting from the optical axis 1 to the side to be illuminated 100 ' executed a second, also from the at least one light emitting diode 101 running contour 7 on. This is the 4 and 5 especially good to remove.

In order to deflect light directed away from the light-emitting diode to the front, ie away from the surface to be illuminated, onto the surface, the first contour has 6 in the illustrated advantageous embodiment, a rounded, of the at least one light emitting diode 101 away curved course.

The second contour 7 In the variant shown, has a substantially rectilinear course directed away from the at least one light-emitting diode.

To Rear light emerging from the LED can thus better over distributed the height of the surface to be illuminated be and along with the over the first, front contour Deflected light can increase the area over its height be evenly lit.

In the variant shown according to 1 - 7 is the minimum distance section 5 stepped. Such a stage may prove favorable for design or computational reasons, but is not necessary for optical reasons, and in the 10 and 11 variant shown an optical element shows z. B. a continuous, steady transition between the two contours 6 . 7 in the minimum distance section 5 ,

In the variant shown ( 1 - 7 ), it is useful if the second contour 7 in the range of the minimum distance section 5 closer to the at least one light emitting diode 101 lies as the first contour 6 ,

How further the 6 and 7 can still be seen, the two flanks 4 a substantially symmetrical course in order to achieve a uniform splitting of the incoming light in the optical element in the width.

Optimum width division of the light is achieved if, as shown in the figures, the recess 3 in the first sectional planes E1 starting from its lowest point one to the at least one light-emitting diode 101 has curved, rounded contour, which in a substantially rectilinear or away from the at least one LED curved flanks 4 passes.

To go from the light emitting diode 101 strong "lighted" to the sides radiated light and for the width illumination indicator 100 to be able to use, is further provided in the variant shown that the flanks 4 a kink 4 ' and then to the kink 4 ' the flank contour 4 '' a likewise substantially straight or from the at least one light-emitting diode 101 Has directed course, which against a horizontal plane E3 (see 2 ) has a lower inclination than the rectilinear or of the at least one light emitting diode 101 away curved edge 4 ,

Due to the strong refraction of this described freeform optics to the side and towards the license plate, the light becomes homogeneous on the license plate 101 distributed. However, this optics alone can not guarantee a sufficient illumination of the label corners, as by a further increase in the curvature of the optics no light could penetrate them, but would be reflected on the surface.

To ensure adequate illumination of the corners of the license plate 100 to be able to realize, is accordingly further provided that the optical element 1 laterally adjacent to the light entry area 2 , after the flanks 4 . 4 '' outwardly wedge-shaped, outwardly tapering Lichtleitbereiche 30 having.

Furthermore, it is envisaged that the optical element 1 a the light entry area 2 opposite, substantially planar light exit area 20 having.

Part of the light in the optical element 1 passes through this flat light exit area 20 from the optical element and is on the plate 100 directed. Another part will be on the flat surface 20 inside the optic element 1 reflected and in the Lichtleitbereiche 30 reflected where it due to the wedge-shaped configuration by multiple reflections in the Lichtleitbereichen 30 and by light leakage at the light entry area 2 opposite side 31 to an illumination of the license plate 100 also comes in the width.

Easy to manufacture and optimal in terms of optical properties, if further the light exit surface 31 the wedge-shaped Lichtleitbereiche 30 and the light entry area 2 opposite light exit area 20 to form a common level.

At the upper "top surface" 33 the wedge-shaped Lichtleitbereiche 30 then no or no appreciable loss of light takes place and almost all in the Lichtleitbereiche 30 reflected light may be used for the side and corner illumination of the license plate.

The lid surface 33 forms a flat outlet surface at a defined angle to the opposite light exit surface 31 , By this arrangement results in a reduction of the reflection angle on the inside of the light exit surface 31 by the angle of inclination of the lid surface 33 ,

This reduction of the reflection angle occurs at each successive reflection on a surface until the total reflection angle of the lens material to the environment is reached. Then the light beam emerges from the optics 30 and contributes to the illumination of the license plate.

By this principle is achieved that reflects the otherwise lost Light can also be used. Also carries the multiple reflection to broaden the radiating surface and more homogeneous illumination. Another very positive effect for illumination of the license plate edges is the by the Size of the inclination angle of the inner surface the exit angle to the side in a range around the total reflection angle can be controlled.

The light guide areas 30 have on their outside no light entry areas or is not provided that light over the lid surface 33 into the light guide areas 30 arrives. Accordingly, to be able to use the entire light emerging from the light emitting diode, the light entry area 2 and the wedge-shaped light guide region 30 through a step area 32 separated from each other.

In this step area, the laterally emitted light of the light-emitting diode is "captured" and into the optical element 1 introduced therein.

Furthermore, it is still favorable if the light entry area 2 as in 3 and 4 easy to recognize in the direction of the surface to be illuminated 100 ' through a total reflection optical barrier 40 is limited.

With this optic barrier 40 is the directly emitted in the direction of the surface to be illuminated light of the LED 101 captured and over the opticsement 1 on the surface 100 ' directed.

To get the light out of the optics barrier 40 To be able to distribute over a larger angular range, extends the optical barrier 40 essentially over the entire width of the light entry area 2 and is of the area to be illuminated 100 ' curved away, so in fact has an arcuate Ge (in a plan view of the optical element as in 3 shown).

The emitted LED light strikes first on an entrance surface curved towards the license plate (outside) 50 , The curvature becomes the surface 50 brought into an angle as steep as possible to the light rays, so that no light on this surface 50 reflected and the light in the direction of the plate 100 is broken. Light whose entry point into the optical body is so high that the refraction can not deflect it in the direction of license plate, is at least so deflected that on the back 51 the optics 40 , due to the now flat angle to this surface, a total reflection occurs. These reflected rays of light can now, depending on the curvature and angle of the back 51 be directed to the desired area of the license plate.

Finally, it is still useful when following the first contour 6 a third contour directed away from the horizontal E3 6 ' is provided.

With this forward, from the surface to be illuminated 100 ' directed upwards rising surface 6 ' can forward, ie directed away from the surface direct light of the LED 101 captured and over the opticsement 1 be directed to the surface.

In principle, a plurality of light-emitting diodes can be arranged opposite a depression. It is optimal, however, if a recess is arranged opposite exactly one light emitting diode. When using two or more light-emitting diodes, it is therefore advantageous if each well 3 exactly one LED is opposite.

Such an optical element 1 For 2 Light-emitting diodes is in the 10 and 11 shown in more detail, wherein the reference numerals from the 1 to 7 also the corresponding, construction or functionally identical elements in 10 and 11 describe.

Each LED has the optical element 1 thus each one optics area or one light entry area 2 as described above with depression 3 , Flanks 4 , etc. from. The wedge-shaped Lichtleitbereiche 30 on the other hand, they remain unchanged in number and can be "shared" by all light-emitting diodes.

In order to realize a thorough mixing of the LED light and a homogenization of the color impression, it can also be provided that the light entry area 2 at least in areas having an optical structure, such as a microstructure.

A Such micro-optical structure arises z. B. by roughening the Surface, by providing a laser grating, etc. where the structure lies in the μm range.

It is expedient in this case if, in essence, those between the optical barrier 40 and the minimum distance range 5 lying areas are provided with the optical structure.

at These areas are for those with regard to the color splitting critical areas. The other uncritical Areas do not have such a structure to avoid unnecessary ones To avoid light losses.

Additionally or alternatively, also essentially the area around the third contour 6 ' be provided with an optical structure, since it can also be a critical area here.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 1101983 B [0005]
• EP 0453887 A1 [0005]
• - DE 202005014363 U1 [0005]

Claims (19)

Optical element for illuminating a page ( 100 ' ) of a substantially planar element, such. B. a vehicle registration number ( 100 ), whereby the optical element ( 1 ) a light entry area ( 2 ), via which light from at least one light-emitting diode ( 101 ) into the optical element ( 1 ) can occur and wherein in the mounted state, the optical element ( 1 ) at a distance above / below the element to be illuminated ( 100 ) and at a distance from the side to be illuminated ( 100 ' ) of the element ( 100 ) is arranged, characterized in that the optical element *) a the light entry area ( 2 ), substantially flat Lichtleitbereich ( 20 ), *) in a first sectional plane (E1) substantially parallel to the surface to be illuminated (E1) 100 ), the light entry area ( 2 ) of the at least one light-emitting diode ( 101 ), a recess ( 3 ) and on both sides of the optical axis (OA) of the LED ( 101 ), starting from the depression ( 3 ), towards the at least one light emitting diode ( 101 ), rising edges ( 4 ), and *) in a second, vertical sectional plane (E2), substantially normal to the surface to be illuminated (E2) 100 ' ), the light entry area ( 2 ) outside the optical axis (OA) of the light-emitting diode ( 101 ), starting from an approximately in the region of the optical axis (OA) lying minimum distance portion ( 5 ), from the side to be lit ( 100 ' ) running away, one of the light emitting diode ( 101 ) directed first contour ( 6 ) and from the optical axis ( 1 ), to the side to be illuminated ( 100 ' ), a second, also from the at least one light emitting diode ( 101 ) running contour ( 7 ) having. Optical element according to claim 1, characterized in that the first contour ( 6 ) a rounded, from the at least one light emitting diode ( 101 ) has a curved course. Optical element according to claim 1 or 2, characterized in that the second contour ( 7 ) has a rectilinear, away from the at least one light emitting diode course. Optical element according to one of claims 1 to 3, characterized in that the minimum distance section ( 5 ) is stepped. Optic element according to claim 4, characterized in that the second contour ( 7 ) in the region of the minimum distance section ( 5 ) closer to the at least one light emitting diode ( 101 ) lies as the first contour ( 6 ). Optical element according to one of claims 1 to 5, characterized in that the two flanks ( 4 ) have a substantially symmetrical course. Optical element according to one of claims 1 to 6, characterized in that the depression ( 3 ) in first cutting planes (E1) starting from its lowest point one to the at least one light-emitting diode ( 101 ) has curved, rounded contour, which in substantially rectilinear or from the at least one light emitting diode curved away flanks ( 4 ) passes over. Optical element according to claim 7, characterized in that the flanks ( 4 ) a kink ( 4 ' ) and then to the kink ( 4 ' ) the flank contour ( 4 '' ) also has a substantially straight course or directed away from the at least one light-emitting diode, which has a lower inclination relative to a horizontal plane (E3) than the rectilinear or of the at least one light-emitting diode ( 101 away curved edge ( 4 ). Optical element according to one of claims 1 to 8, characterized in that it laterally adjacent to the light entry region ( 2 ), after the flanks ( 4 . 4 '' ), outwardly wedge-shaped, outwardly tapering Lichtleitbereiche ( 30 ) having. Optic element according to claim 9, characterized in that the light exit surface ( 31 ) of the wedge-shaped light guide regions ( 30 ) and the light entry area ( 2 ) opposite light exit area ( 20 ) form a common plane. Optic element according to one of claims 9 and 10, characterized in that the light entry region ( 2 ) and the wedge-shaped light exit area ( 30 ) by a step area ( 32 ) are separated from each other. Optic element according to one of claims 1 to 11, characterized in that the light entry region ( 2 ) in the direction of the surface to be illuminated ( 100 ' ) through a total reflection optical barrier ( 40 ) is limited. Optical element according to claim 12, characterized in that the optical barrier ( 40 ) substantially over the entire width of the light entry region ( 2 ) and from the surface to be illuminated ( 100 ' ) is curved away. Optic element according to one of claims 1 to 13, characterized in that subsequent to the first contour ( 6 ) a third contour directed away from the horizontal (E3) ( 6 ' ) is provided. Optical element according to one of claims 1 to 14, characterized in that in the case of a plurality of light-emitting diodes ( 101 ) each well ( 3 ) is exactly opposite a light emitting diode. Optic element according to one of claims 1 to 15, characterized in that the light entry region ( 2 ) has an optical structure, such as a microstructure, at least in regions. Optical element according to claim 16, characterized in that substantially between the optical barrier ( 40 ) and the minimum distance range ( 5 ) areas are provided with the optical structure. An optical element according to claim 16 or 17, characterized in that substantially the area around the third contour ( 6 ' ) is provided with an optical structure. Illumination device for a vehicle license plate with at least one light-emitting diode ( 101 ) and with at least one optical element according to one of claims 1 to 18, in which light from the at least one light-emitting diode ( 101 ) can be fed.