DE102011016413A1 - Indicator device for vehicle, has indiactor frame fixed on vehicle outer contour, and indicator plate having top surface, where illumination device illuminates top surface - Google Patents

Abstract

The indicator device (1) has an indiactor frame (3) fixed on a vehicle outer contour (5), and an indicator plate (6) having a top surface, where an illumination device illuminates the top surface. The indicator plate is a light guide plate, which have light-scattering nanoparticles. The indicator symbols (8) are arranged on the top surface. The illumination device is integrated into the indicator plate. An independent claim is included for a method for manufacturing an indicator device.

Description

A license plate device for a vehicle and a method for manufacturing the license plate device will be described. In this case, the license plate device has a license plate frame which can be fixed to a vehicle outer contour on. On a plate top of a license plate plate indicator symbols of a vehicle registration plate are arranged.

From the publication EP 1 477 368 B1 For this purpose, a luminous license plate for vehicles is known. The known luminous license plate has a light guide with opposite front and rear major surfaces and arranged between these edge sides for backlighting the license plate. In addition, the known luminous license plate has an elongated light source for illuminating the light guide on one of the edge sides. In front of the front surface of the light guide, a transparent license plate is arranged, which consists of several layers of film and has a print of license plate symbols.

In addition, the known device has a license plate frame with the plate having the optical waveguide and the transparent plate plate, so that three plate-shaped units are arranged one behind the other, namely the base plate of the license plate frame, the light guide as a backlight plate and a transparent license plate, which is labeled with license plate symbols ,

An object is to provide an improved license plate device and to provide a cost effective method of manufacturing the same.

This object is achieved with the subject matter of the independent claims. Advantageous developments emerge from the dependent claims.

As an embodiment of the invention, a license plate device for a vehicle and a method for manufacturing the license plate device will be described. An embodiment of the license plate device which is fixable to the vehicle has a license plate with a top plate. The license plate has a light guide plate with edge regions. The light guide plate has distributed in its volume light-scattering nanoparticles. On the top of the plate three-dimensional license plate symbols are arranged. A lighting device is integrated in the license plate.

There is the advantage associated with this license plate device that no backlight is required for the license plate of the license plate, but rather the light guide plate itself is coated and prepared so that it can be used as a license plate without an additional backlighting optical fiber as disclosed in the above document is. This is not only a cost advantage, but also the advantage that the entire license plate device can be performed significantly thinner than the known illuminated license plate, which allows additional weight savings and thus fuel saving for the vehicle.

In addition, the three-dimensional license plate symbols stand out more clearly and plastically from the top of the license plate. Thin soiling layers do not immediately lead to the unrecognizability of the vehicle registration. Another advantage is the integrated in the license plate plate lighting device, whereby the final assembly can be made cheaper, since fewer components are to be kept in stock and a variety of assembly operations such as attaching a license plate or the use of light sources omitted. The susceptibility is also reduced because the lighting device is waterproof embedded in the plastic material of the light guide plate.

In this context, light-scattering nanoparticles are understood as meaning particles having a diameter of from 10 to 200 nanometers. The nanoparticles scatter the coupled-in light largely isotropically. As nanoparticles, colorless particles having a refractive index which differs from the light guide plate by 0.06 ≦ Δn ≦ 0.4 are preferably used. These nanoparticles are distributed in the volume of the light guide plate and may additionally be surrounded by a cladding layer, which improves the embedding of the nanoparticles in the light guide material of the light guide plate. The embedding of the light-scattering nanoparticles results in a light guide material that is transparent in the unlit state, while it shows an effective all-round light emission at a light irradiation by integrated into the light guide material lighting body.

In a further embodiment, the illumination device has at least one light source, which is embedded with its supply lines in edge regions of the light guide plate. This exposure source has an outer diameter or thicknesses that are equal to or less than the plate thickness of the lightguide plate, so that the light source can be embedded in an edge region of the lightguide plate. For this purpose, preferably light emitting diodes can be used, whose Light rays from one of the edge regions is aligned with the volume of the light guide plate with the light-scattering nanoparticles distributed there.

Furthermore, it is advantageous to arrange the light sources in such a way that two light-emitting diodes are embedded on opposite edge regions and couple opposite light into the volume of the light guide plate, so that the plate top side, as far as it is not covered by indicator symbols light up by the light scattering on the nanoparticles can.

In a further embodiment of the invention, it is provided that at least one of the edge regions has a higher concentration of light-scattering nanoparticles than the remaining volume of the light guide plate. This has the advantage that a brightly illuminated edge region is formed when specifically light of a light-emitting diode or a laser diode is coupled into this edge region. At the high concentration of nanoparticles in this edge region, the laser light is scattered and coupled into the remaining volume as scattered light, where the light-scattering nanoparticles light up the top of the plate.

Furthermore, it is possible for the at least one edge region, in which the illumination device is integrated, to have a mirroring layer on its surfaces, in order to avoid a dazzling effect emanating from a light source and the irradiation effect of the light source on the light-scattering nanoparticles distributed in the volume of the light guide plate to improve.

To fix the three-dimensional license plate symbols on the top plate of the license plate, it is provided to connect the license plate symbols with the plate top. For this purpose, a water-resistant adhesive, preferably a thermoset is used, can be fixed with the prefabricated plate symbols on the top of the plate. However, double-sided adhesive films can also be used to fix the three-dimensional license plate symbols.

In a further embodiment of the invention, a perforated retroreflective sheeting is arranged between the top of the plate and the three-dimensional indicia symbols. The perforated retroreflective sheeting has the advantage that, on the one hand, through the perforation openings, which are homogeneously distributed through holes in the film, stray light can pass through the film when the light source is switched on and, on the other hand, has a white reflecting surface, which displays the contrast between the three-dimensional indicator symbols and the label-free top plate enhanced. As a result, areas which are not covered with license plate symbols, when illuminated by third vehicles are illuminated more intense.

Furthermore, as a license plate material for the three-dimensional license plate symbols, a non-transparent license plate material which is contrastingly offset from the top of the plate and not reflective is provided. For a colored or blackened plastic can be used, the license plate symbols are prefabricated plastic parts by injection molding. In addition, the license plate symbols may have a colored or blackened elastomer with rounded edges, which springs back into its three-dimensional characteristic form due to its rubber-elastic properties even with sudden accidental compressive stress. In addition, elastomeric three-dimensional characteristics facilitate adaptation of the flexible vehicle registration mark to curvatures of a vehicle outer contour.

As a three-dimensional markers also appearing colored as red, green or blue indicator symbols can be provided in order to signal, for example, admission restrictions, such as in a transfer number or as in the case of license plates of agricultural vehicles. Also, national license plate symbols such as colored flags and emblems can be applied directly to the top surface of the light guide plate by means of colored transparent film or by color printing.

In a further embodiment of the three-dimensional indicator symbols, these have a metal alloy. This metal alloy may be an electrodeposited metal alloy layer or a vapor deposited metal alloy layer, with which the three-dimensional characteristics are finely coated. The metallic luster can increase the visibility of the vehicle license plate.

It is further provided that the light-guide plate carrying the license plate symbols is a PMMA (polymethyl methacrylate) plastic plate loaded with light-scattering nanoparticles. This Polymethylmethacryl is characterized by its high clarity, wherein the light-scattering nanoparticles ensure that when switching on the illumination device on one of the plate edge areas of these light-scattering nanoparticles scatter the light in the direction of the top of the plate and light-scattering light.

In a further embodiment of the invention, the material of the light guide plate carrying the license plate symbols Softener additive on. This plasticizer additive is added during production of the PMMA plate with the light-scattering nanoparticles of the plastic mass, so that the light guide plate with the number plates symbols of a vehicle outer contour is adaptable and thus can also adapt to curvatures of the vehicle outer contour. At the very least, it is not necessary for the vehicle exterior contour to have a flat depression for receiving, arranging and illuminating the license plate device by means of corresponding license plate lights mounted separately on the vehicle.

In order to further intensify a reversion in daylight and also when the license plate light is switched on in the receiving pocket, a reflector foil can be arranged on the rear side of the light guide plate, which reflects daylight and the light of the light-scattering nanoparticles in the direction of the plate top side, which has the license plate symbols.

In order to enable a rapid change of the license plate carrying the license plate plate at a license plate change, it may be provided to tilt the plate frame or retaining clips to the license plate frame, which hold the license plate plates carrying the number plates in position on the vehicle outer contour and when unfolding the retaining tabs or the Halteklipse the light guide plate with the license plate symbols.

For the license plate frame, a plastic may be provided which has a plasticizer additive, so that the license plate frame of a vehicle outer contour is adaptable without any problems and also curved surfaces can be provided with this license plate device.

A method for producing a license plate device for a vehicle comprises the following method steps. First, an injection mold with built-in light sources and leads is assembled. In an injection molding apparatus, a mixing of an optical waveguide material with light-scattering nanoparticles to form an injection-molding compound is preliminarily carried out. Then, a light guide plate is molded in the dimensions of a vehicle license plate while embedding the light sources and the wiring lines except for two power supply terminals protruding from the light guide plate.

With this method, a neutral license plate can be provided on the top of plate still no three-dimensional license plate symbols are arranged, but only color foil with national symbols, abbreviations or flags are applied. An application of the license plate symbols on an upper side of the light guide plate can be selected from a supply of three-dimensional license plate symbols and applied cohesively to the license plate.

Furthermore, before applying the license plate symbols to the light guide plate, it is possible to coat the top side of the light guide plate with a perforated retroreflective sheeting in order to improve the detectability of the vehicle license plate in daylight and in the dark. To reinforce the illumination of the top surface of the light guide plate not covered by mark symbols, the rear side of the light guide plate may additionally be coated with a reflector foil so that scattered light scattered backward on the light scattering nanoparticles in the volume of the light guide plate is reflected by the reflector foil applied on the back side is reflected towards the top of the plate. This has the additional advantage that the top of the plate, which is not covered by license plate symbols, appears brighter even in daylight and makes the three-dimensional license plate symbols clearly and sharply demarcated on the license plate device.

A license plate frame made of plastic with retaining tabs for the light guide plate with integrated lighting device can be made in a plastic injection molding process to complete the license plate device. In order to ensure the applicability of the light guide plate in the license plate frame, the outer dimensions of the light guide plate are dimensioned such that the license plate frame rests on edge regions of the light guide plate on the top of the plate. The light guide plate is fitted before being attached to the license plate frame with license plate symbols of the vehicle.

The light-scattering nanoparticles then cause some of the light to illuminate the top surface of the light guide plate in areas that are not covered by license plate symbols. Thus, with this method, license plate devices having a minimum thickness determined by the thickness of the light guide plate with embedded light sources and the thickness of the license plate holding the light guide plate can be manufactured.

For coating the light guide plate with the three-dimensional indicator symbols, the light guide plate can be heated in a further embodiment of the method to permanently and materially connect the license plate symbols by means of a thermoplastic adhesive.

With this license plate device accounts for all the space on a vehicle, as previously provided as license plate troughs and additional license plate lights. Also, the freedom to design rear end and front end of a vehicle is increased, with the minimum dimensions of the license plate illuminated indicator appear less disturbing to the overall design of the rear sides or front sides of a vehicle. Finally, in this manufacturing method, the advantage is that still a plate bearing plate characteristics in a license plate frame, for example when changing a license plate, can be clipped without great installation effort.

Embodiments of the invention will now be described with reference to the accompanying figures.

1 shows a schematic view of a vehicle with a license plate device on a front side;

2 shows a schematic view of a vehicle with a license plate device on a rear side;

3 shows a schematic plan view of a license plate of a light guide material with embedded light source according to a first embodiment;

4 shows a schematic plan view of the license plate according to 3 after application of three-dimensional license plate symbols;

5 shows a schematic plan view of a license plate plate of an optical fiber material with embedded light source according to a second embodiment;

6 shows a schematic plan view of the license plate according to 5 after application of three-dimensional license plate symbols;

7 shows a schematic cross section through the license plate along the section line AA according to 6 ;

8th shows a schematic plan view of a license plate plate of an optical fiber material with embedded light source according to a third embodiment;

9 shows a schematic plan view of the license plate according to 8th after application of three-dimensional license plate symbols;

1 shows a schematic perspective view of a vehicle 2 the front 25 the same with a license plate device 1 , The license plate device 1 is from a license plate frame 3 surrounded by a vehicle license plate 9 on a license plate 6 wearing. The vehicle license plate 9 on the license plate 6 has three-dimensional license plate symbols 8th on, wherein the license plate device 1 is made of materials that make it possible the license plate device 1 any vehicle outer contour 5 the front 25 adapt.

2 schematically shows a plan view of a rear side 26 of a vehicle 2 , On the stern side 26 in this embodiment is the license plate device 1 the outer contour of a tailgate 27 adjusted without being in the tailgate 27 a license plate recess and / or one in the tailgate 12 integrated license plate lights are to be provided.

3 shows a schematic plan view of a license plate 6 from a light guide plate 11 before applying three-dimensional license plate symbols to a top of a plate 7 , The light guide plate 11 has four border areas 12 . 13 . 14 and 15 on. The light guide plate 11 is transparent and shows in its volume 16 light-scattering nanoparticles 17 on, leaving the top of the plate 7 in areas where they are not, as in 4 shown with license plate symbols 8th a vehicle license plate 9 is covered, can light up.

The light guide plate 11 has two opposing light sources 22 and 23 one in the license plate 6 integrated lighting device 10 on. The light sources 22 and 23 are in opposite edge areas 12 and 14 the light guide plate 11 embedded with their electrical leads except for external connection contacts. The light sources 22 and 23 are on the with light-scattering nanoparticles 17 filled volumes 16 the light guide plate 11 aligned. When the exposure device is switched on 10 scatter the nanoparticles 17 the rays of light 32 the embedded light sources 22 and 23 towards the top of the plate 7 so that it lights up. The border areas 12 and 14 can at least at the positions of the light sources 22 and 23 superficially on three sides mirroring layers 37 to enhance the lighting effect and to reduce glare.

In a border area 30 the edge side 12 can the light guide plate 11 also color covers 20 exhibit. The border area 30 the top of the plate 7 is both with a national sign 31 as well as with a blue colored area 35 with the star wreath of the European Community Mistake. The light guide plate 11 can as a license plate 6 be used in a license plate frame in a few simple steps and the in 4 shown license plate device 1 complete.

The plate top 7 the light guide plate 11 may be covered with an invisible perforated retroreflector sheeting to illuminate the license plate in the dark in a spotlight. In addition, the invisible back panel 4 have a white reflective film to enhance the scattered light intensity.

4 shows a schematic plan view of a license plate device 1 with a license plate 6 according to a first embodiment of the invention after application of three-dimensional license plate symbols 8th , The license plate symbols 8th can be taken as a self-supporting letters, numbers or characters from a supply and on the top of the plate 7 of the light guide plate 11 be upset. Where is the license plate frame 3 so dimensioned that it's the edge areas 12 to 14 in which the light sources 22 and 23 are arranged so overlapped that the light sources are not visible.

To the license plate symbols 8th supporting light guide plate 11 in the license plate frame 3 can insert, for example, a lower edge 33 of the license plate frame 3 be tilted so that the light guide plate 11 from bottom to top, for example, from an upper edge area 13 the light guide plate 11 outstanding and in 3 shown electrical connection contacts 36 in the light guide plate 11 integrated lighting device 10 corresponding contact elements of the license plate frame, not shown 3 touch.

5 shows a schematic plan view of a license plate 6 a license plate device 40 according to a second embodiment of the invention with embedded light sources 22 before applying three-dimensional license plate symbols. Components with the same functions as in the preceding figures are identified in the following figures with the same reference numerals and not discussed separately. In this second embodiment, the light sources 22 in the license plate 6 integrated lighting device 10 one-sided in the upper edge area 13 the light guide plate 11 integrated. Also in this embodiment, the surfaces at the positions of the light sources 22 mirror coatings 37 so that dazzling effects are avoided and the illumination intensities on the light-scattering nanoparticles 17 is reinforced.

6 shows a schematic plan view of the license plate device 40 according to the second embodiment with the license plate 6 according to 5 after application of three-dimensional license plate symbols and insertion of the license plate 6 into a license plate frame 3 , In doing so, contact the in 5 shown from the light guide plate 11 outstanding electrical connection contacts 36 the light sources 22 corresponding contact elements of the license plate frame 3 , Further shows 6 a section line AA for the location of a cross section of the following 7 ,

7 shows with the 7A and 7B a schematic cross section through the license plate device 40 according to 4 along the section line AA. The license plate frame 3 fixed like 7A shows the license plate symbols 8th supporting light guide plate 11 at their edge areas shown here 13 and 15 , The transparent light guide plate 11 points in its volume 16 the light-scattering nanoparticles 17 on which the light rays 32 a light source 22 a lighting device 10 scatter so that in the direction of arrow C, the top of the plate 7 in those places where they are not aware of the three-dimensional license plate symbols 8th is covered, can light up.

This is indicated by the light source 22 a light emitting diode in the upper edge area 13 the light guide plate 11 is embedded and whose thickness is less than the thickness of the light guide plate 11 , like it 7B in detail shows. From the light guide plate 11 protrude electrical connection contacts 36 out, for example, in contact elements 39 of the license plate frame 3 can be inserted, wherein the contact elements 39 with electrical supply lines 34 to supply the light sources 22 the lighting device 10 communicate electrically.

On the lower edge side 15 has the license plate frame 3 a foldable bottom edge 33 on, which can be tilted in the direction of arrow B, so that the license plate symbols 8th supporting light guide plate 11 in the license plate frame 3 upwards with contacting the electrical connection contacts 36 with the contact elements 39 as 7B shows is insertable.

On the back side 4 the light guide plate 11 can be a reflector foil 21 be arranged to increase the lighting effect towards the top of the plate 7 the light guide plate 11 to reinforce. On the plate top 7 is the perforated retroreflector sheeting 24 arranged, the perforation openings, which are homogeneously distributed through holes in the film, has and scattered light when the light source 22 through the retroreflector film 24 let penetrate. On the other hand, the retroreflector film has 24 white reflective surface areas on which the Contrast between the three-dimensional indicator symbols 8th and license plate free top 7 improved. This allows areas that are not tagged with symbols 8th are illuminated, when illuminated by third vehicles illuminate more intense.

8th shows a schematic plan view of a license plate 6 a license plate device 50 according to a third embodiment of the invention. The difference from the previous embodiments is that in the upper edge region 13 and the lower edge area 15 the light guide plate 11 one luminary each 41 respectively. 42 is embedded. The luminous bodies 41 and 42 are made of an optical fiber material such as PMMA (polymethylmethacrylic) and have a higher concentration of light-scattering nanoparticles in their volume 17 as in the volume of the remaining light guide plate 11 on.

In at least one end area 43 respectively. 44 the luminary 41 respectively. 42 are in the light guide material of the filament 41 respectively. 42 laser diodes 45 respectively. 46 embedded a concentrated laser beam 47 in the filament 41 respectively. 42 can couple, so the high concentration of nanoparticles 17 an intense stray light 38 in the direction of arrow C in the volume of the light guide plate 11 scatters.

The scattered light 38 the filament 41 and 42 is through a mirroring layer on the outer surfaces of the luminous body 41 and 42 in the direction of the volume of the light guide plate 11 strengthened. At the same time, the reflective coating of the luminous body surfaces reduces the glare effect of the luminous bodies. At the nanoparticles 17 the circuit board 11 becomes the intense stray light 38 the filament 41 and 42 towards the top of the plate 7 scattered and makes them light up. Out of the volume 16 the light guide plate 11 can electrical connection contacts 36 stand out with embedded leads 48 and 49 to the laser diodes 45 and 46 communicate electrically.

9 shows a schematic plan view of the license plate 6 according to 8th after application of three-dimensional license plate symbols 8th and inserting the license plate 6 into a license plate frame 3 , to complete the license plate device 50 , In the 9 indicated residual surface of the luminous body 41 and 42 is only visible as far as the edge areas by the above-mentioned mirror-effect layer 13 and 15 the license plate 6 not by overlaps of the license plate frame 3 to be covered.

LIST OF REFERENCE NUMBERS

1

mark device

2

vehicle

3

plate frame

4

back

5

Vehicle outer contour

6

License plate

7

Plate upper side

8th

Mark symbol

9

vehicle registration

10

lighting device

11

Light guide plate

12

border area

13

border area

14

border area

15

border area

16

volume

17

nanoparticles

20

color cover

21

reflector sheet

22

light source

23

light source

24

Retro reflector sheet

25

front

26

rear side

27

tailgate

30

border area

31

national sign

32

beam of light

33

lower edge

34

electrical line

35

colored area

36

electrical connection contact

37

mirror coating

38

scattered light

39

contact element

40

mark device

41

illuminant

42

illuminant

43

end

44

end

45

laser diode

46

laser diode

47

laser beam

48

supply

49

supply

50

mark device

A-A

intersection

B

arrow

C

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1477368 B1 [0002]

Claims (15)

License plate device of a vehicle ( 2 ) comprising: - a license plate ( 6 ) with a top plate ( 7 ), the license plate ( 6 ) on the vehicle ( 2 ) is fixable; A lighting device ( 10 ), which the top of the plate ( 7 ) lights up; the license plate ( 6 ) a light guide plate ( 11 ), wherein the light guide plate ( 11 ) in their volume ( 16 ) distributes light-scattering nanoparticles ( 17 ), and wherein on the top of the plate ( 7 ) three-dimensional indicator symbols ( 8th ), and wherein the illumination device ( 10 ) in the license plate ( 6 ) is integrated. License plate device according to claim 1, wherein the illumination device ( 10 ) at least one light source ( 22 . 23 ), with their supply lines ( 48 . 49 ) into border areas ( 12 to 15 ) of the light guide plate ( 11 ) is embedded. License plate device according to claim 2, wherein the light source ( 22 . 23 ) Has light-emitting diodes, which in at least one edge region ( 12 to 15 ) of the light guide plate ( 11 ) are embedded. License plate device according to one of the preceding claims, wherein the light source ( 22 . 23 ) has opposing light emitting diodes, which in opposite edge regions ( 1 . 14 ) are embedded. License plate device according to one of claims 1 to 4, wherein at least one edge region ( 12 to 15 ) a higher concentration of light-scattering nanoparticles ( 17 ) than the remaining volume ( 16 ) of the light guide plate ( 11 ). License plate device according to claim 5, wherein in the edge region ( 12 to 15 ) with a higher concentration of light-scattering nanoparticles ( 17 ) At least one laser diode or light emitting diode is arranged. License plate device according to one of claims 1 to 4, wherein at least one edge region ( 12 to 15 ), in which the lighting device ( 10 ) is integrated on surfaces of the positions of the light sources ( 22 . 23 ) Mirroring layers ( 37 ) having. License plate device according to one of the preceding claims, wherein the three-dimensional license plate symbols ( 8th ) a non-transparent color from the top of the plate ( 7 ) have contrast-rich deposited and non-reflective characteristic material. License plate device according to one of the preceding claims, wherein the license plate symbols ( 8th ) have a colored or blackened plastic and cohesively with the top plate ( 7 ) are connected. License plate device according to one of the preceding claims, wherein the license plate symbols ( 8th ) have a colored or blackened elastomer with rounded edges. License plate device according to one of the preceding claims, wherein between the top of the plate ( 7 ) and the three-dimensional indicator symbols ( 8th ) a perforated retroreflective sheeting is arranged. License plate device according to one of the preceding claims, wherein the license plate symbols ( 8th ) supporting light guide plate ( 11 ) one with light-scattering nanoparticles ( 17 ) loaded PMMA (polymethyl methacrylate) plastic sheet is and wherein on a back ( 4 ) of the light guide plate ( 11 ) a reflector foil ( 21 ), the daylight, and the light-scattering nanoparticles ( 17 ) scattered light towards the top of the plate ( 7 ) of the license plate symbols ( 8th ) supporting light guide plate ( 11 ) reflected. Method for producing a license plate device ( 1 ) for a vehicle ( 2 ), comprising the following method steps: - Assembly of an injection molding tool with embedded light sources ( 22 . 23 ) and supply lines; Mixing an optical waveguide material with light-scattering nanoparticles ( 17 ) to an injection molding compound; Injection molding of a light guide plate ( 11 ) in the dimensions of a license plate with embedding of the light sources ( 22 . 23 ) and the supply lines ( 48 . 49 ) except for the light guide plate ( 11 ) outstanding electrical connection contacts ( 36 ); - producing three-dimensional indicator symbols ( 8th ); - applying the license plate symbols ( 8th ) on a plate top ( 7 ) of the light guide plate ( 11 ). The method of claim 13, wherein prior to application of the license plate symbols ( 8th ) on the light guide plate ( 11 ) the top of the light guide plate ( 11 ) with a perforated retroreflective sheeting ( 24 ) and the back of the light guide plate ( 11 ) with a reflector foil ( 21 ) is coated. Method according to one of claims 12 to 14, wherein a license plate frame ( 3 ) made of plastic with retaining tabs for the light guide plate ( 11 ) and the Lighting device ( 10 ) is produced in a plastic injection molding process.

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