DE102020201645A1 - Lighting device for a motor vehicle - Google Patents

Abstract

The invention relates to a lighting device for a motor vehicle, with at least one light module (1) which has a light body (30) and at least one illuminant (51), the light rays of which can be coupled into a surface (34) of the light body (30) serving as a light coupling surface or are coupled in, wherein the light beams can exit or exit via a light exit surface surrounded by surfaces of the light body (30) in the direction of a light emission direction of the lighting device. The invention proposes that the light body (30) is flat and consists of a first part (30a) and a second part (30b), the first part (30a) being transparent and the second part (30b) being light-diffusing and the two parts (30a, 30b) being integrally connected to one another, the light rays of the at least a lighting means (51) can be coupled into a side surface (34) of the first part (30a) or are incorporated are coupled and the second part (30b) has the light exit surface.

Description

The invention relates to a lighting device for a motor vehicle having the features from the preamble of claim 1.

Such a lighting device is for example in the DE 10 2011 110 630 A1 described. In the case of the lighting device, light from light-emitting diodes is coupled into a light body made of milky acrylic glass, distributed in it and coupled out in the direction of a transparent lens.

From the DE 10 2011 110 629 A1 a lighting device for a motor vehicle is known in which light from light emitting diodes is initially coupled into a transparent, elongated light guide and from this in turn is coupled into an opaque, milky light body. The opaque light body decouples the light rays diffusely.

From the DE 198 60 697 A1 a light module has become known. Specifically, the light module has an optical waveguide with a light exit surface. A light-reflecting or diffusely backscattering film is arranged on the surface of the light module opposite the light outlet surface and on the side surfaces of the optical waveguide connecting the light outlet surface and the opposite surface. Furthermore, a light source for the lateral coupling of light is present on one of the side surfaces. At the light exit surface of the optical waveguide, the surface is provided with alternating light-scattering and flat surfaces. The area ratio of the flat surfaces to the light-scattering surfaces is selected as a function of the luminance at the respective location of the optical waveguide. The reflective layer is applied practically after the production of the optical waveguide, which is produced by injection molding. During production, the injection mold is previously covered with the film on the bottom surface and at least part of the side surface. When the plastic hardens after injection molding, the film adheres to the optical waveguide.

In the DE 199 02 774 A1 Finally, a luminous body with light-emitting diodes for backlighting information elements is described. The light-emitting diodes are used to introduce light into the interior of a hollow body, which has a light-emitting surface for backlighting the information elements. Opposite the light-emitting surface, a rear wall is formed, which is also formed to be light-emitting, self-luminous or simply opaque. Both surfaces are connected to one another by opaque or diffusely reflective side walls. The side walls have light entry openings in which light-emitting diodes or ends of light guides are arranged so that they can feed their light completely into the cavity. The opaque wall of the side surfaces consists of a material that is reflective with a high degree of reflection. The light exit surface and the opposite surface are made of light-scattering material with a low degree of absorption.

Furthermore, it should be mentioned that in the production of motor vehicle lighting devices, for reasons of space and to achieve certain optical effects, the use of flat OLED lamps (OLED = organic light-emitting diode) is often considered. However, OLED lamps are expensive and, due to their organic structure, have disadvantages with regard to their resistance to aging and robustness.

The present invention is therefore based on the object of providing a lighting device for a motor vehicle with which the use of OLED lighting means can be modeled optically, which is constructed in a space-saving and cost-effective manner.

The above object is achieved by a lighting device with the features of claim 1. Advantageous designs or further developments of the invention can be found in the dependent claims.

The invention is based on a lighting device for a motor vehicle, with at least one light module which has a light body and at least one illuminant. The light beams of the illuminant can be coupled into a surface of the light body serving as a light coupling surface or are coupled into it, the light beams being able to exit or exit via a light exit surface surrounded by surfaces of the light body to the outside in the direction of a light emission direction of the lighting device

The lighting means can be designed as a monochrome LED (LED = light-emitting diode) that emits light, or as an RGB LED for emitting light of any color.

The invention now proposes that the light body is flat and consists of a first part and a second part. The first part is transparent (that is, transparent, but can be colored) and the second part is light-diffusing, preferably diffuse light-diffusing. The two parts are connected to one another in one piece (that is, cohesively). The material connection can be chosen with plastic Material can be made inexpensively in the two-component injection molding process.

Furthermore, the light beams of the at least one illuminant can be coupled into a side surface of the first part or are coupled into this. The second part has the said light exit surface.

For the purposes of the invention, flat is intended to mean that the light body has a surface extension which runs in two mutually perpendicular directions and which is several times greater in each direction than a thickness of the light body. A side surface should be understood to mean a surface running perpendicular to the surface extension of the light body.

The features mentioned above make it possible, on the one hand, to simulate the flatness and homogeneity of an OLED light source, and on the other hand, such a lighting device can be produced very simply, compactly and inexpensively. Furthermore, the basic requirements for an impressive appearance of the lighting device are created by the features of the invention.

According to a first development of the invention, light-scattering imperfections are arranged in a distributed manner in the second part of the light body. In this way, a certain scattering of the light beams coupled into the light body can be achieved, which leads to the realization of a homogeneous light emission by the lighting device. Because the light-scattering imperfections are distributed in the second part of the light body and not just on its surface, the light-scattering properties of the second part of the light body can also be maintained for a long time in everyday operation of the lighting device in a motor vehicle.

In order to achieve a particularly good homogeneity of the light emission, it has proven to be advantageous if the second part of the light body has a degree of transmission (= light permeability) in a range of approximately 85 percent to approximately 95 percent.

When light is coupled in, the light body only has a slightly scattering effect. The light body particularly preferably has a transmittance of approximately 92-90 percent.

In order to bring about the greatest possible light yield and effectiveness of the light module, it is proposed that at least one collecting optic facing the at least one illuminant be molded onto the first part of the light body.

According to another embodiment of the inventive concept, the second part of the light body is colored red. This contributes to a high photometric or optical efficiency of the lighting device.

In an advantageous development of the invention, a rear surface opposite the light exit surface and / or at least one side surface of the second part of the light body can be coated with a metal layer. This allows the lighting efficiency of the lighting device to be optimized.

The metal layer can for example be an aluminum layer. As a manufacturing method, the metal layer can preferably be vapor-deposited (so-called sputtering).

Alternatively, it is also conceivable for this purpose that a rear surface opposite the light exit surface and / or at least one side surface of the second part is covered by the light body with a reflective material layer which is integrally connected to the light body. In the case of plastic as the material, the material layer can then preferably be applied using the two-component injection molding process.

A further, advantageous alternative is given in that a rear surface opposite the light exit surface and / or at least one side surface of the second part of the light body is provided with printing. By printing, a lettering, a pattern, a symbol, a logo or the like can be implemented cost-effectively. The printing can preferably be metallic or white printing. The so-called pad printing process is preferred as the manufacturing process. This method is well known and is therefore not explained further here.

The light body can advantageously be fastened on a circuit board which also carries the at least one light source. This development contributes to the ease with which the lighting device can be assembled.

In this case it is very useful if the light body is locked to the circuit board. In this way, the mountability or dismountability of the light body can be optimized.

According to another embodiment, the light of a plurality of illuminants can be coupled into the light body. The lighting means expediently have a mutual distance from one another which is approximately the same as the distance between the lighting means and the side surface serving as the light coupling surface is equivalent to. This contributes to a homogeneity in the light distribution in the light body and thus ultimately to a homogeneous light emission of the lighting device.

Under certain circumstances it may be desirable to arrange several such light modules in a lighting device. It is then very useful for easier assembly of the lighting device if several light bodies are connected to one another in one piece. Furthermore, the lighting means assigned to the individual light modules can all be arranged on a common circuit board.

Finally, protection is also desired for a motor vehicle which is equipped with at least one lighting device according to the invention.

Preferred exemplary embodiments of the invention are shown in the figures and are explained in more detail in the following description with reference to the figures. This also makes further advantages of the invention clear. The same reference symbols, even in different figures, relate to the same, comparable or functionally identical components. Corresponding or comparable properties and advantages are achieved, even if a repeated description or reference is not made. The figures are not, or at least not always, to scale. In some figures, proportions or distances can be exaggerated in order to be able to emphasize features of an exemplary embodiment more clearly.

• 1 eine Explosionsdarstellung eines Lichtmoduls der Beleuchtungsvorrichtung, in einer ersten Variante,
• 2 eine Schnittdarstellung gemäß Schnittverlauf II aus 1, jedoch nicht in einer Explosionsdarstellung auseinandergezogen,
• 2a eine seitliche Teilansicht nur des Lichtkörpers vom Lichtmodul, in einer zweiten Variante,
• 2b eine seitliche Teilansicht nur des Lichtkörpers vom Lichtmodul, in einer dritten Variante,
• 2c eine Darstellung des Lichtkörpers gemäß Ansicht Ilc aus 2b,
• 3 eine Prinzipdarstellung des montierten Lichtmoduls,
• 4 eine Explosionsdarstellung einer aus drei Lichtmodulen bestehenden Lichteinheit,
• 5 eine Darstellung einer montierten, als Heckleuchte ausgebildeten Beleuchtungsvorrichtung mit erfindungsgemäßen Lichtmodulen und Lichteinheiten und
• 6 ein Kraftfahrzeug mit erfindungsgemäßen Beleuchtungsvorrichtungen.

It show, each schematically

• 1 an exploded view of a light module of the lighting device, in a first variant,
• 2 a sectional view according to section II 1 , but not pulled apart in an exploded view,
• 2a a partial side view of only the light body from the light module, in a second variant,
• 2 B a side partial view of only the light body from the light module, in a third variant,
• 2c a representation of the light body according to view IIc from 2 B ,
• 3 a schematic diagram of the mounted light module,
• 4th an exploded view of a light unit consisting of three light modules,
• 5 a representation of a mounted, designed as a rear light lighting device with light modules and light units according to the invention and
• 6th a motor vehicle with lighting devices according to the invention.

First of all, the 1 and 2 Referenced. In the figures there is a light module 1 can be seen, which is a flat body of light 30th and a circuit board 50 with bulbs 51 includes. The bulbs 51 are preferably designed as light emitting diodes.

The light body 30th can for example have a rectangular outline and is flat. It has a surface extension F. which is several times greater than its thickness in each direction d . Also other outlines of the light body 30th are conceivable.

The light body 30th has marginal side surfaces 31 , 32 , 33 and 34 on. These side surfaces surround a light exit surface 35 . The light emitting surface 35 lies on a rear surface 36 opposite to.

The light body 30th consists of a first part 30a and a second part 30b and is preferably made of a plastic. The two parts 30a and 30b are in one piece, so firmly connected to one another. The integral connection of the parts 30a , 30b is preferably manufactured using a two-component injection molding process.

The first part 30a acts as a light guide and is transparent (see-through). He shows the side face 34 on, in which the light from the bulbs 51 can be coupled in or is coupled in. The second part 30b shows the light exit surface 35 and preferably has a transmittance (light transmittance) in a range of about 85 percent to about 95 percent. The degree of transmission is particularly preferably approximately 90 percent.

The only slight scattering property of the second part 30b from the light body 30th is caused by light-scattering imperfections 38 caused that spread in the second part 30b of the light body 30th are arranged. The light-scattering imperfections 38 can enter the light body as interfering particles during manufacture 30th have been introduced. Alternatively, it is also conceivable to use the light-scattering imperfections 38 via laser processing into the light body 30th bring in.

The light body 30th can preferably be colored red to increase the photometric or optical efficiency. It can consist of PMMA (polymethyl methacrylate) or PC (polycarbonate), for example.

The already mentioned board 50 with the lighting means designed as light emitting diodes (LEDs) 51 is at a close distance b below the lower side surface that can be seen in the figures 34 arranged. The distance b is preferably about 10 millimeters. It can also be seen that the light sources 51 a mutual distance a have, which in the exemplary embodiment is also preferably about 10 millimeters.

Furthermore, in the 2 Metal layers 12a indicated by dashed lines (in the 1 not shown). The metal layers 12a cover the back surface 36 in the area of the second part 30b from the light body 30th and the side surface at the top in the figure 31 , which of the side surface serving as the light coupling surface 34 opposite. The metal layers 12a are preferably on the light body 30th vaporized. This creates very thin layers of material 12a realizable. It is preferably an aluminum layer.

Through the metal layers 12a can be the photometric efficiency of the light body 30th can be increased significantly even without an additional component.

Deviating from the exemplary embodiment, it is conceivable that in addition to the rear surface 36 and to the upper side surfaces 31 also the side surfaces 32 and 33 at least in the area of the second part 30b from a metal layer 12a are coated.

The formation of the light body 30th causes over the bulbs 51 in the first part 30a of the light body 30th coupled light rays L. initially almost loss-free due to total reflection on the second part 30b of the light body 30th be directed. There the rays of light can L. at the light-scattering imperfections 38 “Get stuck” or be diffusely scattered. This contributes to a homogeneous illumination of the light body 30th at.

Rays of light L. , which on the optionally applied metal layers 12a impinging are in the direction of the light body 30th reflected back or diffusely backscattered. This makes a significant contribution to achieving homogeneous light emission and a high light yield of the light module 1 done.

• So kann der flächige Lichtkörper 30 im Bereich des zweiten Teils 30b in Abwandlung zur 2 mit einer reflektierenden Materialschicht 12b überdeckt sein. Die Materialschicht 12b kann bevorzugt ein weißer Kunststoff sein, der zweckmäßigerweise im Zweikomponenten-Spritzgussverfahren auf den Lichtkörper 30 aufgebracht wird (vgl. 2a).

Based on 2a until 2c are now further variants of the light body 30th to be discribed:

• This is how the flat body of light can 30th in the area of the second part 30b as a modification of 2 with a reflective material layer 12b be covered. The layer of material 12b can preferably be a white plastic, which is expediently applied to the light body in a two-component injection molding process 30th is applied (cf. 2a) .

In the 2 B and 2c are the back surface 36 and at least the side face 31 in the area of the second part 30b from the light body 30th with a print 12c Mistake. The printing 12c can be designed, for example, using the so-called pad printing process and, for example, as a metallized color, as a white or black color. The printing 12c preferably forms any pattern, lettering, symbol, logo or the like. In this way, a particularly interesting appearance of a lighting device can be achieved that uses the described light module 1 having.

Based on 3 you can now see how the light module 1 can be mounted. So can on the board 50 angular brackets 53 be present, which with the board 50 connected, preferably screwed or glued.

The flat body of light 30th can on its opposite, vertical side surfaces 32 , 33 in each case protruding locking means in the lower area 18th exhibit. The locking means 18th engage in counter-locking means 52 of the resiliently deflectable brackets 53 on.

Alternatively, it is also conceivable that the light body 30th at least one flange-like projection 39 with a bend 39a and with at least one molded locking body 39b having. The locking body 39b can then in a locking opening 50a the board 50 intervene with a latching action. In this way, a simple, quickly assembled connection can be created.

Furthermore, are between the lower side surface 34 of the light body 30th and the light sources 51 each collecting optics 60 indicated by dashed lines. These are optional and contribute to that of the light sources 51 emitted light rays L. "Collected" and in the direction of the light body 30th be aligned. The collecting optics 60 can also be attached to the lower side surface 34 be molded.

By means of a configuration as required, in particular a height of the first part 30a from the light body 30th can even cover a large distance in a simple manner and while maintaining a good photometric efficiency H of the second part 30b off the board 50 can be realized, which can be several centimeters. This can be particularly important if several Light modules 1 to be arranged in a lighting device.

the 4th is a light unit 100 to see which of three light bodies 30th consists, each of which has a first and a second part 30a and 30b (as described). Additional layers of metal 12a , Layers of material 12b or printing 12c , as described above, are conceivable, but not shown for the sake of clarity.

The light bodies 30th can be connected to one another in one piece, for example by a web-like connecting element 37 . They can thus be produced in a simple manner in one operation, preferably in a common injection molding tool.

Finally, there is a circuit board 50 ' present, which is correspondingly larger or longer than the board 50 (see. 1 ) and, for example, nine lamps 51 takes up, of which three each are a light body 30th assigned.

Based on 5 is shown that the light modules 1 or light units consisting of these 100 ' respectively 100 " also in a lighting device 2 of a motor vehicle indicated by dashed lines K can be used. The lighting device 2 can be a rear lighting of the motor vehicle K be, with a body-side part 2a the lighting device 2 in a body 3 and a tailgate-side part 2 B the lighting device 2 in a tailgate 4th of the motor vehicle K can be installed.

It is conceivable to use a control unit, not shown here, to control the individual light modules 1 to be controlled one after the other in such a way that technical lighting animations A1 respectively A2 (compare arrow direction). This is conceivable, for example, to implement a so-called coming home or leaving home function.

Finally shows the 6th the entire motor vehicle K , in which two lighting devices serving as rear lights 2 are installed. A control unit 5 is used via signal and control lines S. for controlling the lighting devices 2 .

List of reference symbols

1

Light module

2

Lighting device

2a

Body-side part of the lighting device

2 B

Tailgate-side part of the lighting device

3

body

4th

Tailgate

5

Control unit

12a

Metal layers

12b

reflective material layer

12c

Oppression

18th

Locking means

30th

flat light body

30a

first part of the flat body of light

30b

second part of the flat body of light

31

Side face

32

Side face

33

Side face

34

Side face

35

Light exit surface

36

back surface

37

bar-like connecting element

38

light-scattering imperfections

39

flange-like molding

39a

Angulation

39b

Locking body

50, 50 '

circuit board

50a

Locking opening

51

Illuminants, LEDs

52

Counter-locking means

53

bracket

60

Collecting optics

100, 100 ', 100 "

Light units

a

distance

A1, A2

animation

b

distance

d

thickness

F.

Area extension

H

distance

K

Motor vehicle

L.

Rays of light

S.

Signal and control line

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102011110630 A1 [0002]
• DE 102011110629 A1 [0003]
• DE 19860697 A1 [0004]
• DE 19902774 A1 [0005]

Claims (13)

Lighting device (2; 2a, 2b) for a motor vehicle (K), with at least one light module (1), which has a light body (30) and at least one illuminant (51), the light rays (L) of which in a surface serving as a light coupling surface ( 34) of the light body (30) can be or are coupled in, the light beams (L) being able to exit outwardly in the direction of a light emission direction of the lighting device (2; 2a, 2b) via a light exit surface (35) surrounded by surfaces of the light body (30) or emerge, characterized in that the light body (30) is flat and consists of a first part (30a) and a second part (30b), the first part (30a) being transparent and the second part (30b) being light-diffusing and wherein the two parts (30a, 30b) are integrally connected to one another, wherein the light beams (L) of the at least one illuminant (51) can be coupled into a side surface (34) of the first part (30a) are or are coupled in and the second part (30b) has the light exit surface (35). Lighting device (2; 2a, 2b) according to Claim 1 , characterized in that light-scattering imperfections (38) are distributed in the second part (30b) of the light body (30). Lighting device (2; 2a, 2b) according to Claim 1 or 2 , characterized in that the second part (30b) of the light body (30) has a transmittance in a range from about 85% to about 95%, preferably a transmittance of about 90%. Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that at least one collecting optic (60) facing the at least one illuminant (51) is formed on the first part (30a) of the light body (30). Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that the second part (30b) of the light body (30) is colored red. Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that a rear surface (36) opposite the light exit surface (35) and / or at least one side surface (31-33) of the second part (30b) of the light body (30) is coated with a metal layer (12a). Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that a rear surface (36) opposite the light exit surface (35) and / or at least one side surface (31-33) of the second part (30b) of the light body (30) is covered with a reflective material layer (12b) which is integrally connected to the light body (30). Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that a rear surface (36) opposite the light exit surface (35) and / or at least one side surface (31-33) of the second part (30b) of the light body (30) is provided with a print (12c). Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that the light body (30) is attached to a circuit board (50) which also carries the at least one illuminant (51). Lighting device (2; 2a, 2b) according to Claim 9 , characterized in that the light body (30) is locked to the circuit board (50). Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that the light of a plurality of illuminants (51) can be or is coupled into the light body (30), the illuminants (51) having such a mutual distance (a) have to each other, which corresponds to a distance (b) of the lighting means (51) from the side surface (34) serving as a light coupling surface. Lighting device (2; 2a, 2b) according to one of the preceding claims, characterized in that a plurality of light bodies (30) are present and are connected to one another in one piece. Motor vehicle (K), characterized by at least one lighting device (2; 2a, 2b) according to one of the preceding claims.

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