Lighting device

Abstract

Lighting device (1), in particular for a motor vehicle (K), with at least one light source (11) and at least one light guide (13), into which the light of the at least one light source (11) can be coupled, wherein at least one point (14) for coupling out the light is provided, wherein the at least one point (14) for coupling out the light is part of an opaque body (14) and at least one light-guiding, transparent layer (13) is arranged between the at least one light source (11) and the opaque body (14), wherein the transparent layer (13) is part of the light guide (13), characterized in that the light guide (13) and the opaque body (14) are held together by a snap-fit ​​connection (16), which is realized by a transparent cover (15) of the opaque body (14).

Description

[0001] The invention relates to a lighting device according to the preamble of claim 1.

[0002] Such lighting devices are well known and are often used in automotive engineering, for example, for design reasons in order to give the lighting devices a high-quality or extravagant appearance.

[0003] However, there is still the disadvantage that the light sources of the lighting device, whose light is coupled into the light guide, are too easily visible to an observer from outside.

[0004] Unfortunately, this takes away some of the “optical magic” of a lighting fixture.

[0005] Furthermore, EP 2 354 637 A2, which has the features of the preamble of patent claim 1, describes a lighting device for vehicles with a housing in which a first light unit and a second light unit connected to the first light unit are arranged. The first light unit has a planar light-guiding element with a rear side, a front side, and a narrow side connecting the rear side to the front side. A plurality of lighting elements for coupling light into the planar light-guiding element are assigned to the narrow side as a light-coupling surface. The rear side and / or the front side of the planar light-guiding element is provided with a number of output elements, so that a light beam with a predetermined luminous intensity distribution can be emitted from the front side of the planar light-guiding element.The second light unit also has a flat light-guiding element with a first narrow side configured as a light coupling surface, a first flat side adjacent to the first narrow side, and a second flat side opposite the first narrow side. A second narrow side connecting the first flat side and the second flat side is configured as a linear light coupling area.

[0006] DE 10 2005 040 100 A1 discloses a rear light for a motor vehicle, comprising light sources arranged in a light housing and a transparent light cover plate enclosing the light housing. A light source assigned to a first functional area of ​​the light is preceded, on the side facing the light cover plate, by a luminous element arrangement consisting of several translucent luminous elements with light-diffusing means. At least one separating area is provided between the luminous elements, relative to which the luminous elements protrude spatially.

[0007] DE 10 2007 036 793 B4 also describes a lighting device for a motor vehicle. This device comprises a housing enclosing a light source for generating light, a light guide guided within the housing, which is coupled to the light source for guiding and emitting the generated light, and a diaphragm device located within the lighting device. The diaphragm device is positioned upstream of the light guide in predetermined emission directions and surrounds it at least in part, forming a light space. The diaphragm device is partially transparent and has an additional optical means for generating a predetermined emission characteristic of the lighting device. This occurs in such a way that the light guide, in the illuminated state, generates a homogeneous luminous body on the diaphragm device.The housing simultaneously accommodates another light, with a screen element arranged in front of the additional light in the main beam direction, so that the light guide forms a light loop with a three-dimensional light impression when illuminated.

[0008] DE 10 2009 042 358 A1, which also includes the features of the preamble of patent claim 1, discloses a lighting device for generating lighting effects, comprising a glass body and illuminants for generating light rays. The illuminants are spaced from the glass body by light guide rods. Light rays from the illuminants reach the glass body via total internal reflection in the light guide rods. There, the light rays are refracted by the structure of a randomly formed inner surface of an interior space.

[0009] Finally, DE 10 2008 019 125 A1 discloses a vehicle lamp comprising a light source, a first reflector, and scattering intermediate light panels. These are arranged such that light emitted by the light source is reflected by a reflector surface of the first reflector, forming a first luminous surface of the lamp. The vehicle lamp further comprises a second reflector, the reflector surface of which is arranged separately from the reflector surface of the first reflector and is arranged such that light emitted by the light source is reflected by the reflector surface of the second reflector, forming a second luminous surface of the lamp. The first and second luminous surfaces are not contiguous.

[0010] The invention is therefore based on the object of developing a lighting device according to the preamble of claim 1 in such a way that the view of the illuminants whose light is coupled into the light guide is made more difficult for an external observer. In particular, an easily implemented mechanical connection between the light guide and a body having at least one point for coupling out the light should be possible.

[0011] The above-mentioned object is achieved by the characterizing features of patent claim 1. Advantageous embodiments and further developments of the invention can be found in the subclaims.

[0012] The invention therefore relates to a lighting device, in particular for a motor vehicle, having at least one illuminating means and at least one light guide into which light from the at least one illuminating means can be coupled, wherein at least one point is provided for coupling out the light.

[0013] It is also proposed that the at least one point for coupling out light is part of an opaque body and that at least one light-conducting, transparent layer is arranged at least between the at least one illuminant and the opaque body.

[0014] This design creates the impression that there is air between the lamp(s) and the light guide, although the lamps are barely or not at all visible from certain viewing angles due to total reflection in the transparent layer.

[0015] This optical effect can be further enhanced by the opaque body having a milky appearance and the transparent layer being clear and uncolored.

[0016] A milky appearance of the opaque body can be achieved, for example, by roughening its surface through sandblasting or by coloring it with particles within the body. The opaque body thus acts as a light distributor or luminous body, from which the light is diffusely coupled out in all directions.

[0017] The clear, transparent layer (comparable, for example, to a thick window glass) is preferably polished, especially on the side facing the light source, where the light is coupled into the transparent layer.

[0018] In an advantageous embodiment of the invention, it can be provided that only the transparent layer is designed as a support for the opaque body. In this case, the transparent layer thus performs a kind of dual function, namely, on the one hand, conducting light and, on the other hand, supporting the opaque body. This can achieve the optical effect that the opaque body appears to an observer as floating freely and luminously within the lighting device.

[0019] Furthermore, the transparent layer is a component of the light guide. According to the invention, the light guide and the opaque body are held together by a snap-in connection. This allows for easy connection between the light guide and the opaque body.

[0020] As a further feature of the invention, the snap-in connection is realized by a transparent cover for the opaque body. The transparent cover can thus perform a dual function: on the one hand, providing a desired signal color (if appropriately colored) and, on the other hand, creating a mechanical connection between the light guide and the opaque body. The cover can also contribute to a visually "clean" transition of the connection between the light guide and the opaque body.

[0021] Alternatively, however, it is also possible, although not part of the present invention, for the transparent layer to be part of the light guide, with the light guide and the opaque body being integrally connected to one another. For example, it is conceivable for the light guide and the opaque body to be manufactured using a two-component injection molding process. This allows for a reduction in the number of components and also in manufacturing costs.

[0022] In order to optimize the light yield with regard to the coupled light, it has proven to be expedient if the opaque body has a cross-section which tapers with increasing distance from the at least one light source.

[0023] A further embodiment of the inventive concept provides that the light guide is enclosed vertically between two housing walls, wherein the at least one illuminant is arranged on one side of the housing walls and the opaque body is arranged on another side of the housing walls.

[0024] This measure can achieve two effects: Firstly, it enables a very stable mounting of the light guide, and secondly, the housing walls can thus contribute to additional concealment of at least one light source.

[0025] According to a further, highly expedient development, the opaque body can be elongated, and at least one illuminant for coupling light is arranged in front of a longitudinal side of the opaque body. This allows the light from significantly more illuminants to be coupled into the opaque body, thereby providing more light output when needed (e.g., when the brake light function is activated) and achieving a more homogeneous light distribution.

[0026] Although the invention is particularly suitable for the lighting system of a motor vehicle (e.g., for taillights, turn indicators, daytime running lights, and the like), other applications outside the automotive industry are also conceivable. For example, applications in the advertising sector (three-dimensional illuminated signs), lamps, and simply for illuminating certain objects are conceivable.

[0027] Preferred embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Like reference numerals refer to like, comparable, or functionally identical components.

[0028] They show, schematically Fig. 1 the rear view of a motor vehicle with two lighting devices according to the invention, Fig. 2 a perspective individual view of a lighting device according to the invention, Fig. 3 a sectional view according to section III from Fig. 2 and Fig. 4 shows a plan view of a second embodiment of the lighting device not covered by the invention.

[0029] Fig. 1 shows the rear view of a motor vehicle K with two lighting devices 1 according to the invention extending like wings from the body of the motor vehicle K.

[0030] The lighting devices 1 are each designed as a rear / brake light and are essentially identical in construction.

[0031] Fig. Figure 2 now shows the left lighting device 1 alone. It can be seen that the lighting device 1 has a housing 10. Light-emitting diodes (LEDs) 11 (indicated by dashed lines) are arranged in the housing 10, which serve to couple light into a transparent, elongated light guide 13. An equally elongated, but opaque body 14 (cf. Fig. 3) is used to couple out the light.

[0032] In particular Fig. 3 it can be seen that the opaque body 14 has a conical cross-section which tapers with increasing distance to the light-emitting diodes 11 and is enclosed by a transparent cover 15.

[0033] The transparent cover 15 simultaneously serves to create snap-in connections 16 between the opaque body 14 and the transparent light guide 13.

[0034] The LEDs 11 and their circuit boards are thermally connected to a heat sink 12 made of aluminum. Fig. 3 shows that the transparent light guide 13 forms a light-conducting, transparent layer between the LEDs 11 and the opaque body 14.

[0035] This makes it possible for the (switched on) LEDs 11 to be barely or not at all perceptible to the eye A of a viewer, particularly from an angle of view obliquely from above, due to total reflection in the light guide 13.

[0036] In addition, the light guide 13 is held securely between two housing walls 18, 19 extending vertically in the direction of the light guide 13 via a tongue and groove joint 20. The housing walls 18, 19 also contribute to concealing the LEDs 11.

[0037] Above the arrangement consisting of the light guide 13 and the body 14, a transparent cover 17 is provided, which is connected to the housing 10.

[0038] The cover 17 is in Fig. 2 is partially omitted to better visualize the light guide 13 and the cover 15. It can be seen that in this exemplary embodiment, the cover 15 is essentially wrapped around the light guide 13 and is connected to the housing 10 by means of two fastening areas B1 and B2. The cover 15 thus contributes to the support of the body 14 and the light guide 13.

[0039] For example, to generate a desired red signal color, the LEDs 11 can be designed as red light-emitting diodes. Alternatively or additionally, the covers 15 and / or 17 can be colored red.

[0040] It should also be noted that the opaque body 14, which acts as a light distributor or luminous element, has a milky appearance. This can be achieved, for example, by sandblasting the body 14 or by appropriately coloring it.

[0041] The transparent light guide 13, on the other hand, is completely clear. It can be made of polished Plexiglas, for example.

[0042] Based on Fig. A second embodiment of a lighting device not covered by the invention will now be explained in more detail in Figure 4. This shows a lighting device 1' in which a plurality of light-emitting diodes 11 are also arranged in a housing 10', the light from which is coupled into a light-conducting, transparent layer or into a transparent light guide 13' and diffusely coupled out again in an opaque body 14'.

[0043] In this embodiment, the light guide 13' serves a dual function. Firstly, it guides the light to the body 14'; secondly, the light guide 13' serves to support the body 14'.

[0044] This creates the impression, especially when the LEDs are switched on, that the 14' body is completely suspended within the 10' housing. This creates an extremely mysterious and appealing appearance.

[0045] In this embodiment, the light guide 13' and the body 14' are integrally connected to one another via a two-component injection molding process.

[0046] It should also be noted that, in particular, Fig. 4 that the opaque body 14' is elongated in plan view, with longitudinal sides 141 and transverse sides 140. As can be seen, the light-emitting diodes 11 (as in the embodiment according to the Fig.1 to 3) are arranged in front of a longitudinal side 141 of the body 14'. This allows more light output to be coupled into the body 14' if required, thus achieving a very homogeneous light distribution.

[0047] Although the body 14' is approximately rectangular in plan view in the illustrated embodiment, an arrangement of the LEDs 11 along one long side can also be used with other, elongated shapes of the body 14'. For example, the body 14' can be elongated but slightly curved. List of reference symbols 1.1' lighting device 10.10' enclosure 11 LEDs 12 aluminum heat sinks 13.13' transparent light guide 14.14' opaque body (light distributor) 140 Transverse side of the opaque body 141 Long side of the opaque body 15 red, transparent cover 16 Snap connection 17 red, transparent cover 18 vertical housing wall 19 vertical housing wall 20 tongue and groove joint B1,B2 fastening areas K Motor vehicle

Claims

[1] Lighting device (1), in particular for a motor vehicle (K), with at least one illuminating means (11) and at least one light guide (13) into which light from the at least one illuminating means (11) can be coupled, wherein at least one point (14) is provided for coupling out the light, wherein the at least one point (14) for coupling out the light is a component of an opaque body (14) and at least one light-conducting, transparent layer (13) is arranged at least between the at least one illuminating means (11) and the opaque body (14), wherein the transparent layer (13) is a component of the light guide (13), characterized by that the light guide (13) and the opaque body (14) are held together by a snap-in connection (16) which is realized by a transparent cover (15) of the opaque body (14). [2] Lighting device (1) according to claim 1, characterized bythat the opaque body (14) has a milky appearance and the transparent layer (13) is clear and uncolored. [3] Lighting device (1) according to claim 1 or 2, characterized by that only the transparent layer (13) is designed as a holder for the opaque body (14). [4] Lighting device (1) according to one of the preceding claims, characterized by that the opaque body (14) has a cross-section which tapers with increasing distance from the at least one illuminant (11). [5] Lighting device (1) according to one of the preceding claims, characterized by that the light guide (13) is enclosed vertically between two housing walls (18, 19), wherein the at least one illuminating means (11) is arranged on one side of the housing walls (18, 19) and the opaque body (14) is arranged on another side of the housing walls (18, 19). [6] Lighting device (1) according to one of the preceding claims, characterized by that the opaque body (14) is elongated and the at least one illuminating means (11) for coupling in light is arranged in front of a longitudinal side (141) of the opaque body (14). [7] Motor vehicle (K) with at least one lighting device (1) according to one of claims 1 to 6.

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