Lighting devices for motor vehicles

Abstract

A lighting device for a motor vehicle, the lighting device comprising a light source (1), a light conductor (3) having an incident surface (7), and a hologram (10) disposed on or in the light conductor (3), wherein the lighting device is configured such that light (2) emitted from the light source (1) is incident on the incident surface (7) of the light conductor (3) and interacts with the hologram (10), thereby reconstructing an image (10) stored in the hologram and making it visible to an observer of the lighting device, wherein the light conductor (3) has a first exit surface (9a) and a second exit surface (9b), wherein the lighting device is configured to emit light that has interacted with the hologram (10) through the first exit surface (9a) and emit light (2) that does not interact with the hologram (10) through the second exit surface (9b).

Description

Technical Field

[0001] This invention relates to a lighting device for motor vehicles. Background Technology

[0002] The above-described type of lighting device is known from DE 10 2017 124 296 A1. The lighting device described therein includes a light source configured as a light-emitting diode (LED), a light conductor having an incident surface and a reflecting region, and a hologram disposed on the light conductor. Here, light emitted from the light source is incident on the incident surface of the light conductor in a direction toward the reflecting region and is reflected within the light conductor by the reflecting region in a direction toward the hologram. For example, an image stored in the hologram can be reconstructed by illuminating the hologram to generate an luminous sign.

[0003] To generate holograms with good imaging quality within the limited installation space conditions in automotive lighting technology, a small light source is required, provided by the use of light-emitting diodes (LEDs). Considering the construction of typical reflection hologram systems or edge-illuminated hologram systems, it is worth noting that the efficiency of such systems is quite low.

[0004] In an edge-illuminated hologram, there exists a defined incident surface of a light conductor illuminated by a light source. The distance from the light source to the incident surface produces a typically small solid angle, which describes the light available from the light source. Light radiated by the light source into the space adjacent to the incident surface cannot be used by the light conductor and the hologram. Furthermore, the overall efficiency is determined by the graphic nature of the hologram, where the larger the luminescent area relative to the total hologram area, the higher the efficiency. Since 3D logos are generally generated using luminescent surfaces or elements (e.g., lines, stripes, faces, blocks, or volumes) distributed in space, only a portion of the hologram area ultimately emits light. Overall, this results in only a relatively low efficiency for use.

[0005] The efficiency of the hologram itself must also be considered, as holograms are calculated over a small wavelength range, ideally a single wavelength. In contrast, typically used light-emitting diodes have a spectral width of 18 nm to 20 nm.

[0006] In a simplified example calculation, the overall efficiency of a lighting device comprising a light-emitting diode (LED), a photoconductor, and a hologram should be estimated. Here, we start with an exemplary luminous flux of 30 lm for a red LED. The proportion of light incident from the LED onto the incident surface of the photoconductor is, for example, 20%. Therefore, only 6 lm remains. If the area ratio between the luminous area of ​​the hologram and the total area of ​​the hologram is 50%, then 3 lm remains. Thus, if we assume an efficiency of 70% for the hologram, the net luminous flux is 2.1 lm. Therefore, the overall efficiency of the lighting device is 7%.

[0007] Therefore, holographic functionality alone cannot fulfill the desired signal functions in the form of taillights, brake lights, turn signals, or daytime running lights. The light power of the LEDs would have to be significantly higher, which is physically limited and very difficult or expensive due to the size of the chips typically used and from a thermal perspective. Summary of the Invention

[0008] The problem upon which this invention is based is to create a lighting device of the type mentioned at the beginning, which in particular has improved overall efficiency despite relatively small installation space.

[0009] According to the invention, this is achieved by a lighting device according to the invention.

[0010] According to the present invention, a lighting device for a motor vehicle comprises: a light source; a light conductor having a V-shaped cross-section, the light conductor having a first arm, a second arm, and a connecting region connecting the first arm and the second arm; a hologram disposed on or in the light conductor; and a first light-shielding plate disposed between the first arm and the second arm, wherein the lighting device is configured such that light emitted from the light source located on the first light-shielding plate is incident on an incident surface on the first arm of the light conductor and interacts with the hologram, thereby reconstructing an image stored in the hologram and making it visible to an observer of the lighting device; the second arm of the light conductor has a first exit surface and a second exit surface, such that light incident on the incident surface of the light conductor exits from both the first exit surface and the second exit surface; wherein the lighting device is configured to: exit light interacting with the hologram through the first exit surface, the light interacting with the hologram during or after exiting from the first exit surface; and the lighting device is configured to: exit light that does not interact with the hologram through the second exit surface, the light neither interacting with the hologram during nor after exiting from the second exit surface. Therefore, a holographic image is generated in a larger area, such as the light conductor, while a smaller area, also containing the light conductor, is used for conventional light transmission and redirection. This improves efficiency because a larger share of the available light from the light source is used to generate higher light intensities to satisfy the optical function. This creates the possibility of implementing a signal function that utilizes only the mounting space and the size of the light conductor, and in particular, requires no additional emitting surfaces or additional optical functions.

[0011] It can be specified that the second exit surface is located on the same side of the optical conductor as the first exit surface. Therefore, not only the light passing through the second exit surface but also the light corresponding to the reconstructed image of the hologram can exit from the optical conductor in substantially the same direction, and thus jointly contribute to the signal function.

[0012] There is a possibility that the second emitting surface is positioned adjacent to the first emitting surface, specifically, the second emitting surface is directly adjacent to the first emitting surface, or the second emitting surface is spaced apart from the first emitting surface by a distance. Furthermore, it can be specified that the second emitting surface is parallel to the first emitting surface, or that the normal on the second emitting surface forms an angle not equal to 0° with the normal on the first emitting surface. Both measures can improve the interaction of light components decoupled from the optical conductor through the two emitting surfaces during signal generation.

[0013] There is a possibility that the lighting device includes a light-shielding plate disposed between the second emitting surface and the first emitting surface and / or covering a section of the second emitting surface and / or covering a section of the first emitting surface. The light-shielding plate in front of the light conductor enables the separation of the second emitting surface and the first emitting surface from which light is directly radiated, thus separating the two light regions by design, even if the lighting element or the light conductor behind the light-shielding plate is implemented as a single piece.

[0014] It can be specified that the second emitting surface is dislocated relative to the first emitting surface, particularly oriented towards a direction parallel to the normal on the first emitting surface. The possibility of dislocating the second emitting surface relative to the first emitting surface (e.g., making it protrude) creates additional degrees of freedom in the design of the optical conductor or radiating surface for generating high-intensity signal capabilities.

[0015] There is a possibility that the second exiting surface has scattering optics, particularly in the form of cushion-shaped or strip-shaped optics, and / or that the second exiting surface has a structure, particularly an optical structure, such as an etched or corrugated structure, or a diffractive diffuser structure. This allows for targeted influence on the distribution of light emitted through the second exiting surface.

[0016] It can be specified that the optical conductor has a first reflective region, wherein the lighting device is configured such that light emitted from the light source is incident on the incident surface of the optical conductor in a direction toward the first reflective region and is reflected within the optical conductor by the first reflective region in a direction toward the hologram. It can also be specified that the optical conductor has a second reflective region, wherein the lighting device is configured such that light emitted from the light source is incident on the incident surface of the optical conductor in a direction toward the second reflective region and is reflected within the optical conductor by the second reflective region in a direction toward the second exit surface. By generating overlapping optical paths of light interacting with the hologram and directly emitted light through each reflective region, the lighting device generally requires less installation space.

[0017] There is a possibility that the illumination device is configured such that light emitted from the light source is incident on the incident surface of the light conductor in a direction toward the first reflecting region; a portion of the light incident on the light conductor is reflected within the light conductor by the first reflecting region in a direction toward the second reflecting region; and a portion of the light incident on the second reflecting region is reflected within the light conductor by the second reflecting region in a direction toward the second exit surface. Furthermore, there is a possibility that the illumination device is configured such that light emitted from the light source is incident on the incident surface of the light conductor in a direction toward the second reflecting region; a portion of the light incident on the light conductor is reflected within the light conductor by the second reflecting region in a direction toward the first reflecting region; and a portion of the light incident on the first reflecting region is reflected within the light conductor by the first reflecting region in a direction toward the hologram. Both measures optimize the optical path within the light conductor, thereby enabling reliable light redirection toward the hologram and the two exit surfaces within a smaller installation space.

[0018] The illumination device can be specified to include a reflector disposed outside the light conductor, wherein the illumination device is configured such that light emitted from the light source is incident on the reflector, reflected by the reflector in a direction toward the light conductor, particularly toward an additional incident surface of the light conductor, and incident into the light conductor in a direction toward a second exit surface. Therefore, the efficiency of light emitted from the light source reaching the second exit surface can be improved. Furthermore, light used for the signal function to be implemented can be used through the additional reflector, thus avoiding direct incident into the light conductor through the incident surface.

[0019] There is a possibility that the hologram is an edge-illuminated hologram, specifically one whose illumination angle is greater than the critical angle for total internal reflection at the first exit surface of the light conductor. With such a large illumination angle, the portion of light incident on the decoupling surface that does not interact with the hologram is completely reflected and does not exit from the decoupling surface. This prevents interference from unintentionally emitted light, particularly by suppressing 0th-order light. This improves the quality of holographic imaging and the reconstruction of the image stored in the hologram.

[0020] It can be specified that the hologram is a transmission hologram, which is specifically disposed on the first emitting surface of the photoconductor. The transmission hologram can be configured as a volume hologram stored in a thin film, wherein the thin film can be adhered to the outer side of the first emitting surface.

[0021] Alternatively, the hologram may be a reflection hologram, particularly disposed on the surface of the optical conductor opposite to the first emitting surface of the optical conductor. For example, the reflection hologram may also be configured as a volume hologram stored in a thin film, wherein the thin film may be adhered to the side of the optical conductor opposite to the first emitting surface.

[0022] An illumination device with a light source and a light conductor can be used as a single element, such as for a taillight or position light. Alternatively, the illumination device can also be used in a multi-arrangement structure, particularly for extended functional arrangements where light conductors are arranged side-by-side, such as for turn signals, brake lights, or position-daytime running lights. This is especially meaningful when a single element does not meet the desired light value or required area for the function.

[0023] In the red-signal taillights and brake lights, or in the yellow-signal turn signals, the color of the hologram corresponds to the color of the signal function. In the white-signal position lights and daytime running lights, the hologram can be designed according to any wavelength of the white light-emitting diode spectrum, and therefore emits light in a defined and desired color (such as blue, green, yellow, red, cyan, magenta, or other colors).

[0024] The hologram can display any image or graphic, such as a manufacturer's logo or an arrow graphic in a turn indicator, or letters or words or other content, such as welcome and goodbye functions when the vehicle is turned on and off. Attached Figure Description

[0025] The invention will now be explained in more detail with reference to the accompanying drawings. In the drawings:

[0026] Figure 1 A cross-sectional view of a first embodiment of the lighting device according to the invention is shown;

[0027] Figure 2 Showing according to Figure 1 A cross-sectional view of the lighting device, in which the light beam is schematically drawn;

[0028] Figure 3 Showing according to Figure 1 A perspective view of the lighting fixture;

[0029] Figure 4 A cross-sectional view of a second embodiment of the lighting device according to the invention is shown, wherein the light beam is schematically depicted;

[0030] Figure 5 A cross-sectional view of a third embodiment of the lighting device according to the invention is shown, wherein the light beam is schematically depicted;

[0031] Figure 6 A cross-sectional view of a fourth embodiment of the lighting device according to the invention is shown, wherein the light beam is schematically depicted;

[0032] Figure 7 A perspective view of a fifth embodiment of the lighting device according to the invention is shown;

[0033] Figure 8 Showing according to Figure 7 Another perspective view of the lighting fixture;

[0034] Figure 9 Showing according to Figure 7 A cross-sectional view of the lighting device;

[0035] Figure 10 Showing according to Figure 7 A cross-sectional view of the lighting device, in which the light beam is schematically drawn;

[0036] Figure 11 A cross-sectional view of a sixth embodiment of the lighting device according to the invention is shown, wherein the light beam is schematically depicted;

[0037] Figure 12 A cross-sectional view of a seventh embodiment of the lighting device according to the invention is shown, wherein the light beam is schematically depicted;

[0038] Figure 13 The wavelength spectrum of a white light-emitting diode used as a light source in the lighting device according to the present invention is shown. Detailed Implementation

[0039] In the accompanying drawings, identical and functionally identical components are given the same reference numerals.

[0040] The lighting device according to the present invention Figures 1 to 3 The first embodiment shown includes a light source 1 configured as a light-emitting diode (LED), from which light 2 is emitted when the lighting device is in operation.

[0041] The lighting device also includes a light conductor 3 with a basic V-shaped cross-section (see Figure 3 The photoconductor 3 has a first arm 4, a second arm 5, and a connecting region 6 connecting the two arms 4 and 5. Here, the first arm 4 is configured to be significantly shorter than the second arm 5.

[0042] The first arm 4 has an incident surface 7 for light 2 emitted from the light source 1 at its end opposite to the connecting region 6 (see [link]). Figure 2 The incident surface 7 is concave and curved, and in particular has the shape of a partially hollow sphere, thereby achieving neutral light incident that is adapted to the divergence of light 2 emitted from the light source 1.

[0043] Starting from the incident surface 7, the first arm 4 extends in the transverse direction (see...). Figure 3 The V-shaped widening (from left to right) extends to its maximum extension in the connecting region 6. This V-shaped widening creates space on the outer side of the first arm 4 for fastening elements 13, which can be used to secure the optical conductor 3. Here, the incident surface 7 is positioned close to and mostly above the two fastening elements 13 (see [reference]). Figure 3 ).

[0044] The second arm 5 has an upper segment 8 and a lower segment 9 that is slightly inclined relative to the upper segment 8. The lower segment 9 of the second arm 5 forms a first exit surface 9a on its side opposite to the first arm 4, so as to read a hologram in the form of a volume hologram into the thin film. Figure 10 It is applied from the outside to the first emission surface 9a, in particular, it is adhered to the first emission surface 9a.

[0045] Below the first exit surface 9a, a second exit surface 9b is formed, the second exit surface being... Figure 1 and Figure 2 The middle part extends less in the vertical direction. The second exit surface is equipped with scattering optics, particularly in the form of pad-shaped optics or stripe optics. Alternatively or additionally, structures, particularly optical structures, such as etched or corrugated structures, or diffractive diffuser structures may also be provided.

[0046] holographic Figure 10 It is a transmission hologram, and light passing through the exit surface can interact with it. When the angle between the two arms 4 and 5 is relatively small, the hologram is also an edge-illumination hologram, because holography... Figure 10 The illumination angle α that must be illuminated becomes relatively large in order to reconstruct the holographic image (see [link]). Figure 2 ).

[0047] The alternative site may specify a hologram that is instead constructed as a transmission hologram. Figure 10 A reflection hologram (not shown) is disposed on the surface of the second arm 5 facing the first arm 4. For example, the reflection hologram can also be configured as a volumetric hologram stored in a thin film, wherein the thin film can be adhered to the surface of the lower segment 9 of the second arm 5 facing the first arm 4. In this case, light emitted from the reflection hologram can exit from the photoconductor 3 through a first exit surface 9a formed on the side of the lower segment 9 of the second arm 5 facing away from the first arm 4. The reflection hologram can also be configured as an edge-illuminating hologram illuminated at a large angle.

[0048] A light-shielding plate 14 is provided between the two arms 4 and 5. The light-shielding plate 14 can be painted black on the side facing the second arm. The light-shielding plate 14 prevents light 2 emitted from the light source 1 from directly penetrating into the second arm 5, since the second arm 5 of the light conductor 3 is covered by the light-shielding plate 14.

[0049] The connecting region 6 is mostly coated with a reflective coating on its exterior and thus serves as the first reflective region 11. Accordingly, light 2 emitted from the light source 1, passing through the incident surface 7 and incident into the light conductor 3, penetrates the first arm 4, incident on the first reflective region 11, and is reflected by the first reflective region 11. Figure 2 The light 2 is reflected downwards into the second arm 5. In the second arm 5, a portion of the light 2 passes through the first exit surface of the lower segment 9 of the second arm 5 and strikes the hologram. Figure 10 middle.

[0050] Here, the first reflecting region 11 is convex and curved, and in particular, is configured as a parabola. This curvature achieves the effect that the components of light 2 striking the first reflecting region 11 at different angles... Figure 9 The light beams reflect downwards in essentially the same direction. The essentially parallel beams of light 2 ensure the holographic effect. Figure 10 The essentially equal illumination angle α is beneficial for the efficient reconstruction of holographic images.

[0051] Alternatively, the first surface 11 may be configured as a freeform surface to enable further optimization of illumination or to optimize the adaptation of the coupled light 2 of the light source 1. Depending on the desired light shaping of the reflected light 2, the first reflective region 11 may alternatively be equipped with additional optics.

[0052] At the lower end of the second arm 5, a second reflecting region 12 is formed by an inclined portion. This second reflecting region reflects light 2 emitted from the first reflecting region 11, which has already moved past the exiting surface 9a, towards the second exiting surface 9b. This light 2 can then... Figure 2 The light is emitted from the light conductor 3 to the right.

[0053] According to Figure 4 In this implementation, the second exiting surface 9b is not located below the first exiting surface 9a, but rather above it. To redirect the light 2 incident on the photoconductor 3 through the incident surface 7 directly onto the second exiting surface 9b, the second reflecting region 12 is not located at the lower end of the second arm 5, but rather on the side of the connecting region 6 facing away from the second arm 5. The light 2 is directly reflected forward by the second reflecting region 12 and exits from the photoconductor 3 through the second exiting surface 9b, and this light does not interact with the hologram. Figure 10 Interacting with or interfering with the hologram.

[0054] A light-shielding plate 15 is provided in front of the second arm 5 of the light conductor 3, between the first emitting surface 9a and the second emitting surface 9b. The light-shielding plate 15 makes it possible to separate the second emitting surface 9b, which directly radiates light, from the first emitting surface 9a. This separation allows for the design separation of the two light regions, even if the light conductor behind the light-shielding plate is implemented as a single piece.

[0055] Of course, this possibility exists, namely, based on Figures 1 to 3 Such sunshades are also installed in the implementation of the project.

[0056] according to Figure 5 Implementation form and basis Figure 4 The difference in the implementation is that the second emitting surface 9b protrudes from the second arm 5 of the photoconductor 3. The second emitting surface is displaced relative to the first emitting surface 9a in a direction parallel to the normal on the first emitting surface 9a.

[0057] The lighting device according to the invention Figure 6 The embodiment shown also has an exit surface 9b positioned above the first exit surface 9a. The lighting device includes a reflector 16 positioned outside the light conductor. This reflector 16 can be connected, preferably in one piece, to a light-shielding plate 17, which covers the light conductor 3 in the upper region. Alternatively, the light-shielding plate 17 can be omitted.

[0058] In this embodiment, the first arm 4 of the light conductor 3 has an additional incident surface 18, which is disposed on the side of the first arm 4 opposite to the second arm 5. Here, light 2 emitted from the light source 1 strikes the reflector 16, is reflected by the reflector 16 in the direction toward the additional incident surface 18, and then enters the light conductor through the additional incident surface in the direction toward the second exit surface 9b. The component of light 2 reflected by the reflector 16 can exit the light conductor 3 through the second exit surface 9b.

[0059] The lighting device according to the invention Figures 7 to 10 The embodiment shown includes a light-emitting diode (LED) serving as a light source 1, from which light is emitted laterally. The lighting device includes a light conductor 3 coordinated with such an LED, the light conductor being configured in a generally L-shape and having a first arm 4 and a second arm 5, wherein the two arms 4 and 5 form an obtuse angle.

[0060] The first arm 4 has a recess 19 on its upper side, into which the light source 1 extends. In the recess 19, in... Figure 9 An incident surface 7 for light 2 emitted from the light source 1 is formed on the upper left side or on the side opposite to the second arm 5 (see [reference]). Figure 10 ).

[0061] The second reflective area 12 is disposed on the end of the first arm 4 away from the second arm 5, while the first reflective area 11 is disposed in the connection area 6 between the first arm 4 and the second arm 5. Figure 8 As shown, the second reflective region is concave and curved, particularly cylindrical and curved. The first reflective region 11 is planar. The first reflective region 11 is inclined both relative to the first arm 4 and relative to the second arm 5.

[0062] As in accordance with Figures 1 to 6 In this embodiment, the first emitting surface 9a occupies the largest portion of the second arm 5 on the side opposite to the first arm 4. The second emitting surface 9b is relatively narrow and is positioned between the first reflecting region 11 and the first emitting surface 9a (see [reference]). Figure 7 , Figure 9 and Figure 10 ).

[0063] Light 2 emitted from light source 1 is incident on the first arm 4 of light conductor 3 via incident surface 7 and towards the second reflection region 12. A portion of the light 2 incident on light conductor 3 is reflected within the light conductor by the second reflection region 12 towards the first reflection region 11, and then by the first reflection region towards the hologram. This portion of light 2 can be combined with the hologram... Figure 10 Interact and reconstruct stored in holography Figure 10 The image shows that another portion of the light 2 incident on the second reflection region 12 is directly reflected by this region onto the second exit surface 9b, and the light 2 can then exit directly from the photoconductor 3 through the second exit surface 9b (see image 12). Figure 10 ).

[0064] According to Figure 11 and Figure 12 In this embodiment, the photoconductor is configured as a flat, basically disk-shaped photoconductor 3, which is connected to the hologram. Figure 10 Together, they form a so-called waveguide hologram system. In the illustrated embodiment, the incident surface 7 of the optical conductor 3 is disposed on the upper end surface of the optical conductor 3.

[0065] holographic Figure 10 It is configured as a reflection hologram and set in Figure 11 and Figure 12 On the long side of the left side of the center. The first exit surface 9a is formed on the optical conductor 3 and the hologram. Figure 10 On the opposite side. Here, the first exit surface 9a can be at least partially used as a first reflection region, the first reflection region facing the hologram. Figure 10 2. Reflected light in the direction of .

[0066] For example, a reflection hologram can also be configured as a volume hologram stored in a thin film, wherein the thin film can be attached to the photoconductor 3. Figure 11 and Figure 12 On the upper outer side of the left side. A reflection hologram can also be constructed as an edge-illuminated hologram illuminated at a large angle.

[0067] Alternative sites, holographic Figure 10 It can also be configured as a transmission hologram, which is formed on the first exit surface 9a, particularly by external attachment to the first exit surface 9a. In this case, the surface opposite to the first exit surface 9a can at least partially serve as a first reflecting region, the first reflecting region facing the hologram. Figure 10 2. The reflected light is directed in the direction of the light source. A transmission hologram can also be constructed as an edge-illuminated hologram illuminated at a large angle.

[0068] Light 2, which is incident on the light conductor 3 through the incident surface 7, can... Figure 11 and Figure 12 The incident surface 7 moves downwards and is reflected multiple times along the two long sides. (Similar to holography) Figure 10 Interacting light 2 reconstruction stored in holography Figure 10 The image is visible from the outside through the first exit surface 9a.

[0069] Light 2, incident on the optical conductor 3 through the incident surface 7, can travel from the incident surface 7 towards... Figure 11 and 12 It moves downwards and is reflected multiple times along its two long sides. (Similar to holography) Figure 10 Interacting light 2 reconstruction stored in holography Figure 10 The image is visible from the outside through the first exit surface 9a.

[0070] According to Figure 11 In one embodiment, the second emitting surface 9b is adjacent to the first emitting surface 9a below. The optical conductor 3 in... Figure 11 A slope is formed on the lower middle part, which is used to prevent it from interfering with the hologram. Figure 10 The second reflection region 12 of the interacting light 2. The light 2 is reflected by the second reflection region 12 toward the second exit surface 9b and exits from the second exit surface.

[0071] According to Figure 12 In this embodiment, the second emitting surface 9b is also disposed below the first emitting surface 9a. However, the second emitting surface protrudes outward relative to the first emitting surface. The lower end region of the photoconductor 3 has a geometry that serves as the second reflecting region 12 for light deflection and transmission to the second emitting surface 9b. In this embodiment, a light-shielding plate 15 is disposed between the first emitting surface 9a and the second emitting surface 9b.

[0072] The lighting device having a light source 1 and a light conductor 3 can be used as a single element, for example, for a taillight or position light. Alternatively, the lighting device can also be used in a multi-arrangement structure, particularly in the case of side-by-side arrangement of the light conductors 3, for an extended functional arrangement structure, for example, for a turn signal, brake light, or position-daytime running light.

[0073] holographic Figure 10 It can display any image or graphic, such as the manufacturer icon or the arrow graphic in the turn indicator, or display letters or text or other content, such as the welcome and goodbye functions when the vehicle is turned on and off.

[0074] In the red signal taillights and brake lights, or in the yellow signal turn signals, the color of the holographic image corresponds to the color of the signal function.

[0075] White light-emitting diodes (LEDs) can be used in white signal position lights and daytime running lights. The wavelength spectrum of white LEDs spans the entire color range from blue to red with varying intensities. Figure 13 The image shows a typical wavelength spectrum of a white light-emitting diode, where intensity 20 is plotted in arbitrary units with respect to wavelength λ in nm.

[0076] Because white light-emitting diodes (LEDs) are based on a blue chip, which generates white light by color mixing using conversion devices, particularly phosphors, complementary light sources exhibit a high intensity peak in the blue range of approximately 450 nm. This peak decreases until it reaches a minimum in the cyan range of approximately 490 nm. Another high intensity peak exists in the yellow-green range between 530 nm and 590 nm, while the light power decreases again in the red range of approximately 640 nm.

[0077] When using white light-emitting diodes (LEDs), holograms can be designed according to any wavelength of the white LED spectrum and thus emit light in a defined and desired color (e.g., blue, green, yellow, red, cyan, magenta, or other colors).

[0078] List of reference numerals

[0079] 1. Light source

[0080] 2. Light emitted from the light source

[0081] 3. Optical Conductor

[0082] 4. The first arm of photoconductor 3

[0083] 5. The second arm of the optical conductor

[0084] 6. Optical Conductor Connection Area

[0085] 7. Incident surface of a light conductor

[0086] 8. Upper section of the second arm

[0087] 9. Lower section of the second arm

[0088] 9a First exit surface

[0089] 9b Second exit surface

[0090] 10 Holograms

[0091] 11 First Reflection Area

[0092] 12 Second Reflection Area

[0093] 13 Fastening elements for optical conductors

[0094] 14 visor

[0095] 15 visor

[0096] 16 Reflectors

[0097] 17 visor

[0098] 18. Additional incident surface of a light conductor

[0099] 19. The recess in the first arm of the optical conductor

[0100] 20. Intensity of light emitted from a light-emitting diode

[0101] Illumination angle of the α hologram

Claims

1. A lighting device for a motor vehicle, the lighting device comprising: - Light source (1) - A light conductor (3) with a V-shaped cross-section, the light conductor (3) having a first arm (4), a second arm (5) and a connection region (6) connecting the first arm (4) and the second arm (5). - A hologram (10), which is disposed on or in the photoconductor (3). - A first light-shielding plate (14) is disposed between the first arm (4) and the second arm (5). -The illumination device is configured such that light (2) emitted from a light source (1) located on the first light-shielding plate (14) is incident on the incident surface (7) of the first arm (4) of the light conductor (3) and interacts with the hologram (10), thereby reconstructing the image stored in the hologram (10) and making it visible to an observer of the illumination device. The second arm (5) of the optical conductor (3) is characterized in that it has a first exit surface (9a) and a second exit surface (9b), so that light incident on the incident surface (7) of the optical conductor (3) exits from both the first exit surface (9a) and the second exit surface (9b). The illumination device is configured to emit light that interacts with the hologram (10) through a first emitting surface (9a), the light interacting with the hologram (10) during or after emission from the first emitting surface (9a); and the illumination device is configured to emit light (2) that does not interact with the hologram (10) through a second emitting surface (9b), the light interacting with the hologram (10) neither during nor after emission from the second emitting surface (9b).

2. The lighting device according to claim 1, characterized in that, The second emitting surface (9b) is disposed on the same side of the photoconductor (3) as the first emitting surface (9a).

3. The lighting device according to claim 1 or 2, characterized in that, The second exit surface (9b) is configured to be adjacent to the first exit surface (9a).

4. The lighting device according to claim 3, characterized in that, The second exiting surface (9b) is directly adjacent to the first exiting surface (9a), or the second exiting surface (9b) is spaced apart from the first exiting surface (9a).

5. The lighting device according to claim 1 or 2, characterized in that, The second exit surface (9b) is parallel to the first exit surface (9a), or the normal on the second exit surface (9b) forms an angle not equal to 0° with the normal on the first exit surface (9a).

6. The lighting device according to claim 1 or 2, characterized in that, The lighting device includes a second light shield (15) disposed between the second emission surface (9b) and the first emission surface (9a) and / or covering a section of the second emission surface (9b) and / or covering a section of the first emission surface (9a).

7. The lighting device according to claim 1 or 2, characterized in that, The second exit surface (9b) is dislocated relative to the first exit surface (9a).

8. The lighting device according to claim 7, characterized in that, The second exit surface (9b) is displaced relative to the first exit surface (9a) in a direction parallel to the normal on the first exit surface (9a).

9. The lighting device according to claim 1 or 2, characterized in that, The second exit surface (9b) has a scattering optics, and / or the second exit surface (9b) has a structure.

10. The lighting device according to claim 9, characterized in that, The scattering optics are in the form of a cushion-shaped optics or a strip-shaped optics, and / or the structure is an optical structure.

11. The lighting device according to claim 10, characterized in that, The optical structure is an etched structure, an etching structure, or a diffractive diffuser structure.

12. The lighting device according to claim 1 or 2, characterized in that, The light conductor (3) has a first reflective region (11), wherein the lighting device is configured such that light (2) emitted from the light source (1) is incident on the incident surface (7) of the light conductor (3) in the direction of the first reflective region (11) and is reflected in the interior of the light conductor (3) by the first reflective region (11) in the direction of the hologram (10).

13. The lighting device according to claim 12, characterized in that, The light conductor (3) has a second reflective region (12), wherein the lighting device is configured such that light (2) emitted from the light source (1) is incident on the incident surface (7) of the light conductor (3) in the direction of the second reflective region (12) and is reflected in the interior of the light conductor (3) by the second reflective region (12) in the direction of the second exit surface (9b).

14. The lighting device according to claim 13, characterized in that, The lighting device is configured such that light (2) emitted from the light source (1) is incident on the incident surface (7) of the light conductor (3) in the direction of the first reflection area (11), a portion of the light (2) incident on the light conductor (3) is reflected in the interior of the light conductor (3) by the first reflection area (11) in the direction of the second reflection area (12), and a portion of the light (2) incident on the second reflection area (12) is reflected in the interior of the light conductor (3) by the second reflection area (12) in the direction of the second exit surface (9b).

15. The lighting device according to claim 13, characterized in that, The lighting device is configured such that light (2) emitted from the light source (1) is incident on the incident surface (7) of the light conductor (3) in the direction of the second reflection area (12); a portion of the light (2) incident on the light conductor (3) is reflected in the interior of the light conductor (3) by the second reflection area (12) in the direction of the first reflection area (11), and a portion of the light (2) incident on the first reflection area (11) is reflected in the interior of the light conductor (3) by the first reflection area (11) in the direction of the hologram (10).

16. The lighting device according to claim 1 or 2, characterized in that, The lighting device includes a reflector (16) disposed outside the light conductor (3), wherein the lighting device is configured such that light (2) emitted from the light source (1) hits the reflector (16), is reflected by the reflector (16) in the direction toward the light conductor (3), and is incident into the light conductor (3) in the direction toward the second exit surface (9b).

17. The lighting device according to claim 16, characterized in that, The lighting device is configured such that light (2) emitted from the light source (1) is reflected in the direction of the additional incident surface (18) of the light conductor (3).

18. The lighting device according to claim 1 or 2, characterized in that, The hologram (10) is an edge-illuminated hologram.

19. The lighting device according to claim 18, characterized in that, The illumination angle (α) of the hologram (10) is greater than the critical angle of total internal reflection at the first exit surface (9a) of the photoconductor (3).

20. The lighting device according to claim 1 or 2, characterized in that, The hologram (10) is a transmission hologram.

21. The lighting device according to claim 20, characterized in that, The transmission hologram is disposed on the first exit surface (9a) of the optical conductor (3).

22. The lighting device according to claim 1 or 2, characterized in that, The hologram (10) is a reflection hologram.

23. The lighting device according to claim 22, characterized in that, The reflection hologram is disposed on the surface of the photoconductor (3) opposite to the first emitting surface (9a) of the photoconductor (3).

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