Lighting device for motor vehicle

Abstract

The invention relates to a lighting device for a motor vehicle, comprising: a first lighting device having at least one first light source, a planar light guide having at least one entry surface and at least one exit surface, and at least one optical component; the light generated by the at least one first light source at least partially enters the light conductor through the at least one incident surface, and the light entering through the at least one incident surface at least partially exits from the at least one exit surface; the light exiting from the at least one exit surface of the light conductor at least partially passes through and / or is reflected by the at least one optical component, and the light exiting from the at least one exit surface of the light conductor at least partially exits the lighting device through the cover plate; and at least one second light-emitting device having at least one second light source, light emitted by the at least one second light-emitting device exiting the lighting device through the cover plate.

Description

Technical Field

[0001] The present invention relates to a lighting device for a motor vehicle according to the preamble of claim 1. Background Technology

[0002] For the signaling functions of motor vehicles (such as taillights, brake lights, directional indicators, or daytime running lights), the design of the taillights or headlights has long been a decisive factor. Since the introduction of LED technology, the design of these lighting devices has become even more important because, compared to large incandescent bulbs, smaller light-emitting diodes, often used in greater numbers, can be used much more flexibly as light-emitting devices for signaling functions, allowing for a wide variety of design possibilities when combined with the chosen optical system.

[0003] A variant of LED technology emerges in the form of OLED technology. In OLED, the light-emitting device is not a small dot like in LEDs, but is designed to be larger and flatter to form a desired light-emitting surface that can illuminate very uniformly. A significant drawback of OLED technology has been its significantly higher cost compared to LED technology. This higher cost is due to complex manufacturing methods, pre-designed different shapes, and small production volumes. Furthermore, there are specific and stringent requirements in the automotive sector, such as durability under UV loads and forces (e.g., vibration, shock, and shaking) and temperature durability within a range of -40°C to +85°C or +100°C. These requirements are significantly more difficult to meet for organic light-emitting diodes than for standard LEDs.

[0004] This led to the search for alternative possibilities to achieve designs similar to those using organic light-emitting diodes (OLEDs), particularly for uniformly illuminated surfaces. This is achieved by using light-emitting diodes (LEDs) with planar light conductors and front-facing optics (in the form of microstructured films or thin optical lenses) to scatter the light emitted from the light conductors. This results in a flat-light module that provides high performance while uniformly illuminating the entire surface.

[0005] Then, much like with organic light-emitting diodes (OLEDs), when integrated into taillights, multiple Flat-Light modules can be staggered side-by-side and positioned front-to-back to produce the desired individualized appearance for signal functions such as taillights or tail brake lights. Finally, Flat-Light modules can also be implemented as large planar light-emitting elements instead of single modules. As such planar lighting devices, they can also be used for backlighting displays.

[0006] A lighting device of the type described at the beginning, configured as a Flat-Light module, is known from DE102022113052A1. The described lighting device includes at least one light source configured as a light-emitting diode (LED) and a planar light conductor having an incident surface and at least one exiting surface, wherein the incident surface is configured as the front surface of the light conductor. The lighting device also includes at least one optical lens. Here, the lighting device is configured such that light generated by at least one light source enters the light conductor at least partially through the incident surface, light entering through the incident surface at least partially exits from at least one exiting surface, and light exiting from at least one exiting surface of the light conductor at least partially passes through at least one optical lens. Here, the Flat-Light module can use LEDs of different colors, such as red, yellow, or white, to achieve a combination of signal functions, such as a tail brake flashing light or an additional reversing light.

[0007] An exemplary lighting device constructed as a Flat-Light module according to the prior art is from Figure 16 and Figure 17 As can be seen, the Flat-Light module includes a light source 1 having multiple light-emitting diodes (LEDs). The Flat-Light module also includes a housing 2 having a rear housing portion 2a and a front housing portion 2b, which are connected to each other by snap-fit ​​connections. Between the housing portions 2a and 2b, a plate-shaped light conductor 3 with micro-optical devices, a white diffuse reflection film 4 located behind the light conductor 3, and two or three optical components 5a and 5b, constructed as micro-optical films, located in front of the light conductor 3, are introduced. These optical components are responsible for the overall light distribution and efficiency of the system by coordinating the various micro-optical components with each other. The principle of this basic construction is to provide light-emitting elements with a surface that is consistently and uniformly illuminated. For this purpose, the lighting device includes a cover plate 6, which serves as the illuminated emitting surface of the lighting device.

[0008] Here, the optical component 5a adjacent to the light conductor 3 is constructed as a diffuser, while the second optical component 5b is constructed as a so-called BEF optics device. In this context, BEF stands for "Brightness Enhancement Film." Therefore, the BEF optics device is used to increase the brightness of light passing through the optical component 5b. The BEF optics device can be implemented on a film or as a thin injection-molded optical lens. A system with two BEF optics devices orthogonally oriented to each other can also be provided, in which case the diffuser optics are sometimes omitted.

[0009] In the prior art, this type of Flat-Light module is configured to form a fully luminous, monolithic surface extending up to the rear light or the entire rear light, as a module of smaller or any size. The focus of implementation in the prior art Flat-Light module is mainly on planar luminous surfaces or surfaces with a slight curvature in one direction, such as cylindrical surfaces.

[0010] Even if the Flat-Light module itself is designed to generate signal functions with high light intensity (such as brake lights, driving direction indicators, or daytime running lights), there may still be unfavorable geometric designs of the Flat-Light module, especially in the case of the light conductor of the possible three-dimensional design of the Flat-Light module, which make it impossible to realize such signal functions alone. Summary of the Invention

[0011] The problem upon which this invention is based is to provide a lighting device of the type described at the beginning, wherein, despite unfavorable geometry in some cases, particularly the geometry of the light conductor, it is possible to generate a signal with high light intensity.

[0012] According to the invention, this is achieved by a lighting device of the type described at the beginning having the characteristic features of claim 1. The dependent claims relate to preferred embodiments of the invention.

[0013] According to claim 1, the lighting device includes at least a second light-emitting device having at least one second light source, wherein the lighting device is configured such that light emitted from the at least one second light-emitting device exits the lighting device through a cover plate. This measure allows a first light-emitting device, particularly configured as a Flat-Light module, to be combined with and operate in conjunction with the second light-emitting device, the first light-emitting device particularly including a light conductor having a three-dimensional curved surface or other unfavorable implementation (e.g., an extremely distorted mounting position). Here, the lighting device can be configured such that the first light-emitting device generates at least one first signal function, such as a position light, and that the second light-emitting device generates at least one second signal function, such as a daytime running light or a driving direction indicator. In particular, the at least one second signal function is a signal function requiring high light intensity.

[0014] It is possible for the second light-emitting device to have at least one lens, particularly a Fresnel lens, preferably a Fresnel lens constructed as a Typhoon lens, wherein the illumination device is configured such that light generated by at least one second light source passes through at least one lens and then exits the illumination device through a cover plate. Alternatively or additionally, the second light-emitting device may have at least one reflector, wherein the illumination device is configured such that light generated by at least one second light source passes through at least one reflector and then exits the illumination device through a cover plate. Alternatively or additionally, the second light-emitting device may have at least one light conductor, wherein the illumination device is configured such that light generated by at least one second light source passes through at least one light conductor and then exits the illumination device through a cover plate. Each of these three different embodiments can be designed such that the second light-emitting device provides the high light intensity required for at least one second signal function.

[0015] It is possible for the cover to have a micro-optical device and / or diffuser structure, wherein the illumination device is configured such that light emitted by both the first and second light-emitting devices passes through the micro-optical device and / or diffuser structure. By positioning the different signal functions behind the structured cover, a unified appearance is achieved for the observer. In particular, this implementation can be implemented as both a rear light and a headlight. The novel approach of incorporating the micro-optical device and / or diffuser structure into the cover is also advantageous in terms of sustainability, as it eliminates the need for additional internal lenses and molds for such lenses, reduces development effort, and simplifies the overall headlight assembly.

[0016] It can be specified that the light conductor has bends in two different directions, particularly in two perpendicular directions, wherein preferably, the surface of the light conductor is at least partially bent in two different directions, particularly in two perpendicular directions. This creates a three-dimensional curved surface, which enables simpler integration of lighting devices into the curved design of motor vehicles.

[0017] It is possible for an optical conductor to have a structured portion, particularly a micro-optical structured portion, on its surface opposite to at least one emitting surface, which can induce or enhance the output coupling of light entering through at least one incident surface from at least one emitting surface. Specifically, this structured portion has a density distribution, wherein the density of the structured portion on the surface opposite to at least one emitting surface increases with increasing distance from the at least one incident surface. This design achieves uniform intensity of the output-coupled light along the longitudinal extension of the optical conductor.

[0018] It can be specified that the optical conductor is at least partially and substantially U-shaped, wherein the optical conductor has two U-shaped legs and a connecting portion that connects the U-shaped legs to each other, and in particular, wherein the two U-shaped legs are spaced apart from each other. Here, each U-shaped leg of the optical conductor may partially have a longitudinal direction and a transverse direction perpendicular to it, as well as a depth perpendicular to both the longitudinal and transverse directions, and in particular, wherein the extension of each U-shaped leg of the optical conductor in the longitudinal direction is greater than its extension in the transverse direction and the extension in the transverse direction is greater than its extension at the depth perpendicular to the transverse direction, such that each U-shaped leg of the optical conductor has an end surface on the end side in the longitudinal direction, two narrow surfaces extending locally in the longitudinal direction, and two wide surfaces extending locally in the longitudinal direction.

[0019] It is possible for the optical conductor to have at least two incident surfaces, with at least one incident surface arranged on each U-shaped leg. Here, one of the incident surfaces can be arranged on the end surface of the U-shaped leg opposite to the connecting portion, and / or one of the incident surfaces can be arranged on a narrow surface extending along the longitudinal direction of the U-shaped leg. Depending on the desired design, the shape and size of the exiting surface of the optical conductor, one of these two possibilities can be chosen for input coupling. In particular, the incident surface for the light to be input coupled into the optical conductor can also be arranged both on the end surface of the U-shaped leg opposite to the connecting portion and on a narrow surface extending along the longitudinal direction of the U-shaped leg.

[0020] It can be specified that the second light-emitting device is arranged in the lighting device such that, during the operation of the lighting device, the light emitted by the second light-emitting device passes between the two U-shaped legs of the light conductor and then shines onto the cover plate. With this design, in particular, the first light-emitting device, constructed as a Flat-Light module, forms a light-emitting frame as a flat U-shaped element, wherein the signal function of the second light-emitting device is arranged between the two U-shaped legs.

[0021] It is possible that at least one optical component is constructed as a microstructured film and / or a microstructured optical lens, wherein at least one microstructured film or at least one microstructured optical lens is particularly disposed between the light conductor and the cover plate. Furthermore, it can be specified that the light conductor has at least two exit surfaces, wherein a first exit surface faces away from the cover plate and a second exit surface faces the cover plate, wherein at least one optical component is constructed as a reflective surface that is at least partially reflective, disposed on the side of the light conductor facing away from the cover plate, wherein the illumination device is configured such that light exiting from the first exit surface of the light conductor strikes the reflective surface, is reflected back from the reflective surface to the first exit surface, and at least partially re-enters the light conductor, then exits from the second exit surface and passes through at least one cover plate. In this way, as in the Flat-Light module, the illumination device can provide high performance while uniformly illuminating the cover plate by backside reflection of light exiting the light conductor and / or by targeted scattering on the microstructured film and / or optical lens. Attached Figure Description

[0022] The invention will now be described in more detail with reference to the accompanying drawings. Herein:

[0023] Figure 1 A front view of a first embodiment of the lighting device according to the invention is shown, illustrating different light functions;

[0024] Figure 2 Showing according to Figure 1 A cross-sectional view of the lighting device;

[0025] Figure 3 Showing according to Figure 1 A front view of the part of the lighting device that generates signals;

[0026] Figure 4 Showing according to Figure 1 A perspective view of the part of the lighting device that generates signals;

[0027] Figure 5 Showing according to Figure 1 A top view of the part of the lighting device that generates signals;

[0028] Figure 6 Showing according to Figure 5 Detailed image of arrow VI in the image;

[0029] Figure 7 Showing according to Figure 5 Detailed image of arrow VII in the image;

[0030] Figure 8 Showing according to Figure 1 Rear view of the part of the lighting device that generates signals;

[0031] Figure 9 Showing a cover and a housing, according to Figure 1 Rear view of the part of the lighting device that generates signals;

[0032] Figure 10 Showing a device having a cover, housing, and rear cover, according to Figure 1 Rear view of the part of the lighting device that generates signals;

[0033] Figure 11 The density distribution of the structured parts is shown, according to Figure 1 The part of the lighting device that generates signals and Figure 5 The corresponding top view;

[0034] Figure 12 Showing according to Figure 1 The lighting device and Figure 1 The corresponding main view shows only the signal light function;

[0035] Figure 13 A second embodiment of the lighting device according to the invention is shown. Figure 1 The corresponding main view shows the different lighting functions;

[0036] Figure 14 The third embodiment of the lighting device according to the invention is shown. Figure 1 The corresponding main view shows the different lighting functions;

[0037] Figure 15 The fourth embodiment of the lighting device according to the invention is shown. Figure 1 The corresponding main view shows the different lighting functions;

[0038] Figure 16 A perspective view of a lighting device according to the prior art is shown;

[0039] Figure 17 Showing according to Figure 16 An exploded view of the lighting fixtures. Detailed Implementation

[0040] In the accompanying drawings, parts that are identical or have the same function are given the same reference numerals.

[0041] The illustrated embodiment of the lighting device is constructed as a headlight for a motor vehicle. However, it is entirely possible that a similar geometry could also be used for taillights or interior lights in the same manner.

[0042] In a lighting device configured as a headlight, a main beam function area 10 is provided for both low beam and high beam, and a signal function area 11 is provided for common position lights, daytime running lights, and driving direction indicators (see [reference]). Figure 1 ).

[0043] The lighting device includes a cover plate 12, which has a recess 13 in a portion of the cover plate 12 (see...). Figure 2 A light conductor 14 is arranged behind the cover plate 12, extending at least partially parallel to the cover plate 12. The light conductor 14 has bends in two different directions, particularly in two perpendicular directions.

[0044] The optical conductor 14 is at least substantially U-shaped, wherein the optical conductor 14 has two U-shaped legs 15 and a connecting portion 16 that connects the U-shaped legs 14 to each other (see [link]). Figure 3 and Figure 4 Here, the two U-shaped legs 15 are spaced apart from each other. Each U-shaped leg 15 of the light conductor 14 locally has a longitudinal direction and a transverse direction perpendicular to it, as well as a depth perpendicular to both the longitudinal and transverse directions. Here, the extension of each U-shaped leg 15 of the light conductor 14 in the longitudinal direction is greater than its extension in the transverse direction, and the extension in the transverse direction is greater than its extension at the depth perpendicular to the transverse direction (see...). Figure 4 Therefore, each U-shaped leg 15 of the optical conductor 14 has an end surface 17 on the end side in the longitudinal direction, two narrow surfaces 18 that extend locally in the longitudinal direction, and two wide surfaces 19 that extend locally in the longitudinal direction.

[0045] The lighting device has multiple first light sources 20 configured as light-emitting diodes (see...). Figure 4 The light 21 emitted by these first light sources 20 is coupled into the light conductor 15. In the depicted embodiment, the end surfaces 17 on both ends of the U-shaped leg 15 serve as the incident surfaces 22 of the light 21.

[0046] Here, each U-shaped leg 15 is provided with four first light sources 20, such that the light emitted by the first light sources 20 enters the incident surface 22. Here, two of the four first light sources 20 provided to one of the U-shaped legs 15 are respectively constructed as white light-emitting diodes, and the other two of the four first light sources 20 are constructed as yellow light-emitting diodes.

[0047] Alternatively, it is entirely possible to specify that the two narrow surfaces 18 of the U-shaped leg 15, which extend locally in the longitudinal direction, serve as the incident surfaces 22 for the light 21 emitted by the first light source 20. It is entirely possible to use both the end surface 17 on the end side of the U-shaped leg 15 and the narrow surface 18 of the U-shaped leg 15 as the incident surfaces 22 for the light 21 emitted by the first light source 20.

[0048] The optical conductor has two exiting surfaces 23 and 24, wherein the first exiting surface 23 faces away from the cover plate 12 and the second exiting surface 24 faces the cover plate 12. Here, the wide surface 19 of the U-shaped leg 15, which extends locally in the longitudinal direction, and the front and rear sides of the connecting portion 16 serve as exiting surfaces 23 and 24 for the light 21 coupled to the optical conductor 14 through the incident surface.

[0049] Micro-optical structuring elements are arranged on the first exit surface 23 away from the cover plate. These micro-optical structuring elements can induce or enhance the output coupling of light 21 entering through the incident surface 22 from the second exit surface 24. The structuring elements have a density distribution 25, wherein the density of the structuring elements on the first exit surface 23 increases with increasing distance from the incident surface 22. Here, density refers to the number of micro-optical devices per unit area. The density distribution 25 is schematically shown in... Figure 11 middle.

[0050] The illumination device also includes an optional optical component (not shown) configured as a reflective surface that is at least partially reflective. This optical component is arranged on the side of the light conductor 14 facing away from the cover plate 12. Here, the illumination device is configured such that light 21 exiting from the first exit surface 23 of the light conductor 14 strikes the reflective surface of the optical component, is reflected back to the first exit surface 23, and at least partially re-enters the light conductor 14, then exits from the second exit surface 24 and passes through the cover plate 12.

[0051] The lighting device also includes at least one optional optical component (not shown), which is configured as a microstructured film or a microstructured optical lens. Here, at least one microstructured film or at least one microstructured optical lens is arranged between the light conductor 14 and the cover plate 12.

[0052] The lighting device also includes a housing 26, in which or on the housing are arranged a light source 20, a light conductor 14, a cover plate 12, and any optical components that may be present (see [link]). Figure 9 and Figure 10 Here, a rear cover 27 is also provided on the side of the photoconductor 14 facing away from the cover plate 12.

[0053] The first light source 20, the light conductor 14, and at least one optical component are part of a first light-emitting device. This first light-emitting device is used to generate a first signal light function, which may be, for example, a position light. Due to the three-dimensional surface of the light conductor 14 and the generally unfavorable geometry caused by the funnel-shaped recess, although the surrounding surface of the cover plate 12 is uniformly backlit or illuminated by the light conductor 14, the limited number of first light sources 20 arranged on the laterally incident surface 22 only provides position lights with lower light intensity requirements, and cannot meet the requirements of daytime running lights or driving direction indicators with much higher light intensity.

[0054] Therefore, in addition to the first light-emitting device, the lighting device also includes a second light-emitting device 28 (see Figure 4 The second light-emitting device 28 is used to generate a second signal light function, which may be, for example, a daytime running light or a driving direction indicator.

[0055] The second light-emitting device 28 is arranged in the lighting device such that, during the operation of the lighting device, the light emitted by the second light-emitting device 28 passes between the two U-shaped legs 15 of the light conductor 14 and then shines onto the cover plate 12. Figure 3 The first light-emitting device, specifically constructed as a Flat-Light module, forms a light-emitting frame as a flat U-shaped element, wherein the signal function of the second light-emitting device 28 is arranged between the two U-shaped legs 15.

[0056] The second light-emitting device 28 includes a plurality of second light sources 29 configured as light-emitting diodes and two lenses 30, which are Fresnel lenses, and more particularly typhoon lenses (see [link]). Figure 6 and Figure 7 Each of the two lenses 30 is equipped with four second light sources 29, such that light emitted from these four light sources 29 passes through the lens 30 and then strikes the cover plate 12. Here, two of the four second light sources 29 assigned to one of the lenses 30 are configured as white light-emitting diodes, and the other two are configured as yellow light-emitting diodes. The first light source 20 and the second light source 29 can be arranged on a common circuit board 31.

[0057] Figure 12 The illuminated area 11 shows the signal function. This area frames the inner area 10 of the low beam function, for which a microcylindrical optics are required as vertical stripe optics. Microcylindrical optics having a pitch of less than or equal to 0.5 mm, preferably between 0.4 mm and 0.2 mm, can also be used in the same manner for the signal function area 11, such that the entire area within the cover plate 12 is implemented as a micro-stripe optics with a uniform vertical orientation (see [link]). Figure 13 ).

[0058] Alternatively, the signal-functional region 11 may be implemented with an optical structure, such as a knurled, etched, or corroded structure, or with a calculated diffuser structure, such as a laser structure, and with defined scattering (see [link to relevant documentation]). Figure 14 ).

[0059] Alternatively, the signal function region 11 can be implemented with micro-optical devices, which are in the form of small micro-pad-like optical devices with a size less than or equal to 1 mm, preferably less than or equal to 0.5 mm (see [link]). Figure 15 These structures can be milled or laser-machined into the mold inserts used for manufacturing as injection-molded parts made of plastic during the manufacture of the cover plate 12.

[0060] List of reference numerals

[0061] 1. Light source

[0062] 2 shells

[0063] 2a, 2b Shell sections

[0064] 3 Photoconductors

[0065] 4. Reflective film

[0066] 5a and 5b are optical components constructed as micro-optical films.

[0067] 6 cover plates

[0068] 10 areas used for main light function

[0069] 11 Areas used for signal functions

[0070] 12 cover plates

[0071] 13 Recess of the cover plate

[0072] 14 Photoconductors

[0073] 15 U-shaped legs of optical conductors

[0074] 16. Connecting part of optical conductor

[0075] 17. End surface of the U-shaped leg end side

[0076] Narrow surface of 18 U-shaped legs

[0077] 19 Wide surface of U-shaped legs

[0078] 20 First Light Source

[0079] 21. Light emitted by a light source

[0080] 22 Incident surface of the optical conductor

[0081] 23 First exit surface of the optical conductor

[0082] 24. Second exit surface of the optical conductor

[0083] 25 Density distribution of the structured portion on the first ejection surface

[0084] 26 shell

[0085] 27 back cover

[0086] 28 Second light-emitting device

[0087] 29 Second Light Source

[0088] 30 Lens of the second light-emitting device

[0089] 31 Common circuit board for the first and second light sources

Claims

1. A lighting device for a motor vehicle, comprising: - A first light-emitting device, the first light-emitting device having at least one first light source (20), a planar light conductor (14) and at least one optical component, the planar light conductor having at least one incident surface (22) and at least one exiting surface (23, 24). - Cover plate (12), the lighting device is configured such that light (21) generated by the at least one first light source (20) enters the light conductor (14) at least partially through the at least one incident surface (22), such that light (21) entering through the at least one incident surface (22) exits at least partially from the at least one exiting surface (23, 24), such that light (21) exiting from the at least one exiting surface (23, 24) of the light conductor (14) passes at least partially through the at least one optical element and / or is reflected by the at least one optical element, and such that light (21) exiting from the at least one exiting surface (23, 24) of the light conductor (14) exits from the lighting device at least partially through the cover plate (12); Its features are, The lighting device includes at least one second light-emitting device (28) having at least one second light source (29), and the lighting device is configured such that light emitted by the at least one second light-emitting device (28) exits the lighting device through the cover plate (12).

2. The lighting device according to claim 1, characterized in that, The lighting device is configured such that the first light-emitting device generates at least one first signal function, such as a position light, and the second light-emitting device (28) generates at least one second signal function, such as a daytime running light or a driving direction indicator.

3. The lighting device according to claim 1 or 2, characterized in that, The second light-emitting device (28) has at least one lens (30), especially a Fresnel lens, preferably a Fresnel lens constructed as a typhoon lens, and the lighting device is configured such that light generated by the at least one second light source (29) passes through the at least one lens (30) and then exits the lighting device through the cover plate (12).

4. The lighting device according to any one of claims 1 to 3, characterized in that, The second light-emitting device (28) has at least one reflector, and the lighting device is configured such that light generated by the at least one second light source (29) passes through the at least one reflector and then exits the lighting device through the cover plate (12).

5. The lighting device according to any one of claims 1 to 4, characterized in that, The second light-emitting device (28) has at least one light conductor, and the lighting device is configured such that light generated by the at least one second light source (29) passes through the at least one light conductor and then exits the lighting device through the cover plate (12).

6. The lighting device according to any one of claims 1 to 5, characterized in that, The cover plate (12) has a micro-optical device and / or diffuser structure, and the lighting device is configured such that light emitted by the first light-emitting device and light emitted by the second light-emitting device (28) both pass through the micro-optical device and / or diffuser structure.

7. The lighting device according to any one of claims 1 to 6, characterized in that, The light conductor (14) has bends in two different directions, especially in two perpendicular directions. Preferably, the surface of the light conductor (14) is at least partially bent in two different directions, especially in two perpendicular directions.

8. The lighting device according to any one of claims 1 to 7, characterized in that, The optical conductor (14) has a structured portion, particularly a micro-optical structured portion, on its surface opposite to the at least one emitting surface (23, 24), which can cause or enhance the output coupling of light (21) entering through the at least one incident surface (22) from the at least one emitting surface (23, 24), and in particular, the structured portion has a density distribution (25) that increases in density on the surface opposite to the at least one emitting surface (23, 24) as the distance from the at least one incident surface (22) increases.

9. The lighting device according to any one of claims 1 to 8, characterized in that, The optical conductor (14) is at least partially substantially U-shaped, having two U-shaped legs (15) and a connecting portion (16) that connects the U-shaped legs (15) to each other, particularly the two U-shaped legs (15) being spaced apart from each other.

10. The lighting device according to claim 9, characterized in that, Each U-shaped leg (15) of the optical conductor (14) locally has a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, as well as a depth perpendicular to both the longitudinal and transverse directions. In particular, each U-shaped leg (15) of the optical conductor (14) has a greater extension in the longitudinal direction than in the transverse direction and a greater extension in the transverse direction than in the depth perpendicular to the transverse direction, such that each U-shaped leg (15) of the optical conductor (14) has an end surface (17) on the end side in the longitudinal direction, two narrow surfaces (18) locally extending in the longitudinal direction, and two wide surfaces (19) locally extending in the longitudinal direction.

11. The lighting device according to claim 9 or 10, characterized in that, The optical conductor (14) has at least two incident surfaces (22), with at least one of the incident surfaces (22) arranged on each U-shaped leg (15).

12. The lighting device according to claim 11, characterized in that, One of the incident surfaces (22) is arranged on the end surface (17) of the U-shaped leg (15) on the end side opposite to the end of the connecting portion (16), and / or one of the incident surfaces (22) is arranged on the narrow surface (18) extending along the longitudinal direction of the U-shaped leg (15).

13. The lighting device according to any one of claims 9 to 12, characterized in that, The second light-emitting device (28) is arranged in the lighting device such that, during the operation of the lighting device, the light emitted by the second light-emitting device (28) passes between the two U-shaped legs (15) of the light conductor (14) and then shines onto the cover plate (12).

14. The lighting device according to any one of claims 1 to 13, characterized in that, The at least one optical component is configured as a microstructured film and / or a microstructured optical lens, wherein the at least one microstructured film or the at least one microstructured optical lens is disposed between the optical conductor (14) and the cover plate (12).

15. The lighting device according to any one of claims 1 to 14, characterized in that, The light conductor (14) has at least two emitting surfaces (23, 24), a first emitting surface of the emitting surfaces (23, 24) facing away from the cover plate (12) and a second emitting surface of the emitting surfaces (23, 24) facing the cover plate (12), the at least one optical element is configured as a reflective surface that is at least partially reflective, the reflective surface being arranged on the side of the light conductor (14) facing away from the cover plate (12), the illumination device being configured such that light (21) exiting from the first emitting surface (23) of the light conductor (14) hits the reflective surface, is reflected back from the reflective surface to the first emitting surface (23), and at least partially re-enters the light conductor (14), then exits from the second emitting surface (24) and passes through the at least one cover plate (12).

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