Lighting equipment for a motor vehicle

Abstract

Lighting device (1) for a motor vehicle (K) with several light sources (16, 17, 23), wherein the light sources (16, 17, 23) are assigned at least partially different types of lighting functions in the lighting device (1) and the light (L) of the light sources (16, 17, 23) can be coupled into at least one light guide (12, 13, 19, 19', 20, 21, 22), through which the light (L) of the light sources (16, 17, 23) can be coupled out again via at least one light emission surface (121, 131, 191, 211) at least in one main emission direction (H) and thereby the different types of lighting functions can be provided, wherein at least two light guides (12, 13, 19, 19', 20, 21, 22) are provided, into each of which light (L) can be coupled to provide at least one lighting function, wherein the light guides (12, 13, 19, 19', 20, 21, 22) are arranged perpendicular to the main emission direction (H) above and / or next to each other, and the light guides (12, 13, 19, 19', 20, 21,22) have at least one surface extension (F) pointing in the main emission direction (H) which exceeds a wall thickness (d1, d2, d3) of the optical fibers (12, 13, 19, 19', 20, 21, 22), characterized in that at least two optical fibers (19, 19', 20, 21, 22) are designed and arranged relative to each other such that, at least in the main emission direction (H), the light emission surface (201, 221) of at least one optical fiber (20, 22) is covered by a part of another optical fiber (19, 19', 21, 22) which branches off laterally from a surface extension (F) of the optical fiber extending in the main emission direction (H), wherein light (L) coupled into the covered optical fiber (20, 22) is guided through it in the main emission direction (H) and, after exiting from a Light exit surface (201,221) is coupled into a light entry surface (192,213,223) from the covering part of the other light guide (19,19',21,22) and from this via a light exit surface (191,221,211) is decoupled again.,

Description

[0001] The invention relates to a lighting device for a motor vehicle with the features of the preamble of claim 1.

[0002] Typical lighting devices for motor vehicles are known from the general state of the art. They can be designed as taillights or headlights.

[0003] Especially with headlights, it is now common for such lighting devices to be able to provide at least the light functions of low beam, high beam, daytime running light and a direction indicator.

[0004] Light-emitting diodes (LEDs) are frequently used as light sources, at least for daytime running lights and for the direction indicator, whereby the LEDs can be operated in groups to realize the aforementioned lighting functions.

[0005] In full LED headlights, the lighting functions of the low beam and high beam are also taken over by LEDs.

[0006] Grouped LEDs can emit light of only one color (for example, white or yellow) to perform functions such as daytime running lights or turn signals. However, it is also possible for LEDs to be designed to emit different colors (so-called RGB LEDs).

[0007] For the actual (visible) provision of the lighting functions, the light from the LEDs is coupled into light guides. The light guides can preferably be crystal clear and transparent.

[0008] From DE 10 2010 006 348 A1, a lighting device for vehicles is known in which several planar light guides are arranged one behind the other at a distance along the main emission direction of the lighting device. Light is coupled laterally from LEDs into the light guides via their narrow sides, perpendicular to the main emission direction, and coupled out again in the direction of the main emission direction via coupling elements arranged in the longitudinal sides. The coupling elements of the light guides are spatially coordinated. This is intended to create a three-dimensional appearance of the lighting device, in particular an appearance with depth effect. However, the required spacing of the light guides also results in a comparatively large installation space requirement.

[0009] EP 2 161 494 B1 describes a lighting device designed as a headlight, in which a plurality of LEDs are used as light sources. The LEDs can couple light for different lighting functions into a single, common light guide, with white light-emitting LEDs and yellow light-emitting LEDs being arranged on a common light source carrier.

[0010] However, using only one light guide limits the design possibilities for the lighting system. Furthermore, the described solution does not appear to offer optimal flexibility in adapting the lighting to a given installation space.

[0011] German patent DE 10 2011 089 575 B3 describes a lighting device for a motor vehicle with the features of the preamble of claim 1, comprising a light guide structure having a planar light guide area. The planar light guide area has a first wide side and a second wide side equidistant from the first wide side. Furthermore, narrow sides are present connecting the first wide side to the second wide side. A second narrow side is configured to align light incident from the first narrow side onto the second narrow side and direct it onto a third narrow side, which forms a light-emitting surface of the light guide structure.In the lighting device, the second narrow side has a first parallelizing sub-surface and a second parallelizing sub-surface, wherein the second parallelizing sub-surface is arranged in a step-like manner relative to the first parallelizing sub-surface in the direction towards the interior of the planar light guide area.

[0012] DE 10 2008 048 765 A1 describes a lighting device for motor vehicles with a light source and a planar light guide positioned in front of it.

[0013] The light emitted by the light source is guided by the optical fiber and can be extracted according to a predefined lighting function. The optical fiber has two opposing flat sides and two opposing narrow sides. One narrow side of the planar optical fiber, facing the light source, is designed as a light coupling surface and serves to couple in the light emitted by the light source. The coupled light is totally reflected at the opposite flat sides and can be extracted at the second narrow side of the planar optical fiber, which forms a light extraction surface. In this way, the lighting device can be used to generate a narrow band of light.

[0014] The present invention is based on the objective of providing a lighting device which, despite its compact design, offers a high degree of flexibility in creating an appealing lighting design.

[0015] The aforementioned problem is solved by a lighting device with the features of claim 1. Advantageous further developments or embodiments of the invention can be found in the dependent claims.

[0016] The invention relates to a lighting device for a motor vehicle with multiple light sources. The light sources are assigned at least partially different lighting functions within the lighting device. The light from the light sources can be coupled into at least one light guide, through which the light from the light sources can be coupled out again via at least one light-emitting surface, at least in one main emission direction, thereby providing the different lighting functions. Furthermore, at least two light guides are provided, each serving to provide at least one lighting function. The light guides are arranged transversely to the main emission direction, one above the other and / or next to each other.

[0017] Therefore, at least two separate light guides are used, into which light from light sources can be coupled and from which it can also be coupled, in order to serve to realize a lighting function.

[0018] For example, yellow light can be coupled into the light of one light guide to generate a direction indicator, and white light can be coupled into the other light guide to generate a daytime running light or position light.

[0019] In this way, a very high degree of design freedom can be achieved with regard to the optical design of the lighting functions, especially when viewed from the front, i.e., against the main direction of radiation, onto a light disc of the lighting device.

[0020] Furthermore, this allows for a comparatively compact design of the lighting device despite the use of multiple light guides. Preferably, the light guides are arranged directly above and / or next to each other, perpendicular to the main direction of light emission. Ideally, they are in abutting each other. This contributes to a particularly compact design of the lighting device.

[0021] For the purposes of the invention, the main emission direction is understood to be the intended emission direction of the lighting device, in which the lighting device predominantly emits or is intended to emit light. Normally, the main emission direction for headlights will therefore be approximately in the direction of travel and for taillights approximately opposite the direction of travel of a motor vehicle.

[0022] According to features of the invention, at least two optical fibers are designed and arranged relative to each other such that, at least in the main emission direction, the light-emitting surface of at least one optical fiber is covered by a portion of another optical fiber that branches off laterally from a surface extension of the optical fiber extending in the main emission direction. Light coupled into the covered optical fiber via a corresponding light-entry surface passes through it in the main emission direction (under total internal reflection). After exiting a light-emitting surface of the covered optical fiber, the light enters a light-entry surface of the covering portion of the other optical fiber and is coupled out again via a light-emitting surface.

[0023] This design makes it possible to create the impression for a viewer looking at the lighting device in the opposite direction to the main beam direction that, despite the use of several separate light guides for providing different lighting functions, only one light guide with one light output area is used for different lighting functions.

[0024] In this context, it is conceivable that two or more light guides, to which different light functions are assigned, overlap in this way in the main direction of emission.

[0025] In the aforementioned covering, according to a further embodiment of the inventive concept, it is advantageous if the light-emitting surface of a covered light guide and / or the light-entry surface of a covering light guide are each provided with optics that fan out the light.

[0026] In this way, the light from the covered light guide can be optimally coupled into the covering light guide.

[0027] It is very advantageous if the light-emitting surface of each light guide, which is not covered by part of another light guide, has step-like ledges in its cross-section.

[0028] This design ensures that, in addition to the main direction of emission, sufficient light from the lighting device can also be emitted upwards at an angle to the main direction of emission. This makes it easier to meet legal requirements.

[0029] Furthermore, it is proposed that the optical fibers have at least one surface area extending in the main emission direction that exceeds the wall thickness of the optical fibers, preferably by a multiple. This allows for greater design flexibility regarding the location and configuration of a suitable light coupling point.

[0030] It is conceivable and offers distinct advantages if the light sources with different lighting functions are mounted on separate light source carriers. This further increases the flexibility regarding the design of the lighting device and the location of the desired light coupling. Finally, within the scope of this invention, protection is also sought for a motor vehicle that has at least one lighting device according to the invention.

[0031] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Reference numerals refer to identical, comparable, or functionally equivalent components, achieving corresponding or comparable properties and advantages, even if a repeated description is omitted.

[0032] They show, schematically, each one Fig. 1 a motor vehicle with lighting devices according to the invention in a top view, Fig. 2 a view of a lighting device from view II according to Fig. 1, Fig. 3 a longitudinal section according to section line III from Fig. 2, Fig. 4 a view comparable to Fig. 3, but essentially only the optical fibers are shown in a different embodiment, Fig. 5 a view comparable to Fig. 4, in yet another embodiment of the light guide, Fig. 6 a representation comparable to Fig. 4, in another training of the light guides and Fig. 7 a representation comparable to Fig. 2, however with a design of the light guides according to Fig. 4.

[0033] First, attention will be drawn to the Fig. Reference is made to 1 to 3.

[0034] In Fig. Figure 1 shows a motor vehicle K equipped with two lighting devices 1 designed according to the invention. The lighting devices 1 are designed as headlights. However, in contrast to the exemplary embodiment, it is also conceivable to design lighting devices serving as taillights according to the invention.

[0035] FR denotes a normal direction of travel (i.e., forward) of the motor vehicle K, which has a main direction of radiation H (see, e.g., also Fig. 3) roughly corresponds.

[0036] In Fig. 2 shows the lighting device 1 from the front with a view of a light disc 11.

[0037] The lighting device 1 is designed in particular as a double headlight, with two light sources 100, which can be designed, for example, as xenon or bi-xenon spotlights or in LED technology and are responsible for the low beam and high beam functions.

[0038] In the given illustration, each of the light sources 100 is covered from above by two light guides 12 and 13. The light guides 12 and 13 are preferably crystal clear and transparent. In cross-section, they have approximately the shape of an inverted U, widening towards the legs of the U.

[0039] It is particularly from Fig. 2 and Fig. Figure 3 shows that the optical fibers 12 and 13 are arranged one above the other and next to the other, respectively, perpendicular to the main emission direction H. In particular, the optical fibers 12 and 13 are arranged so close together that they touch each other.

[0040] The light guides 12 and 13 are arranged between a first aperture 14 and a second aperture 15, which are in Fig. 2 are shown only as dashed lines for clarity.

[0041] Furthermore, the light guide 12 has a plurality of light entry surfaces 120 and a front light exit surface 121.

[0042] The light guide 13 is provided with a multitude of light entry areas 130 and also with a front light exit surface 131.

[0043] The light emission surfaces 121 and 131 are each equipped with step-like ledges 122 and 132, respectively. This causes the light rays coupled into the light guides 12 and 13 to be emitted upwards at an angle in addition to the main emission direction H.

[0044] The optical fibers 12 and 13 have a surface area F aligned approximately parallel to the main emission direction H, which is several times larger than the wall thickness d1 and d2 of the optical fibers 12 and 13, respectively.

[0045] The light guide 12 serves to provide a primary lighting function, namely that of a direction indicator. Therefore, yellow light is coupled into the light guide 12 via the light entry surfaces 120 of a multitude of light sources 16, which are designed as light-emitting diodes (LEDs). The LEDs 16 are positioned against the light entry surfaces 120. Their light is thus coupled in perpendicular to the main emission direction H, then deflected by optical deflection means 123 in the direction of the main emission direction H, and passes through total internal reflection to the light exit surface 121.

[0046] The light guide 13, on the other hand, serves to provide the daytime running light function. For this purpose, white light is coupled into the entry areas 130 via a multitude of LEDs 17. As can be seen, the LEDs 17 are spaced slightly apart from the light entry areas 130. In order to reduce the resulting light losses, the light entry areas 130 have a circular recess 135, the base of which is designed as a convex light entry surface 133 directed towards the LEDs 17.

[0047] The light from the LEDs 17, coupled into the light entry areas 130, is therefore also initially coupled perpendicular to the main emission direction H and then deflected in the direction of the main emission direction H by means of an optical deflecting device 134. Under total internal reflection, the light again travels in the main emission direction H to the light emission surface 131.

[0048] Both LEDs 16 and LEDs 17 are mounted on a common light source carrier 18, which is designed as a circuit board. LEDs 16 and 17 can each be configured as a single LED chip (only one light-emitting diode on a base carrier) or as multiple LED chips (several light-emitting diodes of the same color on a base carrier) and mounted on the common light source carrier 18.

[0049] As can be seen, the apertures 14 and 15 form a slit-like opening through which the light guides 12, 13 protrude slightly forward in the direction of the main emission direction H with their light-exit surfaces 121, 131. The light guide 13 projects slightly beyond the light guide 12 in the main emission direction H, by approximately the amount indicated by the recess 132.

[0050] The housing of the lighting device 1 is numbered 10 and is covered by the light lens 11 at the front, i.e. in the main direction of emission H.

[0051] In Fig. 4 is now a view comparable to Fig. Figure 3 shows, but essentially only the light guides are depicted, specifically in a modified embodiment. A light guide 19 and a light guide 20 are visible.

[0052] The optical fiber 19 has a light entry area 190 and a light exit area 191. The light entry area of ​​the optical fiber 20 is numbered 200, and its light exit area is numbered 201.

[0053] Yellow light is coupled into the light guide 20 via LEDs 16, and white light into the light guide 19 via LEDs 17. The LEDs 16 thus serve to implement the light function of a turn signal, and the LEDs 17 to implement the light function of a daytime running light. The LEDs 16 and 17 are mounted on a common light carrier 18 in the form of a circuit board. In contrast to the embodiment according to Fig. 3. However, the light from LEDs 16 and 17 is coupled in parallel to the main emission direction H. It is also conceivable to couple the light in perpendicular to the main emission direction H (indicated by dashed lines). In this case, however, additional optical deflection devices 195 and 203 must be provided in the light guides. Furthermore, in this case, LEDs 16 and 17 must also be mounted on separate light carriers 18.

[0054] An important difference to the design and arrangement of the light guides according to Fig. However, the following should be mentioned in point 3: The light-emitting surface 201 of the light guide 20 is covered at its front, i.e., in the main emission direction H, by a portion of the light guide 19. The covering portion of the light guide 19 branches off from a surface area F of the light guide 19 at an angle of approximately 90° towards the light guide 20. This covering creates the impression, when viewed from the front of the lighting device 1, that despite the use of two separate light guides for both lighting functions (daytime running lights, turn signals), only one light guide (19) with a single (thicker) light-emitting surface 191 is used. D denotes the thickness of the light guide 19 that covers the front of the light guide 20.

[0055] When yellow light L from the LEDs 16 is coupled into the light guide 20, it is guided through the light guide 20 under total internal reflection in the main emission direction H and finally emerges from the light-emitting surface 201 of the light guide 20. From there, the light L passes into a light-entry surface 192 of the covering area of ​​the light guide 19 and finally to the light-emitting surface 191.

[0056] Advantageously, the light emission surface 201 and / or the light entry surface 192 are equipped with a diverging optic 202 or 193, respectively. These diverging optics fan out the light rays L generated by the LEDs 16 and distribute them optimally onto the light emission surface 191 visible to an observer.

[0057] In this embodiment as well, the light emission surface 191 is provided with step-like ledges 194.

[0058] To realize the light function of a daytime running light, white light is again coupled into the light guide 19 via the LEDs 17, which in turn is guided through the light guide 19 in the main emission direction H and exits at the light exit surface 191.

[0059] In Fig. 5 is a modification of the embodiment according to Fig. 4 shown. In contrast to the Fig. In section 4, the light-emitting surface 201 of the light guide 20 is not only covered by a second light guide 19', but the light guide 19' even completely encloses the entire light guide 20 on both sides. LEDs 17 serve to couple white light in order to provide a daytime running light function, while LEDs 16 couple yellow light into the light guide 20 to provide the light function of a turn signal.

[0060] The Fig. Figure 6 shows another possible embodiment of the lighting device 1, wherein, in contrast to the Fig. 4 and Fig. 5 Three optical fibers 20, 21 and 22 with thicknesses d1, d2 and d3 are optically connected in series. The thicknesses d1, d2 and d3 can be the same or different.

[0061] It is evident that the end-face light emission surface 201 of the light guide 20 is covered by a part of the light guide 22 and an end-face light emission surface 221 of the light guide 22 is in turn covered by a part of the light guide 21.

[0062] White light from LEDs 17 is coupled into the light guide 21 via a light entry surface 210 and coupled out again at a front light exit surface 211 which has step-like ledges 212. The LEDs 17 together with the light guide 21 thus serve to implement a daytime running light.

[0063] To implement a direction indicator, light is coupled into the light guide 20 via the LEDs 16 and passes through the light emission surface 201 into a light entry surface 224 of the part of the light guide 22 that covers the light guide 20. From there, the light emerges from a light emission surface 221, which also has a diverging optic 222. In the area of ​​the light emission surface 221, the light rays then enter a light entry surface 213 of a part of the light guide 21 that covers the light emission surface 221. The light entry surface 213 is again equipped with a diverging optic 214, so that the light rays coupled into the light guide 20 via the LEDs 16 can be coupled out over the entire thickness D of the light emission surface 211.

[0064] The generation of a third lighting function, for example a position light, is conceivable via light-emitting diodes 23.

[0065] The light from the LEDs 23, coupled in via a light entry surface 220, is again coupled out via the light exit surface 221 and enters the light guide 21 via the light entry surface 213. Coupling out again takes place across the entire thickness D of the light exit surface 211.

[0066] In the explanations according to Fig. 4 and Fig. 5. The light guides 19, 19' thus serve to provide two lighting functions (daytime running lights, direction indicators), while in the embodiment according to Fig. 6 of the light guide 21 can serve to provide three lighting functions (daytime running light, direction indicator, position light) due to the mutual overlap of the light guides 20, 21 and 22.

[0067] Since the light from LEDs is coupled into separate light guides for each light function, the structure of the LEDs or the light carrier 18 and also the effort required to control the LEDs can be kept comparatively simple.

[0068] Finally, in Fig. 7 a view of the lighting device 1 according to the variant after Fig. 4 shown.

[0069] From this view it can be seen that a large number of LEDs 16 and 17 are arranged behind the light guides 19 and 20 respectively (indicated by dashed lines).

[0070] Due to the covering of the light guide 20 by the light guide 19, only the common light emission surface 191 with its thickness D is visible to an observer.

[0071] Furthermore, it should be noted that the information contained in the Fig.The gaps between the light guides, shown as 2 to 6, are exaggerated for clarity. In reality, these gaps should be kept as small as possible to minimize light loss. Ideally, the light guides should be touching.

[0072] The invention is not limited to the embodiment(s) described above. These were only used to generally illustrate the core concept of the invention. Within the scope of its protection, the invention may also include embodiments or configurations other than those described above. In particular, it may also include features that represent a combination of individual features of the respective claims. Reference symbol list 1.1' Lighting equipment 10 cases 11 Light disc 12 optical fibers 13 optical fibers 14 aperture 15 aperture 16 light sources (LED, yellow light) 17 light sources (LED, white light) 18 Light source carriers (circuit board) 19, 19` fiber optic cable 20 fiber optic cables 21 fiber optic cables 22 optical fibers 23 light sources (LED, white light) 100 light bulbs 120 light entry surfaces 121 Light emission area 122 step-like landing 123 Deflection devices 130 light entry areas 131 Light emission area 132 step-like paragraph 133 convex light entry surface 134 Deflection devices 135 circular depressions 190 light entry area 191 Light emission area 192 Light entry area 193 Divergence optics 194 step-like ledges 195 deflection devices 200 light entry area 201 Light emission area 202 Divergence optics 203 Deflection devices 210 Light entry area 211 Light emission area 212 step-like landings 213 Light entry area 214 Divergence optics 220 light entry area 221 Light emission area 222 Divergence optics 223 Divergence optics 224 Light entry area d1-d3 Wall thicknesses of the optical fibers Thickness F Area of ​​the optical fiber in the main direction of emission FR direction of travel H Main radiation direction K motor vehicle

Claims

[1] Lighting device (1) for a motor vehicle (K) with a plurality of lighting means (16, 17, 23), wherein the lighting means (16, 17, 23) are at least partially assigned different lighting functions in the lighting device (1), and the light (L) of the lighting means (16, 17, 23) can be coupled into at least one light guide (12, 13, 19, 19', 20, 21, 22), through which the light (L) of the lighting means (16, 17, 23) can be coupled out again at least in a main emission direction (H) via at least one light exit surface (121, 131, 191, 211), and the different lighting functions can thereby be provided, wherein at least two light guides (12, 13, 19, 19', 20, 21, 22) are present, into each of which light (L) can be coupled in to provide at least one lighting function, wherein the light guides (12,13, 19,19',20,21,22) are arranged transversely to the main radiation direction (H) one above the other and / or next to the other, and the light guides (12,13, 19,19',20,21,22) have at least one surface extension (F) pointing in the main emission direction (H), which exceeds a wall thickness (d1,d2,d3) of the light guides (12,13, 19,19',20,21,22) in each case, , characterized bythat at least two light guides (19, 19', 20, 21, 22) are designed and arranged relative to one another in such a way that, at least in the main emission direction (H), the light exit surface (201, 221) of at least one light guide (20, 22) is covered by a part of another light guide (19, 19', 21, 22) which branches off laterally from a surface extension (F) of the light guide running in the main emission direction (H), wherein light (L) coupled into the covered light guide (20, 22) is guided through it in the main emission direction (H) and, after exiting from a light exit surface (201, 221), is coupled into a light entry surface (192, 213, 223) by the covering part of the other light guide (19, 19', 21, 22) and is guided therefrom via a light exit surface (191,221,211) is coupled out again. [2] Lighting device (1) according to claim 1, characterized bythat the light exit surface (201,221) of a covered light guide (20,22) and / or the light entry surface (192, 213,223) of a covering light guide (19,19', 21,22) are each provided with an optical system (193, 202, 214, 222,223) which spreads out the light. [3] Lighting device (1) according to one of the preceding claims 1 and 2, characterized by that the light exit surface (121,131,191,211) of each light guide (12,13,19,21), which is not covered by a part of another light guide, has stair-like steps (122,132,194,212) in cross-section. [4] Lighting device (1) according to one of the preceding claims, characterized by that the lamps (16,17) of different lighting functions are held on separate lamp supports (18). [5] Motor vehicle (K) with at least one lighting device (1) according to at least one of the preceding claims.

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