EP2357396A2 - Motor vehicle lighting device with an integrated light - Google Patents

Abstract

The device e.g. headlight (100), has an optic element (36) i.e. reflector, collecting and radiating light of a light source (34) i.e. LED, via a light exit surface. A rod-shaped light conductor (102) covers a small portion of the light exit surface and releases a large portion of the light exit surface. The light conductor leads the light coupled via a light coupling surface (104) to a side wall (22) and opaque tube walls and radiates the light in determined spatial angle regions via a light uncoupling surface (111). The light conductor is bent, curved or arbitrarily formed.

Description

The present invention relates to a motor vehicle lighting device according to the preamble of claim 1. Such a motor vehicle lighting device is known in the form of a motor vehicle headlight per se and has an integrated light having a light source and an optical element which is adapted to collect light from the light source and to radiate via a light exit surface, wherein the illumination device has structures that obstruct a propagation of the outgoing from the optical element through the light exit surface luminous flux in certain solid angle ranges.

The term of the lighting device is used in this application as a generic term for lights and headlights. The term of the luminaire refers throughout to means for the realization of signal light functions. Signal light functions serve to make other road users aware of their own motor vehicle. Such signal light functions are for example the flashing light, the brake light and the limiting light. In contrast, headlight lighting functions are used to illuminate the vehicle environment, for example, to enable the driver to perceive non-self-illuminating obstacles in the travel path. Such light functions are, for example, the high beam and the low beam. In addition to light modules that fulfill its headlight functions, a headlamp may have integrated lights such as direction indicators and / or daytime running lights and / or marker lights.

Examples of optical elements of luminaires are reflectors and lenses. As a rule, certain light intensities in certain solid angle ranges in the surroundings of the motor vehicle and thus in the surroundings of a luminaire must be achieved for the visibility of luminaires. This is made more difficult, for example, by the fact that a luminaire is arranged comparatively deep in a headlight and in close proximity to a lateral housing wall and / or other light modules serving light functions. Such adjacent light modules and housing walls represent examples of structures which obstruct propagation of the luminous flux emanating from the optical element through the light exit surface into certain solid angle ranges.

A known measure, with which the prescribed intensity values can be achieved even under the abovementioned unfavorable installation conditions of the luminaire, consists in a headlamp being a transparent cover pane of the headlamp with line structures provided that scatter the light in the specific solid angle areas. These line structures interfere with the visual appearance and are therefore executed only very finely if possible. The fineness means that the lighting effect of the line structures can only be simulated with a comparatively disturbingly wide spread, which makes the design of new headlights more difficult and delays development and makes it more expensive. This applies analogously to other lighting devices in the form of bow and / or tail lights.

Against this background, the object of the invention is to specify a lighting device of the type mentioned above, with which the required light intensity values can be achieved without having to accept delays and increases in the development of new lighting devices and disturbances in the visual appearance.

This object is achieved with the features of claim 1. Thereafter, the illumination device according to the invention has at least one light guide, which covers a first, relatively smaller portion of the light exit surface of the optical element with a light-coupling surface of the light guide, leaving a second, comparatively larger portion of the light exit surface, and wherein the light guide is set up to direct light introduced via the light-coupling surface past the structures and to radiate via a light-coupling-out surface of the light guide into the specific solid angle ranges.

Opposite the line structures in a cover have optical fiber in this context, the advantage that their properties in terms of recorded and emitted in certain directions light fluxes predict well and thus can simulate well. The dimensioning of the portion of the area covered by the light guide allows an accurate prediction of the proportion of the light received by the light guide to the total light flux of the optical element of the light.

Because only a comparatively smaller part of the light exit surface of the optical element is covered, the larger part of the light exit surface for the radiation remains in the solid angle region, which is not obstructed by the shading structures of the illumination device.

The coupling of the light into the light guide and the coupling of the light from the light guide can be largely predetermined independently of the shape that has the light guide between its light on or out coupling surfaces. Therefore, there is a great deal of design freedom for the design of the lighting device. Disturbing line structures in a transparent cover are no longer required at least to ensure the visibility of the lamp in the entire prescribed solid angle range and can be omitted. In addition, the light guide can serve with its lighting effect itself as an additional design element that improves the overall aesthetic impression of the lighting device.

The light guide can be bent, curved or shaped as desired. In addition, one or more optical fibers may be arranged in front of the optical element. In a In a preferred embodiment, the light-coupling surface has light-collecting structures and / or a light-collecting form in order to provide as much light as possible for a deflection into the otherwise shadowed solid angle regions with a small cover. For the same reason, it is also preferred that the light-coupling surface of the light guide has light-directing structures, is coupled by the light with a certain preferred direction in the light guide, this direction facilitates a coupling over the outcoupling of the light in the solid angle ranges and / / or reinforced.

This desired effect is enhanced by embodiments in which the light-coupling surface has light coupling-out structures, in particular those which are adapted to decouple light preferably in the specific solid angle ranges.

In particular, optical fibers in the form of a light guide plate which has a top side, a bottom side and side faces, wherein the light-coupling-out surface of the light guide is a narrow side face of the plate-shaped light guide, are suitable as design elements enabling these effects.

Further light effects and enhanced illumination of the otherwise shadowed solid angle ranges are achieved by virtue of the fact that the light guide plate has light extraction structures on the side surface and / or on the top side and / or bottom side.

Other aesthetic lighting effects and enhanced illumination of the otherwise shadowed Solid angle ranges are achieved with a configuration in which a rear side of the light guide plate has a section extending at least partially outside a reflector serving as an optical element and a light source is arranged such that light emanating therefrom is coupled into the section.

An improved illumination of the otherwise shadowed solid angle ranges is also achieved with a configuration in which the light guide plate has recesses as light-directing elements.

Instead of light guide plates and rod-shaped light guides can be used, which is particularly in confined spaces in the lighting device advantage.

For the light guide plates as well as for the rod-shaped light guides applies that the one or more light guides can be arranged horizontally or vertically or arbitrarily in front of the optical element. In this respect, there are no restrictions on the freedom of design.

In a preferred embodiment, the optical element is a simple reflector. The invention can be used both in lighting equipment set up for use in the bow and in rear lights. The integrated light can be a daytime running light, a flashing light or a position light, and a tail light can also be a brake light. Particularly preferred is a use in a headlight, because there often shadowing by the plurality of light modules and the space requirement of individual light modules, in particular of Projection light modules result.

Further advantages will be apparent from the dependent claims, the description and the attached figures.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

drawings

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In this case, the same reference numerals in the various figures denote the same elements.

Fig. 1

eine Schnittdarstellung eines bekannten Scheinwerfers in einer Draufsicht;

Fig. 2

eine Schnittdarstellung eines ersten Ausführungsbeispiels der Erfindung in einer Draufsicht;

Fig. 3

eine Vorderansicht einzelner Elemente des Ausführungsbeispiels aus der Fig. 2;

Fig. 4

weitere Ausgestaltungen einer Anordnung von einem oder mehreren Lichtleiterplatten in Bezug auf einen Reflektor;

Fig. 5

eine Ausgestaltung, bei der Lichtleiterplatten in vertikaler Ausrichtung vor einem Reflektor angeordnet sind;

Fig. 6

eine Ausführung, bei der stabförmige Lichtleiter verwendet werden; und

Fig. 7

eine Draufsicht auf eine Lichtleiterplatte, die wenigstens eine Aussparung als Licht richtendes Mittel aufweist.

In each case, in schematic form:

Fig. 1

a sectional view of a known headlamp in a plan view;

Fig. 2

a sectional view of a first embodiment of the invention in a plan view;

Fig. 3

a front view of individual elements of the embodiment of the Fig. 2 ;

Fig. 4

further embodiments of an arrangement of one or more light guide plates with respect to a reflector;

Fig. 5

an embodiment in which light guide plates are arranged in vertical alignment in front of a reflector;

Fig. 6

an embodiment in which rod-shaped optical fibers are used; and

Fig. 7

a plan view of a light guide plate having at least one recess as a light directing means.

In the following, the invention will be explained with reference to a headlight as a lighting device. However, the invention is useful not only in a headlight, but generally in a lighting device, especially in a tail light or not serving as a headlight front light.

In detail, the shows FIG. 1 a section through a lighting device 10 in the form of a presumed as known headlamp when viewed from above. It is a headlamp 10 that is adapted to be used on a left side of a vehicle. A direction 12 points in the apron of the vehicle, not shown. The headlight 10 has a lamp 14 and two further light modules 16 and 18 and is bounded by an intransparent housing with a rear wall 20 and a side wall 22 and in the light emission direction forward through a transparent cover 24. The light 14 is a flashing light. The light module 16 is a projection module which is delimited from the luminaire 14 and the adjacent light module 18 by non-transparent tube walls 26. The light module 18 is, for example, a daytime running light module.

In order to comply with the legal requirements regarding the visibility of the flashing light, the light of the luminaire 14 must reach predetermined intensity values in a solid angle range which includes a main emission direction 28 and bounded by an inner limit direction 30 and an outer limit direction 32.

The inner limit direction 30 is inclined to the vehicle 12 with respect to the direction 12 pointing into the vehicle apron, and thus also with respect to the main emission direction 28, while the outer limit direction 32 is inclined away from the vehicle. The inner boundary direction 30 includes, for example, with the main emission direction 28 an angle of 45 ° + 5 ° in the horizontal, or + 15 ° in the vertical direction. The outer boundary direction 32 includes with the main radiation direction 28 an angle of 80 ° + 5 ° in the horizontal, or + 15 ° in the vertical direction.

The luminaire 14 has a light source 34 and an optical element in the form of a reflector 36. The light generated by the light source 34 and focused by the reflector 36 is at the in the FIG. 1 Shade geometry shown shaded on one side of the inner side wall 22 of the spotlight housing and on the other side of the tube wall 26 or a lens 38 of the projection light module 16.

The light cone resulting from the shading is limited by the marginal rays 39 and 40 and lies within the limited by the boundary directions 30 and 32 solid angle in which the lamp 14 must be visible. The side wall 22 of the headlamp housing and the tube wall 26 and / or the lens 38 therefore represent examples of structures that obstruct a propagation of the outgoing light from the optical element 36 in certain solid angle ranges 42, 44. These particular solid angle ranges 42, 44 are in the FIG. 1 through the direction 30 and the Edge beam 39 on the inner side and limited by the direction 32 and the edge beam 40 on the outer side.

FIG. 2 shows a first embodiment of the invention. In detail, the shows FIG. 2 a section through a lighting device 100 in the form of a motor vehicle headlight when viewed from above. The headlight 100 is, as the known headlight 10 from the FIG. 1 , adapted for use on a left side of a vehicle and, like this, has the light 14 and the two light modules 16, 18. The headlight 100 is bounded by a housing with a non-transparent rear wall 20 and side wall 22 and in the light emission direction forward through a transparent cover 24. The light 14 is a flashing light. The light module 16 is a projection module that is delimited by opaque tube walls 26 from the adjacent lights and light modules 16 and 18. The light module 18 is, for example, a daytime running light module. The luminaire 14 has a light source 34 and an optical element in the form of a reflector 36.

The headlight 100 differs from the known headlight 10 by a light guide 102. The here designed as a light guide plate light guide 102 is adapted to conduct over the light coupling surface coupled-in light on the structures 22, 26, 38 and over a light auskoppelnde surface of the optical fiber in the otherwise shadowed solid angle ranges radiate. This will be described below with varying reference to Figures 2 and 3 explained.

FIG. 3 shows a view of the arrangement of the light source 34, the optical element 36 and the light guide 102 from the front and thus from a viewing direction, which is directed opposite to the main emission of the optical element 36. How to consider that in conjunction with each other Figures 2 and 3 takes the light guide 102 covers a first, relatively smaller portion of a light exit surface of the optical element 36 with a light-coupling surface 104 of the light guide 102, wherein a second, relatively larger portion of the light exit surface is left free. The light exit surface is in the FIG. 3 the projection of the area bounded by the outer edge 106 of the reflector 36 in the plane of the drawing.

As the beam path with the rays 108, 110 in the FIG. 2 shows, the light guide 102 is configured by its geometry and arrangement to pass over the light-coupling surface 104 coupled light on the structures 22, 26 and radiate via a light-coupling surface 111 of the light guide 102 in the specific solid angle ranges. This results from the fact that the rays 108, 110 in the FIG. 2 enclosed angle is about the same size as that in the FIG. 1 angles included by the boundary directions 30 and 32.

In the embodiment, in the FIG. 3 is illustrated, the light source 34 consists of a semiconductor light source 112 and an associated primary optics 114. The semiconductor light source 112 is preferably a light emitting diode (LED). As the primary optics 114, a light-harvesting LED attachment optics is preferably used, which uses a total internal reflection, in order to diffuse the light into the reflector 36 in the form of a cone. As an alternative to the semiconductor light source, the lamp with a light bulb operate. When using the incandescent lamp, a light guide plate is preferably arranged such that the filament of the incandescent lamp lies approximately in the middle plane of the light guide plate. In the case of an incandescent lamp with a transverse coil, the arrangement is preferably made such that the coil is aligned parallel to the light guide plate.

The reflector 36 is in the embodiment of Figures 2 and 3 designed as a concave basic shape having a number of concentrically extending steps 116 and 118.

In a preferred embodiment, the light-coupling surface 104 of the light guide 102 has a convergence-increasing and thus light-collecting and / or a the Lichteinfangquerschnitt the light guide 102 and thus increasing light collecting geometry.

Alternatively or additionally, it is preferred that the light-coupling surface of the light guide 102 has light-directing structures, is coupled by the light with a certain preferred direction in the light guide 102, this direction a taking place via the decoupling surface 111 coupling the light in the solid angle ranges 42, 44 facilitated and / or strengthened. In one embodiment, prismatic structures are used as elevations or depressions in the light-coupling surface 104 as light-directing structures.

Alternatively or additionally, another embodiment has light extraction elements in the form of elevations 113 on the light coupling-out surface 111 or in the form of depressions 115 in the light coupling-out surface 111 of the light guide 102.

The elevations and depressions can be shaped in principle very diverse. This diversity results from the fact that the light-conducting effect of light guides is known to be based on an internal total reflection at an interface of the light guide. The Lichtauskoppelelemente 113, 115 are characterized by a geometry in which due to changing angles, with the propagating in the interior of the light guide 102 light strikes an interface, no total reflection takes place at the light-coupling surface 111 forming interface more and there instead at least a portion of the incident light is coupled out through the interface.

It is understood that instead of prism-like elevations and depressions and light extraction elements of different geometry can be used. Thus, a coupling out, for example, by Lichtauskoppelelemente 113, 115 in the form of steps, inclined planes or lens structures, for example in pillow form, take place, wherein the proportion of decoupled radiation and its direction by the shape, size, number and arrangement of Lichtauskoppelelemente and due to the fine structure of their surface, which may be smooth or frosted, for example, is adjustable. Unevenly rough matting achieves a previously wide scatter around an intensity maximum compared to a smooth surface, while a smooth surface allows for greater focusing in a narrow solid angle range.

In a preferred embodiment, the light extraction structures are set up to decouple light preferably into the specific solid angle regions 42, 44.

In the embodiment, in the Figures 2 and 3 is shown, a single light guide plate is used as a light guide 102. In this case, the light guide plate 102 is arranged horizontally in front of the reflector 36.

It is also possible to arrange several light guides in front of the optical element 36.

As far as described so far, the light coupling surface 111 of the light guide 102 is a narrow side surface of the plate-shaped light guide 102nd

The light extraction structures are preferably arranged on this side surface. Alternatively or additionally, however, it is also possible to arrange light extraction structures on the upper side and / or the underside of the light guide plate.

The light guide plate 102 can also be used vertically or in an angular position lying between a vertical and a horizontal angular position, wherein the arrangement of the light coupling-out surface 111 and the light extraction structures 113, 115 is then optionally adapted. In a further embodiment, a partition wall of a lamp chamber and / or a tube wall and / or a part of a cover frame which serves to conceal certain areas of the interior of the illumination device from outside is mirrored on one side, for example by a metallic coating.

The light guides 102 may also have a two-dimensionally curved or three-dimensional curved curved shape.

The FIG. 4 shows further embodiments of an arrangement of one or more optical fibers 102 with respect to a reflector 36. In detail, the FIG. 4 an arrangement with a plurality of horizontally oriented light guide plates 120a, 120b, 120c. The light guide plates 120a, 120b and 120c surround the reflector 36 and extend into the reflector 36 inside. In one embodiment, in addition, light from at least one light source 124, which is located outside the optical element 36 or outside of the reflector 36, is coupled into at least one rear side of the light guide plates 120a, 120b, 120c. In such an arrangement, areas can be provided in the reflector, from which the light is coupled into the light guide plate.

For this purpose, a rear side 122 of the optical waveguide plate 120a has a section 121 extending at least partially outside a reflector 36 serving as an optical element, and a light source 124 is arranged so that light emanating therefrom is coupled into the section 121.

The light source 124 is preferably a further semiconductor light source, which is arranged in the immediate vicinity of the rear side 122. However, the semiconductor light source 124 can also be arranged at some distance from the rear side 122, and its light can be coupled into the light guide plate 120a, 120b, 120c via one or more further optical fibers which connect the light source 124 to the rear side 122 the back 122 belongs.

In a further embodiment, not only the comparatively narrow side surface of a Light guide plate 120a, 120b, 120c provided as a light Auskoppelnde surface 111. Thus, in the embodiment, in the FIG. 4 is shown, an additional coupling of light via a light output element 126 which is disposed on an upper surface 128 of the upper light guide plate 120a. Such a light extraction element 126 is designed in one embodiment as an elongated, prism-shaped elevation or depression in the upper side 128.

As an alternative or in addition to such a coherent light output element, an arrangement of separate light output elements can also be distributed on the upper side 128. This applies analogously to an underside 130 of the light guide plate 120a opposite the upper side 128. Alternatively or additionally, the further light guide plates 120b, 120c or a selection of these light guide plates 120b, 120c at least one such light extraction element 126 and / or a light coupling via at least one additional light source 124.

FIG. 5 shows an embodiment in which light guide plates 132a, 132b, 132c are arranged in vertical alignment in front of a reflector 36. In the illustrated embodiment, the front sides 134a, 134b, 134c of the light guide plates 132a, 132b, 132c are inclined obliquely to the main emission direction in order to extract light preferably to the side.

FIG. 6 shows an embodiment in which instead of light guide plates rod-shaped light guides 136a, 136b, 136c are used. It shows the FIG. 6a a plan view of a cut headlight and is so far with the illustrations of Figures 1 and 2 comparable.

FIG. 6b shows a front view of the rod-shaped optical fibers 136a, 136b and 136c.

The illustrated cross-sectional shapes of a quadrilateral, a circle and a polygon, in particular a hexagon, illustrate that one has a great deal of design freedom with respect to the cross-sectional area of the rod-shaped light guides.

In addition, the rod-shaped optical fibers 136a, 136b, 136c may also have a curved course and be directed, for example, with their end facing away from the light source in said solid angle ranges, which would otherwise be undesirable shaded by the structures of the lighting device.

The rod-shaped optical fibers can also be arranged in arrangements other than the illustrated horizontal row. It can also be used more or less than the three illustrated rod-shaped light guides. Incidentally, this also applies to the embodiments with the light guide plates for the number of light guide plates.

FIG. 7 shows a plan view of a light guide plate 138 having at least one recess 140, 142. Since total reflection and refraction of light take place at the edges of these recesses 140, 142, these recesses 140, 142 can be used as light-directing elements in order to direct as much light as possible to the surfaces coupling out the light, for example to the light-coupling surface 111 the light extraction preferably takes place in the otherwise shadowed solid angle ranges. The shape of the recess Determines the desired light directing effect and can be determined in the design of the headlight and easily simulated in their effect. In a further embodiment, areas are provided in the reflector, which cause a bundling of the incident light in the areas in the light guide plates.

Claims (20)

Motor vehicle lighting device (100) with an integrated light (14), which has a light source (34) and an optical element (36), which is adapted to collect light from the light source (34) and radiate via a light exit surface, and structures ( 22, 26) which obstruct propagation of the luminous flux emanating from the optical element through the light exit surface into certain solid angle regions (42, 44), characterized by at least one light guide (102) having a first, comparatively smaller portion of the light exit surface of the optical element (102; 36) with a light coupling surface (104) of the light guide (102) covers, and leaves a second, comparatively larger portion of the light exit surface, wherein the light guide (102) is adapted to coupled via the light coupling surface (104) coupled to the light Passing structures (22, 26) past and over a light extracting surface (111) of the light guide (102) in the specific solid angle ranges (42, 44). Lighting device (100) according to claim 1, characterized characterized in that the light guide (102) is bent, curved or arbitrarily shaped. Lighting device (100) according to one of the preceding claims, characterized in that a plurality of light guides (120a, 120b, 120c) are arranged in front of the optical element (36). Lighting device (100) according to claim 1, characterized in that the light-coupling surface (104) has light-collecting structures and / or a light-collecting form. Lighting device (100) according to any one of the preceding claims, characterized in that the light-coupling surface (104) of the light guide (102) has light-directing structures, is coupled by the light with a certain preferred direction in the light guide (102), this direction a coupling out of the light into the solid angle regions (42, 44) taking place via the light-emitting surface (111) is facilitated and / or amplified. Lighting device (100) according to any one of the preceding claims, characterized in that the light-coupling surface (111) Lichtauskoppelstrukturen (113, 115). Lighting device (100) according to claim 6, characterized in that the light extraction structures are adapted to light out preferably in the specific solid angle ranges (42, 44). Lighting device (100) according to one of preceding claims, characterized by at least one light guide (102) in the form of a light guide plate (120a) having a top (128), a bottom (130) and side surfaces, wherein the light coupling surface of the light guide (120a) has a narrow side surface of the plate Optical fiber (120a) is. Lighting device (100) according to claim 8, characterized in that the light coupling-out surface Lichtauskoppelstrukturen on the side surface. Lighting device (100) according to claim 8 or 9, characterized in that the light guide plate Lichtauskoppelstrukturen on the top (128) and / or underside (130). Lighting device (100) according to one of Claims 8 to 10, characterized in that a rear side (122) of the light guide plate (120a) has a section (121) extending at least partially outside a reflector 36 serving as an optical element 36 and has a light source (124). is arranged so that outgoing light is coupled into the section (121). Lighting device (100) according to any one of claims 8 - 11, characterized in that the light guide plate (138) has recesses (140, 142). Lighting device (100) according to one of claims 1 to 12, characterized in that the light guide is a rod-shaped light guide (136a, 136b, 136c). Lighting device (100) according to one of the preceding claims, characterized in that the Optical fiber (102) is arranged horizontally or vertically or arbitrarily in front of the optical element (36). Lighting device (100) according to one of the preceding claims, characterized in that the optical element (36) is a reflector. Lighting device (100) according to one of the preceding claims, characterized in that the illumination device (100) is a lighting device (100) set up for use in the nose. Lighting device (100) according to one of claims 1 to 15, characterized in that the illumination device (100) is a tail light. Lighting device (100) according to claim 16 or 17, characterized in that the integrated light is a flashing light or a marker lamp. Lighting device (100) according to claim 17, characterized in that the integrated light is a brake light. Lighting device (100) according to claim 16, characterized in that the illumination device (100) is a headlight.

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