DE202015001004U1 - A lighting device for a motor vehicle having an endless mirror arrangement - Google Patents

Abstract

Illumination device (10) for a motor vehicle, comprising a light source (12) and an end mirror assembly (16) and a light source of the light source and directed to the end mirror assembly optical element (14), characterized in that the optical element comprises a first zone (42) and a second zone (44), the first zone directing the light from the light source toward the end mirror assembly such that after it has exited the end mirror assembly, this light falls within a first solid angle region (32) and the second zone is light the light source directed to the Endlosspiegelanordnung that this light, after it has exited the Endlosspiegelanordnung, falls into a second solid angle region (32), wherein the first solid angle range protrudes at a proper use of the lighting device down over the second solid angle range and the second solid angle range at the intended Verw ending both to the right and to the left beyond the first solid angle range.

Description

The present invention relates to a lighting device for a motor vehicle according to the preamble of claim 1.

Such a lighting device is from the DE 10 2009 053 571 A1 is known and has a light source and an end mirror assembly and a light collecting the light source and directed to the Endlosspiegelanordnung optical element.

Also known are lighting devices for motor vehicles in the form of signal lights, in which light-emitting diodes are used as light sources. Light-emitting diodes are Lambert emitters, which emit their light in a large angular range. Also known is a use of reflectors, which are made of white, highly reflective plastic and reflect the light incident on them with a nearly Lambert radiation characteristic in the half-space. Furthermore, made of white plastic, transparent filters are known, the transmitted light scatter so that it also propagates with an approximately Lambert's radiation characteristic in the half-space.

The radiation in a wide angle range has the advantage that the effect of a large depth of the luminaire, which results from the repeated mirroring of the light source, generated by the endless mirror arrangement, can be perceived from a large viewing angle range. In connection with the lossy multiple reflections in the end mirror assembly, this visibility for large viewing angles results in that only a very small portion of the light emanating from the light source falls within the central area of the light distribution, in which the luminaire must not only be perceptible, but in the Rather, it must still produce prescribed brightnesses in order to be admissible as a motor vehicle light. This part is without use bundling optical element at about one percent.

In the DE 10 2009 053 571 A1 already light of the light sources collecting optical elements are used.

From this prior art, the present invention differs by the characterizing features of claim 1. Accordingly, the optical element has a first zone and a second zone, wherein the first zone directs the light of the light source onto the end mirror assembly such that this light, after it has exited the end mirror assembly, falls into a first solid angle region, and the second zone directs light from the light source onto the end mirror assembly such that, after exiting the end mirror assembly, this light falls within a second solid angle region, the first solid angle region when the lighting device is used as intended, it protrudes downwards beyond the second solid angle range and the second solid angle range protrudes beyond the first solid angle range when used as intended both to the right and to the left.

The first solid angle region is, in particular, an area in which the lighting device has to generate legally prescribed minimum brightness values in certain spatial directions. The intended use is a use in the installed state in a motor vehicle. The spatial directions are defined as angular deviations from an origin, which results as the intersection of a horizontal H, a vertical V and a main emission direction of the illumination device.

The second solid angle region is in particular an area in which the lighting device should still be perceptible, without having to reach certain minimum brightness values in this area. The fact that the second area projects laterally beyond the first area results in the desired perceptibility in the horizontal direction outside the first area. As a result of the fact that the first region protrudes downward beyond the second region, the legal requirements, in particular below the horizon, can be met without using light below the horizon for a visibility outside the first region which is not required there. As a result, the available light of the light source is used more efficiently for satisfying the admission conditions in the first solid angle range and the visibility in the second solid angle range, which facilitates use of the Endlosspiegelanordnung also for signal light functions with higher light power requirements such as taillight brake lights or daytime running lights for bow lights.

A preferred embodiment is characterized in that the illumination device is set up to illuminate a first solid angle range which is 20 ° wide to the right and left and 10 ° wide to the top and bottom.

It is also preferable that the light source is a light-emitting diode.

A further preferred embodiment is characterized in that the endless mirror arrangement has a first mirror and a second mirror, wherein the first mirror in the Compared to the second mirror has a higher reflection and lower transmission.

It is also preferable that the transmission of the first mirror is zero.

A further preferred embodiment is characterized in that the optical element is a reflector, which is arranged and configured such that it collects light emitted by the light source and focused on the first mirror.

It is also preferred that the reflector has the form of a juxtaposition of a first parabolic section, a transition region and a second parabolic section in a cross-sectional plane which is spanned by its main emission direction and a vertical direction when the illumination device is used as intended.

A further preferred embodiment is characterized in that the first parabola section has a first focal length and the second parabola section has a second focal length, wherein the second focal length is greater than the first focal length.

It is also preferred that the two parabolic sections are arranged so that their parabola axes lie on one another and that their focal points coincide.

A further preferred embodiment is characterized in that the basic shape of the parabolic sections is superimposed on an array of convex facets which preferably adjoin one another along the parabolic sections and which cause a widening of the light bundle reflected by the parabola.

It is also preferred that the first parabolic section is configured with facets and is arranged such that it generates a light beam with a vertical opening angle from the light incident from the light source, and that the second parabolic section is configured with facets and arranged such that it emerges from the light beam from the light source incident light also generates a light beam with the same vertical opening angle.

Another preferred embodiment is characterized in that the reflector is a half-shell reflector, which as such completely detects the light emanating from the light-emitting diode as a half-space radiator.

It is also preferred that the reflector is composed of a first zone, a transition region and a second zone.

A further preferred embodiment is characterized in that the first zone and the second zone are zones of paraboloid of revolution.

It is also preferred that the transition region has a first end adjoining the first parabolic section and a second end adjoining the second parabolic section, wherein the transitional region at the first end merges tangentially into the first parabolic section and wherein the transitional region at the second end with a kink goes into the second parabola section.

A further preferred embodiment is characterized in that the transition region between its first end and its second end is rectilinear.

It is also preferred that a width of the transition region in mutually different angular positions, which lie between the angular positions of a horizontal bundle when used as intended and a vertical bundle, is different from each other.

A further preferred embodiment is characterized in that the reflection surface of the transition region has molded facets.

Further advantages will become apparent from the following description, the drawings and the dependent claims. 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.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description.

Show, in schematic form:

1 a cross section of an embodiment of a motor vehicle lighting device according to the invention;

2 a first solid angle region illuminated by the illumination device;

3 a second solid angle region illuminated by the illumination device;

4 a superposition of the first solid angle region and the second solid angle region;

5 an arrangement of a light source and a reflector which illuminates a first solid angle range, in a vertical section;

6 one on the object of 5 based arrangement that additionally illuminates a second solid angle area;

7 a perspective view of a reflector, an embodiment of in connection with the 6 described zones and a transition region;

8th Sections through light beams emanating from a transition region of a reflector and which determine a vertical opening angle and a horizontal opening angle of the light emanating from a reflector;

9 an arrangement of a light source and a light guide as an optical element; and, which here is a cross-sectional area increasing in the light transporting direction; and

10 a catadioptric optical attachment as an optical element.

In this case, the same reference numerals in different figures denote the same or at least functionally comparable elements.

In detail, the shows 1 a cross section of an embodiment of a motor vehicle lighting device according to the invention 10 , wherein the sectional plane is parallel to a plane which is spanned by a vertical V and a main emission x of the illumination device in a proper use of the motor vehicle lighting device in a motor vehicle. A horizontal H is perpendicular to this plane.

The motor vehicle lighting device 10 has an arrangement of a light source 12 , an optical element 14 and an endless mirror assembly 16 from a first mirror 18 and a second mirror 20 on. The arrangement is located in a housing 22 the lighting device whose light exit opening through a transparent cover 24 is covered.

The light source is preferably a light emitting diode. As is known, light emitting diodes emit their light in a wide opening angle into a half space. The optical element 14 is a reflector in the illustrated embodiment 26 which is arranged and designed to be from the light source 12 Outgoing light collects and bundles on a first mirror 18 directed. Compared to the second mirror 20 indicates the first mirror 18 prefers a higher reflection and lower transmission. The transmission of the first mirror 18 is ideally zero. The second mirror 20 shows in comparison to the first mirror 18 a smaller reflection and therefore a larger transmission. The transmission of the second mirror is in particular greater than zero, so that a first part of the mirror from the first 18 on the second mirror 20 incident light of the light source passes through the second mirror and exits through the transparent cover from the illumination device. If this light falls into the eye of a viewer, it generates there a first virtual image of the light source, or the light exit surface of the optical element 14 ,

A second part of the first mirror 18 on the second mirror 20 incident light of the light source is at the second mirror 20 reflected. This reflected part meets the first mirror again 18 , becomes the second mirror from there 20 reflected. There, it emerges partly and also falls into the eye of the beholder, creating a second virtual image 30 the light source, or the light exit surface of the optical element 14 is produced. The second picture 30 is seen by the viewer behind the first virtual image 28 , so that a sequential arrangement of the virtual images results. This is continued by further reflections, with the further virtual images becoming weaker as the number of associated reflections increases. This sequential arrangement of the virtual light sources produces the desired impression of a depth of the illumination device which is actually not present in the observer. This applies not only to a reflector as an optical element, but it applies analogously to the other embodiments of the optical element presented here.

2 shows a first, from the lighting device 10 illuminated solid angle area 32 in an area defined by the vertical V and the horizontal H, the vertical V intersecting the horizontal H in the main emission direction x of the illumination device. When used as intended. In the illumination device, the horizontal H intersects the vertical V at the height of the horizon.

The first solid angle area 32 is, for example, 20 ° wide to the right and left and 10 ° high to the top and bottom. In one such area must be the lighting device 10 if it serves as a signal light, produce prescribed minimum brightness in certain angular positions in order to be allowed as a vehicle lighting device. As is clear from the 2 results directly, this applies to both above and below the horizon H spatial directions.

3 shows a second solid angle range 34 which is illuminated by the illumination device and which lies in the same area as the first solid angle area 32 , In the second solid angle area 34 should the lighting device 10 for a viewer who is in this solid angle range, be visible, but no particular minimum brightness values must be achieved. For example, the visibility requirement does not result from licensing conditions of the legislator, but from design specifications of the vehicle manufacturer. It is noteworthy here that the visibility in the embodiment shown here is required only in the two above the horizontal H quadrants and in particular in their horizontal width is greater than the first solid angle range.

4 shows a superposition of the first solid angle range 32 and the second solid angle range 34 , Such a superposition is evident in a light distribution in which the first solid angle range 32 at a proper use of the lighting device 10 down over the second solid angle range 32 protrudes and the second solid angle area 34 when used as intended both to the right and to the left over the first solid angle range 32 protrudes. The solid angle range outside this entire area created by the overlay can remain dark. The illumination device is then not for the observers, who are in the dark area, by the light of the light source 12 visible, noticeable. According to the invention, the light of the light source 12 in a total area resulting from the superposition and described in the 4 concentrated and thus efficiently used.

5 shows an arrangement of a light source 12 and an optical element in a cross section which is in the xV plane of 1 and thus lies in a plane spanned by the main emission direction x and the vertical V. The optical element used in the 1 the reference number 14 owns, is in the case of 5 a parabolic concave mirror reflector in its basic form 36 , The 5 shows a parabolic basic shape 37 of the reflector 36 in the cutting plane as a dashed line. The light source 12 is located at the focal point of the parabola. The light source is preferably a light-emitting diode which illuminates the reflector and thus in particular the parabola along its illustrated length, but does not radiate beyond the edges of the reflector. As a result, only such light carries the light source 12 for illuminating the first solid angle range 32 at that on the surface of the reflector 36 has been reflected.

In the case of a pure parabolic shape of the illustrated reflector cross-section, the opening angle μ1 of the light reflected at the reflector would be zero in the illustrated vertical section. The parable 37 reflected light would be parallel in itself. In the illustrated embodiment, the basic shape of the parabola 37 an arrangement of convex facets 38 superimposed, along the parabolic curve 37 preferably connect to each other and causes a widening of the light beam reflected by the parabola on the legally required vertical angular width μ1. The angular width μ1 is in the 2 the vertical height of the first solid angle area 32 ,

In the direction leading out of the plane of the drawing, the reflector 36 have different shapes. It is preferably at least partially curvilinearly delimited in the HV plane perpendicular to the plane of the drawing and to the main emission direction x, and in particular a so-called half-shell reflector which as such completely detects the light emanating from the light-emitting diode as a half-space radiator.

6 shows an arrangement of a light source 12 and an optical element in the form of a reflector 40 , the element of the reflector 36 from the 5 having. The drawing plane of the 6 corresponds to the plane of the drawing 5 , The Indian 6 exemplified reflector 40 is made up of a first zone 42 , a transition area 43 and a second zone 44 together. The reflector 40 has in the illustrated cross-sectional plane which the Vx cross-sectional plane of 5 corresponds to the form of a juxtaposition of a first parabola section 42 ' (in the first zone 42 ), a transition area 43 and a second parabola section 44 ' (in the second zone 44 ). The first parabola section has a first focal length f1, and the second parabola section has a second focal length f2. The second focal length f2 is greater than the first focal length f1. The two parabolic sections, respectively zones 42 . 44 , are arranged so that their parabolic axes lie on each other and that their focal points coincide. The zones 42 . 44 are in a preferred embodiment, wherein the reflector 40 a half-shell reflector is zones of paraboloid of revolution.

The first parabola section is analogous to the parabolic section 37 from the 5 arranged so and with facets 38 designed to be out of the light source 12 incoming light 46 also generates a light beam with a vertical opening angle μ1. This bundle is in the 6 not shown for reasons of clarity.

The second parabolic section is also analogous to the parabolic section 37 from the 5 arranged and with facets 38 designed to be out of the light source 12 incoming light 46 also generates a light beam with a vertical opening angle μ1. Also this bundle is in the 6 not shown for reasons of clarity.

The transition area 43 has a first end adjoining the first parabola section 48 and a second end adjoining the second parabola section 50 , At the first end 48 is the transition area 43 preferably tangentially in the first parabola section over. But this is not mandatory. The only important thing is that between the transition area 43 illuminated solid angle area 34 out 2 and that of the parabola sections, respectively zones 42 . 44 illuminated solid angle area 32 out 3 no uncovered gap results. At the second end 50 the transition region preferably merges with a kink in the second parabola section.

Between his first end 48 and his second end 50 the transition area runs 43 preferably straight. In conjunction with the tangential port this has the effect of being at the first end 48 incident on the transition region light of the light source 12 is reflected parallel to the parabola axis, while further from the first end 48 removed to the transition area 43 incident light of the light source 12 is reflected at an angle to the parabola axis with increasing distance of the light impingement point from the first end 48 steadily growing. This results in an outgoing light beam from the transition region, which has an opening angle μ2 in the plane spanned by the parabolic axis and the vertical plane. Since the lowermost beam of this bundle is parallel to the parabolic axis and this in turn is parallel to the roadway when used as intended, the light bundle emanating from the transition region only illuminates an area lying above the horizon in the illustrated embodiment.

7 shows a perspective view of a reflector 40 which is an embodiment of the in connection with the 6 described first parabolic zone 42 , the transition area 43 and the second parabolic zone 44 The two straight lines indicate the emission direction of the parabolic sections which is parallel to the parabola axis, if they do not have any facets widening the bundle and the light source is arranged in the common focal point of the parabolic sections.

The 7 also shows two cuts through light bundles 52 . 54 coming from the transition area 43 as a result of the focal point of the parabolic zones 42 . 43 arranged light source 12 out. The dashed vertical bundle 52 determines the vertical opening angle μ2. The dotted horizontal bundle 54 determines the horizontal opening angle. Between the angular positions of the horizontal bundle shown by way of example 54 and the vertical bundle 52 are any other angular positions. In these different angular positions, the width of the transition area 43 to be different. Due to a different width of the transition area 43 For example, the direction and the width of the bundle reflected in this angular position can be fixed in the design of the reflector.

is. The 8th shows the two bundles 52 . 54 , or their sections. The vertical bundle shown on the left 52 is above an angle of about 5 ° to the direction of the parabola axis, which is parallel to the x-direction. The bundle 52 therefore intersects in the vertical direction with those of the parabolic zones 42 . 44 produced bundles, which cover an opening angle in the vertical direction up to approx. +/- 10 °. The horizontal bundle shown on the right 54 lies laterally at an angle of approximately 20 ° to the parabolic axis (x-direction). This bundle 54 joins the parabolic zones 42 . 44 in the horizontal illuminated angle range of +/- 20 ° to the parabola (x-direction) laterally so that this bundle 54 the illuminated area is extended to the side in. This applies to both the left and the right side of the light distribution, as it is in the 3 and 4 shown

The reflection surface of the transition region 43 may also have molded facets. Such facets are preferably concave or convex. Such facets are particularly preferably partial surfaces of spheres, ellipsoids or cylinders, or they are free-form surfaces.

Without such facets, a bundle cross-section results in each plane containing the axis of the parabolic zones. The bundle cross-sections of different planes can differ in their central main direction x and, if appropriate by shaped facets, in their opening angle.

Instead of a faceted reflector, a smooth, non-faceted parabolic reflector can also be used. The necessary Opening angle can be generated in such a configuration by a arranged in the beam path of the outgoing light from the reflector lens, which in turn carries two different scattering elements. First scattering elements are realized, for example, as concave or convex spherical sections and, by their arrangement, dimensions and number, are arranged to emit incident light from the light source into the first solid angle region 32 to judge. Of course, these scattering element also contribute to the generation of the depth effect. Second scattering elements are also realized, for example, as concave or convex spherical sections and, by their arrangement, dimensions and number, are arranged to emit light from the light source into the second solid angle area from the reflector 34 to judge. Of course, these second scattering elements contribute to the creation of the depth effect.

In a further embodiment, a weakly faceted reflector, which alone does not yet effect the required bundle widening, is combined with a likewise slightly scattering diffusion disk. The reflector and the diffuser are adapted to each other so that the desired scattering angle result by summation of the individual effects.

The 9 shows an arrangement of a light source and an optical element 56 , which here is a light guide with cross-sectional area Q increasing in light transport direction x. Such a light guide is known to have the property that the light rays by reflections on between the light entry surface 58 and the light exit surface 60 lying side surfaces 62 be parallelized. The opening angle of the light propagating between the light entry surface and the light exit surface is reduced by such reflections. Parameters with which the extent of this parallelizing effect in the design of the illumination device can be set are the ratio of the light entry surface of the light guide to the light exit surface of the light source facing the light entry surface, the distance of this light exit surface to said light entry surface, the ratio of the light entry surface of the light guide to his Light exit surface, the opening angle of the side surfaces 62 , The length of the light guide, so the distance between its light entrance surface and its light exit surface. In addition, the radiation characteristic of the light guide can be changed by changing the shape of its lying transversely to the main light propagation direction cross-section Q (rectangular, circular, oval, ...) and / or by a variation of the cross-sectional shape over the length of the light guide. An example of this is a monotone transition between a circular light entry surface and a rectangular light exit surface. The course of the light guide material lying between the light entry surface and the light exit surface also plays a role. For example, it can make a difference if the gradient is straight or curved. An influence also has the shape of the light exit surface, so in particular their surface curvature in the room and their design as having facets or as having no facets surface. By clever choice and variation of these parameters, light distributions of the in the 2 to 4 and in the accompanying description, light distributions may also be realized by using optical elements in the form of such optical fibers instead of concave mirror reflectors.

In a further embodiment, an array of lenses is used as the optical element.

The 10 shows a katadioptrische intent optics 64 as an optical element. In a central area 66 the optical attachment is the change in the opening angle of the bundle 68 due to double refraction. In an outer edge area 70 The optical attachment is the change in the opening angle through an interplay of refraction, total reflection and refraction. The central region is preferred for illuminating the solid angle range 32 and the edge area for illuminating the solid angle area 34 designed. Both areas contribute to the depth effect.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009053571 A1 [0002, 0005]

Claims (18)

Lighting device ( 10 ) for a motor vehicle, with a light source ( 12 ) and an endless mirror arrangement ( 16 ) and a light collecting the light source and directed to the Endlosspiegelanordnung optical element ( 14 ), characterized in that the optical element is a first zone ( 42 ) and a second zone ( 44 ), wherein the first zone directs the light of the light source onto the end mirror assembly in such a way that this light, after having emerged from the end mirror assembly, moves into a first solid angle range (FIG. 32 ), and wherein the second zone directs light from the light source onto the end mirror assembly such that, after exiting the end mirror assembly, this light enters a second solid angle region (FIG. 32 ) falls, wherein the first solid angle range protrudes at a proper use of the lighting device down over the second solid angle range and the second solid angle range extends in the intended use both to the right and to the left over the first solid angle range. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the illumination device ( 10 ) is adapted to a first solid angle range ( 32 ), which is 20 ° wide to the right and left and 10 ° wide to the top and bottom. Lighting device ( 10 ) according to claim 1 or 2, characterized in that the light source is a light-emitting diode. Lighting device ( 10 ) according to one of the preceding claims, characterized in that the endless mirror arrangement comprises a first mirror ( 18 ) and a second mirror ( 20 ), wherein the first mirror ( 18 ) compared to the second mirror ( 20 ) has a higher reflection and lower transmission. Lighting device ( 10 ) according to claim 4, characterized in that the transmission of the first mirror ( 18 ) is equal to zero. Lighting device ( 10 ) according to claim 4 or 5, characterized in that the optical element ( 14 ) a reflector ( 36 . 40 ) which is arranged and configured such that it is separated from the light source ( 12 ) collects outgoing light and focused on the first mirror. Lighting device ( 10 ) according to claim 6, characterized in that the reflector in a cross-sectional plane which is spanned by its Hauptabstrahlrichtung (x) and a vertical direction under normal use of the illumination device in the form of a juxtaposition of a first parabolic section, a transition region and a second parabolic section. Lighting device ( 10 ) according to claim 7, characterized in that the first parabola section has a first focal length f1 and the second parabola section has a second focal length f2, the second focal length f2 being greater than the first focal length f1. Lighting device ( 10 ) according to claim 7 or 8, characterized in that the two parabolic sections are arranged so that their parabolic axes lie on each other and that their foci coincide. Lighting device ( 10 ) according to any one of claims 7 to 9, characterized in that the basic shape of the parabolic sections is an array of convex facets ( 38 ), which preferably adjoin one another along the parabolic sections and which cause an expansion of the light beam reflected by the parabola. Lighting device ( 10 ) according to one of claims 7 to 10, characterized in that the first parabolic section with facets ( 38 ) and arranged so as to be out of the light source 12 incoming light ( 46 ) generates a light beam with vertical opening angle (μ1), and that the second parabolic section with facets ( 38 ) and arranged so that it from the of the light source ( 12 ) incident light ( 46 ) also generates a light beam with a vertical opening angle (μ1). Lighting device ( 10 ) according to one of claims 7 to 11, characterized in that the reflector ( 36 . 40 ) is a half-shell reflector, which as such completely detects the light emanating from the light emitting diode as half space radiator. Lighting device ( 10 ) according to one of claims 7 to 12, characterized in that the reflector ( 40 ) from a first zone ( 42 ), a transitional area ( 43 ) and a second zone ( 44 ). Lighting device ( 10 ) according to claim 13, characterized in that the zones ( 42 . 44 ) Are zones of paraboloid rotors. Lighting device ( 10 ) according to one of claims 13 to 14, characterized in that the transition region ( 43 ) adjoining the first parabolic section first end ( 48 ) and one to the second parabola section subsequent second end ( 50 ), the transition region ( 43 ) at the first end ( 48 ) merges tangentially into the first parabola section and wherein the transitional area at the second end merges with a kink into the second parabola section. Lighting device ( 10 ) according to one of claims 12 to 14, characterized in that the transition region between its first end ( 48 ) and its second end ( 50 ) runs straight. Lighting device ( 10 ) according to any one of claims 13 to 15, characterized in that a width of the transitional region in angular positions different from each other between the angular positions of a horizontal bundle when used as intended ( 54 ) and a vertical bundle ( 52 ) are different from each other. Lighting device ( 10 ) according to one of claims 13 to 17, characterized in that the reflection surface of the transition region ( 43 ) has molded facets.

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