EP3604903A1 - Motor vehicle headlamp with an ellipsoid reflector and collimator - Google Patents

Abstract

A motor vehicle headlight (100) contains an ellipsoid reflector (130), which allows light coupled in from a light source (110) to exit through a reflector light exit opening (132), a collimator (140) and projection optics (160). The collimator (140) is set up to bundle the light beam incident from the ellipsoid reflector (130) and to direct it in the direction of a first image plane (170). The projection optics (160) projects a light image generated by the light beam in the radiation direction of the motor vehicle headlight (100) according to a second image plane (180) of the projection optics (160). Here, the first image plane (170) and the second image plane (180) intersect or overlap. An optical element (150) with at least one optically active edge (151) is arranged in the beam path of the light beam between the collimator (140) and the projection optics (160) such that the first and / or the second image plane (170, 180) passes through the optical element (150) extends in order to hide part of the light beam and guide another part to the projection optics (160).

Description

The invention relates to a motor vehicle headlight.

In the development of the current headlight systems, the desire to be able to project a light image onto the roadway is becoming more and more important, the efficiency in the light generation being essential for the quality and the economy of a motor vehicle headlight. For this purpose, various headlights, for example main and auxiliary headlights, are used that generate different light images on the road. The term "roadway" is used here for a simplified illustration, because it depends of course on the local conditions whether a photograph is actually on the roadway or extends beyond it. In principle, the photograph in the sense used corresponds to a projection onto a vertical surface in accordance with the relevant standards relating to automotive lighting technology.

An example of a motor vehicle headlight of the type considered here is in AT 511760 B1 to the applicant; its optical components are shown in schematic form in Fig. 1 shown. The headlight 10 of a conventional type generates, for example, a light distribution for a partial high beam function. For this purpose, the headlight comprises a light source 11, which is located in a (in Fig. 1 is held and positioned by a circle symbolized) light module 12, a collimator lens 40, an aperture 50 and a projection lens, which here z. B. is designed as a single lens 60. The light coming from the light source 11 is coupled into the collimator optics 40 at a collimator light entry surface 41. The collimator optics, e.g. B. designed as a collimator in the form of a light guide finger, is used to focus the light and let it exit through a collimator light exit surface 42. The collimator 40 is positioned so that the light source 12 is at the collimator entry focal point; the aperture 50 is arranged with respect to the collimator 40 so that it lies in the collimator exit focal length. As a result, a light image is formed in the plane of the aperture 50, and the aperture is set up to hide part of the light image. Downstream of the aperture 50 is a projection lens 60 which is located at a distance from the light image at the location of the aperture 50, this distance being the focal length (more precisely: input focal length) of the projection lens 60 corresponds to. The projection optics 60 are set up to project the light image in the radiation direction of the motor vehicle headlight 10 and thus to produce a light distribution of the desired type on a projection surface (eg street).

In motor vehicle headlights of this type, the light generated by light sources is to be shaped, bundled and projected onto the road as efficiently as possible as a light image. Lenses are often either too expensive or their transmission properties limit them. Undesired chromatic aberration can also occur in certain configurations. Another important problem is the accessibility of the light source to optical components, which is often difficult due to the structure of the light source and its supply components (electrical leads, cooling). In connection with this is the heat development in the light source, in particular if it is a laser light source, whereby other components of the headlight, in particular a light-shaping component such as collimator optics, which must be positioned near the light source due to the required geometry of the optics, are damaged by heating can take.

It is an object of the invention to overcome the disadvantages mentioned.

• eine Lichtquelle, welche dazu eingerichtet ist, Licht zu emittieren, und
• einen Ellipsoid-Reflektor mit einem ersten und einem zweiten Fokalpunkt, wobei der Ellipsoid-Reflektor dazu eingerichtet ist, das von der Lichtquelle über den ersten Fokalpunkt eingekoppelte Licht zu dem zweiten Fokalpunkt zu bündeln und durch eine Reflektor-Lichtaustrittsöffnung austreten zu lassen, und
• einen Kollimator, welcher eine Kollimator-Lichteintrittsfläche und eine Kollimator-Lichtaustrittsfläche aufweist, wobei die Reflektor-Lichtaustrittsöffnung vor der Kollimator-Lichteintrittsfläche in einer Eintritts-Brennweite des Kollimators angeordnet ist, wobei dem Kollimator eine erste Bildebene in einer Austritts-Brennweite des Kollimators zugeordnet ist, und wobei der Kollimator dazu eingerichtet ist, das aus dem Ellipsoid-Reflektor austretende Licht in die Richtung der ersten Bildebene zu einem Lichtstrahlbündel zu bündeln und dort, das heißt in der ersten Bildebene, ein Lichtbild zu formen, und
• eine Projektionsoptik, welcher eine zweite Bildebene in einer Eingangs-Brennweite zugeordnet ist, wobei die erste Bildebene und die zweite Bildebene einander schneiden oder überlappen, wobei die Projektionsoptik dazu eingerichtet ist, ein (durch das Lichtstrahlbündel erzeugtes und vorzugsweise im Bereich der zweiten Bildebene gelegenes) Lichtbild in die Abstrahlrichtung des Kraftfahrzeugscheinwerfers zu projizieren,
• wobei im Strahlengang zwischen dem Kollimator und der Projektionsoptik ein Optikelement mit zumindest einer optisch wirksamen Kante positioniert ist, welches Optikelement dazu eingerichtet ist, das Lichtstrahlbündel mithilfe der zumindest einen optisch wirksamen Kante zu begrenzen, sodass es teilweise zur Projektionsoptik gelangt, und das Optikelement so angeordnet ist, dass die erste und/oder die zweite Bildebene, auf dem Optikelement liegt bzw. durch das Optikelement verläuft.

The object is achieved by a motor vehicle headlight, which comprises:

• a light source which is set up to emit light, and
• an ellipsoid reflector with a first and a second focal point, the ellipsoid reflector being set up to bundle the light coupled in from the light source via the first focal point to the second focal point and to let it exit through a reflector light exit opening, and
• a collimator which has a collimator light entry surface and a collimator light exit surface, the reflector light exit opening being arranged in front of the collimator light entry surface in an entry focal length of the collimator, the collimator being assigned a first image plane in an exit focal length of the collimator , and wherein the collimator is configured to bundle the light emerging from the ellipsoid reflector in the direction of the first image plane to form a light beam and to form a light image there, that is to say in the first image plane, and
• projection optics, to which a second image plane is assigned in an input focal length, the first image plane and the second image plane intersecting or overlapping one another, the projection optics being set up to produce a (generated by the light beam and preferably located in the region of the second image plane) To project the light image in the direction of radiation of the motor vehicle headlight,
• wherein an optical element with at least one optically active edge is positioned in the beam path between the collimator and the projection optics, which optical element is set up to limit the light beam using the at least one optically active edge, so that it partially reaches the projection optics, and the optical element is arranged in this way is that the first and / or the second image plane lies on the optical element or extends through the optical element.

In other words, the optical element is set up to partially reflect or absorb the light beam, and to partially let it pass.

A highly efficient light collection in a motor vehicle headlight can be designed with an ellipsoid reflector, since the reflector surrounds the light source and a very large solid angle is thus available for the focal point or the light collection. This can be advantageously combined in particular with the Lambertian radiation characteristic of a laser light source. In addition, the ellipsoid reflector creates a virtual light source, namely in the second focal point, which virtual light source is more geometrically accessible than the actual light source for the optical system connected to the reflector, in particular the projection optics. As a result, it is possible to use a collimator of significantly smaller size. By using reflective components for the reflector and collimator, chromatic aberration is also avoided. Furthermore, the ellipsoid reflector enables a spatial distance between the light source and the collimator optics to be created, thus alleviating the problem of heat development with the (laser) light source, since better heat dissipation is ensured without impairing the optical components. This additional reflector also increases the contrast of the system.

Rotationally symmetrical ellipsoid reflectors have two conjugate focal points. The light from one focus passes through the other focus after reflection. Due to the ellipsoidal design, it is possible to use a much larger part of the total emitted light, compared to spherical mirrors or conventional lens systems, which among other things leads to a better light output and an increased brightness value at the maximum of the light distribution. In addition, there is a space-saving geometry that is well suited for the small installation space in a headlight.

The motor vehicle headlight according to the invention can be designed for light functions such as, for example, a high beam, a partial high beam, a low beam, but also for additional light functions or the like.

The arrangement according to the invention permits efficient bundling of light beams to form a light beam bundle, the light beam bundle being able to be shaped in a simple manner in accordance with predetermined standards and being projected in the direction of radiation of the motor vehicle headlight. The bundling can be adapted particularly well to specific emission characteristics from specific light sources, such as, for example, semiconductor laser diodes. Thus, for example, a specifically adapted and appropriately shaped reflector device with different dimensions or focal points of the ellipsoid can be used for each type of light source used.

As a result of the arrangement according to the invention, the collimator does not lie directly on the light source, as is customary in the prior art. As a result, the collimator is subjected to less thermal stress and it is thus possible, for example, to use polymethyl methacrylate (PMMA) as the material for the collimator instead of the tarflon (polycarbonate, PC) otherwise customary in the prior art. PMMA is less expensive and absorbs less light because, unlike Tarflon (PC), it can be polished to a high gloss. Furthermore, the arrangement according to the invention makes it possible to use a smaller collimator, as a result of which material can be saved.

The projection system fed from the reflector system contains a collimator, an optical element that effectively acts as a diaphragm and a projection optic, for example in the form of a projection lens, the focal planes of the collimator and the projection lens coinciding with the location of the diaphragm of the optical element. This construction enables the light image generated by the collimator in the focal plane to be trimmed in a suitable manner with the aid of the optical element, ie to shade certain areas, in order to then image the trimmed light image with the projection optics.

Some optional advantageous developments of the invention described above are presented below:
It is advantageous if the at least one edge runs straight and is oriented essentially horizontally when the headlight is installed in a vehicle. This makes it easy to cut the projected light distribution in accordance with the relevant standards.

It is particularly favorable if the motor vehicle headlight, in particular the optical element, has at least two edges, each of which runs straight and is arranged in the beam path of the light beam in such a way that a light-dark boundary can be generated for a low-beam function of the motor vehicle headlight. This makes it easy to trim the projected light distribution in accordance with relevant standards (e.g. SAE, ECE) for a low beam function.

It is advantageous if the light source has at least one semiconductor light source, preferably at least one laser diode. A particularly high efficiency of the motor vehicle headlight can be achieved by combining a laser light source with an ellipsoid reflector.

It is also advantageous if the motor vehicle headlight also has a light conversion means which is arranged in the beam path of the light beam and is set up to additionally excite at least one further light beam with a second wavelength range that deviates from the first when excited by the light beam with a first wavelength range. By combining, for example, a laser light source emitting in the invisible UV range of the light spectrum with an ellipsoid reflector, in combination with a corresponding light conversion means which converts the invisible into a visible light spectrum, a particularly high efficiency and luminous intensity can be achieved of the motor vehicle headlight can be reached.

It is advantageous if the ellipsoid reflector is designed as a reflector shell curved in accordance with an ellipsoid of revolution (strictly speaking, a partial shell thereof).

As a result, the light emitted by the light source can be shaped particularly effectively into a desired light beam.

A particularly inexpensive embodiment results if the collimator is TIR optics.

It is also advantageous if the collimator is formed by a converging lens with a distance contour, the distance contour defining a plane which is located in front of the collimator light entry surface in the collimator entry focal length. This allows a precise alignment between the collimator and, for example, a holder to which the ellipsoid reflector is attached, to be achieved in a simple manner.

In an advantageous development of the invention, the second focal point of the ellipsoid reflector is in the plane of the distance contour, which enables particularly simple attachment with the ellipsoid reflector.

It is also advantageous if the projection optics have at least one converging lens, as a result of which an inexpensive arrangement is created in a simple manner.

In a development of the invention, the optical element is a diaphragm and the diaphragm is set up to reflect or absorb a first part of the light beam on the optical element away from the projection optics and to allow a second part of the light beam to pass the at least one edge to the projection optics. As a result, the light beam can be shaped in a simple manner in accordance with the requirements for the desired, projected light image.

It can also be advantageous if the optical element is arranged in a substantially vertically oriented manner in a vehicle when the headlight is installed.

In an alternative development of the invention, the optical element is designed such that it contains a reflective component or is a reflector at all, and the component / reflector is set up to deflect a first part of the light beam by means of a reflection on a surface of the optical element to the projection optics , and a second part of the light beam on the at least one edge and on the Let projection optics pass by. This allows the light beam to be shaped in a simple manner in accordance with the requirements for the desired, projected light image.

It can additionally be advantageous if the surface of the optical element is arranged in an installed position of the headlight in a vehicle at an angle of inclination with respect to the horizontal, which is essentially in a range from 10 ° to 50 °, preferably from 20 ° to 40 ° and is particularly preferably 30 °.

It can also be advantageous if the first image plane intersects with the second image plane in a straight line in which straight line the at least one edge also lies.

The stated embodiments and developments of the invention can be combined with one another.

It is clear to the person skilled in the art that a headlight contains many other parts, not mentioned, which enable a sensible use in a motor vehicle, such as in particular a car or motorcycle, which are not further elaborated for the sake of clarity.

Fig. 1

eine perspektivische, schematische Ansicht einer Optik eines Kraftfahrzeugscheinwerfers mit Kollimator und Blende, die dem Stand der Technik entspricht;

Fig. 2

eine perspektivische, schematische Ansicht einer ersten Ausführungsform der Erfindung,

Fig. 3

eine perspektivische, schematische Ansicht einer zweiten Ausführungsform der Erfindung,

Fig. 4

eine schematische Seitenansicht der ersten Ausführungsform gemäß Fig. 2,

Fig. 5

eine schematische Seitenansicht der zweiten Ausführungsform gemäß Fig. 3;

Fig. 6

illustriert ein simuliertes Lichtbild eines Laser-Teilfernlichts, das für eine Scheinwerfer-Optik des Scheinwerfers der Fig. 1 (Stand der Technik) erzeugt worden ist;

Fig. 7

illustriert ein simuliertes Lichtbild eines Laser-Teilfernlichts, das für eine Scheinwerfer-Optik des Scheinwerfers der Fig. 2 erzeugt worden ist;

Fig. 8

illustriert ein simuliertes Lichtbild eines Laser-Teilfernlichts, das für eine Scheinwerfer-Optik des Scheinwerfers der Fig. 3 erzeugt worden ist.

The invention and further advantages are described in more detail below with reference to non-limiting exemplary embodiments, which are illustrated in the accompanying drawings. The drawings show in

Fig. 1

a perspective, schematic view of an optics of a motor vehicle headlight with collimator and aperture, which corresponds to the prior art;

Fig. 2

2 shows a perspective, schematic view of a first embodiment of the invention,

Fig. 3

2 shows a perspective, schematic view of a second embodiment of the invention,

Fig. 4

is a schematic side view of the first embodiment Fig. 2 .

Fig. 5

is a schematic side view of the second embodiment Fig. 3 ;

Fig. 6

illustrates a simulated light image of a laser partial high beam, which is used for a headlamp optic of the headlamp Fig. 1 (Prior art) has been generated;

Fig. 7

illustrates a simulated light image of a laser partial high beam, which is used for a headlamp optic of the headlamp Fig. 2 has been created;

Fig. 8

illustrates a simulated light image of a laser partial high beam, which is used for a headlamp optic of the headlamp Fig. 3 has been generated.

With reference to 2 to 8 Embodiments of the invention will now be explained in more detail. In particular, parts which are important for the invention are shown in a headlight, it being clear that a headlight also contains many other parts, not shown, which enable sensible use in a motor vehicle, such as in particular a car or motorcycle. For the sake of clarity, cooling devices for components, control electronics, further optical elements, mechanical adjustment devices or brackets are not shown, for example.

The orientations of components mentioned below relate to an installation position of the headlight in a motor vehicle. Of course, other arrangements with different installation positions are also possible.

Fig. 2 and Fig. 4 show a first exemplary embodiment of a motor vehicle headlight 100, comprising a light source 110 which is set up to emit light. The light source 110 is held in a light module 120 in a defined, optionally adjustable position.

The light distribution that can be generated is particularly suitable for a partial high beam function.

Furthermore, an ellipsoid reflector 130 is shown with a reflector light entry point 131, into which the emitted light is coupled, and a reflector light exit opening 132, the contour of which advantageously lies in a plane which, for example, is oriented essentially vertically in the exemplary embodiment shown. The ellipsoid reflector 130 is set up to deflect the light coupled in from the light source 110 in the direction of the reflector light exit opening 132. At the same time, the light is through the second Focus of the reflector 130 is focused, thereby achieving that it is formed into a light beam. By concentrating the light into a focal point or a small area around the focal point, it is possible to use a collimator (as described below) which is designed for point light sources without the actual light source 110 having to be arranged in the input focal point of the collimator; instead there is a virtual light source in the input focal point, which lies in the second focal point 133 of the reflector 130. Instead of the entire light beam, only the path of a single light beam of the emitted light 111 is shown in the figures. This light beam represents the beam path in the headlight shown.

The reflector light entry point is advantageously chosen so that it essentially coincides with the first focal point (focal point) of the ellipsoid. If the light source cannot be regarded as point-like, e.g. B. if a flat phosphor of a laser light source is used, it is usually favorable to position a brightest point of the flat light source in the focal point.

The light bundled by the second focal point 133 of the ellipsoid reflector 130 exits through the reflector light exit opening 132. The result is a well-defined light beam. The light beam, which leaves the reflector 130 starting from the second focal point 133, has a large divergence, which is why additional optical elements such as. B. a collimator 140 can be used to further focus the light.

A collimator 140 is preferably provided, which has a collimator light entry surface 141 and a collimator light exit surface 142, as well as a collimator entry focal length 145 and a collimator exit focal length 146. A collimator entry focal point is at a distance of the collimator entry focal length 145 from the center of the collimator light entry surface 141, and a collimator exit focal point is at a distance from the collimator exit focal length 146 from (the center point) of the collimator Light exit surface 142.

A first image plane 170 lies in the collimator exit focal length 146. As illustrated in the exemplary embodiment shown, the collimator 140 can also be set up to focus the light beam incident from the ellipsoid reflector 130 and into it To steer direction of the first image plane 170. With the aid of the collimator, a light image is formed there, that is to say in the first image plane 170. For this purpose, it is advantageous if the second focal point of the reflector 130 lies in the collimator entry focal point (entry focal length 145).

A projection lens 160 is located at a distance from the light image that corresponds to the focal length (more precisely: input focal length) 161 of the projection lens 160. The associated focal point of the input focal length 161 thus lies in a second image plane 180, which coincides with the first image plane 170 in this exemplary embodiment. The projection optics 160 are set up to project a light image generated by the light beam bundle and located in the second image plane 180 into the radiation direction of the motor vehicle headlight 100.

In general, the first and second image planes 170, 180 intersect or overlap.

An optical element 150 with two optically active edges 151, 152 is arranged in the beam path of the light beam between the collimator 140 and the projection optics 160. In the first exemplary embodiment, the optical element 150 is an aperture. The aperture 150 is described in more detail below.

The optical element 150 is set up to limit the light beam with the aid of the at least one optically active edge 151, 152, so that it partially reaches the projection optics 160, i.e. partially reflecting or absorbing, and partially omitting, and the optical element 150 is arranged such that the first and second image planes 170, 180 lie on the optical element 150.

The two edges 151 and 152 ( Fig. 2 ) run straight and the edge 151 is oriented essentially horizontally when the motor vehicle headlight is installed in a vehicle, as prescribed by the approval regulations and standards. The edges 151, 152 run at an angle to one another according to the relevant standards (eg SAE or ECE). Depending on the standard, three edges or even more edges may be necessary, for example, in order to produce a desired contour in a projected light image. It can also be useful if the edges are free-formed, that is, they do not run straight.

The motor vehicle headlight can have two edges, which each run straight and are arranged in the beam path of the light beam in such a way that a light-dark boundary can be generated for a low-beam function of the motor vehicle headlight.

The light source 110 has a semiconductor light source, which is preferably a laser diode.

Optionally, the motor vehicle headlight 100 also has a light conversion means (not shown) which is arranged in the beam path of the light beam and is designed to additionally excite at least one further light beam with a second wavelength range which deviates from the first when excited by the light beam having a first wavelength range , This light conversion means can be used to convert a non-visible light area into a visible light area, or also for the pure color change of the light beam, for example by adding red and green spectral components by means of corresponding additional light beam bundles to a blue, originally stimulating light beam bundle of a laser light beam, by additive to produce a white beam of light. This aspect is not shown in the figures.

The light conversion means can, for example, be arranged directly on the emitting surface of a laser light source or on a surface of an optical lens.

The ellipsoid reflector 130 is a reflector in the form of a three-axis curved ellipsoid. However, the shape of the ellipsoid reflector 130 may differ from the ellipsoid at certain points, for example in order to take into account an adaptation of radiation patterns with special light sources, which can lead to an improvement in the light yield.

In the embodiment shown, the collimator 140 is formed by TIR optics (TIR lens). As a result, the luminous efficacy can be increased further, starting from the ellipsoid reflector 130. Of course, other configurations of the collimator are possible in design variants and can be useful depending on the application.

The collimator 140 is, for example, a converging lens with a distance contour 143, the distance contour 143 defining a plane in which the collimator entrance focal point (entrance focal length 141) is located.

The spacing contour 143 is preferably aligned with respect to the reflector light exit opening 132, for example in such a way that its plane coincides with that of the reflector light exit opening 132. This serves z. B. to align the input focal point of the collimator with other parts of the headlamp 100 in a simple manner during assembly of the headlamp 100. Thus, the spacing contour 143 can rest on a holder which, for example, carries the ellipsoid reflector 130, as a result of which the two optics 130 and 140 are adjusted relative to one another.

The distance contour 143 is preferably arranged annularly and concentrically to the optical axis of the collimator. Other shapes of the spacer contour 143 that are adapted to specific holders are also possible, such as, for example, a three-point support, through which an imaginary spacer contour extends, which defines a plane through which the reflector light exit opening 132 also runs in the assembled state.

In this example, the projection optics 160 is realized by a converging lens, but can also comprise light-guiding elements, for example.

In this first exemplary embodiment, the optical element 150 is a diaphragm, and is designed to reflect or absorb a first part of the light beam on the optical element 150 away from the projection optics 160, and to allow a second part of the light beam to pass the edges 151, 152 to the projection optics 160.

The aperture 150 can be designed to be reflective or absorbent. For example, an absorbent coating can be applied to the surface of the screen. In order to avoid unwanted reflections from single or multiple reflections in the headlight 100 in the direction of the projection optics 160, further surfaces within the headlight housing of the motor vehicle headlight 100 can also be designed to be absorbent. It can also be expedient to design the diaphragm 150 to be reflective, for example through a mirrored surface of the diaphragm 150 be directed in order to specifically suppress undesired by single or multiple reflections in the headlight 100 in the direction of the projection optics 160; however, light components can also be redirected so that they contribute to the light image in the illuminated areas, which results in an increase in efficiency.

The optical element 150 in the form of the diaphragm is arranged essentially vertically oriented in the vehicle when the headlight is installed.

In this disclosure, “essentially vertically oriented” means an angular position (of the respective plane or aperture 150) which can deviate from the vertical by up to ± 10 °, preferably up to ± 5 °. The exact angular position is particularly relevant when implementing light functions in which the edges 151, 152 need to be imaged sharply, for example in the case of a low-beam light function with a light-dark boundary. For other light functions, an angular position can be selected, which can deviate from the vertical by up to ± 25 °.

The optical element 150 can also comprise a plurality of diaphragms, which are rotatably arranged in the form of an diaphragm shaft, only one diaphragm of the diaphragm shaft being optically active or effective in the beam path of the light beam. The diaphragm shaft can implement a plurality of light functions, for example a low beam or a high beam light function of the headlight 100.

A rotatable diaphragm shaft preferably has an axis of rotation which lies in the first or second image plane 170, 180.

In Fig. 4 As an example, a light beam 111 is shown, which is emitted by the light source 110. Of course, the light source 110 emits further unbundled light beams, for example diffuse light, in an emission pattern specific to the light source. The light beam 111 is coupled into the ellipsoid reflector 130 at the reflector light entry point 131 (in the first focal point) and is reflected on the reflecting surface, passing through the second focal point of the ellipsoid reflector 130 and coupling out again at the reflector light exit opening 132 becomes. The reflector light entry point 131 corresponds to the first focal point into which the point light source 110 (or a location of the light source with the highest intensity as already mentioned) is positioned. The ellipsoid reflector 130 first bundles the individual light beams of the emitted light into a light beam bundle.

The collimator 140 bundles the light beam further and focuses it in the first, virtual image plane 170, in which the diaphragm 150 is also located.

The light beam is projected by the projection optics 160 from its focal plane, which forms the second, imaginary image plane 180, in the direction of radiation of the headlight 100. By arranging the diaphragm 150 and the two edges 151, 152 in the focal plane of the projection optics 160, the contour, which is formed by the two edges 151, 152, is sharply imaged.

Fig. 3 and Fig. 5 show a second exemplary embodiment of a motor vehicle headlight 200 according to the invention, the difference from the first exemplary embodiment primarily being that the optical element 250 contains a component designed as a reflector. For the second embodiment of the Fig. 3 and 5 apply the explanations of the embodiment of the Fig. 2 and 4 Unless otherwise stated in the following, in the same way, corresponding numbers with a leading number 2 (instead of a 1 for the reference numbers of the first exemplary embodiment) are used for reference numbers.

The reflector 250 has two edges 251 and 252 ( Fig. 3 ) and is set up to deflect the first part of the light beam by means of a reflection on a surface of the optical element 250 to the projection optics 260, and to allow a second part of the light beam to pass the two edges 251, 252 and the projection optics 160. In other words, the reflector 250 can influence the light beam in such a way that it is (only) partially guided to the projection optics 260.

The reflector 250 can be embodied, for example, by a mirrored surface of the reflector 250. Those locations in the headlight 200 to which the light rays of the light beam bundle passed by the reflector 250 can advantageously be designed to be absorbent, for example in the form of a separate absorber component 255, in order to target undesired ones by single or multiple reflections in the headlight 200 in the direction of the projection optics 260 to suppress. Likewise, on the im An additional aperture (not shown) can be arranged on the inner surface of the projection optics 260 on the headlight 200, in order, for example, to suppress unwanted reflections in the direction of the projection axis. Alternatively, for example, a further mirror component could be arranged in place of the absorber component 255 in order to deflect the light beams to a location within the headlight at which absorption takes place.

In addition, the surface of the optical element 250 in the form of the reflector is arranged at an inclination angle 253 with respect to the horizontal, which is essentially in a range from 10 ° to 50 °, preferably from 20 ° to 40 ° and particularly preferably at 30 °.

The first image plane 270 intersects with the second image plane 280 in a straight line in which the edge 251 also lies.

The arrangement of the light source 210, the light module 220, the ellipsoid reflector 230 (including the associated reflector light entry point 231 and reflector light exit opening 232 and the second focal point 233) and the collimator 240 in the second exemplary embodiment corresponds to that of the first exemplary embodiment, but these are Components slightly inclined compared to the first exemplary embodiment with respect to the projection optics 260 in order to enable the reflection of the light beam by the projection optics 260 in an installation position which is favorable for a motor vehicle headlight 200.

The explanations regarding the beam path of the light beam 211 on the one hand from the light source 110 through the reflector 230 to the collimator 240 and on the other hand from the projection optics 260 to the outside of the headlamp 200, also with regard to the focal lengths 245, 246, 261 of the collimator and projection optics, correspond to those the Fig. 4 ,

Since the reflector 250 lies only in one straight line in the focal plane of the projection optics 260, namely in the intersection line of the first and second image planes 270, 280, it can be advantageous if the edge 251 is located in the straight line, thereby reducing the contour caused by edge 251 is formed, is sharply imaged.

The other locations of the reflector 250, like the edge 252, cannot then be imaged sharply, which is why this second embodiment of the invention cannot be used for all of the light functions mentioned.

An arrangement according to the invention according to the second embodiment serves to increase the light yield for other light functions.

The reflector 250 can be arranged such that it can rotate, for example in order to implement headlight range control for the motor vehicle headlight 200. The angle of inclination 253 can be controlled or regulated electronically, for example, manually or by a vehicle system. The angle of inclination 253 is preferably rotatable about the straight line which lies in the intersection line of the first and second image planes 270, 280.

The particular benefit of the invention can also be seen from the 6 to 8 are illustrated, each of which shows an exemplary light image according to a simulation of a light distribution for a partial high beam. The simulation was computer-aided by the applicant for each of the in the Fig. 6-8 headlight optics shown performed in order to obtain a simulated light image of the respective headlight as a result. Each light image describes the solid angle-related light distribution generated by the respective headlight from the driver's point of view, the right and vertical axes being labeled in degrees according to the deflection from the center of the image. The scale on the right edge of each photograph illustrates the grayscale used in the intensity distribution, given in cd [Candela].
For the sake of clarity, isolines of the brightness are drawn in each case, with some isolines additionally giving the assigned brightness value in cd.

Fig. 6 shows a light image that for a headlight assembly according to the Fig. 1 was generated, which corresponds to the prior art, that is, with a collimator arranged immediately after the light source.

Fig. 7 shows a photograph that for the headlamp according to the invention Fig. 2 and 4 , with the inventive ellipsoid reflector and collimator with a vertical diaphragm.

Fig. 8 shows a photograph that for the headlamp according to the invention Fig. 3 and 5 , with an ellipsoidal reflector according to the invention and with a diaphragm component acting as a reflector.

Using a comparison between the light distribution of the Fig. 7 or 8 with that of Fig. 6 it can be seen that the system according to the invention with an ellipsoid reflector has a light distribution ( Fig. 7 or 8) which produces a brightness maximum with a value which is approximately twice as high as that according to the prior art ( Fig. 6 ) and which is also much better concentrated around the maximum.

LIST OF REFERENCE NUMBERS

10, 100, 200

Motor vehicle headlamps

11, 110, 210

light source

111, 211

beam of light

12, 120, 220

Light module, light source holder

130, 230

Ellipsoidal reflector

131, 231

Reflector light entry point (first focal point)

132, 232

Reflector light exit opening

133, 233

second focal point

40, 140, 240

collimator

41, 141, 241

Light entry surface

42, 142, 242

Light-emitting surface

143, 243

distance contour

50, 150

Optical element, aperture

151, 152, 251, 252

edge

250

Optical element, reflector

253

tilt angle

255

absorber

60, 160, 260

projection optics

145, 245

Entry focal length of the collimator

146, 246

Collimator exit focal length

161, 261

Input focal length of the projection optics

170, 180, 270, 280

image plane

Claims (15)

Motor vehicle headlights (100, 200), comprising
a light source (110, 210), which is configured to emit light, and
an ellipsoidal reflector (130, 230) with a first and a second focal point, the ellipsoidal reflector (130, 230) being set up to couple the one coupled in from the light source (110, 210) via the first focal point (131, 231) Bundle light to the second focal point and let it exit through a reflector light exit opening (132, 232), and
a collimator (140, 240) which has a collimator light entry surface (141, 241) and a collimator light exit surface (142, 242), the reflector light exit opening (132, 232) in front of the collimator light entry surface (141, 241) is arranged in an entry focal length (145, 245) of the collimator, the collimator being assigned a first image plane (170, 270) in an exit focal length (146, 246) of the collimator, and the collimator (140, 240) is set up to bundle the light emerging from the ellipsoid reflector (130, 230) in the direction of the first image plane (170, 270) to form a light beam and to form a light image there, and
projection optics (160, 260) to which a second image plane (180, 280) is assigned in an input focal length (161, 261), the first image plane (170, 270) and the second image plane (180, 280) intersecting or overlap, the projection optics (160, 260) being set up to project the light image in the radiation direction of the motor vehicle headlight (100, 200),
wherein an optical element (150, 250) with at least one optically active edge (151, 152, 251, 252) is positioned in the beam path of the light beam between the collimator (140, 240) and the projection optics (160, 260), which optical element (150 , 250) is set up to limit the light beam with the aid of the at least one optically effective edge, so that it partially reaches the projection optics (160, 260) and the optics element (150, 250) is arranged such that the first and / or the second image plane (170, 270, 180, 280) runs through the optical element (150, 250). Motor vehicle headlight (100, 200) according to claim 1, wherein the at least one edge (151, 251) runs straight and is oriented essentially horizontally. Motor vehicle headlight (100, 200) according to claim 1 or 2, wherein the motor vehicle headlight (100, 200) or optical element (150, 250) comprises at least two edges, which each run straight and are arranged in the beam path of the light beam so that a bright Dark limit for a low beam function of the motor vehicle headlight (100, 200) can be generated. Motor vehicle headlight (100, 200) according to one of claims 1 to 3, wherein the light source (110, 210) has at least one semiconductor light source, preferably at least one laser diode. Motor vehicle headlight (100, 200) according to any one of claims 1 to 4, wherein the motor vehicle headlight (100, 200) further comprises a light conversion means, which is arranged in the beam path of the light beam and is set up, when excited by the light beam with a first wavelength range additionally at least to excite a further light beam with a second wavelength range deviating from the first. Motor vehicle headlight (100, 200) according to one of claims 1 to 5, wherein the ellipsoid reflector (130, 230) is designed as a curved reflector shell according to an ellipsoid of revolution. Motor vehicle headlight (100, 200) according to one of claims 1 to 6, wherein the collimator (140, 240) is a TIR optic. Motor vehicle headlight (100, 200) according to any one of claims 1 to 7, wherein the collimator (140, 240) is formed by a converging lens with a distance contour (143, 243), the distance contour (143, 243) defining a plane which is defined located in the collimator entrance focal length (141, 241) in front of the collimator light entrance surface. Motor vehicle headlight (100, 200) according to claim 8, wherein the second focal point of the ellipsoid reflector lies in the plane of the distance contour (143, 243). Motor vehicle headlight (100, 200) according to one of claims 1 to 9, wherein the projection optics (160, 260) has at least one converging lens. Motor vehicle headlight (100) according to one of claims 1 to 10, wherein the optical element (150) is a diaphragm and is configured to reflect or absorb a first part of the light beam on the optical element (150) away from the projection optics (160), and allow a second part of the light beam to pass the at least one edge (151, 152) to the projection optics (160). Motor vehicle headlight (100) according to claim 11, wherein the optical element (150) is arranged substantially vertically oriented. Motor vehicle headlight (200) according to one of claims 1 to 10, wherein the optical element (250) has a reflective component and is set up to deflect the first part of the light beam by means of a reflection on a surface of the optical element (250) to the projection optics (260), and to let a second part of the light beam pass the at least one edge (251, 252) and the projection optics (160). Motor vehicle headlight (200) according to claim 13, wherein the surface of the optical element (250) is arranged at an angle of inclination (253) with respect to the horizontal, which is essentially in a range from 10 ° to 50 °, preferably from 20 ° to 40 ° and is particularly preferably 30 °. Motor vehicle headlight (200) according to claim 13 or 14, wherein the first image plane (270) intersects with the second image plane (280) in a straight line in which the at least one edge (251) also lies.

Images