EP3657066B1 - Illumination unit for a motor vehicle headlight for generating a light distribution with a cut-off line - Google Patents

Description

• zumindest eine Lichtquelle,
• zumindest einen ersten Reflektor mit mindestens einem Brennpunkt, wobei die zumindest eine Lichtquelle in dem zumindest einen Brennpunkt angeordnet ist, sowie
• der zumindest eine erste Reflektor zur Abstrahlung und Weiterleitung von Licht an einen zweiten Reflektor eingerichtet ist,
• zumindest einen zweiten Reflektor mit mindestens einem Brennpunkt, wobei der zumindest eine zweite Reflektor im Strahlengang dem zumindest einen ersten Reflektor nachgeordnet und dazu konfiguriert ist, ein vom ersten Reflektor erzeugtes Zwischenlichtbild abzubilden, sowie
• zumindest eine Blende, die im Strahlengang zwischen dem zumindest einen ersten Reflektor und dem zumindest zweiten Reflektor angeordnet ist,
  umfasst.

Weiters wird im Rahmen der Erfindung ein Kraftfahrzeugscheinwerfer mit zumindest einer erfindungsgemäßen Beleuchtungseinheit angegeben.Out JP 2000 348508 A a motor vehicle headlight is known which has a first elliptical reflector and a second parabolic reflector. A screen is arranged between the two reflectors. The invention relates to a lighting unit for a motor vehicle headlight for generating a light distribution with a cut-off line, the lighting unit

• at least one light source,
• at least one first reflector with at least one focal point, wherein the at least one light source is arranged in the at least one focal point, and
• the at least one first reflector is set up to emit and forward light to a second reflector,
• at least one second reflector with at least one focal point, wherein the at least one second reflector is arranged downstream of the at least one first reflector in the beam path and is configured to image an intermediate light image generated by the first reflector, and
• at least one diaphragm which is arranged in the beam path between the at least one first reflector and the at least second reflector,
  includes.

Furthermore, a motor vehicle headlight with at least one lighting unit according to the invention is specified within the scope of the invention.

Numerous embodiments of lighting units for a motor vehicle headlight for generating a light distribution with a cut-off line are already known from the prior art. The creation of a defined cut-off line in the photo of a motor vehicle headlight is either required by law - for example, a low beam with a horizontal cut-off line is mentioned - or such a cut-off line is used by vehicle manufacturers as a defined additional light function of the corresponding Motor vehicle headlights desired. For example, the light functions of glare-free high beam or adaptive driving light, which can usually be ordered as special equipment when buying a new car, should be mentioned. Here, light-dark boundaries are required in a vertical, horizontal or combined form. Technically, light-dark boundaries in lighting units for motor vehicle headlights are implemented either by direct mapping of sufficiently large gradients of the illuminance of the light source or - if the light source used is used does not have such gradients - artificially generated by introducing appropriate diaphragms into the beam path of the lighting unit. The correspondingly produced intermediate light images then have areas which are cropped or darkened by one or more diaphragms and which are imaged with the aid of lenses or reflectors as a light distribution in front of the road in front of the motor vehicle headlight. The disadvantage of using such screens to create cut-off lines, however, always leads to undesirable losses in the luminous flux of the lighting unit or the motor vehicle headlight and thus to an overall reduced efficiency of the lighting system, the efficiency being the quotient of the luminous flux used to the luminous flux exiting each specified in lumen [lm]) is determined.

This problem arises in particular in the case of lighting units that are intended to generate a wide light distribution perpendicular to the cut-off line. This is the case, for example, when a wide horizontal light image with a vertical cut-off line is to be generated. Obviously, this is also true for lighting units with which a light pattern that is high in the vertical direction and with a horizontal light-dark boundary is to be generated.

For those cases in which the design of the light source does not allow the creation of a vertical cut-off line through direct imaging of the light source, for example, since the requirements for the width of the light distribution or the quality of the cut-off line cannot be met, a corresponding cut-off line can be created by introducing a diaphragm into the beam path. Since the desired light patterns are often restricted to small angular ranges or high illuminance levels are required, if the emitter has wide radiation cones - as can be the case, for example, when using LED light sources or laser light sources - focusing in the area of the beam diaphragm must take place. Such an optical arrangement therefore in any case requires a light source as an emitter, a first reflector that concentrates the light from the light source or the emitter on a focal point, a diaphragm that shades part of the light, and a second reflector that covers the Focal plane of the focal point generated intermediate light image.

In the event that the first reflector has only one focal point, the entire intermediate light image in the focal plane is formed by the diaphragm or trimmed by the diaphragm. Since the desired light image generated by the motor vehicle headlight usually not only has a light-dark boundary, but also has to meet defined requirements, for example with regard to its light image width in the front of the road, it is usually not sufficient to depict the intermediate image directly in the case of homogeneously radiating light sources or emitters it has to go through a second reflector be widened accordingly. In order to avoid an undesirable softening of the light-dark boundary, i.e. a reduction in the gradient of the light-dark transition, the second reflector can be subdivided into several facets or designed with facets, each of the facets being the part of the Slightly shifts the intermediate image in the horizontal direction. The sum of the individual facet images then results in the entire light image of the motor vehicle headlight. The disadvantage of such an arrangement, however, is that the diaphragm for generating the light-dark border is effective in each individual one of the facet images, and not only in an outer or in the outermost of the facet images, where the use of the diaphragm for generating the light- Dark border is actually needed. This disadvantageously reduces the luminous flux of the motor vehicle headlight, which also reduces its overall efficiency.

The present invention therefore has the object of avoiding the disadvantages known from the prior art for lighting units of the type mentioned, reducing the losses in the luminous flux of the lighting unit caused by the diaphragm and increasing the efficiency of the lighting unit.

According to the invention, this object is achieved in a generic lighting unit according to the preamble of claim 1 with the features of the characterizing part of claim 1. Particularly preferred embodiments and developments of the invention are the subject of the subclaims.

• der erste Reflektor zumindest zweiteilig aufgebaut und weist einen ersten Reflektorabschnitt sowie zumindest einen separaten zweiten Reflektorabschnitt auf, wobei jeder Reflektorabschnitt jeweils mindestens einen Brennpunkt besitzt, sowie
• mindestens ein Brennpunkt des ersten und des zumindest zweiten Reflektorabschnitts jeweils deckungsgleich am Ort der zumindest einen Lichtquelle angeordnet sind, wobei
• der zumindest zweiteilige erste Reflektor das aus der zumindest einen Lichtquelle austretende Strahlenbündel zumindest in zwei separate Strahlenbündel aufspaltet, sowie
• die zumindest eine Blende so angeordnet ist, dass diese dem ersten Reflektorabschnitt des ersten Reflektors zugeordnet und in einem geringen Abstand nahe des vom ersten Reflektorabschnitt ausgehenden Strahlenbündels angeordnet ist und das im ersten Reflektorabschnitt erzeugte Zwischenlichtbild unter Bildung einer Hell-Dunkel-Grenze beschneidet, und
• die zumindest eine Blende in einem größeren Abstand fern des vom zumindest zweiten Reflektorabschnitt ausgehenden Strahlenbündels beabstandet angeordnet ist und das zumindest im zweiten Reflektorabschnitt erzeugte Zwischenlichtbild im Wesentlichen frei von Einfluss durch Abschattung der Blendenanordnung ist.

In a generic lighting unit for a motor vehicle headlight for generating a light distribution with a cut-off line

• the first reflector is constructed in at least two parts and has a first reflector section and at least one separate second reflector section, each reflector section having at least one focal point, and
• at least one focal point of the first and the at least second reflector section are each arranged congruently at the location of the at least one light source, wherein
• the at least two-part first reflector splits the bundle of rays emerging from the at least one light source into at least two separate bundles of rays, and
• the at least one diaphragm is arranged so that it is assigned to the first reflector section of the first reflector and is arranged at a small distance near the beam emanating from the first reflector section and cuts the intermediate light image generated in the first reflector section to form a cut-off line, and
• the at least one diaphragm is arranged at a greater distance away from the beam of rays emanating from the at least second reflector section and the intermediate light image generated at least in the second reflector section is essentially free of the influence of shadowing of the diaphragm arrangement.

By dividing the first reflector into at least two reflector sections, each with at least one focal point of their own, the emerging beam is split into at least two separate beam. By suitably arranging the at least one diaphragm in the beam path, it is possible to assign the diaphragm to a specific, first reflector section of the first reflector, in which the generation of a partially cropped or partially shaded intermediate light image with the formation of a light-dark boundary is required and desired. This is achieved by a corresponding arrangement of the diaphragm at a small distance near the first beam emanating from this first reflector section.

From the at least second reflector section and the second bundle of rays emanating from it, however, said at least one diaphragm is spaced at a comparatively significantly greater distance than the small distance set between said diaphragm and the first bundle of rays of the first reflector section. It is thus possible to crop only the intermediate light image generated in the first reflector section with the diaphragm to form a light-dark boundary, but not the intermediate light image generated in at least the second reflector section, for which due to the comparatively larger distance between the outgoing second beam and the diaphragm whose diaphragm edge is not suitable for forming a light-dark boundary. The intermediate image generated at least in the second reflector section thus remains essentially free from the influence of shadowing of the diaphragm arrangement.

The invention also includes embodiments of a lighting unit in which the first reflector is subdivided into three or more reflector sections, for example, as well as embodiments in which one or more diaphragms are assigned to individual reflector sections. In these cases too, the losses in the luminous flux of the lighting unit caused by the diaphragm are advantageously minimized and the overall efficiency of the lighting unit is increased if at least one of the three or more reflector sections is essentially free of the influence of shading of the diaphragm arrangement.

The at least two or more separate reflector sections of the first reflector can, for example, be designed in one piece, with a transition area being formed, for example in the form of a curve or a line, between adjoining reflector sections. As an alternative to this, individual or all of the reflector sections of the first reflector can also consist of one or more individual ones Components exist and the first reflector can thus be made in several pieces from several assembled components.

According to the definition, an intermediate light image generated in the diaphragm plane is then categorized as "essentially free of influence due to shading of the diaphragm arrangement" if the luminous flux of the intermediate light image in question is not or only slightly reduced by introducing the diaphragm into the beam path and thus with such a diaphragm arrangement no functional cut-off line is achieved.

The ordinal numerals used here and below to uniquely denote a first, second or third reflector section of the first reflector or a first, second or third reflector segment of the second reflector are only intended to improve understanding and simplify readability. Due to the selected ordinal numbers, the relevant individual reflector sections or reflector segments are, however, neither ranked in the sense of a rating, nor are their location, position or alignment to one another fixed.

For example, in a lighting unit with four reflector sections into which the first reflector is divided, a first screen can be assigned to the first reflector section and a second screen can be assigned to the third reflector section of the first reflector and the said screens are each a short distance away from the first reflector section or be arranged from the third reflector section emanating beam, the intermediate light images generated in the first and in the third reflector section are each cropped to form corresponding light-dark boundaries. In this example, the second and fourth reflector sections are each free from the influence of shading by the diaphragm arrangements. Depending on the requirements of the motor vehicle headlamp, the multiple reflector sections can be positioned here with regard to their installation positions, for example in a row, essentially in the horizontal direction next to one another, in columns, essentially in a vertical direction, one below the other, or in any desired matrix arrangement.

In a lighting unit according to the invention, the first reflector can particularly advantageously be constructed in several parts and have several reflector sections with at least one focal point, and the at least one light source can each be arranged in the at least one focal point, the at least one diaphragm being arranged so that it exclusively assigned to the first reflector section of the first reflector and arranged at a small distance near the beam emanating from the first reflector section and the intermediate light image generated in the first reflector section is cropped to form a light-dark boundary, and the at least one aperture at a greater distance away from the second and if necessary, the further reflector sections of the first reflector outgoing ray bundles spaced apart is arranged and the intermediate light images generated in the second and optionally the further reflector sections are essentially free of the influence of shading of the diaphragm arrangement.

Thus, according to the invention, by suitable arrangement of the at least one diaphragm, the diaphragm-related losses in the luminous flux of the lighting unit can be further minimized and the efficiency of the lighting unit can advantageously be increased further.

These advantages also apply, for example, to the embodiment in which a plurality of diaphragms are arranged in the beam path between the first and the second reflector. In this case, too, by appropriately assigning the multiple diaphragms exclusively to the first reflector section and away from the at least second reflector section and optionally the further reflector sections, these can be positioned so that the intermediate image generated at least in the second reflector section and, if applicable, those generated in one or more further reflector sections Intermediate light images are in each case essentially free from the influence of shadowing of the diaphragm arrangement.

In a lighting unit according to the invention, the second reflector can particularly expediently be divided into two or more reflector segments in the manner of facets, a first reflector segment of the second reflector being assigned to the intermediate light image generated in the first reflector section of the first reflector.

In this embodiment, the transitions between the reflector sections of the first reflector fall on transitions between the reflector segments of the second reflector or the transitions between the reflector sections and the reflector segments are also assigned to one another. The proportion of undesired scattered light can therefore advantageously be reduced.

In a further preferred embodiment of the invention, the second reflector in a lighting unit can be divided into two or more reflector segments in a facet-like manner, the first reflector segment of the second reflector being assigned to the intermediate light image generated in the first reflector section of the first reflector.

In this embodiment, only the facet image of the first reflector segment of the second reflector is advantageously trimmed, the remaining reflector segments each provide a complete image of the light source used. The division of the first reflector is matched to the faceting of the second reflector in such a way that the light focused on the first reflector section only hits the first reflector segment. This embodiment also offers the advantage that the proportion of undesired scattered light can be reduced.

In one embodiment variant of the invention, a lighting unit can advantageously be constructed in such a way that the at least one screen is fastened directly on or at least close to the first reflector section of the first reflector.

Attaching the diaphragm to the first reflector in this way can contribute to a higher mechanical stability of the diaphragm, the positioning accuracy of the at least one diaphragm to one or more focal points also being increased and the tolerance chain of the positioning inaccuracy of the at least one diaphragm being reduced. This compact design can advantageously reduce the tolerances of the at least one diaphragm. The term “tolerance chain” used here is understood in the sense of tolerances with regard to the fluctuations, the positioning and the stability of the diaphragm.

According to an alternative embodiment, it can also be advantageous if, in the case of a lighting unit according to the invention, the at least one screen is attached directly to or at least close to the first reflector segment of the second reflector.

This compact design, according to which the diaphragm is connected to the second reflector or is at least fastened close to the first reflector segment of the second reflector, can advantageously reduce the tolerances of the diaphragm.

In a particularly preferred embodiment of the invention, in a lighting unit, a diaphragm plane of the at least one diaphragm can correspond to a focal plane of the at least one focal point of the first reflector segment of the second reflector.

If the diaphragm plane and the focal plane coincide, a sharp light-dark boundary advantageously results with a large gradient of the light-dark transition not only near the focal point or focal point, but also at a certain distance from it.

Within the scope of the invention it is also conceivable to arrange the at least one diaphragm in such a way that a diaphragm plane of the at least one diaphragm and a focal plane of the at least one focal point of the first reflector segment of the second reflector only intersect in a line through this focal point or focal point. In such an embodiment, a sharp cut-off line can deliberately only be achieved in the vicinity of the focal point or focal point, with a diaphragm edge far from the focal point being shown blurred - i.e. with a smaller gradient of the light-dark transition. Such designs with only partially or partially sharp light-dark lines can also be favorable and desirable for applications in the automotive industry.

In an advantageous development of the invention, in a lighting unit, at least the first reflector section of the first reflector can be an ellipsoid reflector, which ellipsoid reflector has a second focal point, wherein the at least one diaphragm is arranged so that it is at a small distance from the second focal point of the first reflector portion is spaced.

In this embodiment, point-like light sources can advantageously be mapped as points. Furthermore, the design of a reflector, the surface of which is an ellipsoid of revolution, also offers advantages in terms of manufacturing technology. From a photometric point of view, the use of such an ellipsoid reflector can possibly avoid undesirable distortions in the imaging of the light source in the focal plane.

In a lighting unit according to the invention, the two or more reflector sections of the first reflector can expediently each be ellipsoidal reflectors, the ellipsoidal reflectors each having a second focal point and the at least one diaphragm being arranged so that it is at a small distance near the The second focal point of the first reflector section is arranged and the diaphragm is arranged at a greater distance away from the second focal points of all further reflector sections of the first reflector.

In a lighting unit according to the invention, the small distance from the beam and / or from the second focal point of the first reflector section of the first reflector to a diaphragm edge of the diaphragm can be defined as close to the diaphragm if the distance is less than 1.7 times the value of a Reference length, preferably less than 1.5 times the value of a reference length, particularly preferably less than 1.3 times the value of a reference length, and the intermediate light image generated in the first reflector section is cropped to form a light-dark boundary, wherein the reference length is selected as the smallest distance from the distances between the maximum illuminance of all reflector sections of the first reflector and the diaphragm edge of the diaphragm.

• Für alle Reflektorabschnitte R₁₁, R₁₂, R_1N des ersten Reflektors wird jeweils der Abstand des Maximums der Beleuchtungsstärke E_MAX zur Blendenkante der Blende gemessen;
• der kleinste dieser gemessenen Abstände wird als Referenzlänge L ausgewählt.

The reference length L, which can be used to assess or categorize the distance between the beam and the diaphragm and / or, in the case of an ellipsoidal reflector, between the second focal point of the first reflector section of the first reflector and the diaphragm, is useful as follows certainly:

• For all reflector sections R ₁₁ , R ₁₂ , R _{1N of} the first reflector, the distance between the maximum of the illuminance E _MAX and the diaphragm edge of the diaphragm is measured;
• the smallest of these measured distances is selected as the reference length L.

The distance of that bundle of rays from the diaphragm, which bundle of rays emanates from the first reflector section of the first reflector, for which the diaphragm is effective, is thus defined as close to the diaphragm or near the diaphragm edge if the distance is less than 1.7- times the value, preferably smaller than 1.5 times the value, particularly preferably smaller than 1.3 times the value, the previously defined reference length, provided that the intermediate light image generated in the first reflector section also forms a light-dark -Border is trimmed.

The maximum of the illuminance E _MAX can be measured, for example, by a luminance camera, which records an image of the intermediate light image in the diaphragm plane, which is made visible, for example, by introducing a matt plane into the diaphragm plane. A further possibility for measuring the maximum of the illuminance E _MAX offers the introduction of a mirror or further optics in the beam path or in the diaphragm plane in order to measure the intermediate light image with a luminance camera or some other sensor system.

If the lighting unit is designed with an ellipsoidal reflector as the first reflector, the distance from the second focal point of the first reflector section of the first reflector to the diaphragm or to the diaphragm edge is expediently used for the same categorization. Thus, a calculation scheme is advantageously specified to determine which conditions a diaphragm arrangement must meet in order to be selectively assigned to a first reflector section of the first reflector and to be suitable for the formation of a cut-off line of the corresponding intermediate light image.

If the conditions set out above are not met, the distance between a bundle of rays and / or a second focal point of the corresponding reflector section of the first reflector away from the diaphragm or from its diaphragm edge is defined and the diaphragm arrangement is essentially free of shading influences on that generated in this reflector section Intermediate photo.

It can also be advantageous if, in a lighting unit according to the invention, the greater distance from the beam and / or from the second focal point of the second reflector section and possibly the further reflector sections of the first reflector to a diaphragm edge of the diaphragm is defined as being far from the diaphragm if by Introducing the diaphragm into the beam path, the luminous flux of the intermediate light image generated in the second and optionally the further reflector sections is reduced by at most 10%, preferably by at most 7%, particularly preferably by at most 5%.

According to the definition, an intermediate light image is essentially free of the influence of shading of the diaphragm arrangement if the shape of the intermediate light image generated does not change or changes only insignificantly as soon as the corresponding diaphragm is completely removed from the beam path. This is the case when the luminous flux reduction caused by the diaphragm fulfills the values given above of at most 10%, preferably by at most 7%, particularly preferably by at most 5%. Minor interferences, according to which, under certain circumstances, for example, small edge areas of the intermediate light image generated can be shaded, but without being perceived as a functional cut-off line, thus by definition do not represent any significant shadowing or impairment of the corresponding intermediate light image.

In an advantageous development of the invention, the at least one diaphragm in a lighting unit can have a first diaphragm edge for generating a first light-dark boundary and a second diaphragm edge for generating a second light-dark boundary and / or in the beam path between the at least one first The reflector and the at least second reflector can be arranged to be adjustable.

For example, it is conceivable within the scope of the invention to implement a lighting unit in which the at least one panel is designed essentially L-shaped, with each of the two legs of this L-shaped panel acting as a panel edge, with each of which has its own light Dark border can be generated, for example a horizontal and a vertical light-dark border. If the first reflector is divided into three, it would also be possible in such a case to assign the first diaphragm edge of the diaphragm to a first reflector section of the first reflector and the second diaphragm edge of the diaphragm to a further second reflector section of the first reflector by means of a suitable diaphragm arrangement. In this case, the third reflector section can be so far removed from the two diaphragm edges that the intermediate light image generated in this reflector section is in turn free from the influence of shadowing of the diaphragm arrangement. This increases the luminous flux yield in a favorable manner.

It can also be provided within the scope of the invention to design a lighting unit with at least one screen which is essentially V-shaped or in which three screen edges are arranged in a triangular shape and the screen edges form the sides of the triangular screen recess. For example, in such a case, two diaphragm edges can be optically active and the third diaphragm edge can be arranged in such a way that it is not optically active.

In the case of one or more adjustable diaphragm edges, inaccuracies in the positioning of the diaphragm can advantageously be compensated for, whereby the robustness of such a lighting unit can be further increased.

In a particularly compact embodiment, the at least one light source in a lighting unit according to the invention can be an LED light source.

In a further advantageous embodiment variant, in the case of a lighting unit according to the invention, the at least one light source can be a laser light source.

In the context of the invention, a motor vehicle headlight with at least one lighting unit according to the invention can also be specified.

All of the aforementioned advantages and advantageous effects of a lighting unit according to the invention also apply mutatis mutandis to a motor vehicle headlight that is equipped with at least one lighting unit according to the invention.

• Fig. 1 in einer Schnittansicht von der Seite eine Beleuchtungseinheit nach dem Stand der Technik, welche einen ersten und einen zweiten Reflektor aufweist, wobei der zweite Reflektor in vier Reflektorsegmente aufgeteilt ist, die jeweils einer Blende im Strahlengang zwischen dem ersten Reflektor und dem zweiten Reflektor zugeordnet sind;
• Fig. 2a bis Fig. 2d jeweils Zwischenlichtbilder der einzelnen Reflektorsegmente des in Fig. 1 skizzierten zweiten Reflektors;
• Fig. 2e veranschaulicht das aus den jeweils in den Figuren 2a bis 2d gezeigten Zwischenlichtbildern zusammengesetzte Gesamtlichtbild;
• Fig. 3a in einer Schnittansicht von der Seite eine erfindungsgemäße Beleuchtungseinheit mit einem zweiteilig aufgebauten ersten Reflektor, wobei hier der Strahlengang in einem ersten Reflektorabschnitt des ersten Reflektors veranschaulicht ist, welcher erste Reflektorabschnitt nahe der Blende angeordnet und dieser zugeordnet ist;
• Fig. 3b in einer Schnittansicht von der Seite einen weiteren, zweiten Reflektorabschnitt der in Fig. 3a gezeigten erfindungsgemäßen Beleuchtungseinheit, wobei hier in Fig. 3b der Strahlengang desjenigen zweiten Reflektorabschnitts veranschaulicht ist, welcher von der Blende in einem größeren Abstand entfernt angeordnet ist;
• Fig. 4a ein Zwischenlichtbild, welches in dem in Fig. 3a veranschaulichten ersten Reflektorabschnitt des ersten Reflektors erzeugt ist und das eine Hell-Dunkel-Grenze aufweist;
• Fig. 4b bis Fig. 4d jeweils Zwischenlichtbilder, welche in dem in Fig. 3b veranschaulichten zweiten Reflektorabschnitt des mehrteiligen ersten Reflektors erzeugt sind und die nicht beschnitten sind;
• Fig. 4e veranschaulicht das aus den in den Figuren 4a bis 4d gezeigten Zwischenlichtbildern zusammengesetzte Gesamtlichtbild;
• Fig. 5a in einer Schnittansicht von der Seite eine alternative Ausführungsform der Erfindung mit einem mehrteiligen ersten Freiform-Reflektor, bei der die Blende direkt am zweiten Reflektor befestigt und einem ersten Reflektorabschnitt des ersten Freiform-Reflektors zugeordnet ist;
• Fig. 5b in einer Schnittansicht von der Seite einen weiteren, zweiten Reflektorabschnitt des ersten Freiform-Reflektors der in Fig. 5a gezeigten erfindungsgemäßen Beleuchtungseinheit, wobei hier in Fig. 5b der Strahlengang desjenigen zweiten Reflektorabschnitts veranschaulicht ist, welcher frei von Abschattungseinfluss durch die Blende ist;
• Fig. 6 in einer isometrischen Ansicht schräg von vorne eine Beleuchtungseinheit gemäß der Erfindung;
• Fig. 7 in einer isometrischen Ansicht schräg von vorne ein Detail eines Kraftfahrzeugscheinwerfers mit der in Fig. 6 dargestellten Beleuchtungseinheit gemäß der Erfindung;
• Fig. 8 in einer schematischen Gegenüberstellung links im Bild eine Blendenanordnung nahe des vom ersten Reflektorabschnitt erzeugten Zwischenlichtbild mit abgeschatteter Hell-Dunkel-Grenze sowie in der rechten Bildhälfte ein erzeugtes Zwischenlichtbild, das im Wesentlichen frei von Einfluss durch Abschattung der Blendenanordnung ist;
• Fig. 9 in einer schematischen Darstellung mehrere unterschiedlich weit von einer Blende beabstandete Zwischenlichtbilder;
• Fig. 10 in einer schematischen Darstellung ein Zwischenlichtbild, welches im Wesentlichen frei von Einfluss durch Abschattung durch die Blendenanordnung ist.

Further details, features and advantages of the invention emerge from the following explanation of the exemplary embodiments shown schematically in the drawings. In the pictures show:

• Fig. 1 in a sectional view from the side, a lighting unit according to the prior art, which has a first and a second reflector, the second reflector being divided into four reflector segments, each of which is assigned to a diaphragm in the beam path between the first reflector and the second reflector;
• Figures 2a to 2d intermediate light images of the individual reflector segments of the in Fig. 1 sketched second reflector;
• Fig. 2e illustrates this from the respective in the Figures 2a to 2d shown intermediate light images composite light image;
• Fig. 3a in a sectional view from the side, a lighting unit according to the invention with a first reflector constructed in two parts, the beam path being illustrated here in a first reflector section of the first reflector, which first reflector section is arranged near the diaphragm and assigned to it;
• Figure 3b in a sectional view from the side, a further, second reflector section of the in Fig. 3a lighting unit according to the invention shown, here in Figure 3b the beam path of that second reflector section is illustrated which is arranged at a greater distance from the diaphragm;
• Figure 4a an intermediate photograph, which in the in Fig. 3a illustrated first reflector section of the first reflector is generated and which has a light-dark boundary;
• Figures 4b to 4d in each case intermediate photos, which in the in Figure 3b illustrated second reflector section of the multi-part first reflector are produced and which are not trimmed;
• Figure 4e illustrates this from the Figures 4a to 4d shown intermediate light images composite light image;
• Figure 5a in a sectional view from the side, an alternative embodiment of the invention with a multi-part first free-form reflector, in which the screen is attached directly to the second reflector and assigned to a first reflector section of the first free-form reflector;
• Figure 5b in a sectional view from the side, a further, second reflector section of the first free-form reflector of FIG Figure 5a lighting unit according to the invention shown, here in Figure 5b the beam path of that second reflector section is illustrated which is free from the influence of shading by the diaphragm;
• Fig. 6 in an isometric view obliquely from the front, a lighting unit according to the invention;
• Fig. 7 in an isometric view obliquely from the front a detail of a motor vehicle headlight with the in Fig. 6 illustrated lighting unit according to the invention;
• Fig. 8 In a schematic comparison on the left in the image, a diaphragm arrangement near the intermediate light image generated by the first reflector section with a shaded light-dark border and in the right half of the image a generated intermediate light image that is essentially free of influence from the shadowing of the diaphragm arrangement;
• Fig. 9 in a schematic illustration several intermediate light images spaced differently from a diaphragm;
• Fig. 10 in a schematic representation, an intermediate light image which is essentially free from the influence of shadowing by the diaphragm arrangement.

Fig. 1 shows schematically a lighting unit according to the prior art, which has a first reflector R ₁ and a second reflector R ₂ , with a diaphragm in a beam path S symbolized by an arrow between the first reflector R ₁ and the second reflector R ₂ B is provided. The second reflector R ₂ is divided here into four reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ arranged horizontally next to one another are each assigned to the aperture B. The first reflector R ₁ is designed here, for example, as an ellipsoid reflector and has a first focal point F _1R1 and a second focal point F _2R1 . A light source 2, for example an LED light source, is located in the first focal point F _1R1 . The second focal point F _{2R1 of} the first reflector R ₁ is spaced a short distance D ₁ from a diaphragm edge BK _{1 of} the diaphragm B. The diaphragm B is arranged such that the second focal point F _{2R1 of} the first reflector R ₁ lies in its diaphragm plane BE. The second reflector R _{2 used here} is, for example, a free-form reflector, each of the reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each having a focal point F _1R2 . These focal points F _{1R2 of} the second reflector R ₂ are also arranged in the diaphragm plane BE. The beam S ₁ emerging from the light source 2 and deflected by the reflector R ₁ emerges from the first reflector R ₁ at the same small distance D ₁ close to the diaphragm edge BK _{1 of} the diaphragm B.

A disadvantage of this embodiment known from the prior art is at least that the diaphragm B cuts off each of the intermediate light images of all four reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R _24, each forming light-dark boundaries. Thus, the overall efficiency of this known lighting unit - expressed as the quotient of the luminous flux used to the luminous flux exiting (in each case specified in lumens [lm]) - is disadvantageously reduced.

The illustrations Figures 2a to 2d show the respective intermediate light images of the individual reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R _{24 of} the in Fig. 1 sketched second reflector R ₂ . Due to the different geometries, each of the reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ generates different intermediate light images, each with different distortions of the intermediate light image, the light-dark boundary created by the diaphragm B being both deformed and rotated in its position. The individual facets or reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ shift the intermediate light image produced by them to different extents in the horizontal direction.

The light-dark boundary of the overall light image, which is shown in Fig. 2e is illustrated as the sum of the Figures 2a to 2d The intermediate light images shown are - apart from slight scattered light, which is here with the in Fig. 2d The intermediate light image shown of the fourth reflector segment R ₂₄ occurs - essentially through the light-dark boundary of the in Fig. 2a shown intermediate light image of the reflector segment R ₂₁ generated.

A light image generated in this way is therefore inefficient, since the light-dark boundary is only actually required in one of the four intermediate light images, namely here in the intermediate light image obtained in the first reflector segment R ₂₁ , whereas the light-dark boundary is required in all intermediate light images of the four Reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R _{24 is} generated. With a luminous flux of a total of 100 lumens [lm] and one Assuming reflectivity of the reflectors used of 0.95 or 95%, an emerging luminous flux of a total of only 53 lumens [lm] is obtained.

Fig. 3a shows a lighting unit 1 according to the invention with a first reflector R ₁ constructed in two parts with a first reflector section R ₁₁ and a second reflector section R ₁₂ , with FIG Fig. 3a the beam path S of the first reflector section R _{11 of} the first reflector R _{1 is} illustrated. This first reflector section R ₁₁ is arranged near the diaphragm B and is assigned to it. The diaphragm B is provided in the beam path S between the first reflector R ₁ and the second reflector R ₂ . The second reflector R ₂ is divided here, for example, into four reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ arranged approximately horizontally next to one another, only the first reflector segment R _{21 being} assigned to the diaphragm B. The two reflector sections R ₁₁ and R _{12 of} the first reflector R ₁ are each designed as ellipsoid reflectors and each have a first focal point F _1R11 or F _1R12 and a second focal point F _2R11 or F _2R12 . A light source 2, for example an LED light source, is located in the first focal point F _1R11 or F _{1R12 of} the two reflector _sections R ₁₁ and R ₁₂ .

Figure 3b shows for the in Fig. 3a Illumination unit 1 according to the invention illustrated the beam path S in the second reflector section R _{12 of} the first reflector R ₁ .

How out Fig. 3a seen, the second focal point F is _2R11 of the first reflector portion R ₁₁ from a diaphragm edge BK ₁ of the diaphragm B spaced a slight distance D ₁ wherein the light emerging from the light source 2 and from the first reflector portion R ₁₁ deflected beam S ₁₁ in this small distance D ₁ near the diaphragm edge BK of the orifice B of the first reflector R ₁ emerges. ₁ The diaphragm B cuts the intermediate light image generated in the first reflector section R ₁₁ , forming a light-dark boundary. This cropped intermediate photograph is in Figure 4a illustrated.

As in Figure 3b the second focal point F _{2R12 of} the second reflector section R _{12 of} the first reflector R ₁ is illustrated at a greater distance D ₂ away from a diaphragm edge BK _{1 of} the diaphragm B. The smaller distance D _{1 of} the second focal point F _{2R11 of} the first reflector section R ₁₁ from the _{diaphragm edge} BK ₁ is in any case smaller than the greater distance D _{2 of} the second focal point F _{2R12 of} the second reflector section R ₁₂ from the _{diaphragm edge} BK ₁ . The diaphragm B is arranged in such a way that the second focal point F _{2R11 of} the first reflector section R ₁₁ and the second focal point F _{2R12 of} the second reflector section R ₁₂ each lie in the diaphragm plane BE of the diaphragm B.

The second reflector R _{2 used here} is, for example, a free-form reflector, each of the four reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ each having a focal point F _1R21 , F _1R22 , F _1R23 and F _1R24 . These focal points F _1R21 , F _1R22 , F _1R23 and F _{1R24 of} the four reflector _segments R ₂₁ , R ₂₂ , R ₂₃ and R _{24 of} the second reflector R ₂ are also arranged in the diaphragm plane BE.

The first reflector segment R _{21 of} the second reflector R ₂ is assigned to the intermediate light image generated in the first reflector section R _{11 of} the first reflector R ₁ , this intermediate light image in Figure 4a is shown.

The further reflector segments R ₂₂ , R ₂₃ and R _{24 of} the second reflector R ₂ are assigned to the second reflector section R _{12 of} the first reflector R ₁ . The corresponding intermediate light images of the second, third and fourth reflector segments R ₂₂ , R ₂₃ and R ₂₄ are shown in the figures Figures 4b to 4d shown. Since the diaphragm B away at a greater distance D ₂ each emanating from the second reflector portion R ₁₂ beam S is disposed at a distance _12, the intermediate light images of the second, third and fourth reflector segment R _22, R ₂₃ R ₂₄ substantially free of or influence by shading the aperture arrangement.

Figure 4e shows the total light image as the sum of the Figures 4a to 4d intermediate light images shown. Since the diaphragm B only acts on the intermediate light image that is obtained from the pairing of the first reflector section R _{11 of} the first reflector R ₁ and the first reflector segment R _{21 of} the second reflector R _{2 associated} therewith, the cut-off line of the overall light image becomes generated only in the first reflector segment R _{21 of} the second reflector R ₂ . The other intermediate _light images that are obtained from the second, third and fourth reflector segments R ₂₂ , R ₂₃ and R ₂₄ are advantageously not shaded or not cropped because there the distance D _{2 of} the diaphragm B from the second focal point F _{2R12 of} the second reflector section R _{12 of} the first reflector R _{1 is} further away compared to the small distance D ₁ and therefore the intermediate light images of the reflector segments R ₂₂ , R ₂₃ and R ₂₄ are essentially free of shading influences.

The in Figure 4e The overall light image shown of the lighting unit 1 according to the invention is given a luminous flux of a total of 100 lumens [lm] used and an assumed reflectivity of the reflectors used of 0.95 or 95%, thus an exiting luminous flux of 62 lumens [lm] in total.

In comparison to the aforementioned example known from the prior art according to FIG Fig. 1 results in the case according to the invention with a lighting unit 1 with a two-part first reflector with the two reflector sections R ₁₁ , R ₁₂ according to the figures Fig. 3a and Figure 3b a particularly advantageous increase in the efficiency of the luminous flux - starting from 53 lumens [lm] with the light distribution known from the prior art as in FIG Fig. 2e shown - to 62 lumens [lm] according to the light distribution according to the invention as in Figure 4a illustrated. This corresponds to an absolute

Increase in efficiency of 9 lumens [lm] or a relative increase in overall efficiency of around 17%.

The two illustrations Figures 5a and 5b each relate to an alternative embodiment of the invention and each show a lighting unit 1 with a multi-part first reflector R ₁ , which is designed here as a two-part free-form reflector. For this purpose, the reflector R ₁ has a first reflector section R ₁₁ with a focal point F _1R11 , the diaphragm B being arranged at a distance D ₁ close to the beam S ₁₁ emanating from the first reflector section R ₁₁ . The diaphragm B cuts the intermediate light image generated in the first reflector section R ₁₁ , forming a light-dark boundary.

The second reflector R ₂ is segmented here, for example, into four reflector segments R ₂₁ , R ₂₂ , R ₂₃ and R ₂₄ arranged next to one another. The diaphragm B is here attached directly to the second reflector R ₂ on its first reflector segment R ₂₁ and is only assigned to the first reflector section R _{11 of} the first free-form reflector. Furthermore, only the first reflector segment R _{21 of} the second reflector R _{2 is} assigned to the intermediate light image generated in the first reflector section R _{11 of} the first reflector R ₁ . This is in Figure 5a shown.

Figure 5b shows the further, second reflector section R _{12 of} the first free-form reflector of FIG Figure 5a lighting unit according to the invention shown, here in Figure 5b the beam path S of the second reflector section R _{12 is} illustrated, which is free from the influence of shading by the diaphragm B. The second, third and fourth reflector segments R ₂₂ , R ₂₃ and R _{24 of} the second reflector R ₂ are assigned to the intermediate light image generated in the second reflector section R _{12 of} the first reflector R ₁ . These intermediate light images are advantageously not cropped or shaded because of the lack of a diaphragm.

Fig. 6 shows in a detailed view a lighting unit 1 according to the invention. The lighting unit 1 comprises a light source 2 shown in the picture above, which is positioned behind or below the first reflector R ₁ . The reflector R ₁ is constructed in one piece here and has two reflector sections R ₁₁ and R ₁₂ . Dashed arrows indicate a first bundle of rays S _{11 of} the exiting light from the first reflector section R ₁₁ and a second bundle of rays S _{12 of} the exiting light from the second reflector section R ₁₂ . The aperture B between the first reflector R ₁ and the second reflector R ₂ has a triangular aperture with three aperture edges BK ₁ , BK ₂ and BK ₃ , the aperture edges forming the three sides of the triangular aperture.

The diaphragm B is positioned in such a way that a first diaphragm edge BK _{1 of} the diaphragm B is optically not active here and is arranged somewhat at a distance from the first beam S ₁₁ and from the second beam S ₁₂ . A second diaphragm edge BK ₂ and a third diaphragm edge BK _{3 of} the diaphragm B are optically active here. The first bundle of rays S ₁₁ is focused here near the optically active diaphragm edge BK ₃ . The second beam S ₁₂ is focused near the optically active diaphragm edge BK ₂ .

1. (i) von der optisch aktiven dritten Blendenkante BK₃ nur das im ersten Reflektorabschnitt R₁₁ erzeugte Zwischenlichtbild unter Bildung einer Hell-Dunkel-Grenze beschnitten wird und
2. (ii) von der optisch aktiven zweiten Blendenkante BK₂ nur das im zweiten Reflektorabschnitt R₁₂ erzeugte Zwischenlichtbild unter Bildung einer Hell-Dunkel-Grenze beschnitten wird.

This enables

1. (i) only the intermediate light image generated in the first reflector section R ₁₁ is cropped by the optically active third diaphragm edge BK _{3 to} form a light-dark boundary and
2. (ii) only the intermediate light image generated in the second reflector section R ₁₂ is cropped by the optically active second diaphragm edge BK ₂ , forming a light-dark boundary.

The intermediate light image generated in the first reflector section R ₁₁ remains essentially free from the influence of shadowing of the diaphragm edge BK ₂ . The intermediate light image generated in the second reflector section R ₁₂ remains essentially free from the influence of shadowing of the diaphragm edge BK ₃ .

The second reflector R ₂ is segmented here, for example, into a plurality of reflector segments, with three reflector segments R ₂₁ , R ₂₂ and R ₂₃ arranged next to one another being considered in more detail for the following description. Only the first reflector segment R _{21 of} the second reflector R ₂ is assigned here to the intermediate light image generated in the first reflector section R _{11 of} the first reflector R ₁ . The intermediate light images generated in the second and third reflector segments R ₂₂ , R ₂₃ are advantageously not cropped, which increases the overall efficiency of the illustrated lighting unit 1.

The diaphragm B shown here has a further, second diaphragm edge BK ₂ , which, analogously to the preceding description, can in turn serve for selective shading of the intermediate light image of a further reflector segment of the second reflector R ₂ .

Fig. 7 shows in a detailed view a motor vehicle headlight 10 with the in Fig. 6 illustrated lighting unit 1 according to the invention. The lighting unit 1 is already in the installed position within the motor vehicle headlight 1 and is installed with the corresponding housing components of the headlight. A diffusing screen which is used only to protect the motor vehicle headlight 1 and which has no optical function is shown here in FIG Fig. 7 removed for better overview and not shown.

• Für alle Reflektorabschnitte R₁₁, R₁₂, R_1N des ersten Reflektors R₁ wird jeweils der Abstand des Maximums der Beleuchtungsstärke E_MAX zur Blendenkante der Blende gemessen;
• der kleinste dieser gemessenen Abstände wird als Referenzlänge L ausgewählt.

Fig. 8 shows, in a schematic comparison, a diaphragm arrangement of a first reflector constructed in two parts, for example an ellipsoidal reflector, according to the invention. On the left of the picture, an intermediate light image generated by the first reflector section R ₁₁ with a shaded light-dark boundary is illustrated. The _{diaphragm edge} BK ₁ is here at a small distance D ₁ near the second focal point F _2R11 of the first reflector section R ₁₁ arranged. This distance D ₁ is selected to be equal to a reference length L. The reference length L, which is used to assess or categorize the distance or the distance between the corresponding beam and the diaphragm B or - as is the case here - for an ellipsoid reflector between the second focal point F _{2R11 of} the first reflector section R _{11 of} the first Reflector R ₁ and the aperture B can be used, is determined as follows:

• For all reflector sections R ₁₁ , R ₁₂ , R _{1N of} the first reflector R ₁ , the distance between the maximum of the illuminance E _MAX and the diaphragm edge of the diaphragm is measured;
• the smallest of these measured distances is selected as the reference length L.

The loss of luminous flux in the left half of Fig. 8 The aperture arrangement shown here is over 15%.

In the right half of the picture Fig. 8 a diaphragm arrangement is shown, the distance between the diaphragm _edge BK _{1 of} the diaphragm B and the second focal point F _{2R12 of} the second reflector section R _{12 being arranged} at a greater distance D ₂ from the diaphragm. The distance D ₂ here is greater than one and a half times the value of the reference length L. The intermediate light image produced is, by definition, essentially free from the influence of shadowing of the diaphragm arrangement. The loss of luminous flux in the right half of Fig. 8 The aperture arrangement shown here is below 7%.

Fig. 9 shows in a schematic representation a plurality of intermediate light images spaced differently from a diaphragm B or from its diaphragm edge BK ₁ . The maximum illuminance of each individual intermediate light image has a certain minimum distance to the diaphragm or to the diaphragm edge, the shortest of these distances being defined as the reference length L. By definition, an intermediate light image is precisely close to the diaphragm edge when the smallest distance of the maximum illuminance of the intermediate light image from the diaphragm edge exceeds a specified value.

An example is here in Fig. 9 as the limit value 1.5 times the value of the reference length L shown as a dashed line. In Fig. 9 the two middle intermediate light images shown are positioned far from the diaphragm edge by definition, since their distances D ₁ and D _{2 are} greater than the limit value given here of 1.5 times the reference length L. The outer left intermediate light image is by definition close to the diaphragm edge because it is in a distance according to the reference length L from the diaphragm edge of the diaphragm B. This is also located in Fig. 9 The outer right intermediate light image shown is only a small distance D ₃ away from the diaphragm B and is thus close to the diaphragm edge.

Fig. 10 represents in a schematic representation an intermediate light image, which is essentially free of influence from shadowing by the diaphragm arrangement of the diaphragm B is. The hatched area labeled 93% is bounded by the isoline within which 93% of the luminous flux of the intermediate light image is located. The non-hatched outer area of the intermediate light image thus represents that edge area of the light image through which 7% of the luminous flux flows. By introducing the diaphragm B into the beam path, the luminous flux of the intermediate light image generated is reduced by less than 7% here.

LIST OF REFERENCES:

1

Lighting unit

2

Light source

10

Automotive headlights

B.

cover

BE

Aperture plane

BK ₁

(first) diaphragm edge of the diaphragm

BK ₂

second edge of the diaphragm

D ₁

Distance of the diaphragm from the beam of the first reflector section

D ₂

Distance of the diaphragm from the bundle of rays of the second reflector section

D _N

Distance of the diaphragm from the bundle of rays of the third or further reflector section

E _MAX

maximum illuminance

F _1R1

(first) focal point of the first reflector

F _1R11

(first) focal point of the first reflector section of the first reflector

F _1R12

(first) focal point of the second reflector section of the first reflector

F _1R1N

(First) focal point of the third or further reflector section of the first reflector

F _2R1

second focal point of the first reflector

F _2R11

second focal point of the first reflector section of the first reflector

F _2R12

second focal point of the second reflector portion of the first reflector

F _2R1N

second focal point of the third or further reflector section of the first reflector

F _1R2

(first) focal point of the second reflector

F _1R21

(first) focal point of the first reflector segment of the second reflector

F _1R22

(first) focal point of the second reflector segment of the second reflector

F _1R2N

(First) focal point of the third or further reflector segment of the second reflector

FE

Focal plane of the (first) focal point of the first reflector segment of the second reflector

L.

Reference length

R ₁

first reflector

R ₁₁

first reflector section of the first reflector

R ₁₂

second reflector section of the first reflector

R _1N

third or further reflector section of the first reflector

LIST OF REFERENCES (CONTINUED):

R ₂

second reflector

R ₂₁

first reflector segment of the second reflector

R ₂₂

second reflector segment of the second reflector

R _2N

third or further reflector segment of the second reflector

S.

Beam path

S ₁

Beam of the first reflector

S ₁₁

Beam of the first reflector section of the first reflector

S ₁₂

Beam of the second reflector section of the first reflector

S _1N

Beam of the third or further reflector section of the first reflector

Claims (15)

1. Lighting unit for a motor vehicle headlamp for producing a beam pattern with a cut-off line, wherein the lighting unit (1) comprises:

   - at least one light source (2),

   - at least one first reflector (R₁) having at least one focal point (F_1R1), wherein the at least one light source (2) is arranged in the at least one focal point (F_1R1), wherein

   - the at least one first reflector (R₁) is designed to emit light and transmit it to a second reflector (R₂),

   - at least one second reflector (R₂) having at least one focal point (F_1R2), wherein the at least one second reflector (R₂) in the beam path (S) is arranged downstream of the at least one first reflector (R₁) and is configured to display an intermediate light image produced by the first reflector (R₁),

   - at least one baffle (B), which is arranged in the beam path (S) between the at least one first reflector (R₁) and the at least second reflector (R₂),
   wherein

   - the first reflector (R₁) is constructed at least in two parts (R₁₁, R₁₂) and has a first reflector section (R₁₁) as well as at least one separate second reflector section (R₁₂) , wherein each reflector section (R₁₁, R₁₂) respectively has at least one focal point (F_1R11, F_1R12), and

   - at least one focal point (F_1R11, F_1R12) of the first and of the at least second reflector section (R₁₁, R₁₂) are respectively arranged congruently at the location of the at least one light source (2), wherein

   - the at least two-part first reflector (R₁₁, R₁₂) splits the beam (S₁) emitted by the at least one light source (2) at least into two separate beams (S₁₁, S₁₂),

   characterized in that:

   - the at least one baffle (B) is arranged such that it is assigned to the first reflector section (R₁₁) of the first reflector (R₁) and is arranged at a short distance (D₁) close to the beam (S₁₁) emanating from the first reflector section (R₁₁) and cuts down the intermediate light image produced in the first reflector section (R₁₁) by forming a cut-off line, and

   - the at least one baffle (B) is arranged spaced apart at a larger distance (D₂) away from the beam (S₁₂) emanating from the at least second reflector section (R₁₂) and the intermediate light image produced at least in the second reflector section (R₁₂) is substantially free of influence due to shading of the baffle arrangement.
2. Lighting unit (1) according to Claim 1, characterized in that

   - the first reflector (R₁) has a multi-part design and has a plurality of reflector sections (R₁₁, R₁₂, R_1N) having at least one focal point (F_1R11, F_1R12, F_1R1N), wherein the at least one light source (2) is respectively arranged in the at least one focal point (F_1R11, F_1R12, F_1R1N), wherein

   - the at least one baffle (B) is arranged such that it is assigned exclusively to the first reflector section (R₁₁) of the first reflector (R₁) and is arranged at a short distance (D₁) close to the beam (S₁₁) emanating from the first reflector section (R₁₁) and cuts down the intermediate light image produced in the first reflector section (R₁₁) by forming a cut-off line, and

   - the at least one baffle (B) is arranged spaced apart at a larger distance (D₂, D_N) away from the beams (S₁₂, S_1N) emanating from the second (R₁₂) and, possibly, the further reflector sections (R_1N) of the first reflector (R₁) and the intermediate light images produced in the second and, possibly, the further reflector sections (R₁₂, R_1N) are substantially free of influence due to shading of the baffle arrangement.
3. Lighting unit (1) according to Claim 1 or 2, characterized in that the second reflector (R₂) is divided in a facet-like manner into two or more reflector segments (R₂₁, R₂₂, R_2N), wherein a first reflector segment (R₂₁) of the second reflector (R₂) is assigned to the intermediate light image produced in the first reflector section (R₁₁) of the first reflector (R₁).
4. Lighting unit (1) according to one of Claims 1 to 3, characterized in that the second reflector (R₂) is divided in a facet-like manner into two or more reflector segments (R₂₁, R₂₂, R_2N), wherein precisely the first reflector segment (R₂₁) of the second reflector (R₂) is assigned to the intermediate light image produced in the first reflector section (R₁₁) of the first reflector (R₁).
5. Lighting unit (1) according to one of Claims 1 to 4, characterized in that the at least one baffle (B) is attached directly to or at least near to the first reflector section (R₁₂) of the first reflector (R₁).
6. Lighting unit (1) according to one of Claims 1 to 4, characterized in that the at least one baffle (B) is attached directly to or at least near the first reflector segment (R₂₁) of the second reflector (R₂) .
7. Lighting unit (1) according to one of Claims 1 to 6, characterized in that a baffle plane (BE) of the at least one baffle (B) corresponds to a focal plane (FE) of the at least one focal point (F_1R21) of the first reflector segment (R₂₁) of the second reflector (R₂) .
8. Lighting unit (1) according to one of Claims 1 to 7, characterized in that at least the first reflector section (R₁₁) of the first reflector (R₁) is an ellipsoidal reflector, which has a second focal point (F_2R11), wherein the at least one baffle (B) is arranged such that it is spaced apart at a short distance (D₁) from the second focal point (F_2R11) of the first reflector section (R₁₁).
9. Lighting unit (1) according to one of Claims 1 to 8, characterized in that the two or more reflector sections (R₁₁, R₁₂, R_1N) of the first reflector (R₁) are each ellipsoidal reflectors, which each have a second focal point (F_2R11, F_2R12, F_2R1N), wherein the at least one baffle (B) is arranged such that it is arranged at a short distance (D₁) close to the second focal point (F_2R11) of the first reflector section (R₁₁) and the baffle (B) is arranged spaced apart at a larger distance (D₂, D_N) away from the second focal points (F_2R12, F_2R1N) of all further reflector sections (R₁₂, R_1N) of the first reflector (R₁).
10. Lighting unit (1) according to one of Claims 1 to 9, characterized in that the short distance (D₁) from the beam (S₁₁) and/or from the second focal point (F_2R11) of the first reflector section (R₁₁) of the first reflector (R₁) to a baffle edge (BK₁) of the baffle (B) is then defined as close to the baffle (B) if the distance (D₁) is smaller than 1.7 times a reference length (L), preferably smaller than 1.5 times a reference length (L), particularly preferably smaller than 1.3 times a reference length (L), and the intermediate light image produced in the first reflector section (R₁₁) is cut down by forming a cut-off line, wherein the reference length (L) is selected as the smallest distance respectively out of the distances of the maximum light intensity (E_MAX) of all reflector sections (R₁₁, R₁₂, R_1N) of the first reflector (R₁) to the baffle edge (BK₁) of the baffle (B).
11. Lighting unit (1) according to one of Claims 1 to 10, characterized in that the larger distance (D₂, D_N) from the beam (S₁₂, S_1N) and/or from the second focal point (F_2R12, F_2R1N) of the second reflector section (R₁₂) and, possibly, of the further reflector sections (R_1N) of the first reflector (R₁) to a baffle edge (BK₁) of the baffle (B) is then defined as far from the baffle (B) if the luminous flux of the intermediate light image produced in the second and, possibly, the further reflector sections (R₁₂, R_1N) is reduced by a maximum of 10 %, preferably by a maximum of 7 %, particularly preferably by a maximum of 5 % by placing the baffle (B) in the beam path (S).
12. Lighting unit (1) according to one of Claims 1 to 11, characterized in that the at least one baffle (B) has a first baffle edge (BK₁) for producing a first cut-off line and a second baffle edge (BK₂) for producing a second cut-off line and/or is adjustably arranged in the beam path (S) between the at least one first reflector (R₁) and the at least second reflector (R₂).
13. Lighting unit (1) according to one of Claims 1 to 12, characterized in that the at least one light source (2) is an LED light source.
14. Lighting unit (1) according to one of Claims 1 to 12, characterized in that the at least one light source (2) is a laser light source.
15. Motor vehicle headlamp (10) having at least one lighting unit (1) according to one of Claims 1 to 14.

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