EP2523022B1 - Lighting module of a motor vehicle headlamp for creating a variable light distribution and motor vehicle headlamp with such a lighting module - Google Patents

Description

• mehrere Lichtquellen zum Aussenden von Licht,
• eine Blendenanordnung zum Abschatten zumindest eines Teils des ausgesandten Lichts, und
• eine Projektionslinse zur Projektion zumindest eines Teils des an der Blendenanordnung vorbeigelangten Lichts als Lichtverteilung auf einer Fahrbahn vor dem Fahrzeug.

The present invention relates to a light module for a motor vehicle headlight for generating a variable light distribution. The light module comprises:

• several light sources for emitting light,
• a diaphragm arrangement for shading at least a part of the emitted light, and
• a projection lens for projecting at least a part of the light passed past the diaphragm arrangement as light distribution on a roadway in front of the vehicle.

The light distribution generated by the light module can be varied by selectively switching (activating and / or deactivating) light source groups comprising in each case at least one of the light sources. In this case, the resulting total light distribution produced by the light module results from a superposition of the light sources of the activated light source groups generated light beams. At least a first light beam generated by the at least one light source of an activated first light source group serves to generate a first partial light distribution below a substantially horizontal light-dark boundary. Furthermore, at least one further light bundle generated by the at least one light source of an activated further light source group serves to produce a further partial light distribution above a substantially horizontal light-dark boundary.

The invention also relates to a

Motor vehicle headlight with such a light module for generating a variable light distribution.

The term "essentially horizontal" in connection with the course of the light-dark boundaries means that the light-dark boundaries of the partial light distributions do not necessarily have to be straight, but may also be formed as a so-called asymmetrical light-dark boundary with at least sections of stepwise or oblique course. An asymmetrical horizontal chiaroscuro boundary includes, for example, a first horizontal section arranged on the own traffic side, a second horizontal section arranged on the oncoming traffic side and a transition section between the two horizontal sections. The second horizontal section on the oncoming traffic side is preferably arranged below the first horizontal section on the own traffic side in order to prevent dazzling of oncoming traffic participants. The transition section may be formed stepwise, obliquely or in any other way. An inclined transition section preferably has a 15 ° rise.

From the prior art, light modules for vehicle headlights are known, which operate according to the so-called projection principle and which can project different light distributions and different light-dark boundary curves onto the road ahead of the vehicle by switching over. The choice of light distribution occurs, for example, by switching, i. by selective activation or deactivation but also by dimming, individual light sources or light source groups. While such a type of switching and variation of the light distribution was previously reserved using the so-called reflection principle working light modules with two-filament lamps, there are lately increasingly concepts to working with the projection principle light modules only by targeted switching of light sources several light functions and variable light distributions to create.

These concepts are particularly suitable for light modules or headlights that operate on the projection principle and use as light sources semiconductor light sources, in particular light emitting diodes (LEDs). In contrast to headlamps with gas discharge lamps, LED headlamps not only have a plurality of light sources (LED chips), which can preferably be controlled individually or in groups, but also have a plurality of primary optics associated with the light sources, which can be configured, for example, as projection or reflection optics. The overall light distribution of an LED headlight is generally formed by a superimposition of the partial light distributions of several LED primary optics modules, optionally after passing through a secondary optic, for example in the form of the projection lens.

Such multi-function projection headlights are for example from the DE 10 2008 036 192 A1 known. There, the beam path for the respective light functions is divided in a diaphragm plane of the projection module, so that the radiation beams required for the individual light functions can be generated by different, independently switchable light sources. This makes it possible to produce different light distributions without moving diaphragms merely by switching light sources. Corresponding multi-function projection headlights are among others also from the US 2006/0120094 A1 as well as from the DE 10 2007 052 696 A1 known.

The division of the beam path can be achieved depending on the physical principle used by means of refraction, reflection or absorption. In the DE 10 2007 052 696 A1 the high beam and the low beam beam path is formed over a total reflecting surface of a glass body, the edge of which generates the light-dark boundary in the low beam light. The high-beam beams are coupled here in the same glass body, but meet at a steeper angle to said surface so that they are not reflected, but pass through the surface and illuminate a portion of the resulting light distribution above the light-dark boundary (high beam partial beam path). The high beam is then formed by superposition of the low beam beam path with the high beam partial beam path. In the US 2006/012 0094 A1 It is described that the beam path above and below the light-dark boundary is divided by two reflecting surfaces, which terminate sharply in the focal plane of the projection lens to form a knife edge. This edge has the contour of the desired light-dark border and is transmitted through the projection lens onto the road projected. This system could also be implemented with absorbent surfaces, albeit with less efficiency.

In all known systems described above, the mapping of the light-dark boundary on the road surface is problematic. The difficulty is to separate the beam paths of the different light functions so that no light is scattered beyond the light-dark boundary (above the light-dark boundary) in the low beam, ie no crosstalk occurs, and in the high beam case no dark, light or colored line at the location of Low beam chiaroscuro border remains. The beam splitters which are used in the known light modules (mirror diaphragms or totally reflecting glass bodies) work only inadequately, so that dark areas, in particular dark lines, can be detected in the resulting high beam distribution in the region of the low beam light-dark boundary or the beam splitter edge.

From the JP 2006-107 875 A Although a way is described how this problem can be circumvented. In this case, a high-beam partial beam path is sent past the diaphragm of the low-beam beam path through the projection lens. However, since the associated high beam distribution would appear far above the horizon, in the known headlight an additional mirror behind the projection lens is required, which redirects the high beam partial beam back down onto the road. In practice, however, such a mirror in front of the projection lens, in particular due to design and styling requirements of vehicle manufacturers, usually can not be realized.

Based on the described prior art, the present invention therefore has the object of designing the light module or the motor vehicle headlight of the type mentioned in such a way and further that at the point of the low beam light-dark boundary no colored, light or dark areas (eg lines) can be seen in the high beam distribution or these areas are at least significantly reduced.

To solve this problem is proposed starting from the light module of the type mentioned that the light module is configured such that the light beams generated by the first light source group and the further light source group pass through different areas of the projection lens and the projection lens in the areas through which at least one further light bundle generated by the further light source group passes, is designed such that the light-dark boundary of the further partial light distribution is arranged below the light-dark boundary of the first partial light distribution.

The at least one first light bundle, which is arranged virtually completely below a horizontal light-dark boundary, corresponds, for example, to a dipped-beam light beam. Of course, it is possible that light of low intensity is arranged above the light-dark boundary in the low-beam beam, for example in order to achieve the legally required upper head values and to illuminate traffic signs and information boards at the roadside and above the roadway. However, glare of other road users by this light is excluded due to the low intensity. The at least one further light bundle corresponds, for example, to the upper part of a high-beam beam (high-beam partial light beam), wherein the at least one first light beam forms a high beam distribution after superposition with the at least one further light beam. According to the invention, it is therefore proposed to design the projection lens at least in regions such that it has different imaging properties for the at least one low-beam beam path and the at least one high-beam partial beam path. In this case, the high-beam partial beam path is lowered relative to the low-beam beam path in the vertical direction such that the upper part of the high-beam distribution generated by the at least one further light beam is imaged on the low-beam light-dark border and superimposed on it so that it reliably shines over becomes. In this way, at the location of the low-beam light-dark boundary, no colored, light or dark areas, in particular lines and lines, can be seen more in the resulting overall high beam distribution.

The light module according to the invention comprises a non-rotationally symmetrical converging lens in which a lens region through which the at least one further light beam passes is lowered in the vertical direction in such a way that the further light bundle passing through is displaced downwards so that the low-beam light-dark boundary, ie the light beam Light-dark border, which limits the at least one first light bundle to the top, outshines. The light-dark boundary of the at least one first light bundle and the at least one further light bundle therefore no longer directly adjoin one another in the present invention, but the first and the further light bundles overlap in a range of the light distribution lying between the low-beam light-dark boundary and the high-beam light-dark boundary.

According to an advantageous development of the present invention, it is proposed that the at least one further light bundle pass through edge regions, preferably through lateral edge regions, of the projection lens and the first light bundle, through a center region of the projection lens.

In this case, it is proposed according to a preferred embodiment of the invention that in vertical sections through edge regions of the projection lens and parallel to a meridional section of the projection lens vertexes of the lens section contours relative to the sectional contour of the meridional section are lowered in the vertical direction. In this case, the lens vertices are the points of contact of the respectively largest vertical circle inscribed in the respective vertical section on the lens contour. Areas in the lens center are preferably not lowered.

In this case, therefore, the lens vertex of the projection lens contour is lowered in at least one vertical section through edge regions of the projection lens relative to the lens vertex of at least one meridional section through the center region of the lens in the vertical direction. As a result, the further light bundles which pass through the edge regions of the projection lens and which preferably illuminate a subarea of the high beam distribution lying above the low-beam light-dark boundary are lowered downward, so that they cover the low-beam light-dark boundary of the first light beam.

By this measure, the at least one further light beam (eg in the form of the high-beam partial beam path), which is sent through the lowered lens edge regions is, relative to the at least one first light beam (eg in the form of the low-beam light path), which passes through the lens in the non-lowered central portions of the lens, are lowered in the vertical direction. Thus, it is possible to illuminate light from the high-beam partial beam path directly onto the region of the low-beam light-dark boundary, thereby avoiding inhomogeneities in the overall light distribution of the light module as a result of superposition of the low-beam beam path and the high-beam partial beam path.

According to a further advantageous embodiment of the present invention, it is proposed that the edge regions with the lowered vertexes of the projection lens are arranged laterally to the right and left of the meridional section through the functional lens. The edge regions are preferably lowered symmetrically to the center of the lens relative to the meridional section of the projection lens. It is particularly preferred that the lowering of the lens edge region or of the lens edge regions takes place continuously from the center of the lens to the edge of the lens or to the lens edges.

According to an alternative development of the present invention, it is proposed that the at least one further light bundle (for example the high-beam partial beam path) runs through the lens central regions around the optical axis of the light module and the at least one first light bundle (for example the low-beam optical path) through lens edge regions. For this case, it is proposed that the apexes of the collecting lens contour are vertically lowered instead of in the lens edge areas in the central areas of the projection lens. The vertices in the lens edge regions are preferably not lowered.

In at least one sectional plane perpendicular to a main optical axis of the projection lens, the latter has an egg-shaped sectional contour, so that the projection lens has a shape tapering from bottom to top. The projection lens are preferably associated with means for color correction. For this purpose, the refractive power in lens areas above and / or below the optical axis can be selectively changed, preferably increased. Such projection lenses with color correction are in itself from the DE 35 07 013 A1 as well as from the DE 10 2008 021 520 A1 known. As a result, color fringes in the resulting total light distribution can be avoided, or at least reduced.

The projection lens is preferably designed as a plano-convex lens. Other embodiments of the projection lens, in particular as a biconvex lens, are conceivable. The projection lens may be made of inorganic or organic glasses. Organic glasses are, for example, polycarbonate (PC), polymethyl methacrylate (PMMA), cycloolefin polymer (COP), cycloolefin copolymer (COC), polymethacrylmethylimide (PMMI) or polysulfone (PSU).

The light module according to the invention can be used particularly preferably in a motor vehicle headlight. In particular, the light module is preferably used in multi-function LED headlamps, e.g. as dipped beam high beam bifunctional light or dipped beam high beam bifunctional base light.

Figur 1

einen erfindungsgemäßen Kraftfahrzeugscheinwerfer gemäß einer bevorzugten Ausführungsform in schematischer Ansicht;

Figur 2

ein aus dem Stand der Technik bekanntes Lichtmodul mit eingezeichnetem erstem Strahlengang;

Figur 3

eine durch den ersten Strahlengang aus Figur 2 auf einem Messschirm erzeugte erste Teil-Lichtverteilung;

Figur 4

ein aus dem Stand der Technik bekanntes Lichtmodul mit eingezeichnetem weiterem Strahlengang;

Figur 5

eine durch den weiteren Strahlengang aus Figur 4 auf einem Messschirm erzeugte weitere Teil-Lichtverteilung;

Figur 6

ein aus dem Stand der Technik bekanntes Lichtmodul mit eingezeichnetem Gesamtstrahlengang umfassend den ersten Strahlengang aus Figur 2 und den weiteren Strahlengang aus Figur 4;

Figur 7

eine durch den Gesamtstrahlengang aus Figur 6 auf einem Messschirm erzeugte Gesamtlichtverteilung;

Figur 8

ein erfindungsgemäßes Lichtmodul gemäß einer bevorzugten Ausführungsform in einer Ansicht in Lichtaustrittsrichtung von schräg oben mit eingezeichnetem erstem Strahlengang;

Figur 9

das erfindungsgemäße Lichtmodul aus Figur 8 in einer entsprechenden Ansicht mit eingezeichnetem weiterem Strahlengang;

Figur 10

eine durch den weiteren Strahlengang aus Figur 9 auf einem Messschirm erzeugte weitere Lichtverteilung;

Figur 11

das erfindungsgemäße Lichtmodul aus Figur 8 in einer Schnittansicht entlang der optischen Achse des Lichtmoduls mit eingezeichnetem ersten Strahlengang und weiteren Strahlengang;

Figur 12

das erfindungsgemäße Lichtmodul aus Figur 8 in einer perspektivischen Ansicht von schräg vorne mit mehreren Vertikalschnitten durch die Projektionslinse;

Figuren 13 bis 15

verschiedene Ansichten einer Projektionslinse eines erfindungsgemäßen Lichtmoduls.

Further features and advantages of the present invention will be explained in more detail below with reference to the attached figures. In this case, the inventive Light module have the specified features and advantages not only in the described and illustrated combination, but also in any other combination. Show it:

FIG. 1

a motor vehicle headlamp according to the invention according to a preferred embodiment in a schematic view;

FIG. 2

a known from the prior art light module with marked first beam path;

FIG. 3

one through the first beam path FIG. 2 first partial light distribution generated on a screen;

FIG. 4

a known from the prior art light module with marked further beam path;

FIG. 5

one through the other beam path FIG. 4 on a measuring screen generated further partial light distribution;

FIG. 6

a known from the prior art light module with marked overall beam path comprising the first beam path FIG. 2 and the other beam path FIG. 4 ;

FIG. 7

one through the entire beam path FIG. 6 total light distribution generated on a screen;

FIG. 8

a light module according to the invention according to a preferred embodiment in a view in Light exit direction obliquely from above with marked first beam path;

FIG. 9

the light module of the invention FIG. 8 in a corresponding view with marked further beam path;

FIG. 10

one through the other beam path FIG. 9 on a measuring screen generated further light distribution;

FIG. 11

the light module of the invention FIG. 8 in a sectional view along the optical axis of the light module with marked first beam path and further beam path;

FIG. 12

the light module of the invention FIG. 8 in a perspective view obliquely from the front with a plurality of vertical sections through the projection lens;

FIGS. 13 to 15

different views of a projection lens of a light module according to the invention.

In FIG. 1 an embodiment of a motor vehicle headlamp according to the invention is shown. The headlamp is designated in its entirety by the reference numeral 1. The headlight 1 comprises a housing 2, which preferably consists of plastic. In a light exit direction 3, the headlight housing 2 has a light exit opening 4, which is closed by a transparent cover 5, to prevent the ingress of dust, dirt and / or moisture into the interior of the housing 2. The cover 5 is made of glass or plastic. You can at least partially with optically effective profiles, eg. As prisms or cylindrical lenses, be provided to scatter passing light rays in the horizontal and / or vertical direction. Preferably, however, the cover 5 is formed without optically effective profiles as a so-called clear disc.

In the headlight housing 2, a light module 6 is arranged, which is designed to generate a variable light distribution. The light module 6 can be fixedly arranged in the housing 2 or can be mounted pivotably in the housing 2 about a vertical axis of rotation 7 and / or a horizontal axis of rotation 8. The light module 6 is preferably designed as a so-called projection module in which a secondary optics, for example in the form of a projection lens, projects an edge of an aperture arrangement arranged in the beam path as a light-dark boundary on the road ahead of the vehicle. The light module 6 can generate light distributions of any headlight functions or parts of these light distributions. For example, it is conceivable that the light module 6 generates a low beam, a high beam, a fog light, a base or base light, a spot light or any other light distribution.

In addition to the light module 6, further light modules can be arranged in the spotlight housing 2, which are arranged in FIG. 1 indicated by dashed lines and designated by the reference numerals 9 and 10 are. It is conceivable that the total light distribution produced by the illumination device 1 consists of a superimposition of the light distributions emitted by at least two of the light modules 6, 9, 10. For example, if that Light module 6 generates a base or base light distribution of a low beam, this could generate together with a spotlight light distribution of another light module 9 or 10 by superposition a the legal requirements corresponding low beam distribution. Furthermore, in the headlight housing 2, a number of almost arbitrarily ausgestalteteter lighting modules can be arranged, of which in FIG. 1 two exemplary drawn and designated by the reference numerals 11 and 12 are. The light modules 11, 12 are used, for example, to generate a position or limiting light, a daytime running light, a flashing light or any other lighting function.

The Figures 2 . 4 and 6 show a well-known from the prior art LED projection module with different marked beam paths, and the Figures 3 . 5 and 7 show the light distributions generated by the respectively marked beam paths on a measuring screen. This in FIG. 2 shown known light module is designated in its entirety by the reference numeral 30. The light module 30 may, for example, instead of the light module 6 in the motor vehicle headlight 1 off FIG. 1 be incorporated, which would then become known from the prior art headlights.

The light module 30 has a plurality of light sources 31 in the form of semiconductor light sources, in particular in the form of light-emitting diodes (LEDs), for emitting light. In the illustrated embodiment, three LEDs 31 are provided. The light sources 31 may in particular comprise one or more LED chips. Furthermore, it is conceivable that the LED chips have not just one but a plurality of light-emitting surfaces, preferably separately controllable. In addition, the LED chips or the light emitting Surfaces of the LED chips emit light of different colors and different wavelengths.

The LEDs 31 are at least indirectly attached to heat sinks 36 and communicate with them in terms of heat technology. The heat sinks 36 serve to dissipate the heat generated during the operation of the LEDs 31 and to deliver the heat to the environment. In the illustrated embodiment, each of the light sources 31 is associated with a separate heat sink 36. Of course, it is conceivable that the heat sink 36 are formed as a single heat sink component.

In the beam path of the light emitted by the LEDs 31, primary optics 32 for bundling the light emitted by the LEDs are provided. In the illustrated embodiment, the primary optics 32 are designed as attachment optics made of a transparent material, preferably glass or plastic. The attachment optics 32 each include at least one entrance surface for coupling the light emitted by the LEDs 31, interfaces for total reflection of at least a portion of the injected light and at least one exit surface for coupling at least a portion of the injected light, optionally after reflection at the interfaces. The attachment optics 32 focus the passing light by total reflection at the interfaces and / or refraction at the entrance exit surfaces. In the illustrated embodiment, each of the LED light sources 31 is assigned a separate attachment optics 32.

The light module 30 further has a diaphragm arrangement 33 arranged in the beam path for shading at least part of the light emitted by the LEDs 31 and of the LEDs Primary optics of 32 bundled light. In the illustrated embodiment, the diaphragm assembly 33 lies in a horizontal plane, which preferably comprises an optical axis of the light module 30. The diaphragm arrangement 33 comprises a front edge 34 which serves to generate a light-dark boundary of the light distribution generated by the light module 30. The diaphragm assembly 33 is preferably formed on its upper side and on its underside at least partially mirrored, so that on the top or the bottom of the diaphragm assembly 33 incident light is largely reflected.

Finally, the light module 30 also includes a secondary optical system 35 arranged in the further beam path, which is designed as a projection lens in the illustrated embodiment, for projecting the light which has passed the diaphragm arrangement 33 as light distribution onto the road ahead of the motor vehicle. The front edge 34 of the diaphragm assembly 33 preferably passes through a focal point of the projection lens 35 or in the vicinity of the focal point 35 of the projection lens 35th

At least one of the light sources 31 is arranged together with the primary optics 32 associated therewith above the horizontal plane in which the diaphragm arrangement 33 extends. Likewise, at least one of the LEDs 31 is arranged with the primary optics 32 associated with it below the horizontal plane. In the illustrated embodiment, an LED 31 with its associated primary optics 32 above and two LEDs 31 are arranged with the primary optics 32 associated with them below the horizontal plane. The LEDs 31 and the primary optics 32 assigned to them are designed, aligned and arranged in the light module 30 such that a main emission direction of the primary optics 32 focused light toward the front edge 34 of the shutter assembly 33 is directed. Preferably, the main radiation directions meet at a common point of intersection or an intersection cloud in the horizontal plane of the diaphragm assembly 33 at or near the leading edge 34 of the diaphragm assembly 33 FIG. 2 a first beam path 37 is shown, which is formed by the arranged above the horizontal plane LED 31 and the associated projection optics 32.

In FIG. 3 a measuring screen 38 arranged at a distance from the light module 30 or the vehicle headlight 1 is shown. On the measuring screen 38, a horizontal axis HH and a vertical axis VV are shown, which intersect at a point HV. On the measuring screen 38, a first light distribution generated by the first beam path 37 is indicated and designated in its entirety by the reference numeral 39. The light distribution 39 has an upper horizontal light-dark boundary 40, which runs just below the horizontal axis HH. Areas of the same or similar illuminance are represented by so-called isolux lines 39 ', the illuminance at the outer edge of the light distribution 39 being lower than in the center. The light distribution 39 is, for example, a low-beam light distribution, in particular a basic or fundamental light distribution of a low-beam light distribution, which together with a spotlight light distribution forms a low-beam asymmetrical light-dark distribution which is common in the European Union.

In FIG. 4 is a known light module 30 from FIG. 2 shown corresponding light module, but here another beam path is shown. In FIG. 4 is instead of the first beam path 37, a further beam path 41, which is formed by the light emitted by the LEDs 31 arranged below the horizontal plane and bundled by their associated primary optics 32. In the known light module 30 is in the Figures 2 and 4 clearly recognize that both the first beam path 37 and the further beam path 41 virtually distributed over the entire cross-sectional area of the projection lens 35 pass through it. In addition, the projection lens 35 has a symmetrical in cross section to the optical axis of the light module 30 construction.

The light distribution formed by the further beam path 41 on the measuring screen 38 is in FIG. 5 located and designated in its entirety by the reference numeral 42. The light distribution 42 is bounded below by a horizontal light-dark boundary 43, which runs just below the horizontal axis HH. The light distribution 42 may be referred to as a high beam partial light distribution. The light-dark boundaries 40, 43 of the light distributions 39 and 42 are generated by a projection of the front edge 34 of the diaphragm assembly 33 through the projection lens 35 from the light beams 37 and 41, respectively.

In FIG. 6 is the well-known from the prior art light module 30 of Figures 2 and 4 shown with two marked beam paths 37, 41. In this case, both the LEDs 31 are activated above the horizontal plane and the LEDs 31 below the horizontal plane. The total light distribution resulting from a superposition of the beam paths 37, 41 on the measuring screen 38 is in FIG. 7 shown and designated their entirety by the reference numeral 44. The two individual light distributions 39, 42 border in the area of their Bright-dark boundaries 40, 43 directly to each other and thus form the total light distribution 44 of the light module 30. The total light distribution 44 may be referred to as a high beam distribution.

In the known light module 30, therefore, the resulting light distribution 39, 42, 44 by activating or deactivating individual LEDs 31 or LED groups, each comprising at least one of the LEDs 31 are varied. The total light distribution 44 results from a superimposition of the light bundles 37, 41 generated by the activated LEDs 31 or the activated LED groups.

The Figures 2 . 4 and 6 Thus, the structure of a known low-beam high-beam Bifunktions projection module 30 with three LED light sources 31 and also many TIR (Total Internal Reflection) -Primäroptiken 32. The low-beam light path 37 is on both sides mirrored diaphragm assembly 33 in the focal plane of the projection lens 35 limited so that the light-dark boundary 40 is formed. The high-beam beam path 37 and 41 is formed as a cumulative light distribution 44 by the low beam beam path 37 and the high beam partial beam path 41.

The problem with the known light module 30 is that in the resulting total light distribution 44 in the region of the light-dark boundaries 40, 43 of the individual light distributions 39, 42, shadows and / or stripes form which cause a disturbing inhomogeneity of the resulting light distribution 44. These inhomogeneities in the resulting total light distribution 44 can be prevented with the present invention, or at least significantly reduced.

In FIG. 8 an inventive light module is designated in its entirety by the reference numeral 20. The light module 20 largely corresponds to the known light module 30 from the basic construction. It differs from the known light module 30 in particular in that the projection lens 21 is designed in a special way. A horizontal axis 45 (see. FIGS. 11 to 15 ) of the light module 30 extends in the main propagation direction of the light. The axis 45 may pass through the thickest portion of the lens 21. The projection lens 21 has a center region 22 extending around the axis 45 of the light module 20. In FIG. 8 a first beam path 23 is shown, which is generated by the arranged above the horizontal plane LED 31 and the primary optics 32 associated therewith. The first beam path 23 serves to generate a first light distribution on a measuring screen. The first light distribution is, for example, a low beam distribution or a basic or base low beam light distribution according to the light distribution 39 FIG. 3 , The LED 31 arranged above the horizontal plane and the primary optics 32 associated therewith are arranged, aligned and designed in the light module 20 such that the beam path 23 predominantly, preferably completely, passes through the projection lens 21 in the center region 22.

In FIG. 9 is the light module 20 of the invention FIG. 8 drawn with a further beam path 24. The further beam path 24 is generated by the LEDs 31 arranged below the horizontal plane and the primary optics 32 assigned to them. The further beam path 24 serves to generate a further light distribution on a measuring screen. The further light distribution is, for example, a high-beam partial distribution, however, with slight deviations from the light distribution 42 FIG. 5 , in particular with regard to the position of the lower bright-dark boundary 43 '(cf. FIG. 10 ). The LEDs 31 arranged below the horizontal plane and the primary optics 32 assigned to them are arranged, aligned and / or configured in the light module 20 such that the further beam path 24 largely, preferably completely, passes through edge regions 25 of the projection lens 21. The center region 22 and the edge regions 25 of the projection lens 21 are preferably formed as separate, mutually separate regions and do not overlap. However, slight overlaps of the edges of the regions 22, 25 are conceivable without affecting the present invention and the advantages associated therewith. It is crucial that the light beams 23, 24 generated by the various LEDs 31 pass through clearly defined areas of the projection lens 21, the areas having at most slight overlaps. The projection lens 21 thus has at most few and in terms of area with respect to the total passage area of the lens 21 small areas through which light from both light bundles 23, 24 passes. At most, a very small proportion of the light beams 23, 24 pass through these common areas.

The particular configuration of the projection lens 21 with the different regions 22, 25 through which different beam paths 23, 24 generated by different light sources 31 of the light module 20 can pass allows the projection lens 21 in the different regions 22, 25 with respect to their refractive properties to specifically change and optimize such that dark shadows or light stripes or a color fringe in the resulting total light distribution of the light module 20 (corresponding to the light distribution 44 FIG. 7 ) can be significantly reduced and possibly even completely avoided.

It is conceivable that the in FIG. 8 drawn first beam path 23 corresponds to a low-beam light path and on a measuring screen 38 in about one of the light distribution 39 from FIG. 3 generates corresponding light distribution. Further, the further beam path 24 correspond to a high-beam partial beam path and on a measuring screen 38 a in FIG. 10 produce light distribution shown 42 '. In order to avoid shadows or stripes and a fringe of color in the resulting total light distribution in the light module 20 according to the invention, those regions 25 of the projection lens 21 through which the at least one further light bundle 24 generated by the light sources 31 below the horizontal plane passes are formed such that the Light-dark boundary 43 'of the at least one further light beam 24 below the light-dark boundary 40 of the at least one first light beam 23 is arranged. In the embodiment FIG. 10 the entire further light distribution 42 is lowered by the variation of the lens 21 in the areas 25, so that the lowered further light distribution 42 'with the downwardly shifted light-dark boundary 43' results.

It is based on the FIG. 10 clearly recognizable that the resulting light bundle 42 'by the proposed inventive design of the projection lens 21 in the edge regions 25 by a value ΔΦ further down, so that the light-dark boundary 43' of the other generated by the other light beam 24 further Light distribution 42 'below the light-dark boundary 40 of the light distribution generated by the at least one first light beam 23 (corresponding to the light distribution 39 from FIG. 3 ) runs.

Overall, a vertical lowering of the high-beam partial light distribution 42 'results through a corresponding configuration of the edge regions 25 of the projection lens 21.

The low-beam beam path 23 and the high beam partial beam path 24 are thus imaged by different lens areas 22, 25 in the present invention. In the in the FIGS. 8 and 9 In the embodiment shown, the low-beam light beam 23 is imaged through the center region 22 of the lens 21 and the high-beam partial beam path 24 through the edge regions 25 on both sides of a meridional section through the projection lens 21. Of course, it would also be conceivable that the Abblendlichtstrahlengang 23 is imaged through the edge regions 25 of the projection lens 21 and the high-beam partial beam path 24 through the center region 22. In this case, then the center region 22 of the projection lens 21 would have to be formed such that the in FIG. 10 shown lowering the high beam partial light distribution 42 ', in particular the reduction of the bright-dark boundary 43', results. Furthermore, it would be conceivable to subdivide the projection lens 21 not only into two different subregions 22, 25 but into more than two subregions. In addition, it would be conceivable to subdivide the projection lens 21 into differently shaped subregions 22, 25, for example upper and lower edge regions.

FIG. 11 shows a longitudinal section through the light module 20 according to the invention along the axis 45 of the Module 20. The sectional view off FIG. 11 includes, inter alia, a meridional section through the center of the projection lens 21, ie along the axis 45. A rearward lens vertex is designated by the reference numeral 26 and a front lens vertex by the reference numeral 27. The two lens vertices 26, 27 form contact points of the largest inscribed circle 28 in the illustrated lens cross-section. In the exemplary embodiment illustrated, the vertices 26, 27 lie on the axis 45 of the light module 20.

In FIG. 12 By way of example, a plurality of vertical sections, each designated by the reference numeral 29, are drawn through the projection lens 21. A vertical section through the lens center forms the meridional section 29 '. It can be clearly seen that the front and the rear points 26, 27 of the lens cross-sections 29 are lowered on both sides of the meridional section 29 'in the vertical direction. The regions of the lens 21 with lowered lens cross-sections 29 are designated by the reference numeral 21 'and lie in the illustrated embodiment in the edge regions 25 of the projection lens 21. In the region around the lens center, ie in the center region 22 of the projection lens 21 are the vertices 26, 27 formed unchanged and not lowered. The front lens crests 27 of the lens cross sections 29 lie on a solid line drawn by the reference numeral 27 'designated virtual line. Accordingly, the rear lens vertices 26 lie on a dashed line and designated by the reference numeral 26 'virtual line. It can be clearly seen that the virtual lines 26 'and 27' and thus also the vertices 26, 27 are lowered towards the edge regions 25.

Of course, it would also be conceivable to lower only the front vertices 27 or only the rear vertices 26 of the projection lens 21.

The FIGS. 13 to 15 show various views of the projection lens 21 of the light module 20 according to the invention according to a preferred embodiment. FIG. 13 shows a side view of the projection lens 21, FIG. 14 shows a vertical section along the line AA FIG. 13 perpendicular to the axis 45 of the light module 20 through the lens 21, and FIG. 15 shows the projection lens 21 with the vertical section in a perspective view. In the FIGS. 14 and 15 is clearly the hatched drawn, egg-shaped, tapering upwards sectional contour of the projection lens 21 recognizable. Overall, the projection lens 21 of the light module 20 according to the invention has a relation to the axis 45 symmetrical projection lenses 35 of conventional light modules 30 has a lower overall height. As a result, large angles of the light rays to the horizontal plane can be avoided, which reduces the color aberrations of the image in the resulting light distribution 39, 42 ', 44. In addition, the projection lenses 21 according to the invention are stylistically and structurally advantageous due to their lower height.

In the embodiment described above, the invention is described with reference to a combination of low beam and high beam. Of course, the present invention can also be used for any other combinations of different light functions (eg dipped beam, cornering light, fog light, daytime running light, high beam, etc.).

When the shutter assembly 33 extends in a horizontal plane and has a leading edge 34 which the projection lens 21 as the light-dark boundary 40, 43 'of the light distribution 39, 42', 44 on the roadway, cut preferably Hauptabstrahlrichtungen of the light sources 31 and - if present - generated by the primary optics 32 light beams 23, 24, the horizontal plane or in the vicinity of the front edge 34 of the diaphragm arrangement 33. The light sources 31 are preferably designed as semiconductor light sources, in particular as light emitting diodes.

Claims (15)

1. Lighting module (20) for a motor vehicle headlamp (1) for creating a variable light distribution (39, 42', 44), the lighting module (20) comprising

   - several light sources (31) for emitting light,

   - a screen arrangement (33) for shadowing at least a part of the emitted light, and

   - a projection lens (35) for projecting at least a part of the light passing through the screen arrangement (33) as light distribution (39, 42', 44) on a road in front of the vehicle,

   and the light distribution (39, 42', 44) can be varied by activating or deactivating light source groups each comprising at least one of the light sources (31), and the light distribution (39, 42', 44) is created by superimposing light bundles (23, 24) generated by the light sources (31) of the activated light source groups, and at least a first light bundle (23) generated by the at least one light source (31) of an activated first light source group is used to create a first partial light distribution (39) below an essentially horizontal cut-off line (40), and at least another light bundle (24) generated by the at least one light source (31) of another activated light source group is used to create another partial light distribution (42') above an essentially horizontal cut-off line (43'), characterised in that the lighting module (20) is configured so that the light bundles (23, 24) generated by the first light source group and the other light source group pass through different regions (22, 25) of the projection lens (21) and in the regions (25) through which the at least one other light bundle (24) generated by the other light source group passes, the projection lens (21) is designed so that the cut-off line (43') of the other partial light distribution (42') is disposed below the cut-off line (40) of the first partial light distribution (39).
2. Lighting module (20) as claimed in claim 1, characterised in that, based on a projection lens which is of symmetrical design with respect to an optical axis or with respect to the projection of the optical axis in every vertical section in a plane parallel with the optical axis, vertices (26, 27) of the projection lens (21) forming the contact points at the lens contour of the biggest circle (28) inscribed in a vertical section are downwardly inclined in the regions (25) of the projection lens (21) through which the at least one other light bundle (24) generated by the other light source group passes.
3. Lighting module (20) as claimed in claim 1 or 2, characterised in that the at least one other light bundle (24) generated by the other light source group passes through peripheral regions (25) of the projection lens (21).
4. Lighting module (20) as claimed in claim 3, characterised in that in vertical sections (29) through peripheral regions (25) of the projection lens (21) and parallel with a meridional section (29') of the projection lens (21), vertices (26, 27) of lens section contours are downwardly inclined in the vertical direction relative to a section contour of the meridional section (29').
5. Lighting module (20) as claimed in claim 4, characterised in that the downwardly inclined vertices (26, 27) of the vertical lens section contours through the peripheral regions (25) of the projection lens (21) are downwardly inclined symmetrically relative to the meridional section (21').
6. Lighting module (20) as claimed in claim 4 or 5, characterised in that the vertices (26, 27) of the vertical lens section contours through the peripheral regions (25) of the projection lens (21) are downwardly inclined constantly from the meridional section (29') to the lens edges.
7. Lighting module (20) as claimed in one of claims 4 to 6, characterised in that vertices (26, 27) of vertical lens section contours through a centre region (22) of the projection lens (21) are not downwardly inclined.
8. Lighting module (20) as claimed in claim 1 or 2, characterised in that the at least one other light bundle (24) generated by the other light source group passes through a centre region (22) of the projection lens (21).
9. Lighting module (20) as claimed in claim 8, characterised in that in vertical sections (29) through the centre region (22) of the projection lens (21) and parallel with a meridional section (29') of the projection lens (21), vertices (26, 27) of lens section contours are downwardly inclined relative to a section contour of vertical sections through peripheral regions (25) of the projection lens (21) and parallel with the meridional section (29').
10. Lighting module (20) as claimed in claim 8 or 9, characterised in that vertices (26, 27) of vertical lens section contours through peripheral regions (25) of the projection lens (21) are not downwardly inclined.
11. Lighting module (20) as claimed in one of claims 1 to 10, characterised in that primary optical systems (32) for bundling the emitted light co-operate with the light sources (31).
12. Lighting module (20) as claimed in claim 11, characterised in that the primary optical systems (32) are provided in the form of supplementary optical systems made from a transparent material which have entrance surfaces for coupling in the light emitted by the light sources, boundary surfaces for producing a total reflection of at least a part of the coupled light and exit surfaces for coupling out at least a part of the coupled light selectively after a reflection at the boundary surfaces, and the light passing through a supplementary optical system by means of total reflection at the boundary surfaces and/or refraction at the entrance and/or exit surfaces is bundled.
13. Lighting module (20) as claimed in one of claims 1 to 12, characterised in that the screen arrangement (33) extends in a horizontal plane and has a front edge (34) which the projection lens (21) images as a cut-off line (40, 43') of the light distribution (39, 42', 44) on the road.
14. Lighting module (20) as claimed in one of claims 1 to 13, characterised in that the projection lens (21) has means for applying colour correction.
15. Motor vehicle headlamp (1) having a lighting module (6; 21) for creating a variable light distribution (39, 42', 44), characterised in that the lighting module (21) is as claimed in one of claims 1 to 14.

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