Illumination device of a motor vehicle headlamp

Lighting device of a motor vehicle headlamp, comprising a lens (1, 10) and at least one light source (2), wherein a lighting pattern (LI) can be generated by the at least one light source (2), wherein the lighting pattern (LI) generated by the light source (2) can be projected in front of the lighting device in the form of a light distribution by means of the lens (1, 10), wherein the lens (1, 10) has at least one projection optics (3, 30, 31) and one projection optics holder (4, 40), wherein at least one receiving means (5, 50, 51) is designed in the projection optics holder (4, 40), wherein the at least one receiving means (5, 50, 51) corresponds to the at least one projection optics (3, 30, 31), the at least one projection optics (3, 30, 31) is accommodated in the at least one receiving means (5, 50, 51), wherein a reference point system (6, 60, 61) is defined in the at least one receiving means (5, 50, 51) for determining a position of the projection optics (3, 30, 31) accommodated in this receiving means (5, 50, 51) in such a way that the lighting pattern (LI) is essentially located in a focal plane of the lens (1, 10), wherein reference points (6-1 to 6-6, 60-1 to 60-16, 61-1 to 61-10) of the reference point system (6, 60, 61) are arranged according to the 3-2-1 rule, wherein the at least one receiving means (5, 50, 51) is closed by means of a closing element (7, 70) in such a way that the at least one projection optics (3, 30, 31) is fixed and held in the at least one receiving means (5, 50, 51) in the position determined by the reference point system (6, 60, 61).

The invention relates to a lighting device of a motor vehicle headlight, in particular a lighting device that functions according to a projection principle. The lighting device comprises at least one light source and a lens for projecting a lighting pattern producible by means of this at least one light source in the form of a light distribution in front of the lighting device. When the lighting device is installed in a motor vehicle headlight, the activated lighting device forms the light distribution in front of the motor vehicle headlight or in front of a motor vehicle if the motor vehicle headlamp is already installed in the motor vehicle. Preferably, the at least one light source comprises a surface on which it can produce the lighting pattern and, when it is switched on, generates this lighting pattern on the surface. In particular, the at least one light source can generate the lighting pattern on a side of the surface facing the lens. The lens comprises at least one projection optics and one projection optics holder, wherein at least one receiving means is designed in the projection optics holder, wherein the at least one receiving means corresponds to at least one projection optics and the at least one projection optics is accommodated in the at least one receiving means.

In addition, the invention relates to a motor vehicle headlight with at least one such lighting device.

The at least one projection optics can be a lens, for example a biconcave, biconvex, flat-concave, flat-convex lens or a lens system of such lenses. In the context of the present invention, the term “lens” is understood to mean a diffusing optical system that generates a real optical representation (light distribution in front of the lighting device) of an object (lighting pattern). The simplest lens can include a single lens element. It is understood that when the light source is not switched on, the lens generates an image of a switched-off light source, preferably of the surface on which the light source can generate the aforementioned lighting pattern.

Lighting devices of the aforementioned type are known from the prior art, see for example AT 517126 B1, DE 102012213842 A1.

In the lighting devices known from the prior art, complex positioning devices are used for the exact positioning of the lens or of the projection optics in the lens. This results in a long tolerance chain, which leads to high processing costs during manufacturing. The positioning device known from AT 517126 B1 is furthermore designed only for rotationally symmetrical lenses.

It is therefore an object of the present invention to create a lighting device which can be adjusted without complex positioning devices, wherein the lens of the lighting device is not limited to containing rotationally symmetrical lenses, and in which lighting device the tolerance chain is shortened, in particular in the lens.

According to the invention, this object is achieved in that a reference point system is defined in the at least one receiving means for determining a position of the projection optics accommodated in this receiving means in such a way that the lighting pattern is essentially located in a focal plane of the lens, wherein reference points of the reference point system are arranged according to the 3-2-1 rule, wherein the at least one receiving means is closed by means of a closing element in such a manner that the at least one projection optics is fixed in the at least one receiving means and held in the position determined by the reference point system.

In the context of the present invention, the term “lighting pattern essentially located in a focal plane of the lens” is understood to mean that lighting pattern which is located in a plane which is arranged at least parallel to the focal plane and preferably coincides with the focal plane. Small inaccuracies of positioning considered acceptable in the subject field, in front of or behind the focal plane, are permitted, especially if a certain blurring of light-dark transitions in the light distribution is to be achieved.

In the context of the present invention, the term “3-2-1 rule” is understood to mean a rule known from the field of tolerance management.

The aforementioned closing element may be designed correspondingly; it may, for example, have a corresponding shape to close the corresponding receiving means. The closing element may, for example, be designed as one of the projection optics that closes the corresponding receiving means—on the inside relative to the projection optics holder. However, the closing element can also be designed as a fastening clip, which encloses the projection optics holder at an open end, for example in the manner of a frame, and closes the corresponding receiving means—on the outside relative to the projection optics holder (see drawings).

The closing element can also prevent the projection optics from falling out of the receiving means. However, a clearance of the at least one projection optics fixed and held in the receiving means corresponding to this projection optics is not excluded. For example, this clearance can simplify inserting the projection optics into the receiving means and facilitate mounting the projection optics in the projection optics holder.

In a preferred embodiment, the projection optics holder may be designed as a single piece. In a particularly advantageous embodiment, the projection optics holder may be made of magnesium diecast. However, it is also conceivable that the projection optics holder is designed as a plastic injection-moulded part. In addition, it is conceivable that the projection optics holder is produced by thixomoulding or thixoforming. The choice of the manufacturing process for the projection optics holder depends on how high the accuracy requirements are or how low the tolerance fluctuations are permitted to be in the production. Plastic injection moulding is a very inexpensive method. Die-casting methods are more expensive than plastic injection moulding but allow for smaller tolerances. Thixomoulding is more expensive than die casting but allows for even smaller tolerances than die casting. In addition, overmilling would be possible as a separate method step. However, overmilling is very expensive, but allows for a flexible adjustment of a predefined target dimension.

It may be expedient if the projection optics holder has a handling area that protrudes from opposite sides of the projection optics holder. The handling area may be provided to enable simple, preferably automatic, handling or simple gripping of the projection optics holder. For this purpose, the handling area may, for example, have tabs or tab-shaped elements extending laterally from the projection optics holder. The handling area can, e.g., be gripped (automatically) by an industrial robot that allows a precise longitudinal adjustment in the axial direction or in the direction of the optical axis of the lighting device. A lighting device having a lens designed in this manner makes it possible to improve the quality of the optical representation in a particularly easy manner. In particular, the image sharpness can be adjusted more precisely, and imaging errors can be at least partially compensated for, which errors are caused by lens shape deviations, lens thickness tolerances or the like. This can be particularly advantageous for those lighting devices that are used to generate logo projections and thus require a high image sharpness.

In a particularly preferred embodiment, the lens may comprise at least two projection optics and at least two receiving means are designed in the projection optics holder, wherein each receiving means corresponds to a projection optics and different receiving means correspond to different projection optics, wherein each projection optics is accommodated in a receiving means corresponding to this projection optics and different projection optics are accommodated in different receiving means. A reference point system is defined in each receiving means for determining the position of the projection optics accommodated in this receiving means. Preferably, different reference point systems are defined in different receiving means. As already described, the reference points of each reference point system are arranged according to the 3-2-1 rule, wherein the reference points of the different reference point systems are designed in such a way that all specified positions of the projection optics are coordinated with each other in such a way that optical axes of the different projection optics coincide and that the lighting pattern is located in the focal plane of the lens.

It can be advantageous if the receiving means are of different sizes. Each receiving means may have a constant size (neither tapering nor widening).

In addition, it may be advantageous if the size of the receiving means gradually decreases toward the at least one light source, for example. For example, a receiving means located closest to the at least one light source may be the smallest.

Furthermore, it is advantageous if each receiving means is closed by means of a closing element, wherein at least one of the closing elements is designed as one of the at least two projection optics. The different projection optics and, consequently, the different receiving means, can be of different sizes. For example, one of the projection optics may consist of two or more partial lenses, which, for example, could be of different sizes, such that the corresponding receiving means consist of two or more partial receiving means, wherein each of the partial receiving means is designed for accommodating a corresponding partial lens. In addition, further reference points may be provided between the partial lenses, which reference the partial lenses to each other, for example in the direction of the optical axis.

Further lighting advantages arise if the at least two projection optics are designed in such a way that the lens has an apochromatic effect. This makes it possible to reduce a colour fringe around a cut-off line in a low beam distribution or to reduce lateral chromatic aberrations, for example.

Further advantages arise if the reference points of the reference point system are arranged according to the area principle or translation-rotation-constraint principle of the 3-2-1 rule.

It is also advantageous if the at least one receiving means has a bottom portion and at least three of the reference points are designed as referencing elements, wherein the at least three referencing elements are arranged between the receiving means bottom and the at least one projection optics, are accommodated in the at least one receiving means, make contact with both the receiving means bottom and the projection optics, and define a primary plane of the reference point system, which is preferably arranged essentially parallel to the receiving means bottom. In the case of multiple receiving means, this preferably applies to each receiving means. The receiving means bottom may be (at least partially) formed by a projection optics or a bottom of the projection optics holder. For example, the at least one projection optics can rest on the referencing elements. Furthermore, the referencing elements may be designed on the at least one projection optics, on one of the partial lenses or on the projection optics holder. In the case of multiple projection optics, the corresponding primary planes are preferably positioned parallel to each other.

In the context of the present invention, the term “bottom of the projection optics holder” is understood to mean a surface arranged perpendicular to the optical axis opposite an opening of the projection optics holder. Therein, the opening of the projection optics holder is understood to be that opening through which the projection optics is/are inserted into the projection optics holder. Thus, the term “receiving means bottom” is understood to mean a surface that is arranged perpendicular to the optical axis.

In addition, it may be advantageous if four referencing elements are provided in the at least one receiving means (and all four define the same primary plane). The fourth referencing element helps prevent, for example, a tilting of the projection optics in the receiving means. In the case of multiple receiving means, it may be expedient if four referencing elements are arranged in each receiving means.

In a particularly advantageous embodiment, the referencing elements may be designed as protrusions, preferably as ridges, in particular as convex ridges, extending in the direction of the optical axis. For example, the referencing elements may be designed as a hemisphere which is flattened at the top. The aforementioned reference or primary plane can be defined by the ends of the referencing elements.

Particular advantages may arise if the referencing elements are designed on the projection optics holder and/or on the at least one projection optics, preferably such that they form a monolithic structure with the projection optics holder and/or with the at least one projection optics. It can be advantageous if one or more projection optics (or partial lenses) have six, eight or more referencing elements. It is particularly advantageous if the referencing elements are designed on the projection optics, namely on the optically ineffective surfaces of the projection optics.

In addition, it can be advantageous if the referencing elements are designed as spacers.

Further design advantages may arise if the projection optics holder and/or the at least one projection optics have/has counter elements corresponding to the referencing elements. The counter-elements may be designed, for example, as indentations, recesses, holes (blind or through holes) corresponding to the protrusions or the spacers, with which the protrusions or the spacers can engage at least partially.

It may be expedient if the at least one receiving means has a side wall, for example adjacent to the receiving means bottom, wherein at least two more of the reference points—those which are not designed as referencing elements—are designed as centring elements or are determined by centring elements. The side wall does not have to be designed in a single piece. For example, the side wall of the receiving means may be formed by a side wall of the projection optics holder or partly by a side wall of the projection optics holder and partly by the closing element.

It may be advantageous if the at least two centring elements are arranged between an interior circumference of the side wall and the at least one projection optics accommodated in the at least one receiving means, touch both the side wall and the projection optics and restrict a movement of the at least one projection optics along the primary plane. It should be noted that, in an assembled state of the lens, not all projection optics have to make contact with the corresponding centring elements. A certain amount of clearance between the projection optics and the centring elements is therefore permissible. If necessary, however, this clearance can be reduced and even completely eliminated by means of spring parts (elastic elements), for example.

It may be useful if the centring elements are designed on the interior circumference of the side wall of the projection optics holder and preferably form a monolithic structure with the projection optics holder.

In a particularly favourable embodiment, the centring elements may be designed as centring ridges extending in the direction of the optical axis, preferably flattened at the top. The longitudinal direction of these ridges may coincide with the direction of the optical axis. In addition, the centring ridges can protrude from the interior of the projection optics holder toward the centre of the lens, preferably perpendicular to the optical axis.

The centring elements can also be designed as centring ridges which have a triangular shape in a sectional view which extends perpendicular to the optical axis, which are connected by means of a bar and which form a V-shape, into which a rotationally symmetrical projection optics can be inserted particularly well. This means that such bars can form a receiving means which is V-shaped (on its lower side), which is particularly suitable for rotationally symmetrical lenses.

In addition, it may be expedient if the at least one projection optics has counter-elements corresponding to the centring elements, for example recesses.

In addition, the at least one receiving means may have a receiving opening, wherein the closing element closing the at least one receiving means is designed such, and is arranged in the receiving opening such, that the light emitted from the at least one projection optics accommodated in the at least one receiving means can pass through the closing element. In the case of multiple receiving means, this preferably applies to each receiving means and each closing element. For this purpose, the closing element may, for example, have an opening.

The closing element can be designed as a fastening clip.

It may be useful if the fastening clip is attached to the projection optics holder in such a way that it pushes the at least one projection optics accommodated in the projection optics holder at least in a direction opposite to the direction of an optical axis of the lens. Preferably, the at least one projection optics is thus fixed in the projection optics holder in such a way that it can no longer move along the optical axis. In the case of multiple projection optics, all projection optics can be fixed by the fastening clip in the direction of the optical axis. This means that the fastening clip clamps the projection optics in the projection optics holder, such that a clearance between the optics in the direction of the optical axis is no longer possible.

In a preferred embodiment, a receiving opening may be designed at that end of the projection optics holder which is located the farthest from the at least one light source. In this case, the fastening clip may be attached to this end of the projection optics holder. For example, the fastening clip may have locking openings corresponding to the locking catches designed at this end of the projection optics holder, such that the fastening clip can lock onto the projection optics holder. The locking catches may be designed on an exterior circumference of the end of the projection optics holder, for example. The fastening clip can surround the (open) end of the projection optics holder in the manner of a frame, for example. In the case of multiple projection optics, it may be expedient if the fastening clip pushes all projection optics toward the light source, i.e., in the direction of the light source or in the opposite direction to the optical axis. For this purpose, the fastening clip may, for example, have two protrusions.

In this case, it may be advantageous if the fastening clip has at least two protrusions in the form of ridges on its side facing the at least one light source, which ridges preferably protrude from the fastening clip in the direction opposite to the direction of the optical axis. This increases the accuracy of pressing the projection optics into the projection optics holder. The number of ridges—at least two—has the advantage that the projection optics which are in contact with the ridges are less susceptible to tilting.

In addition, the at least one light source may comprise a spatial light modulator, in particular a DMD chip, and may be able to generate the lighting pattern on the spatial light modulator. The mirror array of the spatial light modulator may be located in a focal plane of the lens. Thus, the surface on which the lighting pattern can be formed may be designed as a mirror array.

However, the surface can also be designed as a light-emitting surface of one or more LEDs or a light-converting plate, which can be illuminated with a laser light source.

The at least one light source may comprise semiconductor-based elements, such as laser diodes and/or LEDs.

In a preferred embodiment, it may be advantageous if the lens furthermore comprises at least one, preferably two-dimensional, in particular flat aperture device. Therein, the aperture device can extend perpendicular to the optical axis.

It may be useful if the at least one aperture device has an aperture edge that is continuous within itself.

It may be advantageous if the at least one aperture device is designed as a receiving means bottom.

Further advantages may arise if the at least one aperture device is formed as a separate plate, which is preferably arranged perpendicular to the optical axis of the lens.

The at least one aperture device can be used to further improve the quality of the light distribution. If multiple aperture devices are provided, they can be used to correct different optical errors.

In one embodiment, it may be expedient if the separate plate has through-openings. The through-openings may, for example, be designed such that they match the referencing elements designed as ridges. When assembled, the ridges can be accommodated in the through-openings. This makes it possible to specify the position of the plate in the lens relative to the projection optics.

Further advantages may arise if the at least one aperture device has at least one (preferably two) elastic tab(s). As a result, the projection optics(s) can be better clamped in the projection optics holder. Two elastic tabs reduce tilting. In general, reducing tilting reduces decentration errors.

For example, two tabs may be arranged on the side of the aperture edge which is continuous within itself.

A particularly advantageous embodiment results if the at least one projection optics consists of two partial lenses and preferably has an achromatic effect. This can, for example, reduce longitudinal chromatic aberrations. At least three further referencing elements may be provided between the partial lenses. This can be a so-called achromat (see, e.g., DE 10 2010 046 626 84 and in particular paragraphs [0009] to [0013]). One of the two partial lenses may be, for example, biconvex or plano-convex, wherein the other one may be designed in a biconcave or plano-concave shape.

Furthermore, it may be advantageous if the lens comprises elastic elements that are set up to clamp the at least one projection optics in the at least one receiving means. The elastic elements may, for example, be arranged in the projection optics holder and in particular may be integrally designed with the same.

In a preferred embodiment, the lighting device may be designed as a light module. This means that the lighting device forms an assembly when mounted and does not consist of structurally separated elements or subunits.

In addition, it should be clear that direction-related terms such as “horizontal”, “vertical”, “top”, “bottom”, etc. are to be understood in connection with the present invention to have a relative meaning and refer either to the aforementioned appropriate installation position of the subject matter of the invention in a motor vehicle or to a customary orientation of a radiated light distribution in the lighting pattern or in the space to be travelled through.

First, reference is made toFIG.1ato1c.These show a lighting device designed as a light module for a motor vehicle headlight with a lens1and a light source2. The light source2can generate a lighting pattern LI. As can be seen inFIG.1ato1c,the light source2may comprise a surface on which it can generate the lighting pattern LI. In particular, the at least one light source can generate the lighting pattern LI on a side of the surface facing the lens1. This surface may be designed, for example, as a surface of a micromirror array of a spatial light modulator, such as a DMD chip, as a surface of a light-converting means (phosphorus), which can convert light from a laser diode source into essentially white light, as a light-emitting layer of an LED, or as a light-emitting surface of an attachment optics (made of silicone), for example a TIR lens. When the lighting device is switched on, the light source2thus generates the lighting pattern LI, which is projected by the lens1in front of the lighting device in the form of a light distribution. The lens1has at least one projection optics3and one projection optics holder4. A receiving means5corresponding to the projection optics3is designed in the projection optics holder4. The projection optics3is accommodated in the at least one receiving means5. The projection optics3may be, for example, a lens, for example a rotationally symmetrical lens (seeFIG.1ato1c). A reference point system6is defined in the at least one receiving means5, i.e., a system of reference points6-1to6-6, which specify a position of the projection optics3accommodated in the receiving means5. The position is specified in such a way that the lighting pattern is essentially located in a focal plane of the lens1. Therein, the term “essentially located in a focal plane” is taken to mean that the lighting pattern is located at least in a plane which is arranged parallel to the focal plane and preferably coincides with the focal plane, wherein this phrase also covers small, unavoidable inaccuracies commonly accepted in the art with regards to the positioning of the lighting pattern in front of or behind the focal plane.

The reference points6-1to6-6of the reference point system are arranged according to the 3-2-1 rule. This refers to the 3-2-1 rule known from the field of tolerance management, which is less commonly also referred to as the 3-2-1 principle.

In order to fix and hold the projection optics3in the position specified by the reference point system6in the receiving means5, a closing element7is provided. Preferably, the closing element7prevents the projection optics3from falling out of the receiving means5. The closing element7closes the projection optics3in the receiving means5in such a way that it pushes onto the projection optics3from preferably two directions (shown inFIG.1bwith arrows F), in which the projection optics3located in the above position can “fall out” of the receiving means5, and thus fixes and holds the projection optics3in the position specified by the reference point system6. Nevertheless, a certain clearance in the YZ plane, which is considered tolerable in the art, may be permissible.

The projection optics holder4can be designed as a single piece. For example, it can be made from magnesium diecast. However, a plastic injection-moulded part or thixomoulding is also conceivable. This is decided according to the required accuracy requirements (tolerance fluctuations in production) required by the optical design. For very high requirements, post-processing, e.g., milling of the reference surfaces, is also conceivable.

FIG.2is an exploded view of a lighting device with a light source2and a lens10, wherein more than one projection optics is accommodated in the lens10. Specifically,FIG.2shows a lens10with a projection optics holder40, in which two projection optics30,31are accommodated, wherein one of the projection optics30,31—the projection optics30—consists of two partial lenses30aand30b. The projection optics30,31are not rotationally symmetrical. A projection optics30consisting of two partial lenses30aand30bcan reduce achromatic errors, such as, e.g., longitudinal chromatic aberrations.

The projection optics holder40has a handling area40a. For example, the handling area40ais arranged at the end of the projection optics holder40closest to the light source2. The handling area40amay also be arranged in another place along the longitudinal direction X of the projection optics holder40. The handling area40amay, as already described, serve to facilitate automated gripping of the lens10and may include laterally protruding tabs with bars protruding upwards.

Two receiving means50,51are designed in the projection optics holder40for accommodating the projection optics30,31. Each receiving means50,51corresponds to a projection optics30,31and the different receiving means50,51correspond to different projection optics30,31. Therein, each projection optics30,31is accommodated in one of these receiving means50,51corresponding to the projection optics30,31. Different projection optics30,31are accommodated in different receiving means50,51.

A reference point system60,61is defined in each receiving means50,51for specifying the position of the projection optics30,31accommodated in the respective receiving means50,51. As already described above, the reference points60-1to60-16,61-1to61-10of each reference point system60,61are arranged according to the 3-2-1 rule. Therein, the reference points60-1to60-16,61-1to61-10of the different reference point systems60,61are designed in such a way that all specified positions of the projection optics30,31are coordinated with each other in such a way that optical axes of the different projection optics30,31coincide and that the lighting pattern LI is essentially located in the focal plane of the lens10. “Essentially located in the focal plane” means that the lighting pattern LI is located at least in a plane that is arranged parallel to the focal plane and preferably coincides with the focal plane. Small inaccuracies in the positioning, in front of or behind the focal plane, are of course permissible.

Each receiving means50,51is closed by means of a closing element. As indicated inFIG.2(see alsoFIG.4), one of the closing elements, namely the closing element which closes the first projection optics30in its receiving means50, may be designed as the second projection optics31.

Furthermore, it is indicated inFIGS.2to4that the projection optics30,31and the receiving means50,51are of different sizes. This means, for example, that the receiving means50can be smaller than the receiving means51(FIGS.2to4). The size of the receiving means50,51may taper down toward the at least one light source2. In addition,FIGS.2to4indicate that the receiving means50consists of two partial receiving means, wherein each of the partial receiving means is set up/designed for accommodating a corresponding partial lens30a,30b. In addition, three or four, e.g., additional referencing elements (not shown in the drawings) may be arranged between the partial lenses30a,30b, which elements reference the partial lens30bto the partial lens30ain the X direction. The partial receiving means for the first partial lens30amay be smaller than the partial receiving means for the second partial lens30b.

The two projection optics30,31may be designed in such a way that the lens10has an apochromatic effect.

FIGS.1to4further indicate that each of the receiving means has a receiving means bottom, wherein at least three of the reference points are designed as referencing elements arranged between the corresponding receiving means bottom and the at least one projection optics accommodated in the corresponding receiving means. The referencing elements make contact with both the receiving means bottom and the projection optics and are designed in such a way that they define a primary plane YZ—in the sense of the 3-2-1 rule.

Specifically,FIGS.2to4, e.g., indicate that each of the two receiving means50,51has a receiving means bottom50a,51a(the receiving means5inFIG.1ato1calso has a bottom5a). The bottom of the respective receiving means50,51may, for example, be formed either by the upstream projection optics, as is the case with the receiving means51inFIGS.2and4, or by the projection optics holder40, as is the case with the receiving means50(seeFIG.3). This applies mutatis mutandis to the partial receiving means described above (cf.FIGS.2to4). At least three of the reference points are designed as referencing elements60-1to60-4,61-1to61-4, which are arranged between the respective receiving means bottom50a,51aand the respective projection optics30,31. Both the receiving means bottom50a,51ain question and the corresponding projection optics30,31are contacted by the referencing elements60-1to60-4,61-1to61-4. For example, the second projection optics31rests on the referencing elements61-1to61-4, wherein the referencing elements61-1to61-4are designed on the first projection optics30. The first projection optics30, in particular the first partial lens30a, rests on the referencing elements60-1to60-4, which referencing elements are designed on the projection optics holder40.FIG.2shows that these referencing elements61-1to61-4are designed on the second partial lens30b.

The referencing elements60-1to60-4and61-1to61-4each define a different primary plane YZ. The different primary planes are preferably parallel to each other. In addition, it is advantageous if all primary planes YZ are arranged essentially parallel to at least the receiving means bottom50aof the first receiving means50(as seen from the light source).

FIGS.3and4indicate that the referencing elements60-1to60-4(FIGS.3) and61-1to61-4(FIG.4) may be designed as protrusions extending in the direction of the optical axis X. In addition,FIGS.3and4indicate that four referencing elements are provided in each receiving means. The fourth referencing element helps prevent, for example, a tilting of the projection optics30,31in the receiving means50,51. It is quite conceivable that more referencing elements (five, six or more) are provided.

The referencing elements60-1to60-4(FIGS.3) and61-1to61-4(FIG.4) shown here have approximately the shape of a hemisphere flattened at its top. Other geometric shapes of the referencing elements are quite conceivable.

The referencing elements6-1to6-3,60-1to60-4,61-1to61-4can therefore be designed on the projection optics holder4,40and/or on one or more projection optics3,30,31. They can form a monolithic structure with the projection optics holder4,40and/or with at least one projection optics3,30,31. If the referencing elements are designed on the projection optics, it is useful if they are designed on the optically ineffective surfaces of the projection optics.

FIGS.1to4also indicate that the referencing elements6-1to6-3,60-1to60-4,61-1to61-4can be designed as spacers.

Furthermore, it is indicated inFIGS.1to4that the receiving means5,50,51each have a side wall5b,50b,51b. The side wall5binFIG.1ato1cis partly formed by the projection optics holder4and partly by the closing element7. The side walls50b,51binFIGS.2to4are formed by the projection optics holder40. At least two more of the reference points, namely those which are not designed as referencing elements, are designed as centring elements6-4to6-6,60-5to60-16and61-5to61-10, wherein these at least two centring elements6-4to6-6,60-5to60-16and61-5to61-10are arranged between an interior circumference of the side wall5b,50b,51band the projection optics3,30,31accommodated in the corresponding receiving means5,50,51. The centring elements6-4to6-6,60-5to60-16and61-5to61-10make contact with both the side wall5b,50b,51band the projection optics3,30,31and restrict the movement of the at least one projection optics3,30,31along the primary plane YZ.

It should be noted that not all projection optics3,30,31have to make contact with the corresponding centring elements6-4to6-6,60-5to60-16and61-5to61-10when the lens1,10is assembled. This means that some clearance between the projection optics3,30,31and the receiving means5,50,51along the primary plane YZ is permissible. However, a situation is conceivable in which there is no such clearance. For example, spring elements (not shown here) may be provided in the projection optics holder4,40to compensate for the clearance. These spring elements may, for example, be designed integrally with the projection optics holder4,40or as separate inserts.

Preferably, the centring elements6-4to6-6,60-5to60-16and61-5to61-10are designed on the projection optics holder4,40. In the projection optics holder4fromFIG.1ato1c,two centring elements6-4and6-6are designed as two ridges, which are designed in an approximately triangular shape in a cross-section located parallel to the YZ plane and are connected in a lower region of the projection optics holder4by means of a bar to form a V-shape (as seen from the front). The rotationally symmetrical projection optics3, for example a lens, can be inserted in this V-shape. The described V-shape is particularly advantageous when using rotationally symmetrical projection optics. Centring elements that together form a V-shape can also be used with projection optics holders accommodating multiple rotationally symmetrical projection optics.

In the projection optics holder40shown inFIGS.2to4, the centring elements60-5to60-16and61-5to61-10are designed on the interior circumference of the side wall50b,51bof the corresponding receiving means50,51, which wall is formed by the projection optics holder40. Preferably, the centring elements60-5to60-16and61-5to61-10form a monolithic structure with the projection optics holder40.

Specifically, the centring elements60-5to60-16and61-5to61-10are designed in the projection optics holder40as centring ridges extending in the direction of the optical axis X, preferably flattened at their top.

The longitudinal direction of these ridges is the X-direction—the optical axis of the lens10. In addition, the centring elements60-5to60-16and61-5to61-10protrude from the interior of the projection optics holder40toward the centre of the lens10, preferably perpendicular to the optical axis X.

The at least one projection optics30,31may have counter elements60-17to60-22,61-11to61-13corresponding to the centring elements60-5to60-16and61-5to61-10. The counter elements60-17to60-22,61-11to61-13of all lenses30a,30band31are designed as recesses corresponding to the centring ridges. This is particularly evident inFIG.2.

The receiving means5,50,51each have a receiving means opening5c,50c,51c. As already mentioned, each receiving means5,50,51can be, or is, closed by a closing element7,70. The closing element7ofFIG.1ato1cis designed as a (square-shaped) bracket, which, seen laterally, has approximately the shape of a Greek capital letter gamma and, seen from the front, has a centrally arranged opening, such that light emitted from the projection optics3can escape from the lens1. The shape of bracket7can also be different. The closing element7is attached to the projection optics holder4by locking, screwing, clamping or gluing it to the same, for example.

In the lens10fromFIGS.2to4, the first receiving means50is closed by the second projection optics31. The second receiving means51is closed by means of a fastening clip70, which has an opening in the middle from which the second projection optics31protrudes.

The closing elements7,70are designed in such a way that light can be emitted from the corresponding projection optics3,30,31and escape from the lens1,10.

In reference toFIGS.2to4, it is noteworthy that the fastening clip70is attached to the projection optics holder40in such a way that it pushes the at least one projection optics30,31accommodated in the projection optics holder40at least in a direction opposite to the direction of an optical axis X of the lens10. As a result, the projection optics30,31are fixed in the projection optics holder40in such a way that they can no longer move along the optical axis X—thus determining the focal length of the lens10. This means that the fastening clip70clamps the projection optics30,31in the projection optics holder40, such that a clearance between the optics30,31in the direction of the optical axis X is no longer possible. In an advantageous embodiment, which is shown inFIG.2, two protrusions70aare designed on the fastening clip70, which define a preferably horizontal line which extends perpendicular to the optical axis X. The protrusions70a, or ridges, protrude from the fastening clip70in the direction opposite to the direction of the optical axis X. But more than two protrusions70acan also be provided.

In addition, the fastening clip70has locking openings70bcorresponding to the locking catches40bdesigned on the projection optics holder40, such that the fastening clip70can lock onto the projection optics holder40. The locking catches70bare designed on an exterior circumference of the projection optics holder40.

The lens10optionally comprises two, preferably two-dimensional, in particular flat, aperture devices11and12, which are arranged perpendicular to the optical axis X (in the YZ plane). Each aperture device11,12has an aperture edge11a,12awhich is continuous within itself. The (first) aperture device11is designed integrally with, or constitutes, the receiving means bottom50a. The (second) aperture device is designed as a separate plate12. Through-openings12dare provided in the plate, which match the referencing elements9-1to9-4designed as ridges. In the assembled state of the lens10, the ridges9-1to9-4are accommodated in the through-openings12d. This specifies the position of the plate12in the lens10relative to the projection optics30,31. Furthermore, both or only one of the aperture devices11,12may have one or more (preferably two) spring tab(s)12b,12c.FIG.2shows that only the plate12has the spring tabs12b,12c(two in this example). Due to the spring tabs, e.g.,12b,12c, the projection optics30,31are clamped more securely in the corresponding receiving means50,51and the clearance of the projection optics30,31in the YZ plane is reduced. Two spring tabs also reduce the likelihood of tilting. The two tabs12b,12care preferably arranged to the side of the aperture edge12awhich is continuous in itself.

As already described, the first projection optics30fromFIGS.2to4consists of two partial lenses30a,30b.FIG.5shows a section of the lens system fromFIG.2with an XZ plane, i.e., with a plane which defines the optical axis X and the vertical direction Z. The partial lenses30aand30btogether are set up to at least correct longitudinal chromatic aberrations; i.e., they have an achromatic effect. The projection optics30is therefore a so-called air-spaced achromate (see description of the prior art from DE 10 2010 046 626 84 and in particular paragraphs [0009] to) [0013]. An air-spaced achromat has the advantage that multiple parameters are present which enable a more accurate correction of the longitudinal chromatic aberration. These parameters are, for example, the size of the air gap d1, curvatures of the entry and light-emitting surfaces of the partial lenses30a,30b, as well as the material of which the partial lenses30a,30bare made. A three-lens element system has the advantage that the distances d1, d2can be varied to reduce longitudinal and/or lateral chromatic aberrations for further improving the quality of the light distribution generated by the lighting device.

The lighting device described above can be used with advantage in a motor vehicle headlight.

The object of the above description merely is to provide illustrative examples and to indicate further advantages and peculiarities of the present invention. The above description cannot therefore be interpreted as a restriction of the field of application of the invention or the patent rights claimed in the claims. In the above detailed description, for example, various features of the invention are summarized in one or more embodiments for the purpose of streamlining the disclosure. This type of disclosure is not to be understood as reflecting the intention that the claimed invention requires more features than those expressly mentioned in each claim. Rather, as the following claims reflect, inventive aspects are present in fewer than all features of a single embodiment described above. (Thus, the following claims are hereby included in this detailed description, with each claim alone representing a separate preferred embodiment of the invention.)

In addition, although the description of the invention contains the description of one or more embodiments and certain variations and modifications, other variations and modifications, for example those within the skills and knowledge of persons skilled in the art, are within the scope of the invention according to the understanding of the present disclosure.

The reference numbers in the claims merely serve for a better understanding of the present invention and in no way constitute a limitation of the present invention.