EP2431658B1 - Colour correcting projection lens for a light module of a motor vehicle headlamp - Google Patents

Description

The present invention relates to a color-correcting projection optics of a light module of a motor vehicle headlight. The color-correcting projection optics comprises at least two partial lenses arranged one after the other in a light passage direction as well as a distance space formed between the partial lenses. Moreover, the invention relates to a light module of a motor vehicle headlight. The light module comprises at least one light source for emitting light, at least one primary optics for bundling at least part of the emitted light, and at least one secondary optic for projecting at least a part of the collimated light as light distribution onto a roadway in front of the vehicle. The secondary optics comprises a color-correcting projection optics having at least two partial lenses arranged one after the other in a light passage direction as well as a distance space formed between the partial lenses.

From the prior art, various lighting devices for motor vehicles are known, which may include at least one light module. Headlamps are next to lights a kind of lighting equipment. While lights are primarily for the visualization of the vehicle for other road users, headlights are primarily to improve the visibility for a driver of the motor vehicle. They are arranged in the front area of a vehicle and serve in addition to the traffic safety by visualizing the vehicle for other road users in particular the illumination of the road ahead of the vehicle, e.g. in the form of a dipped beam, high beam, fog light, Teilfernlicht-, or hazard marking light distribution and in the form of adaptable to specific environmental situations and / or vehicle conditions light distributions, such as a cornering, city lights, country road, motorway light distribution, etc ..

Headlamps generally comprise a housing in which the at least one light module is arranged to produce one or more desired light distributions. The housing has a light exit opening, which is closed by a transparent cover glass or plastic. The cover pane can be designed as a clear pane without optically effective profiles or at least partially with optically effective profiles (for example prisms or cylindrical lenses).

Headlamps, or their light modules, comprise at least one light source, for example in the form of an incandescent lamp, a gas discharge lamp or one or more semiconductor light sources. You can work according to a reflection principle, whereby the light source emitted light to generate a desired light distribution is reflected by designed as a reflector or intent optics primary optics on the road ahead of the vehicle. Alternatively, the headlamps can operate according to a projection principle, wherein light emitted by the light source is projected onto the roadway in front of the vehicle after bundling by the primary optics to produce the desired light distribution by secondary optics, for example in the form of a projection or condenser lens. To produce a dimmed light distribution, a diaphragm arrangement with an effective upper edge located in the beam path can be arranged between the primary and the secondary optics. The upper edge is displayed by the secondary optics as a bright-dark border on the road ahead of the vehicle.

It is also known to use a color-correcting projection optics as secondary optics for the color correction, which comprises a plurality of partial lenses arranged one behind the other in the light passage direction. This can be, for example, an achromat with two partial lenses, an apochromat with three partial lenses or any other device for adapting different wavelengths to zero errors. Due to the interaction of the partial lenses, the intermediate image generated by a bundling primary optics is projected onto the roadway in front of the vehicle to produce a desired light distribution. In addition, an achromat or an apochromatic can correct for spectral colors of the light that may occur when passing the light through optically effective interfaces, eg at a light entry surface and a light exit surface of a lens. As the light passes through the interfaces, it is refracted differently due to dispersion, resulting in color separation occurs. This is also referred to as color longitudinal error of the figure. Finally, an achromatic or an apochromatic can also correct so-called lateral chromatic aberrations, wherein lateral chromatic aberrations occur at a light-dark transition in the image plane (eg at a light-dark boundary with dimmed light distribution). The spreading takes place because at the interfaces, a wavelength-dependent refraction (dispersion) occurs, the spectral colors of the light are more or less strongly refracted depending on their wavelength. This leads to clearly visible color fringes, which can be reduced or even avoided by an achromatic lens.

Achromats, for example, are optical arrangements which generally comprise two directly successively arranged partial lenses of two different materials, the first partial lens (usually a concave lens) having a negative refractive power and a higher color dispersion (lower Abbe number) and the second partial lens (usually a convex lens) has a positive power and a lower color dispersion (high Abbe number). The Abbe number indicates the degree of dispersion, the Abbe number becoming smaller as the dispersion becomes larger. When Apochromat three partial lenses with different material are arranged one behind the other. The entire system of the achromatic or apochromatic has a resulting positive refractive power.

Depending on a type of Achromaten or apochromatic distance spaces may be formed between the partial lenses. Such an achromat with formed between the partial lenses distance space shows, for example, the DE 34 30 273 A1 , The clearance space may be filled with air or other materials.

A color error compensation with the achromat works so that the negative refractive partial lens first breaks the light spectrum away from an optical axis depending on the wavelength and subsequently the positive refractive Tellinse the light spectrum again in the direction of the optical axis wavelength-dependent breaks and thus ultimately superimposed again to white light. Thus, in the case of an achromatic lens with two partial lenses, it can be achieved that the focal length of the system is the same for two wavelengths. The Apochromat can adjust the focal length for three wavelengths by the three arranged partial lenses. The different materials of the two partial lenses of the achromatic lens are usually a so-called "flint glass" for the concave lens with high dispersion and low Abbe number, as well as a so-called "crown glass" for the convex lens with little dispersion and high Abbe number. The production material or a composition of the production material of the flint glass or the crown glass may vary. Thus, in addition to particularly suitable glass mixtures and optically active plastics are known with similar properties, with only a partial lens of Achromaten can be made of plastic. Plastic lenses have the advantage that they can be shaped more accurately.

The internal structure of the color-correcting projection optics may differ significantly with respect to an arrangement of the partial lenses. In the case of achromats, a distinction is in principle made between so-called cemented achromats and air achromats. at cemented achromats is the distance space between the partial lenses filled with an optically transparent medium (optical cement), in which case the active surfaces of adjacent partial lenses are adjacent to each other. The optical cements used for this purpose generally have such a small thickness that they are essentially optically ineffective and can be optically viewed with one of the partial lenses as a common body. Between two partial lenses thus results in only a single optically effective transition. Thanks to the refractive indices of the cement, which are not very different from the material of the one lens which is associated with the cement, the effective surface thus prepared reflects significantly less between the one part lens and its associated putty, ie the achromat has less effect on this prepared active surface Fresnel reflections and less scattered light. Such systems are efficient because more of the injected light is used in percentage terms.

In so-called Luftachromaten a optically effective air gap between the partial lenses is deliberately allowed. Typical Luftachromate usually have a very small distance between the partial lenses. The individual light rays usually fall on the active surfaces of the partial lenses at large angles. In this case, both facing active surfaces of the partial lenses are optically effective. Increased light reflection causes additional light losses (Fresnel losses) on the active surfaces, which in turn generate scattered light components. The active surfaces usually also have a strong curvature, which is associated with increasing light losses, in particular towards the edge. The transmission efficiency therefore decreases. With the one additional effective area in the distance space one wins but additional degrees of freedom, whereby a better color compensation can be achieved. Last but not least, air achromats are easier to manufacture, since each partial lens can be manufactured and held individually. An example of a Luftachromaten shows the DE 34 30 273 A1 ,

Due to the design, however, air achromats have disadvantages that are of particular relevance to the automotive industry. First, the two partial lenses must be arranged in relation to the light source in fixedly defined positions and fixed in order to ensure long-term defined optical properties of the achromatic. For this purpose, the partial lenses are usually fixed in a lens holder made of sheet metal by means of spring washers. Such a lens holder is for example from the DE 102 16 706 B9 known. As a rule, this forces a circular shape of the holder corresponding to the lens circumference, which can be detrimental from a design point of view.

In addition, air achromats are in an application as imaging optics in a light module due to low tolerances tolerances in the distance of the partial lenses to each other, a tilting of the partial lenses and a decentering of the partial lenses in contrast to cemented achromats less well suited.

Another disadvantage of Luftachromaten is that with time in the narrow space between the partial lenses dust and moisture penetrate and can settle there. Such deposits cause significantly more stray light is generated, thereby the road illumination is deteriorated and dazzling other road users increases. adversely is also that in a view from the outside - even in the off state of the light module - the deposits can be perceived, which is disturbing.

In addition, regardless of the use of air or cemented achromatic devices, soft and dampening supports are desired, so that the partial lens edges are not punctually loaded and instead are exposed to a uniformly distributed and thus a smaller force. When used in a motor vehicle, an elastic but at the same time dimensionally stable bearing surface is of great advantage in order to compensate or neutralize shocks, vibrations and vibrations when the engine is switched on and while driving, without adversely affecting the intended mode of operation. In addition, not only Luftachromaten, but also with cemented Achromaten, a good seal of the partial lenses for mounting in the light module is desirable because dust and moisture penetrate into marginal areas between partial lenses of cemented achromats and can interfere.

The object of the invention is, starting from the color-correcting projection optics of the type mentioned to design and further develop the color-correcting projection optics that the projection optics protected without much effort and additional costs better against vibration, vibration and vibrations and also the color aberration compensation of the projection optics can be improved , In addition, the entire distance space between the partial lenses of the projection optics better against the penetration of dust and moisture are protected.

To solve this problem, it is proposed that the distance space between the partial lenses is completely filled by a multifunctional medium which at least partially encloses the partial lenses along their outer circumference, the medium functioning as an optically active partial medium of a further partial lens in the beam path through the color-correcting medium Projection optics passing light, the function of a filling and sealing medium from a center to an outer edge of the color-correcting projection optics and outside the outer periphery of the color-correcting projection optics fulfills the function of a compensation medium.

This means that the multifunctional medium is translucent, has optical properties and sealing properties. For this purpose, it has a dampening effect and can reduce the effects on the partial lenses of the effects of external mechanical loads, such as impacts, shocks, vibrations or vibrations. It is sufficient if the multifunctional medium on the outer circumference of the partial lenses only in sections, for example. At three distributed over the circumference supporting points, is present. The partial lenses of the color-correcting projection optics can then be secured against vibration and vibration in a conventional rigid lens holder via these locations. The use of additional separate damping means between the partial lenses and the lens holder can be dispensed with.

The optical properties of the multifunctional medium are used to better compensate the color errors in the light distribution. The further partial lens formed by the multifunctional medium gives rise to additional degrees of freedom which enable a further optimization of the color fringe correction.

The introduced into the distance space between the partial lenses and the distance space completely filling multifunctional medium acts sealing against dust and moisture, which could otherwise settle over time in the distance space.

The multifunctional medium may comprise a single material. But it can also be composed of different materials, which are either mixed together or form different layers of a multi-layered multifunctional medium. For example, the material of the edge regions of the partial lenses could also differ from the material of the remaining regions of the partial lenses. Due to the entirety of all properties of the multifunctional medium, the sensitive partial lenses of the color-correcting projection optics are particularly well protected in every respect and ensure a long service life of the color-correcting projection optics. The optical properties of the color-correcting projection optics can be improved.

In a preferred embodiment, it is advantageous for the multifunctional medium to surround the partial lenses along their entire outer circumference. This causes a good edge sealing of the entire projection optics, since thereby the edges of the partial lenses are enclosed or sealed over a large area, so that no dust or moisture can get between the partial lenses of the projection optics. In order to get into the distance space between the partial lenses, dust and / or moisture would first have to creep in substantially parallel to the light transmission direction between the arranged along the outer edge of the projection optics multifunctional medium and the outer periphery of the partial lenses, and then crawl perpendicular to it in the distance space. The remaining space between the partial lenses is protected by the complete filling with the multifunctional medium anyway. The entire seal forms, so to speak, with the material filled in between the partial lenses and the edge seal a T-shape, which runs around the outer circumference of the partial lenses and surrounds the partial lenses flush. The entire peripheral area of the partial lenses is thus completely and almost hermetically sealed.

It is possible that the arranged outside the outer periphery of the partial lenses multifunctional medium for receiving by a lens holder of the light module is formed.

The edge sealing of the multifunctional medium extending along the outer edge of the partial lenses on the one hand guarantees an elastic but nevertheless stable, secure and reliable fixation of the partial lenses in the lens holder. This can be further supported by the fact that the multifunctional medium has at least one radially inwardly directed annular groove on the outer circumference of the at least two partial lenses for receiving an outer edge of at least one of the partial lenses and thus fixes the partial lenses. The annular grooves and the protruding into this edge of the partial lenses also results in an improved sealing of the distance space from dust and Humidity.

On the other hand, in comparison to a conventional seal, the advantage that aging and fatigue effects of the edge seal due to the ambient conditions in the light module (eg vibrations, vibrations and high temperatures) first on the outer edge seal and initially no effect on the optically active region of the multifunctional Mediums between the partial lenses has.

From a manufacturing point of view, the design of the projection optics according to the invention provides a possibility for simplifying the assembly, since the projection optics designed in this way can be treated as an "inserter", ie as a single integral unit. The integral technical unit can be used as a whole in the holder for the projection optics in the light module and fixed there. A complex assembly of the individual partial lenses with spacers and / or elastic compensation elements and their orientation and attachment in predetermined positions is thus unnecessary.

A temperature-induced influence of mechanical and optical properties can easily be included in the calculations in a system design, so that unwanted reactions of the projection optics can be better compensated. From a mechanical point of view, in projection optics in particular problems due to different temperature expansion in the foreground, as on the one hand between the two partial lenses of the projection optics (eg in the combination glass / plastic lens) and on the other hand between the Projection optics and the lens mount can occur. Cracks in the partial lenses and chipped edges in the case of glass as well as crack marks on plastic are the result, which can negatively affect the optical properties of the projection optics. These negative effects can be safely excluded by the elastic multifunctional medium, which acts as an optical, sealing and damping medium between the two partial lenses and around them.

The known from the prior art partial lenses of achromats have substantially a circular shape. For sealing ring seals are preferably used there. Other possible forms of partial lenses, such as e.g. a rectangular, trapezoidal, oval, etc., are very expensive to seal and cause higher punctual loads on the seal. With the projection optical system according to the invention with its large area, the entire outer periphery of the partial lenses surrounding elastic edge seal and non-circular lenses are securely sealed and local loads on the lenses can be avoided. As a result, customer-desired forms of projection optics, which may also differ significantly from a circular shape under certain circumstances, can be realized simply and inexpensively without any functional losses with regard to mounting and sealing of the partial lenses. This allows new degrees of freedom for the design of the light module.

Furthermore, it is advantageous that the multifunctional medium comprises silicone. Silicones can be thin or viscous in the production phase of the projection optics, for example by heating. In this case, the complete filling of the distance space without air pockets succeeds even with complicated geometries and / or small dimensions the distance space much better than traditional materials such as glass, polycarbonate (PC), polymethyl methacrylate (PMMA) or similar materials. After filling, the silicone cools and hardens, so that the multifunctional medium has a solid state of aggregation at the latest after a production process of the color-correcting projection optics. By a suitable choice of a particular silicone can be achieved that the multifunctional medium after cooling, although solid, but still soft and elastic yielding. In this case, provide an annular lens holder made of sheet metal or other suitable stable material for the required stability of the multifunctional medium, so that the projection optics is arranged and fixed in a defined position relative to the remaining light module.

Furthermore, it is advantageous that the multifunctional medium formed along the outer circumference of the at least two partial lenses is colored at least regionally, preferably inwardly directed surface, preferably colored black. By preferably black coloring scattered light components can be absorbed, which would otherwise adversely affect the function of the projection optics. In this case, the peripherally arranged around the partial lenses around edge seal may have a different material than the optically transparent material between the partial lenses, both materials are joined together seamlessly in the manufacturing process.

It is also advantageous that the multifunctional medium arranged in the beam path of the light passing through the color-correcting projection optics Color error compensation supportive dispersion properties at least for a part of the light passing through. This allows more degrees of freedom and improved color compensation. By incorporating the dispersion properties of the multifunctional medium arranged in the beam path, it is possible, for example, to at least partially compensate for a further spectral color in the case of color-correcting projection optics having two partial lenses in addition to the two compensatable spectral colors. The multifunctional medium can also provide a better refractive index adjustment between the partial lenses, since the refractive indices of the partial lenses and the multifunctional medium preferably do not differ as much from one another as, for example, the refractive indices of air and of the material of the partial lenses. As a result, Fresnel reflections are reduced at the interfaces, for example, so that fewer light components lead to scattered light.

The color-correcting projection optics according to the invention can advantageously be designed as an achromat, an apochromat or any other device which adjusts a focal length for several wavelengths.

Figur 1

ein Lichtmodul mit einem Achromaten aus dem Stand der Technik;

Figur 2

einen Luft-Achromaten aus dem Stand der Technik;

Figur 3

einen mit einem optisch durchlässigen Medium "verkitteten" Achromaten aus dem Stand der Technik;

Figur 4

eine erfindungsgemäße farbkorrigierende Projektionsoptik in einer ersten Ausführungsform in einem Schnitt;

Figur 5

die farbkorrigierende Projektionsoptik aus Figur 4 in zwei verschiedenen Schnitten jeweils in einer perspektivischen Darstellung;

Figur 6

eine erfindungsgemäße farbkorrigierende Projektionsoptik in einer zweiten Ausführungsform in einer perspektivischen Darstellung teilweise im Schnitt;;

Figur 7

die farbkorrigierende Projektionsoptik aus Figur 6 mit einer Linsenhalterung;

Figur 8

eine erfindungsgemäße farbkorrigierende Projektionsoptik in einer dritten Ausführungsform in einer perspektivischen Darstellung teilweise im Schnitt; und

Figur 9 bis 11

weitere mögliche Ausführungsformen einer erfindungsgemäßen farbkorrigierenden Projektionsoptik jeweils in einem Schnitt.

Further advantages will become apparent from the following description and the accompanying drawings. It is understood that the features mentioned above and those yet to be explained below can be used not only in the respectively indicated combination but also in other combinations or in isolation, without departing from the scope of the present invention. Embodiments of the invention are illustrated in the figures and are explained in more detail in the following description. Show it:

FIG. 1

a light module with an achromatic lens from the prior art;

FIG. 2

an air achromatic lens of the prior art;

FIG. 3

a "cemented" with an optically transmissive medium achromats from the prior art;

FIG. 4

a color-correcting projection optics according to the invention in a first embodiment in a section;

FIG. 5

the color-correcting projection optics FIG. 4 in two different sections each in a perspective view;

FIG. 6

a color-correcting projection optics according to the invention in a second embodiment in a perspective view partially in section;

FIG. 7

the color-correcting projection optics FIG. 6 with a lens holder;

FIG. 8

a color-correcting projection optics according to the invention in a third embodiment in a perspective view partially in section; and

FIGS. 9 to 11

Further possible embodiments of a color-correcting projection optics according to the invention in each case in a section.

FIG. 1 shows a known from the prior art light module 10 of a motor vehicle headlight in a schematic representation. The light module 10 is designed as a projection module and has a reflector 12 formed as the primary optics, which is preferably ellipsoidal or in a form of an ellipsoid (slightly) deviating freeform. At a focal point of the reflector 12, a light source 16 is arranged on an optical axis 14 of the light module 10. This can be an incandescent lamp, a gas discharge lamp or else at least one semiconductor light source, in particular one or more LEDs. When LEDs are used, the primary optics could also be designed as front optics (not shown). An attachment optics consists of an optically transparent material and focuses light by refraction of light at interfaces of the optical attachment with the environment (eg on a Lichteinkoppelseite and / or a Lichtauskoppelseite the intent optics) and by total reflection at the interfaces.

In the light exit direction 18 after the primary optics 12 a secondary optics is arranged primarily for the projection of the focused light on the road ahead of the vehicle, the in FIG. 1 as a projection optics, in particular as an achromat 22 with two partial lenses 24 and 26, is formed. The projection optics 22 has color-correcting properties in addition to the light-projecting properties. The partial lens 24 is plano-concave and the partial lens 26 is convex-convex. The achromat 22 is designed as a so-called air-achromatic, so that between the two partial lenses 24 and 26 - due to different radii of the partial lenses 24 and 26 - a distance space 28 is formed.

To produce a dimmed light distribution, a diaphragm arrangement 20 with an effective upper edge located in the beam path is arranged in the light exit direction 18 after the primary optics 12, wherein the upper edge of the secondary optics 22 is projected onto the road ahead of the vehicle to produce the desired light distribution.

FIG. 2 shows the partial lenses 24 and 26 of a known Luftachromaten in another embodiment, in which, in contrast to the Luftachromaten from FIG. 1 Do not touch the two partial lenses 24 and 26. The spacing space 28 can also be filled with an optically transparent medium (putty) in the case of an embodiment of the achromatic lens 22 as a "cemented" achromat. FIG. 3 shows the partial lenses of such an achromatic, in which case the distance space 28 is formed very thin and the medium arranged between the partial lenses 24, 26 is not visible. The putty has such a small thickness that it is substantially optically ineffective and can be optically regarded as an integral part of one of the partial lenses 24 or 26.

The achromatic 22 forms an optical system of two partial lenses 24 and 26, which consist of different material with different degrees of dispersion (different Abbe number). Dispersion in optics is a wavelength-dependent refraction of light. Typically, short-wave light components (eg blue) are more strongly refracted than longer-wave components (eg red). The partial lenses 24 and 26 may be made of glass or plastic. The achromatic 22 has a diverging lens 24 (preferably made of flint glass) with a smaller Abbe number (<50) and thus stronger dispersion and a condenser lens 26 (preferably made of crown glass) with a larger Abbe number (> 50) and thus smaller dispersion.

The achromatic 22 is equal to two dispersion spectral colors of visible light, e.g. red and blue, to whitish light which, when passing through optically active interfaces, e.g. at a light entrance side and a light exit side of a lens (so-called. Color longitudinal error) arise. The achromatic 22 can also improve so-called lateral chromatic aberrations, where lateral chromatic aberrations occur at a light-dark transition in the image plane (for example at the light-dark boundary when the light distribution is dimmed).

Color aberration compensation with the achromatic lens 22 functions such that the negative refractive partial lens 24 (concave lens) first breaks the light spectrum away from the optical axis 14 as a function of wavelength, and subsequently the positive refractive lens 26 (convex lens) refracts the bundle again in the direction of the optical axis 14 wavelength-dependent breaks and thus ultimately ideally white or at least whitish light without or with greatly reduced color fringes is joined together.

Usually, the light module 10 is in an in FIG. 1 Housing of a headlamp, not shown, arranged with a arranged in the light exit direction 18 light exit opening, which is closed by a translucent cover.

The FIGS. 4 and 5 show a color correcting projection optics 22 according to the invention with the two partial lenses 24 and 26. Of course, the color-correcting projection optics 22 according to the invention also comprise more than the two partial lenses 24, 26. FIG. 4 shows a longitudinal section through the color-correcting projection optics 22; FIG. 5 shows on the right the longitudinal section FIG. 4 in a perspective view and on the left the same color-correcting projection optics 22 in a perspective and only cut to a quarter view. The partial lens 24 is convex-concave and consists of flint glass (also plastic, such as polycarbonate (PC) is possible) and the partial lens 26 is convex-convex and consists of crown glass (also plastic, such as polymethyl methacrylate (PMMA) or hard silicone is possible). The partial lenses 24, 26 are spaced from each other, so that between them a distance space 28 is formed. The spacer space 28 is filled with a light-transmitting multifunctional medium 30, wherein the medium 30 has the function of a seal between the two partial lenses 24, 26, the function of another optically effective partial lens and the function of damping the lenses 24, 26 with respect to a circumferentially arranged lens holder Fulfills.

The medium 30 seals the area between the two partial lenses 24 and 26 to the outside against the ingress of dust and moisture by completely filling the spacer space 28. The multifunctional medium 30 is formed convex-concave in the illustrated embodiment and has at least after the production of the projection optics 22 on a solid state of matter.

The multifunctional medium 30 may also provide by its optical properties for a better refractive index matching between the partial lenses 24 and 26, as penetrated by the light beams through the multifunctional medium 30 in the optically effective region of the projection optics 22 and by the partial lenses 24 and 26, the refractive indices - compared to air in Luftachromaten - not so much different from each other. As a result, Fresnel reflections are reduced at the interfaces, which contribute less light components to the scattered light and more light components can be used to generate the actual light distribution. The optical properties of the multifunctional medium 30 also have dispersion properties. The inclusion of these dispersion properties in optical modeling allows additional degrees of freedom and improved color aberration compensation. Thus, it is conceivable that in addition to the two essentially compensable spectral colors known from the prior art, the medium 30 forms a third partial lens, by means of which a further spectral color can be at least partially compensated.

Like from the FIGS. 4 and 5 it can be seen, the multifunctional medium 30 extends beyond the partial lenses 24 and 26 radially outward and encloses the two partial lenses 24 and 26 along its outer periphery. It is conceivable that the multifunctional medium 30 surrounds the outer edge region of the partial lenses 24, 26 only in sections, that is not over its entire circumference. The portions of the medium 30 disposed on the outer periphery of the sub-lenses 24, 26 provide a damping effect when the projection optics 22 are disposed in a lens holder, such as the annular holder 36. As a result, vibrations, oscillations and shocks acting on the light module and thus also on the holder 36 can be damped, so that harmful mechanical effects on the lenses 24, 26 are reduced and the resulting light distribution can be stabilized.

In the embodiment of the FIGS. 4 and 5 The multifunctional medium 30 completely surrounds the outer circumference of the partial lenses 24, 26. As a result, the multifunctional medium 30 is T-shaped in section at an edge region of the partial lenses 24 and 26 (see reference numeral 32), so that the entire edge region of the partial lenses 24 and 26 is additionally outwardly flush with the edge due to an edge seal thus formed Ingress of, for example, dust and moisture is sealed. In addition, the projection optics 22 together with the outer damping element 34 is an integral unit, which is particularly easy to handle.

Due to the T-shaped design of the edge seal 32 forms on the outer circumference of the partial lenses 24 and 26, a web 34 which cooperates with a holding ring formed as a lens holder 36 of the light module 10, so that the projection optics 22 can be fixed safely and vibration-free in the light module 10. As a rule, the holder 36 has further design features, so that the projection optics 22 can be held and fixed in the light module 10. Despite the solid state of aggregation of the multifunctional medium 30, this is soft and elastic. The material 30 has a hardness which on the one hand provides the necessary stability for fastening and fixing the partial lenses 24, 26, but on the other hand also has a damping effect. The multifunctional medium 30 is, for example, made of a silicone which has the corresponding optical, sealing and vibration-damping properties. The use of other materials or material combinations for the multifunctional medium 30 are conceivable.

The web 34 of the edge seal may be dyed black in one embodiment. For this purpose, the web 34 may be made of a black-colored material, or else the material of the medium 30 is dyed black in the region of the web 34. Of course, other colors than black are conceivable. By coloring the edge region 34, in particular on a radially inwardly directed side, scattered light components are absorbed there. The edge region 34 merges seamlessly into the remaining multifunctional medium 30 between the partial lenses 24, 26, so that the medium 30 in the optically effective region of the projection optics 22 and the web 34 of the edge region form an integral unit.

FIG. 6 shows a development of the color-correcting projection optics 22 in a perspective view. The web 34 of the edge seal can itself be shaped and configured so that it is stable enough to act as a holder in the light module 10 can. An additional holder, such as the holder 36, would then be unnecessary under certain circumstances. The attachment of the projection optics 22 to the remaining light module could then take place directly on the web 34. In addition, the T-shaped web 24 may include appropriate structural measures, such as a radially inwardly directed annular groove 38, to additionally stabilize and fix the exact position of the sub-lenses 24 or 26 along the optical axis 14. An outer edge of the partial lenses engages in the annular grooves 38 and thus provides additional stabilization of the partial lenses 24, 26 and improved sealing of the spacer space 28 against the ingress of dust or Humidity.

Of course, the annular groove 38 of the outer edge seal 34 can also be realized in a color-correcting projection optics 22 with holder 36. FIG. 7 shows such a projection optics 22 in a perspective view.

FIG. 8 shows a further embodiment of the color-correcting projection optics 22 according to the invention in a perspective and partially cutaway view. In contrast to the previously shown projection optics 22 with substantially circular partial lenses 24 and 26, the partial lenses 24 and 26 of the projection optics 22 are made FIG. 8 an approximately rectangular shape with substantially flat top and bottom sides and slightly outwardly curved sides. In addition, trapezoidal, oval or any other shapes of the partial lenses 24, 26 would be conceivable that can be designed according to customer-specific wishes. The inventive design of the multifunctional medium 30 in the edge region 34 of the projection optics 22, any form of partial lenses 24, 26 are enclosed over a large area, so that the aforementioned properties, in particular the optical properties, the reliable sealing of the partial lenses 24 and 26 and the damping the partial lenses 24, 26 with respect to a rigid outer holder 36 are still satisfied.

The FIGS. 9 to 11 show different embodiments of a color-correcting projection optics 22 according to the invention. In this case, the lenses 24, 26 have different shapes on average, which is also the case different forms of the multifunctional medium 30, in particular in the optically effective region of the projection optics 22 leads. A preferred embodiment shows FIG. 9 in which a convex-concave partial lens 24 and a convex-convex partial lens 26 are connected to one another via the multifunctional medium 30 at a substantially constant distance, ie the thickness of the multifunctional medium 30 in the beam path is constant or at least almost constant. The shape of the multifunctional medium 30 in the optically effective region is convex-concave in this case. It is advantageous that an equal expansion of the multifunctional medium 30 along the optical axis 14 is ensured by the influence of temperature. Effects on the desired focal length of the projection optics and the desired color compensation are thus largely avoided.

The embodiment of FIG. 10 shows a plano-convex partial lens 26 and a formed between the lenses 24, 26 convex-plan multifunctional medium 30. The embodiment of FIG. 11 shows a concave-convex partial lens 26 with a convex-convex multifunctional medium 30 between the lenses 24, 26. The partial lens 24 is in the embodiments of FIGS. 9 to 11 formed substantially the same.

Claims (11)

1. A color-correcting projection lens (22) of a light module (10) of a motor vehicle headlight, in which the color-correcting projection lens (22) includes at least two partial lenses (24, 26), located in line with one another in a light passage direction (18) and a spacer chamber embodied between the partial lenses (24, 26), characterized in that the spacer chamber between the partial lenses (24, 26) is completely filled by a multifunctional medium (30), which encloses the partial lenses (24, 26) in at least some portions, including along their outer circumference, and the medium (30) performs the function of an optically active partial medium of a further partial lens in the beam path of the light passing through the color-correcting projection lens (22), the function of a filling and sealing medium from a center to an outer edge of the color-correcting projection lens (22), and, outside the outer circumference of the achromatic lens (22), the function of a compensation medium.
2. The color-correcting projection lens (22) of claim 1, characterized in that the multifunctional medium (30) surrounds the partial lenses (24, 26) along their entire outer circumference.
3. The color-correcting projection lens (22) of claim 1 or 2, characterized in that the multifunctional medium (30) located outside the outer circumference of the partial lenses (24, 26) is embodied for being received by a lens mount (36) of the light module (10).
4. The color-correcting projection lens (22) of claim 3, characterized in that the multifunctional medium (30) has oscillation- and vibration-damping properties.
5. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the multifunctional medium (30) includes silicone.
6. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the multifunctional medium (30), at the latest after the conclusion of a production process for the color-correcting projection lens (22), is in a fixed aggregate state.
7. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the multifunctional medium (30) located along the outer circumference of the at least two partial lenses (24, 26) has at least one radially inward-oriented annular groove (38) for receiving an outer edge of at least one of the partial lenses (24; 26).
8. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the multifunctional medium (30) located along the outer circumference of the at least two partial lenses (24, 26), at least in some regions, preferably on an inward-oriented surface, is colored, preferably being colored black.
9. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the multifunctional medium (30), located in the beam path of the light passing through the color-correcting projection lens (22), has dispersion properties that reinforce error compensation, at least for some of the light passing through.
10. The color-correcting projection lens (22) of one of the foregoing claims, characterized in that the color-correcting projection lens (22) is an achromatic lens, an apochromatic lens, or an arbitrary other device, which brings together beams of different wavelengths at a common focal point or in the vicinity of the common focal point.
11. A light module (10) of a motor vehicle headlight, the light module (10) including at least one light source (16) for emitting light, at least one primary lens (12) for focusing at least some of the emitted light, and at least one secondary lens (22) for rejecting at least some of the focused light as light distribution over a roadway in front of the vehicle, the secondary lens including a color-correcting projection lens (22) having at least two partial lenses (24, 26) located in line with one another in a light passage direction (18) as well as a spacer chamber embodied between the partial lenses (24, 26), characterized in that the color-correcting projection lens (22) is embodied in accordance with one of claims 1 through 10.

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