DE102022107687A1 - Light module of a motor vehicle headlight and method for controlling a diaphragm element of such a light module - Google Patents

Abstract

The invention relates to a light module (10) of a headlight (101) of a motor vehicle. The light module (10) comprises a plurality of light sources (12) arranged in a matrix-like manner for emitting light (14) and an optical element (16) arranged in the beam path of the light (14) for redirecting at least part of the emitted light (14) and for generating a predetermined Light distribution of the light module (10) in an apron in front of the motor vehicle from the deflected light (14). It is proposed that the light module (10) has a diaphragm element (22) arranged in the beam path of the light (14) with an adjustable diaphragm opening (24), the diaphragm element (22) being arranged and designed in the light module (10) in such a way that that light that leaves the optical element (16) in a central area (26) around an optical axis (28) of the optical element (16) passes through the aperture opening (24) and that the aperture element (22) emits light (14), which leaves or would leave the optical element (16) in an edge region (20) radially outside the central region (26), at least partially shading. The aperture 24 is preferably adjustable between at least two sizes.

Description

The present invention relates to a light module of a headlight of a motor vehicle. The light module comprises a plurality of light sources arranged in a matrix for emitting light and an optical element arranged in the beam path of the light for redirecting at least part of the emitted light and for generating a predetermined light distribution of the light module in an apron in front of the motor vehicle from the redirected light.

The invention also relates to a method for controlling a shutter element with an adjustable shutter opening. The aperture element is part of a light module of a headlight of a motor vehicle. In addition to the aperture element, the light module includes a plurality of light sources arranged in a matrix-like manner for emitting light and an optical element arranged in the beam path of the light for deflecting at least part of the emitted light and for generating a predetermined light distribution of the light module in an apron in front of the motor vehicle from the deflected light.

High-resolution light projection modules are known from the prior art, for example in the form of digital mirror device or DMD modules or matrix LED modules. A matrix LED module is, for example, in the EP 2 306 074 A described. A high-resolution light module with several light sources arranged next to one another is, for example, from the WO 2013/ 020 156 A known. Finally, for example, describes the DE 10 2012 112 127 A a high-resolution light module with an LCD panel in order to be able to shade specific areas of the light beam emitted by the light sources. The shaded areas of the light beam are then included as dark areas in the light distribution projected by projection optics into the apron in front of the motor vehicle.

What all of these known high-resolution projection modules have in common is that the aperture element is arranged between the light sources and the projection optics. In the prior art, the diaphragm element is designed to shade partial areas of the light beam emitted by the light sources. The partially shaded light bundle is then imaged by the projection optics as the resulting light distribution in the area in front of the motor vehicle.

With high-resolution projection modules, the imaging quality of the projection optics usually decreases as the numerical aperture of the optics increases. In particular, so-called edge rays (i.e. light rays that pass through or leave the projection optics through an outer edge region of the optics) lead to a deterioration in the imaging quality. A good efficiency of projection modules results in particular from a high transmission of the projection optics. However, it is precisely these marginal rays that are desirable for high transmission. To achieve high transmission, projection optics with a large diameter are also advantageous. However, this worsens the imaging quality because the projection optics then have to be even more curved, especially in the edge areas.

Typically, an increase in the total light transmission of a projection lens has a negative effect on the image quality (e.g. edge sharpness, color fringes, contrast). Compensation for the effects of a higher transmission of the projection optics on the imaging quality is only possible - if at all - only partially, for example by introducing additional optics. However, this leads to relatively large, heavy and expensive light modules, which attempts are being made to avoid, particularly in the area of motor vehicle headlights.

In relation to the projection optics, this means that on the one hand it should have a high transmission of light and on the other hand it should have good imaging quality. There is therefore a conflict of objectives with high-resolution projection modules in being able to achieve high optical efficiency on the one hand and the best possible imaging quality on the other.

Furthermore, (non-imaging) reflection modules for motor vehicle headlights are known from the prior art. In these cases it is usually the case that, for reasons of efficiency, the main part of the light is, if possible, guided through a center near an optical axis of the reflection module in order not to lose any light, which may no longer reach an edge region of the reflection optics, but to the side of which is lost. With such reflection systems, homogeneity of the illumination or the resulting light distribution is best for light rays from close to the optical axis and decreases towards the edge.

Using the example of a reflection optic designed as a reflector, areas can be defined in the reflector according to the homogeneity of the light distribution that is generated by the corresponding reflector areas. Those reflector areas that produce the largest coil/chip images would then be the areas with the best homogeneity. These in turn are those areas that are usually located in the middle of the reflector near the optical axis, or those areas that are intersected by an optical axis of the light source. For efficiency For this reason, the light source is usually screwed into the reflector.

Based on the described prior art, the present invention is based on the object of proposing a light module with the highest possible efficiency and at the same time the best possible imaging quality or homogeneity of the resulting light distribution.

To solve this problem, a light module with the features of claim 1 is proposed. In particular, based on the light module of the type mentioned at the outset, it is proposed that the light module has a diaphragm element with an adjustable aperture opening arranged in the beam path of the light. The aperture element is arranged and designed in the light module in such a way that light that leaves the optical element in a central region around an optical axis of the optical element passes through the aperture opening and that the aperture element light that leaves the optical element in an edge region radially outside of the central one The area leaves or would leave, at least partially shaded.

The aperture element has an aperture opening that can be adjusted in size. The size of the aperture opening can be adjusted discretely or continuously between at least two positions.

A first position can correspond to a maximum opened aperture. As many marginal rays as possible, preferably all marginal rays, which leave the optical element via an outer edge region of the optical element can pass through the aperture opening. In the first position, only a few, preferably no, edge rays are shaded by the aperture element. Another second position can correspond to an aperture opening that is less than maximally, preferably minimally, open. Fewer marginal rays can pass through the aperture in the second position than in the first position. In the second position, more marginal rays are shaded by the aperture element than by the aperture element in the first position.

Alternatively, it would be conceivable that a first position corresponds to a minimally opened aperture. In the minimally open position, an opening preferably remains in the aperture element, so the aperture opening is not completely closed. In this case, as few marginal rays as possible, preferably no marginal rays, which leave the optical element via an outer edge region of the optical element can pass through the remaining aperture opening. In the first position, many, preferably all, edge rays are shaded by the diaphragm element. Another second position can correspond to an aperture opening that is opened more than minimally, preferably to a maximum. More marginal rays can pass through the aperture opening in the second position than in the first position. The diaphragm element shades fewer marginal rays in the second position than in the first position.

Further positions of the aperture element and corresponding sizes of the aperture opening between the first and second positions but also beyond the first and second positions are conceivable.

With the diaphragm element of the projection module according to the invention, edge rays from the optical element can be shaded as desired or required in a corresponding optical system.

As a result, for example, in a projection module, where the optical element is designed as a projection optics for imaging at least part of the emitted light in the area in front of the motor vehicle in order to generate the predetermined light distribution of the light module from the imaged light, the imaging quality of the light module can be slightly reduced deteriorated overall transmission can be improved. Alternatively, a high overall transmission of the optical element can be achieved in the projection module, at the expense of slightly reduced imaging quality. A projection module can, for example, use a projection lens and/or a projection reflector as imaging optics.

When using imaging optical elements in the projection module, the density of the light rays generally decreases towards the edge of the optics. This means that the efficiency of the light module is only slightly reduced by reducing the aperture opening.

An important aspect of the invention is therefore, in a projection module with the aid of the aperture element, depending on the optical requirements for the light distribution to be generated by the light module, between an operating mode with high transmission (“aperture element opened”) and an operating mode with good imaging quality ( “Aperture element closed” = aperture opening small).

A light distribution in which high transmission is desirable is, for example, “full high beam” (the entire long range above a horizontal line of the light distribution is illuminated). Light distributions where high image quality is more important are, for example, partial high beam (Part areas are cut out of the “full high beam” light distribution, i.e. dark, in which other road users were detected; vertical light-dark borders are formed between the illuminated and shaded areas of the light distribution), or light distributions with a horizontal light-dark border, e.g. a low beam distribution or a fog light distribution . In particular, if symbols (e.g. traffic signs, danger signs, turn symbols of a navigation system) are to be projected onto the road as light distribution, a high imaging quality of the light module is advantageous.

• - volles Fernlicht: Keine Abschattung von Randstrahlen durch das Blendenelement, die Lichtverteilung weist keine Helldunkelgrenzen oder -kanten auf, die Lichtverteilung weist keine Abbildung auf, maximale Effizienz → Blendenöffnung maximal geöffnet,
• - Teilfernlicht: vertikale Helldunkelgrenze möglichst scharf abbilden, geringes Streulicht --> Blendenöffnung teilweise geschlossen,
• - Symbolprojektion: Lichtmenge reduziert, möglichst scharfe Abbildung der Symbole --> Blendenöffnung maximal geschlossen (nicht vollständig geschlossen! Licht muss weiterhin durch Blendenöffnung gelangen)

The size of the aperture opening of the aperture element can be adjusted or changed depending on the requirements of the light distribution to be generated by the light module. The following settings are conceivable, for example:

• - full high beam: No shadowing of edge rays by the aperture element, the light distribution has no chiaroscuro edges or edges, the light distribution has no image, maximum efficiency → aperture opening opened to the maximum,
• - Partial high beam: image the vertical light-dark boundary as sharply as possible, low scattered light --> aperture opening partially closed,
• - Symbol projection: amount of light reduced, image of the symbols as sharp as possible --> aperture opening maximally closed (not completely closed! Light must still pass through aperture opening)

In a reflection module, where the optical element is designed as a reflection optics, which is designed to deflect at least part of the emitted light into the apron in front of the motor vehicle to generate the predetermined light distribution of the light module from the deflected light, the shading of edge rays according to the invention can Homogeneity of the illumination or the resulting light distribution can be improved, while accepting a slight deterioration in the efficiency of the light module.

For the purposes of the present invention, edge rays are those light rays which, regardless of their origin, pass through edge regions of an optical element or leave the optical element via edge regions. The edge rays are therefore independent of where the light rays entered the optical element, whether at an edge region of the optical element or near the optical axis of the optical element.

According to an advantageous development of the invention, it is proposed that the diaphragm element is arranged in the beam path of the light after the optical element. The optical element can have one or more individual optics arranged one behind the other. The optical element can be designed as a reflector (in a reflection module) or as a projection lens (in a projection module). In the case of an optical element with several individual optics, at least one of the optics, preferably the last (or outer) optic in the beam path through which the light rays leave the optical element in the light exit direction, can be designed as a reflector or a projection lens.

The diaphragm element is arranged in the light exit direction either behind the entire optical element or, in the case of an optical element with several individual optics arranged one behind the other in the beam path, arranged near the last optic. It would be conceivable in particular for the diaphragm element to be arranged between the penultimate and the last optics, preferably closer to the light entry surface of the last optics. This has the advantage that when you look at the light module from the outside, the cover element is hidden behind the outer lens and is not visible from the outside. The aesthetic impression that the light module makes on an observer looking into the light module from outside is therefore determined by the outer lens and not by the aperture element.

According to a preferred embodiment of the invention, it is proposed that the aperture opening is adjustable radially symmetrically with respect to an optical axis of the optical element. A diaphragm element designed in this way can be used both in a light module with an optical element with a rotationally or radially symmetrical light exit surface and in a light module with an optical element with a non-rotational or non-radially symmetrical light exit surface.

The aperture opening preferably has at least approximately a circular shape. Of course, differently shaped aperture openings are also conceivable, for example an elliptical one, a square one with edges curved outwards, a square one with rounded corners, or the shape of a regular polygon.

Advantageously, the aperture opening is adjustable in the radial direction with respect to an optical axis of the optical element. The aperture element is adjustable in a vertical plane with respect to the optical axis. The radial adjustability can be achieved, for example, by designing the diaphragm element as a louvre diaphragm or iris diaphragm. In applied optics, an iris diaphragm is a diaphragm with a variable opening width, the opening of which is at a fixed center, through which preferably the The optical axis of the light module can be changed so that it remains approximately circular. Its function corresponds to that of an iris in the human eye, and its technical construction corresponds to that of a central shutter.

Alternatively, it is also conceivable that the aperture opening can be adjusted obliquely to a radial direction with respect to an optical axis of the optical element. The aperture element is not adjustable in a vertical plane with respect to the optical axis, but rather at an angle to it. In particular, the diaphragm element can be adjustable along the surface of an imaginary truncated cone, with an axis of the truncated cone preferably corresponding to the optical axis of the optical element or the light module. This has the advantage that, for example, in the case that the optical element comprises a projection lens, the movement of the aperture element to change the size of the aperture opening can be adapted to a lens curvature or to a curvature of a light exit surface of the projection lens.

Advantageously, the aperture opening of the aperture element can be adjusted between at least two discrete sizes, with a larger proportion of light passing through the aperture opening of a first set size from the edge region of the optical element than through the aperture opening of a second set size. The two different sizes of the aperture opening can correspond to different positions or operating modes of the aperture element or the light module. It is conceivable that further discrete positions of the diaphragm element are provided between or beyond the two discrete positions. Each of the discrete positions of the aperture element can be assigned to a specific light distribution of the light module. To generate a specific light distribution, the aperture element can be adjusted to the appropriate position in order to achieve the optimal setting for transmission and imaging quality or transmission and homogeneity of illumination for the specific light distribution.

In addition, it would also be conceivable for the aperture opening of the aperture element to be continuously adjustable in size between a maximum open size and a minimum open size, with the further the aperture opening is adjusted towards the minimum open size, the smaller the proportion of light from the edge area of the optical element that passes through the aperture opening. The aperture element thus has a large number (almost infinite number) of different positions and the light module can be operated in a large number of corresponding different operating modes. This allows a particularly precise and fine adjustment of transmission and imaging quality or transmission and homogeneity.

It is also conceivable that the aperture opening can be adjusted asymmetrically with respect to an optical axis of the optical element, with a less widely opened section of the aperture element shading more light from the edge region of the optical element than a more widely opened section of the aperture element. This embodiment is particularly suitable for optimal adjustment of transmission and imaging quality or transmission and homogeneity of the illumination of asymmetrical light distributions.

If the light distribution is not symmetrical, it may make sense to use the cover element to shade edge rays in a non-symmetrical manner. For example, in the case of light distributions that only require good imaging quality in one direction (e.g. low beam with horizontal light-dark limit), it is preferable to shade only the part of the optical element that causes the poorer imaging quality. In the example of a low beam light distribution with a horizontal light-dark boundary, the imaging quality in the vertical direction should be as good as possible in order to be able to produce the light-dark boundary sufficiently well (i.e. sharply). This can be achieved by shading the edge rays from the upper and lower areas of the optical element. In this example, poorer image quality in the horizontal direction is not detrimental to the light distribution.

If the optical element comprises a reflector, in particular if the optical element comprises a plurality of optics arranged one behind the other in the beam path of the light and the last or outer optic of the optical element is designed as a reflector, a shape and size of the aperture of the aperture element preferably corresponds to the shape and size of one Light exit opening of the reflector. This applies both to radially symmetrical reflectors and to non-radially symmetrical reflectors, such as those used, for example, in projection modules in the form of matrix reflection systems (light sources arranged in a matrix-like manner and projection optics designed as a reflector).

The aperture element can be designed to be completely opaque to light. Alternatively, it would also be conceivable for the diaphragm element to be designed to be partially transparent to light, for example by allowing a part of the entire light spectrum to pass through (e.g. like frosted glass or frosted glass) or alternatively only certain spectral components (certain frequencies or colors) of the light (e.g like a color filter). A partial permeability of the diaphragm element can result from the fact that parts of the Aperture element is permeable to light and other parts of the aperture element are completely opaque. Alternatively, partial transparency can also result from the entire diaphragm element being transparent to part of the incident light.

For example, it would be conceivable to realize a more attractive daytime design of the light module by arranging such a cover element in a position that is visible from the outside and in the closed position during the day. If the aperture element is illuminated from behind or from the inside by at least one light source, for example one or more light sources of the light module, the aperture element appears illuminated, but without producing a regulation-compliant light distribution that must meet legal requirements. The light emitted by the backlit panel element preferably serves only for design purposes. Alternatively or additionally, it would also be conceivable for it to generate a light distribution that complies with the regulations, for example in the form of a position or daytime running light.

A corresponding partially transparent diaphragm element could also be arranged between the penultimate and the last or outer lens of the projection optics of a projection system, so that when the diaphragm element is illuminated with light, the outer lens appears illuminated. The light emitted by the luminous lens can only be used for design purposes and/or to implement light distribution (e.g. position or daytime running lights). This embodiment has the advantage that the aperture element itself is not visible from the outside because it is covered by the outer lens.

In addition to the possibility of optimal adjustment of the imaging quality and transmission or the homogeneity of the illumination depending on the light distribution, the invention also has the advantage that the diaphragm element can be used to shade solar radiation that fills the light module from outside. This prevents sun rays from entering the light module from outside, being focused by the projection optics, for example onto the light sources, and damaging the light module at the point where the focused sun rays hit. Light rays entering and focused into the light module from outside can damage not only the light sources of the light module, but also other components of the light module that are arranged in a direction opposite to the light exit direction behind the cover element (i.e. further inside) (e.g. decorative frame, bezel, lens holder Etc.).

In this sense, the present invention further proposes a method for controlling a diaphragm element of the type mentioned at the outset, wherein a size of the diaphragm opening is adjusted depending on the light distribution of the projection module. According to a further development, it would be conceivable that the size of the aperture opening is also set depending on solar radiation from outside into the projection module.

• 1 einen Kraftfahrzeugscheinwerfer in einer vereinfachten schematischen Ansicht;
• 2 ein erfindungsgemäßes Lichtmodul gemäß einer bevorzugten Ausführungsform;
• 3 ein erfindungsgemäßes Lichtmodul gemäß einer anderen bevorzugten Ausführungsform in einem ersten Betriebsmodus;
• 4 das Lichtmodul aus 3 in einem zweiten Betriebsmodus;
• 5 einen Querschnitt durch eine Leuchtdichteverteilung in einem Fernfeld für verschiedene Betriebsmodi eines erfindungsgemäßen Lichtmoduls; und
• 6 einen Ausschnitt eines erfindungsgemäßen Lichtmoduls gemäß einer anderen bevorzugten Ausführungsform.

Further features and advantages of the present invention are explained in more detail below with reference to the figures. Show it:

• 1 a motor vehicle headlight in a simplified schematic view;
• 2 a light module according to the invention according to a preferred embodiment;
• 3 a light module according to the invention according to another preferred embodiment in a first operating mode;
• 4 the light module 3 in a second operating mode;
• 5 a cross section through a luminance distribution in a far field for different operating modes of a light module according to the invention; and
• 6 a section of a light module according to the invention according to another preferred embodiment.

In 2 an example of a light module 10 according to the invention is shown in a schematic view. The light module 10 is designed as a projection module. The light module 10 can be part of a headlight 101 of a motor vehicle in the form of a light module 105 and/or 106, as shown for example in 1 is shown and will be explained in more detail below. The projection module 10 comprises a plurality of light sources arranged in a matrix, which are designated in their entirety by the reference number 12. The light sources 12 are used to emit light. In 2 An example of an edge ray 14 of the emitted light is shown. The light sources 12 are preferably designed as semiconductor light sources, in particular as LEDs or as laser diodes. The light sources 12 can be arranged axially symmetrically to an optical axis 28 of the light module 10 or a component thereof.

Furthermore, the projection module 10 includes an optical element 16 arranged in the beam path of the light 14, which in the example shown is used as projection optics for imaging at least part of the emitted light 14 in an apron 18 in front of the motor vehicle. The light imaged in advance serves to generate a predetermined light distribution of the projection module 10. As an edge beam 14 In the context of the present invention, those light rays are referred to which leave the optical element 16 via an edge region 20.

The light module 10 also includes a diaphragm element 22 arranged in the beam path of the light 14 with an adjustable aperture opening 24. The diaphragm element 22 is arranged and designed in the light module 10 in such a way that light 14, which the optical element 16 in a central area 26 around the optical axis 28 of the optical element 16 around, passes through the aperture opening 24 and that the aperture element 22 at least partially shades light 14, which leaves or would leave the optical element 16 via the edge region 20 radially outside the central region 26. The edge beam 14 is shaded or transmitted depending on the state of the aperture element 22 or depending on the set size of the aperture opening 24.

In the example shown, the diaphragm element 22 is arranged downstream of the optical element 16 in the beam path, i.e. further outside. Furthermore, the projection optics include 16 in 2 two individual optics 16.1, 16.2, which are designed as lenses. Of course, the projection optics 16 can also have more than two individual optics. It would also be conceivable for the projection optics 16 to also include a projection reflector. Finally, it would also be conceivable that the diaphragm element 22 is arranged between a penultimate individual optics 16.1 and a last (or outer) individual optics 16.2, so that it is hidden from outside the light module by the optics 16.2. In this case, the diaphragm element 22 would preferably be arranged closer to the outer optics 16.2 than to the optics 16.1, particularly preferably close to or directly in front of a light entry surface of the outer individual optics 16.2.

The headlight for automobiles is in 1 designated in its entirety with the reference number 101. The headlight 101 includes a housing 102, which is preferably made of plastic. In a light exit direction 103, the headlight housing 102 has a light exit opening which is closed by a transparent cover plate 104. The cover plate 104 is made of colorless plastic or glass. The pane 104 can be designed as a so-called clear pane without optically effective profiles. Alternatively, the disk 104 can be provided at least in some areas with optically effective profiles (eg cylindrical lenses or prisms), which cause the light passing through to scatter, preferably in the horizontal direction.

In the example shown, two light modules 105, 106 are arranged inside the headlight housing 102. The light modules 105, 106 are arranged to be fixed or movable relative to the housing 102. A dynamic cornering light function can be implemented by moving the light modules 105, 106 relative to the housing 102 in the horizontal direction. When the light modules 105, 106 move about a horizontal axis, i.e. in the vertical direction, headlight range control can be implemented. Of course, more or fewer than the two light modules 105, 106 shown can also be provided in the headlight housing 102. At least one of the light modules 105, 106 is designed as a projection module 10 according to the invention.

A control device 107 can be arranged in a control device housing 108 on the outside of the headlight housing 102. Of course, the control device 107 can also be arranged at any other location on the lighting device 101. In particular, a separate control device can be provided for each of the light modules 105, 106, whereby the control devices can be an integral part of the light modules 105, 106. Of course, the control device 107 can also be arranged away from the lighting device 101, for example in the engine compartment of the motor vehicle. The control device 107 is used to control and/or regulate the light modules 105, 106 or sub-components of the light modules 105, 106, such as light sources of the light modules 105, 106 or actuators for the horizontal and/or vertical adjustment of the light modules 105, 106 or of aperture elements of the light modules, in particular of actuators for varying the size of an aperture opening of the aperture elements.

The light modules 105, 106 or the subcomponents are controlled by the control unit 107 via connecting lines 110, which are in 1 are only symbolically represented by a dashed line. The light modules 105, 106 can also be supplied with electrical energy via the lines 110. The lines 110 are led from the interior of the lighting device 101 through an opening in the headlight housing 102 into the control unit housing 108 and are connected there to the circuit of the control unit 107. If control devices are provided as an integral part of the light modules 105, 106, the lines 110 and the opening in the headlight housing 102 can be omitted. Finally, the control device 107 can include a plug element 109 for connecting a connecting cable to a higher-level control unit (eg in the form of a so-called body controller unit) and/or an energy source (eg in the form of the vehicle battery).

The invention proposes a preferably high-resolution light module 10 with a diaphragm element 22 to be expanded with a changeable/movable aperture opening 24. The diaphragm element 22 is preferably arranged close to the outermost optics 16.2 (eg exit lens), particularly preferably after the outermost optics 16.2 (towards the image side). With this aperture element 22, edge rays 14 from the optical element 16 can be dimmed in the light module 10 if necessary or as desired in order to increase the imaging quality, depending on the resulting light distribution of the light module 10, using the example of a light module 10 designed as a projection module, while accepting a slight deterioration in the overall transmission improve, or to achieve a high overall transmission with slightly reduced image quality. Using the example of a light module 10 designed as a reflection module, the homogeneity of the illumination can be improved if necessary or as desired using the aperture element 22 with the adjustable aperture 24.

One aspect of the invention is, depending on the requirements for the light distribution to be generated by the light module 10, with the aperture element 22 in a projection module 10 between an operating mode with high transmission (aperture element 22 open = opening 24 large) and an operating mode with good imaging quality (aperture element 22 closed = opening 24 small).

There are light distributions in which high transmission is desirable, e.g. with “full high beam” (i.e. the entire long-distance area in advance is illuminated), and light distributions in which high image quality is important, e.g. with partial high beam (i.e. from the full high beam at least one area in which other road users were detected is excluded or darkened; a vertical light-dark boundary is formed between the illuminated area and an adjacent darkened area), or in the case of low beam with a horizontal light-dark boundary. High image quality is particularly advantageous when symbols are to be projected onto the road.

The diaphragm element 22 is preferably designed as a lamella diaphragm or as a lamella diaphragm or iris diaphragm.

In the 3 and 4 Two different operating or switching states of the diaphragm element 22 are shown. In 3 the aperture 24 is open, whereby a high transmission is achieved. In 4 the aperture 24 is opened less and has a reduced diameter. In this case, at least some of the marginal rays 14 are shaded, the transmission is reduced, but the imaging quality is improved.

The opening 24 of the diaphragm element 22 is preferably adjustable radially symmetrically to the optical axis 28, i.e. the diaphragm element 22 can be moved radially symmetrically. This can be achieved with a louvre or iris diaphragm, but also with other diaphragm elements 22. This also applies if the individual optics 16.2 or the projection optics 16 do not have a radially symmetrical light exit surface, but the light exit surface is not designed to be radially symmetrical, for example for design reasons.

• - volles Fernlicht: keine Ausblendung von Teilbereichen der Lichtverteilung, keine Kanten in der Lichtverteilung, keine Abbildung, maximale Lichtleistung --> Blendenöffnung 24 maximal geöffnet
• - Teilfernlicht: Ausblendung von Teilbereichen der Lichtverteilung, vertikale Helldunkelgrenze möglichst scharf abbilden, Kanten in der Lichtverteilung, geringes Streulicht --> Blendenöffnung 24 weniger stark geöffnet
• - Symbolprojektion: Ausblendung von Teilbereichen der Lichtverteilung, Kanten in der Lichtverteilung, Lichtmenge reduziert, möglichst scharfe Abbildung der Symbole --> Blendenöffnung 24 maximal geschlossen, wobei dann immer noch eine Öffnung 24 um die optische Achse 28 herum verbleibt, durch die das Licht zur Erzeugung der Symbole hindurchtreten kann

The size of the aperture opening 24 results from the requirements for the light distribution to be generated by the light module 10. Examples of the size of the aperture opening 24 for different light distributions are given below:

• - full high beam: no masking out of partial areas of the light distribution, no edges in the light distribution, no image, maximum light output --> aperture opening 24 maximum opened
• - Partial high beam: suppression of partial areas of the light distribution, image the vertical light-dark boundary as sharply as possible, edges in the light distribution, low scattered light --> aperture opening 24 less open
• - Symbol projection: masking out partial areas of the light distribution, edges in the light distribution, the amount of light reduced, the sharpest possible image of the symbols --> aperture opening 24 closed to the maximum, whereby an opening 24 still remains around the optical axis 28 through which the light is transmitted Generation of the symbols can pass through

In 5 a cross section of the luminance distribution is shown in a long-distance area in front of the motor vehicle. A horizontal angle in degrees [°] is plotted on the x-axis. The y-axis has a logarithmic scale. Curve 30 corresponds to an aperture or aperture 24 of 22 mm radius, curve 32 to an aperture of only 15 mm radius. It can be clearly seen that with a larger aperture 24 (curve 30), larger luminance values can be achieved, ie the transmission of the light module 10 is greater.

A concrete example is shown below: A simulated cross section of a light distribution of a 1 mm ² rectangular LED 12 with a luminous flux of 250 Im is assumed. The light distribution is imaged by projection optics 16 with a 30 mm focal length in the long range in front of the motor vehicle. With an aperture of the aperture 24 of Radius 22 mm, the efficiency is 53% and the luminance is 2,700 lm/cm ² /rad. With an aperture of the aperture opening 24 of radius 15 mm, the efficiency is 30% and the luminance is 1,300 lm/cm ² /rad. The width of the distribution at a contrast of 1:100 is 2.8° at a radius of 22 mm and 2.2° at a radius of 15 mm. So a larger aperture improves efficiency and maximum luminance and reduces resolution.

There can be different aperture positions for the aperture element 22, but at least two positions: closed (with a small opening 24) and maximally open (with a larger opening 24).

In addition, there may be other aperture settings for the aperture element 22, which may be useful or advantageous for the respective light distribution, for example only half closed.

A stepless, continuous transition between an open position (with a larger opening 24) and a closed position (with a smaller opening 24) is also conceivable.

In the case of non-symmetrical light distributions, it may make sense to also use the diaphragm element 22 to dim symmetrically, i.e. to shade the edge rays 14 to different degrees depending on the area of the optical element 16 over which they emerge from the optical element 16.

For example, in the case of light distributions that only require good imaging quality in one direction (e.g. low beam with a horizontal light-dark limit), it may make sense to shade only the respective part of the optical element 16 that causes the poorer imaging quality. In the example of a low beam with a horizontal cut-off point, the image quality in the vertical direction should be as good as possible in order to be able to produce the cut-off point sufficiently well (i.e. sharply). This can be achieved by shading the upper and lower edge regions of the optical element 16. In this case, poorer image quality in the horizontal direction is acceptable.

If a projection system with projection optics designed as a reflector is used to image the light distribution on the road in front of the motor vehicle, a non-radially symmetrical reflector is used, as is common in matrix reflection systems, for example, then in this case the aperture element 22 is preferably also not radially symmetrical, but adapted accordingly to the respective reflector cutout or the light exit surface of the reflector.

Furthermore, it would be conceivable that the aperture element 22 additionally contributes to creating an aesthetic appearance of the light module 10. In such a case, the diaphragm element 22 would, for example, not be completely opaque, but partially transparent to visible light, for example like frosted glass. In this way, for example, an attractive day design could be realized if such a diaphragm element 22 is arranged in a position between the individual optics (e.g. lenses) 16.1 and 16.2. The aperture opening 24 could be closed during the day and then illuminated by a light source, for example the light sources 12, so that the optics 16.2 appear illuminated without producing a light distribution that complies with the regulations.

The aperture element 22 with the size-adjustable aperture opening 24 can also be used to protect the light sources 12 or other internal components of the light module 10, for example decorative frames, bezels, lens holders, from direct sunlight in the opposite light path. In the case of a light module 10 designed as a projection module, the sun can shine through the projection lens 16; 16.2 can be imaged onto the light source 12 or the other internal components using a magnifying glass, which can lead to very high temperatures and damage. This can be effectively counteracted by the cover element 22 proposed here. The aperture element 22 could then be varied not only depending on the resulting light distribution of the light module, but also depending on the solar radiation into the light module 10 or into the headlight 101 with regard to the size of the aperture opening 24.

It would also be conceivable for the diaphragm element 22 to be designed in such a way that the direction of movement of the diaphragm element 22 does not run exactly in the radial direction (cf. 3 and 4 ), but at an angle to it, for example along a truncated cone (cf. 6 ), so that the aperture movement causes a curvature of an exit lens 16; 16.2 is adapted.

Furthermore, it can be advantageous to provide, in particular, the edge regions 20 of the optical element 16, which produce a poor-quality image, completely or partially with a microstructure/scattering structure 34 in order to blur the image of the light and thereby display it more homogeneously. In such a case, it is particularly advantageous to cover these areas 20, which are provided with the micro/scattering structure 34, with the aid of the cover element 22, depending on the need or situation.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2306074 A [0003]
• WO 2013020156 A [0003]
• DE 102012112127 A [0003]

Claims (20)

Light module (10) of a headlight (101) of a motor vehicle, comprising a plurality of light sources (12) arranged in a matrix-like manner for emitting light (14) and an optical element (16) arranged in the beam path of the light (14) for redirecting at least part of the emitted light ( 14) and for generating a predetermined light distribution of the light module (10) in an apron in front of the motor vehicle from the deflected light (14), characterized in that the light module (10) further has a diaphragm element (22) arranged in the beam path of the light (14). with an adjustable aperture opening (24), the aperture element (22) being arranged and designed in the light module (10) in such a way that light that passes through the optical element (16) in a central area (26) about an optical axis (28) of the optical element (16), passes through the aperture opening (24) and that the aperture element (22) leaves or leaves the optical element (16) in an edge region (20) radially outside of the central region (26). would be at least partially shaded. Light module (10). Claim 1 , characterized in that the optical element (16) is designed as a reflection optics which is used to deflect at least part of the emitted light (14) into the apron in front of the motor vehicle in order to generate the predetermined light distribution of the light module (10) from the deflected light (14 ) is trained. Light module (10). Claim 1 , characterized in that the optical element (16) is designed as a projection optics for imaging at least part of the emitted light (14) in the apron in front of the motor vehicle to generate the predetermined light distribution of the light module (10) from the imaged light (14). Light module (10) according to one of the preceding claims, characterized in that the diaphragm element (22) is arranged in the beam path of the light (14) after the optical element (16). Light module (10). Claim 3 or 4 , characterized in that the projection optics (16) has a plurality of optics (16.1, 16.2) arranged one behind the other in the beam path of the light (14), the diaphragm element (22) in the beam path of the light (14) near the last optics (16.2) the projection optics (16) is arranged. Light module (10). Claim 5 , characterized in that the diaphragm element (22) is arranged in the beam path of the light (14) between the penultimate optics (16.1) of the projection optics (16) and the last optics (16.2) of the projection optics (16). Light module (10) according to one of the preceding claims, characterized in that the aperture opening (24) can be adjusted radially symmetrically with respect to an optical axis (28) of the optical element (16). Light module (10) according to one of the preceding claims, characterized in that the aperture opening (24) is adjustable in the radial direction with respect to an optical axis (28) of the optical element (16). Light module (10) according to one of the preceding claims, characterized in that the diaphragm element (22) is designed as a louvre diaphragm or iris diaphragm. Light module (10) according to one of the Claims 1 until 7 , characterized in that the aperture opening (24) is adjustable obliquely to a radial direction with respect to an optical axis (28) of the optical element (16). Light module (10) according to one of the preceding claims, characterized in that the aperture opening (24) of the aperture element (22) is adjustable between at least two discrete sizes, with a larger proportion of light coming out of the aperture opening (24) of a first set size Edge region (20) of the optical element (16) passes through the aperture opening (24) of a second set size. Light module (10) according to one of the Claims 1 until 10 , characterized in that the aperture opening (24) of the aperture element (22) is continuously adjustable in size between a maximum open size and a minimum open size, the further the aperture opening (24) is adjusted towards the minimum open size, the smaller it is Proportion of light (14) from the edge region (20) of the optical element (16) which passes through the aperture opening (24). Light module (10) according to one of the Claims 1 until 6 , characterized in that the aperture opening (24) can be adjusted asymmetrically with respect to an optical axis (28) of the optical element (16), with a less wide open section of the aperture element (22) allowing more light from the edge region (20) of the optical element (16) shaded than a more open section of the aperture element (22). Light module (20). Claim 3 and one of the Claims 4 until 13 , characterized in that the projection optics (16) comprises at least one lens. Light module (10). Claim 2 and one of the Claims 4 until 13 , characterized in that the reflection optics (16) comprises at least one reflector. Light module (10) according to one of the preceding claims, characterized in that the optical element (16) comprises a plurality of optics (16.1, 16.2) arranged one behind the other in the beam path of the light (14) and the last optic (16.2) of the optical element (16) as one Reflector is formed. Light module Claim 15 or 16 , characterized in that a shape and size of the aperture opening (24) of the aperture element (22) corresponds to the shape and size of a light exit opening of the reflector. Light module (10) according to one of the preceding claims, characterized in that the diaphragm element (22) is designed to be partially transparent to light. Method for controlling a shutter element (22) with an adjustable shutter opening (24), wherein the shutter element (22) is part of a light module (10) of a headlight (101) of a motor vehicle which, in addition to the shutter element (22), has a plurality of light sources (12) arranged in a matrix ) for emitting light (14) and an optical element (16) arranged in the beam path of the light (14) for deflecting at least part of the emitted light (14) and for generating a predetermined light distribution of the light module (10) in an apron in front of the motor vehicle from the deflected light, characterized in that a size of the aperture opening (24) is adjusted depending on the light distribution of the light module (10). Procedure according to Claim 19 , characterized in that the size of the aperture opening (24) is adjusted depending on solar radiation from outside into the light module (10).

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