Motor vehicle headlamp

The invention relates to a motor vehicle headlamp (101) comprising a light source (105), projection optics (102, 202) and a bracket (106, 206), wherein the light source (105) is mounted on the bracket (106, 206) and is configured to project light in the direction of a projection axis (104, 204) by means of the projection optics (102, 202), wherein the projection optics (102, 202) are mounted in a frame (103, 203) which is movably arranged in the bracket (106, 206). The headlamp further comprises a lever (107, 207) which is rotatably connected, by means of axis elements that form a pivot axis running transversely or normal to the projection axis (104, 204), to the bracket (106, 206). The frame (103, 203) comprises at least one lug (110, 210) which is located between the bracket (106, 206) and the lever (107, 207), and the lever (107, 207) is configured, in the event of a rotational motion around the pivot axis, to press on the at least one lug (110, 210), and thereby to displace the frame (103, 203) in the bracket (106, 206) along the projection axis (104, 204).

The invention relates to a motor vehicle headlamp, comprising a light source, projection optics and a bracket, wherein the light source is connected with the bracket and configured to project light in the direction of a projection axis by means of the projection optics.

The invention further relates to a motor vehicle, which comprises at least one motor vehicle headlamp according to the invention.

During the development of current headlamp systems, the primary objective is increasingly to be able to project a homogeneous light image with the highest possible resolution onto the road. The term “road” is here used by way of a simplified description, since it of course also depends on the local conditions whether a light image is actually on the road or even extends over it. In principle, the light image in the meaning used corresponds to a projection onto a vertical surface according to the relevant standards relating to motor vehicle lighting technology.

In order to meet this requirement, among other things headlamps were developed in which a variably actuatable reflector surface consists of a plurality of micromirrors, and a light emission generated by a light source reflects in the direction of projection of the headlamp. Such lighting devices are advantageous in vehicle construction due to their very flexible light functions, since the illuminance can be individually controlled for different illuminated areas, and any desired light functions with various light distributions can be realized, for example a low beam light distribution, turning light distribution, city light distribution, highway light distribution, curve light distribution, high beam light distribution or the imaging of glare-free high beams.

The micromirror array is fabricated using the so-called digital light processing (DLP®) projection technology, in which images are generated by modulating a digital image onto a light beam. A rectangular array of movable micromirrors, also referred to as pixels, here breaks down the light beam into partial areas, and then projects it pixelwise either into the projection path or out of the projection path.

This technology is based upon an electronic component that contains the rectangular array in the form of a matrix of mirrors and their actuation technology, and is referred to as “digital micromirror device” (DMD).

A DMD microsystem involves a spatial light modulator (SLM), which consists of micromirror actuators arranged in a matrix, i.e., tiltable reflecting surfaces, for example with an edge length of about 16 μm. The mirror surfaces are here constructed in such a way that they can be moved through exposure to electrostatic fields. Each micromirror can be individually adjusted in terms of its angle, and as a rule has two stable end states, which can be switched between up to 5000 times a second. For example, the individual micromirrors can each be actuated via pulse-wide modulation (PWM), so as to image additional states of the micromirrors in the primary beam direction of the DMD array, whose time-averaged reflectivity lies between the two stable states of the DMD. The number of mirrors corresponds to the resolution of the projected image, wherein a mirror can display one or more pixels. DMD chips with high resolutions in the megapixel range have since become available. The technology underlying the adjustable individual mirrors is micro-electro-mechanical systems (MEMS) technology.

While DMD technology has two stable mirror states, and the reflection factor can be adjusted through modulation between the two stable states, a feature of “analog micromirror device” (AMD) technology is that the individual mirrors can be set in variable mirror positions, which are there each in a stable position.

For arrays using DLP® technology, it is important that the individual vehicle assemblies of a vehicle headlamp be mounted in a highly precise manner, meaning with very low tolerances that far exceed the requirements in conventional vehicle headlamps. The individual assemblies, for example light sources, reflectors or projection lenses, must be positioned or adjusted very precisely relative to each other, for example so as to avoid any blurred focus, false imaging, failure to reach the required light values and extraneous light. This is currently not required in vehicle headlamps according to prior art.

Furthermore, adjusting devices for assemblies often have a level of play in the adjusting connections for the optical components, which can unfavorably impair the optical properties of the headlamp.

The object of the invention is to overcome the mentioned disadvantages or satisfy the requirements better than prior art allows. In addition, the ability to compensate for component and assembly tolerances and set optical elements in a highly precise manner is to be created.

The object of the invention is achieved with a motor vehicle headlamp of the kind mentioned at the outset, in that the projection optics are secured in a frame movably arranged in the bracket, and a lever is further provided that is rotatably connected with the bracket by means of axis elements forming a pivot axis that runs transverse, preferably normal to the projection axis, and the frame has at least one lug lying between the bracket and lever, and the lever is set up to press against the at least one lug during a rotational motion around the pivot axis, thereby displacing the frame in the bracket along the projection axis.

As a result of the inventive array, the position of the at least one projection optics can be very finely set by the at least one lever. According to the law of the lever, a large path of the lever arm of the lever to which force is applied, which can be actuated with a slight exertion of force, can be transferred to a smaller path of the load arm, which can displace the position of the projection optics with a greater force.

A favorable configuration of the frame, which together with the at least one bracket provides a displaceable mounting of the at least one projection optics, and the inventive solution can achieve a highly precise setting or adjustment of assemblies in a vehicle headlamp, for example light sources, reflectors or lenses.

The inventive configuration of the vehicle headlamp further enables a very compact design.

In addition, the invention offers great advantages during assembly, since the vehicle headlamp need not be disassembled into its individual parts for adjusting the assemblies or the assemblies need not be successively put together so that they can be set relative to each other. After assembly is complete, an entire array can be adjusted. The extent of adjustment can be observed in the resulting light image of the headlamp.

In a further development of the invention, at least one flexible, elastic spring element is arranged between the at least one lug and the bracket. A flexible spring element makes it possible to apply a pretension to the adjusting connection, so that the adjusting connection can be set free of play. In addition, this creates a connection that can be fixed in any position, so that very individual and precise attention can be paid to the installation conditions. These installation conditions can be caused by tolerances in the geometry or assembly of individual assemblies, which are to be reduced or optimally compensated. This also makes it possible to consider the situation for installing the headlamp in a vehicle.

It is especially advantageous for at least one connecting element, preferably a screw, to further be arranged between the bracket and lever, which is set up to connect the bracket with the lever. This allows the connection to be finely adjustable.

It is beneficial for the light source to comprise at least one semiconductor light source, in particular an LED or a laser diode. For this reason, it is also beneficial for the projection optics to comprise at least one optical lens, as well as for a controllable reflector, in particular a DMD, to be arranged between the light source and projection optics.

In particular for controllable reflectors, the accuracy requirements placed on the entire optical array are particularly stringent, which is why the inventive array can very advantageously be used with a DMD, meaning a controllable reflector in DLP® technology.

It is especially advantageous for the bracket to comprise a guide arranged parallel to the projection axis, which is set up to receive the at least one lug of the frame and guide the at least one lug of the frame along the guide of the bracket. The guide improves the alignment of the projection optics during adjustment.

Selecting a suitable shape for the strap can enable a uniform, symmetrical force transmission.

In an advantageous embodiment of the invention, the lever is bent in the shape of a U, and has two ends, wherein the two ends of the U-shaped lever each have an opening to receive axis elements, through which the pivot axis of the lever runs, with the U-shaped lever further being provided with an opening to receive a connecting element, preferably an adjusting screw, with which the lever can be connected with the bracket. Several openings are also possible for receiving the respective connecting elements. The middle of the lever lies between the two ends of the lever.

The U-shaped lever is beneficial in particular in cases where the bracket and frame with the projection optics are to be displaceable and adjustable over a large path. A guide can be used by way of support for this purpose. The U-shaped lever is particularly well suited, since the lever can thereby have a large lever length, as it envelops the bracket and frame arrangement, and in the process does not cut the beam path of the light.

In another advantageous, alternative embodiment of the invention, the lever is ring-shaped, and has at least one opening to receive at least one axis element, through which the pivot axis runs, wherein the opening runs through the ring-shaped lever tangentially to its mean diameter. Furthermore, the ring-shaped lever is provided with an opening to receive a connecting element, preferably an adjusting screw, which can be used to connect the lever with the bracket. The ring-shaped lever preferably comprises at least one overlay set up to press on the at least one lug, and the frame forms a shared component with the at least one lug.

The ring-shaped lever is beneficial in particular in cases where the at least one bracket and the frame with the projection optics are to be displaceable and adjustable over a small path.

It is further advantageous for the ring-shaped lever to form a shared component with the lug, so as to simplify the structure.

It is further advantageous for an additional optical system to be provided, which has an optical axis, wherein the additional optical system is secured to the bracket, and the optical axis of the additional optical system preferably lies coaxially in the projection axis.

A further development of the invention provides that the motor vehicle headlamp comprise two projection optics with two projection axes and preferably two brackets for receiving the two projection optics. As a result, the optical parameters of the projection optics can be very flexibly adjusted. This is advantageous in particular in cases where one of the two projection optics lies within a housing, and the other of the two projection optics lies outside of the housing. As a result, incremental adjustments can be made based on progress during assembly. The second projection optics lying outside of the housing can then be adjusted to the circumstances during installation into a vehicle, while the first projection optics is no longer adjusted.

A further development of the invention can provide an additional projection optics in the form of an additional optical system, which is secured in the bracket. By adjusting the additional optical system relative to the projection optics, the optical parameters for the overall optics comprised of one or several projection optics and additional optical systems become especially easy to set.

It is here beneficial for the flexible adjustment and setting of optical parameters that the two projection axes run coaxially or parallel.

In a further development of the invention relating to the arrangement of optical elements, it is beneficial for the two projection axes of the two projection optics to have an angle relative to each other, wherein the angle preferably lies only in a horizontal plane in the installed position of the motor vehicle headlamp, and preferably measures between 0° and 10°.

A further development of the invention provides a motor vehicle that comprises at least one inventive motor vehicle headlamp. As a result, the inventive motor vehicle headlamp can be easily adapted and adjusted to the installation situation and position in a motor vehicle.

Drawing reference toFIG. 1toFIG. 11, an exemplary example of the invention will now be explained in more depth. Shown in particular for the invention are the important parts in a headlamp, wherein it is clear that a headlamp still contains many other parts that are not shown, which allow for a sensible use in a motor vehicle, for example in an automobile or motorcycle. For example, cooling devices for components, actuation electronics or other optical elements are thus not shown for the sake of clarity.

An installation position in a vehicle is not shown on a separate figure for an inventive headlamp according to the following description, since the installation position of the inventive headlamp is no different than for known prior art. The adjustability achieved by the inventive headlamp during installation in a vehicle is derived from the description of exemplary embodiments according toFIGS. 1 to 11.

Shown onFIGS. 1 and 2is a motor vehicle headlamp, comprising a light source105, a first projection optics102and a second projection optics202and a first bracket106and a second bracket206, wherein the light source105is connected with the brackets106and206in a mechanically fixed manner. The light source105is further set up to emit by means of the projection optics102and202in the direction of a first projection axis104, or a second projection axis204. An angle304is here present between the projection axes104and204. In this example, the angle304lies in a horizontal plane, proceeding from an installation position of the headlamp in a vehicle, and measures between 0° and 10°, depending on design. However, it may make sense in other exemplary embodiments for the two axes to be situated coaxially or provide an angle304in a spatial plane oriented as desired. Located between the light source105and projection optics102and202is an electronically controllable reflector113in the form of a micromirror array, for example a DLP® or DMD, which can reflect the light emitted by the light source105in the direction of the projection axes104or204, depending on the actuation. Those mirrors of the controllable reflectors113actuated in such a way as to not reflect the light in the direction of the projection axis104can alternatively reflect the light in the direction of an absorber114.

In this exemplary embodiment of the invention, use is made of two projection optics102and202with two projection axes104,204, wherein the two projection axes104,204run coaxially. Further provided are additional components, such as the brackets106,206to receive the two projection optics102,202, also twofold in varying configurations. However, just a single projection optics can be used in a motor vehicle headlamp, for example so as to realize the structure more compactly or cost-effectively. The embodiment shown is characterized by an especially flexible adjustability for the optical parameters of the projection optics or the overall projection optics comprised of the two projection optics. As is clear, two motor vehicle headlamps101can be installed during assembly in a motor vehicle.

The light source105is connected with a heat sink, so as to dissipate heat loss generated by the light source105. The light source105can comprise one or several light-generating components, such as semiconductor light sources, in particular LED's or laser diodes, along with a primary optical system containing one or several optical lenses or apertures. It is also possible to include means for converting light from a first wavelength range to a second wavelength range, for example a conversion phosphorus.

The controllable reflector113is here mounted on a printed circuit board, which can comprise additional electronic components for actuating the controllable reflector113or mechanical elements.

The projection optics102and202each comprise at least one optical lens. Of course, the lens systems can also consist of an array of several lenses, or also include apertures that form projection optics102and202.

The first projection optics102is secured in a frame103that is movably arranged in the bracket106. Also provided is a lever107. The frame103here has two lugs110, which lie between the bracket106and lever107.

The second projection optics202is fastened in a frame203, which is movably arranged in the bracket206. In addition, a lever207is enveloped by two pressing elements211. The frame203here has lugs210that lie between the bracket206and the pressing elements211of the lever207. Arranged between the lug210and bracket206is a respective flexible, elastic spring element209. The frame203is fastened to the bracket206with a connecting element212.

FIG. 3shows a cutout of the motor vehicle headlamp101with elements for setting the first projection optics102, which is fastened in the frame103and movably arranged in the bracket106. Further provided is the lever107, which is rotatably connected with the bracket106by means of axis elements115forming a pivot axis108that runs transverse or normal to the projection axis104. The frame103has two lugs110(only one lug is visible on the figure), which lie between the bracket106and lever107. The lugs110are part of the frame103. The lever107is set up to press against the two lugs110during a rotational motion around the pivot axis108, thereby displacing the frame103in the bracket106along the projection axis104.

Also arranged between the bracket106and lever107is a connecting element112, which is set up to connect the bracket106with the lever107. The connecting element112is preferably a screw, which can be tightened to align the frame with the bracket106, so as to displace the projection optics102along the projection axis104and thereby optically adjust it.

The bracket106comprises a guide111arranged parallel to the projection axis104, which is set up to receive the lugs110of the frame103and guide the lugs110of the frame103along the guide111of the bracket106.

Arranged between the lug110and bracket106is a flexible, elastic spring element109, against which the lug110can press during exposure to a force applied by the lever107.

The lever107is shaped like a U, and has two ends. The two ends of the U-shaped lever107each have an opening, into which the axis elements115can be inserted and the pivot axis108of the lever107runs. The U-shaped lever107is further provided with an opening to receive the connecting element112, preferably an adjusting screw, with which the lever107can be connected with the bracket106.

FIG. 4presents a front view of the projection optics102of the headlamp101, which is fastened in the frame103arranged in the bracket106. The lever107and its pivot axis108are visible.

FIG. 5shows the bracket106with the lever107and its pivot axis108. The guide11formed by elements of the bracket107is discernible. It is clear that each lug110lies in an accompanying guide111.

FIG. 6shows the arrangement according toFIG. 3as viewed in perspective from below. Visible in addition to the description forFIG. 3is an adjustment distance150, which can be used to adjust the projection optics102relative to the bracket. The adjustment takes place by displacing the projection optics102along the projection axis104, wherein the lugs110are displaced into the respective guides111.

FIGS. 7aand 7bdepict the adjustment of the arrangement of the headlamp101, wherein the displacement of the projection optics102can be discerned. The U-shaped lever107has two ends, which each have openings through which the pivot axis108runs and around which the lever107can be pivoted. Located between the two ends of the lever is the middle of the lever, which has an additional opening to receive the connecting element112.

Visible onFIG. 7ais a first adjustment position of the arrangement of the headlamp101, in which the middle of the lever of the U-shaped lever107abuts tightly against the bracket106. The lug110lying in the guide111along the projection axis104here presses against the spring element109. The frame103connected with the lug110has a first adjustment distance150to the bracket106.

FIG. 7bshows a second adjustment position of the arrangement of the headlamp101, in which the middle of the lever of the U-shaped lever107has a larger distance, a second adjustment distance, from the bracket106than in the first adjustment position.

FIG. 8presents an exploded view of the arrangement of the headlamp101for the first projection optics102. The projection optics102, the frame103, the lug110and the projection axis104are visible. Further depicted is the bracket106, the lever107, two axis elements115, the pivot axis108, as well as the spring element109and the guide111.

FIG. 9shows the second projection optics202of the headlamp101.

The projection optics202is fastened in a frame203, which is movably arranged in the bracket206. In addition, a lever207is enveloped by two pressing elements211, and rotatably connected with the bracket206by means of axis elements215forming a pivot axis208that runs transverse or normal to the projection axis204. The frame203has two lugs210, which lie between the bracket106and lever107. The lugs210are part of the frame203. The lever207is set up to press against the lugs210with the pressing elements211during a rotational motion around the pivot axis208, thereby displacing the frame203in the bracket206along the projection axis204. In this embodiment, the lever207and pressing elements211form a shared component, so that the lever207can transmit an acting force directly to the lugs210. Respective flexible, elastic spring elements209are arranged between the lugs210and bracket206. The lever207is adjustably connected with the bracket206via the connecting element212.

The lever207is ring-shaped, and has openings to receive axis elements215, through which the pivot axis208runs, wherein the openings run through the ring-shaped lever207tangentially to its mean diameter. A middle of the lever lies in the region opposite the one through which the pivot axis208runs. The ring-shaped lever207, preferably the middle of the lever, is provided with an opening to receive the connecting element212, preferably an adjusting screw, with which the lever207can be adjustably connected with the bracket206, and the ring-shaped lever207forms a shared component with the pressing elements211. A thread in the form of a screw is provided in the bracket206to receive the connecting element212.

FIG. 10presents another perspective view of the projection optics202of the headlamp101with its projection axis204, which is fastened in the frame203arranged in the bracket206. The lever20with its pivot axis208and pressing elements211is visible, as are the two lugs210of the frame203.

Also arranged between the bracket206and lever207is a connecting element212, which is set up to adjustably or fixedly connect the bracket206with the lever207.

FIG. 11presents an exploded view of the arrangement onFIG. 10, wherein in particular the axis elements215are visible, along with a spring element209.

Further visible is an additional optical system302, which has an optical axis, and the additional optical system302is arranged on and secured to the bracket206. The optical axis of the additional optical system302preferably lies coaxially in the projection axis204. By adjusting the projection optics202relative to the additional optical system302, the optical parameters for the overall optics consisting of the projection optics102and202as well as the additional optical system302can be very easily and flexibly set.

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