Microlens array projection device, lighting device, and vehicle

Abstract

An improved microlens array projection device is provided for generating light patterns that improve the accuracy of active triangulation-based peripheral recognition systems. The present invention relates to a microlens array projection device (1) for generating a light pattern (6) from light emitted by the light source (2), comprising at least one light source (2), a field lens array (3), a projection lens array (4) and a pattern template arranged between the field lens array (3) and the projection lens array (4) in a light path (5) emerging from the light source (2). The microlens array projection device according to the present invention is characterized in that the pattern template is formed from a microslide array (7) comprising at least two microslides (8), at least one microslide (8) being movable by at least one actuator (9) in a plane (E) perpendicular to an optical axis (OA) between the field lens array (3) and the projection lens array (4).

Description

[Technical field]

[0001] The present invention relates to a microlens array projection device, a lighting device, a vehicle and the use of such a lighting device in a vehicle's surroundings perception system for identifying road conditions of the kind detailed in the preamble of claim 1.

[0002] With the increasing digitalization, the degree of vehicle automation is also increasing. For example, today's vehicles are equipped with a wide range of driver assistance systems that assist the person operating the vehicle (driver) in operating the vehicle, thereby improving comfort and / or safety in road traffic. Some driver assistance systems, such as distance control devices or parking assistance systems, require surrounding information, such as the presence of static and / or dynamic surrounding objects around the vehicle and their relative distances to the vehicle. Furthermore, some driver assistance systems, such as adaptive suspension control, require information about the condition of the road on which the vehicle will soon be traveling.

[0003] From the general prior art, various sensor systems for monitoring the surroundings are known. In particular ultrasonic sensors, radar sensors, camera systems with monocular or stereo cameras, but also laser scanners such as LiDAR, have already proven themselves in the automotive sector. However, the quality of the calculation of the volumetric information using stereo cameras depends relatively heavily on the quality of the mapping algorithms that map the image information between the two cameras used. Furthermore, such systems can only be used reliably in daylight and the accuracy is distance-dependent. The use of digitalized "terrestrial LiDAR" for recognizing the road situation is not suitable for mass production due to its high cost and limited vertical angular resolution.

[0004] Another method for perimeter monitoring or volumetric information acquisition is to use active triangulation, which in particular allows the vehicle to analyze its condition by scanning the ground on which it is driving. This allows particularly fast and effective detection of road surface irregularities such as holes in the road surface, speed barriers, or even road surface boundaries such as curbs or grooves running parallel to suburban roads. Here, a projector projects a structured light pattern onto the surroundings, in particular onto the road ahead of the vehicle in the direction of travel, and a camera arranged on the vehicle records the feature points of the light pattern reflected from the surroundings. Distance determination or volumetric information acquisition is then possible by taking into account the so-called epipolar geometry. By positionally offsetting the mounting points of the on-board camera and the projector, it is possible to detect a shift of the feature points of the light pattern in the camera image generated by the camera if the light pattern is distorted by irregularities or surrounding objects. Depending on how strongly the light pattern is distorted, volumetric information can then be calculated. The use of an active triangulation based system for stereo acquisition also allows for use in low light conditions since the scene is actively illuminated.

[0005] For example, the following patent document 1 discloses a corresponding device and an opposing method for recognizing the vehicle surroundings based on active triangulation. In this case, the pixel headlights of the vehicle are used as projectors. The pixel headlights can be the front headlights of the vehicle or independent headlights. The pixel headlights then project a light pattern into the surroundings in a very short time frame, which is not perceptible to humans. The camera recognizing the surroundings and the pixel headlights are then synchronized with each other, so that a camera image of the surroundings is taken as soon as the pixel headlights project the light pattern into the surroundings. Since the light pattern is only projected into the surroundings for a short time and is not perceptible to the driver, the method disclosed in patent document 1 is particularly comfortable to use. In particular, the driver is not distracted by this. The pixel headlights then project the light pattern into the surroundings in addition to the basic lighting, or can briefly deactivate or at least dim the basic lighting during the emission of the light pattern. The light pattern can include, for example, a line pattern, a stripe pattern, a dot pattern, a grid pattern, a checkerboard pattern, and / or a pseudorandom pattern. At this time, the brightness / darkness control of the pixel headlight is performed such that the basic luminance of the basic illumination is constant on a time average when emitting the light pattern. The device and method disclosed in Patent Document 1 can detect road surface irregularities, road surface boundaries, and surrounding objects and identify their relative positions to the vehicle. The device disclosed in Patent Document 1 uses pixel headlights to generate the light pattern, which has a complex structure and is therefore expensive.

[0006] Furthermore, from the general prior art, so-called microlens array projectors (also called multi-aperture projection displays) are known, which allow the emission of structured light patterns. For this purpose, an object structure is arranged in the light path between a light source and a projection surface onto which the light pattern is projected, in order to structure the light. Furthermore, by arranging a field lens array and a projection lens array in front of or behind the object structure in the light path, it is possible to appropriately focus or beam the light rays emitted by the light source. Each lens of the field lens array and the projection lens array is then assigned to a substructure of the object structure. For example, such microlens array projectors are used to create aesthetic vehicle perimeter lighting. Due to the miniaturized lens array, it is possible to generate a relatively deep depth of field compared to other projection systems.

[0007] Such a lighting device for an automobile with a microlens array projector is known, for example, from the following patent document 2. This document describes the use of a light pattern projected by a luminaire into the surroundings of a vehicle as a parking assistance system, a distance control assistance system and / or a narrow road negotiating assistance system. The light pattern projected into the surroundings by the luminaire disclosed in the patent document 2 is focused on a defined distance to the vehicle, so that the display content contained in the light pattern appears clearly at a defined distance between the vehicle and the object onto which the light pattern is projected. When the vehicle approaches the object and reaches the defined distance, the display content appears clearly, so that the driver is informed that a defined distance between the vehicle and the object has been reached at the defined distance. It is also possible to use the luminaire to simultaneously project into the surroundings several light patterns, each focused on separate focusing planes with mutually different distances to the vehicle. This makes it possible to realize a device for conveying information about the distance between the vehicle and the surrounding objects to the driver in a particularly simple and inexpensive manner. Therefore, no other display is necessary for visualizing the distance between the vehicle and the surrounding objects. In this case, the multi-aperture projection display may also be integrated into at least one front headlight and / or taillight of the vehicle.

[0008] Furthermore, the following patent document 3 discloses a method and an apparatus for detecting obstacles in the road of a vehicle using active triangulation. In this document, an arrangement consisting of a light source, a diffraction grating and a lens is used as a projector for generating a light pattern. In this case, the light source is formed in particular by a laser diode and is provided for emitting infrared light. The diffraction grating can be formed from a filter wheel with a large number of different line patterns to generate different light patterns. By rotating the filter wheel, different diffraction gratings can be provided in the light path between the light source and the lens. Furthermore, the arrangement consisting of the light source, the diffraction grating and the lens may be rotatable about a horizontal axis and a vertical axis to be able to project the light pattern on the desired target area. However, a drawback of the filter wheel is that there is a limited space for accommodating further diffraction gratings. This greatly restricts the provision of further diffraction gratings to generate different light patterns. Furthermore, the light pattern projected into the surroundings by the device disclosed in patent document 3 has a relatively low depth of field, which results in a relatively low accuracy in obtaining stereoscopic information of the surrounding area far ahead of the vehicle. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] DE 10 2015 008 774 A1 [Patent Document 2] DE 10 2014 219 371 A1 [Patent Document 3] DE 10 2015 206 936 A1 Summary of the Invention [Problem to be solved by the invention]

[0010] The problem to be solved by the present invention is to provide an improved microlens array projection device for generating a light pattern that improves the accuracy of a surrounding recognition system based on active triangulation and whose accuracy is not affected by the current driving conditions. [Means for solving the problem]

[0011] According to the invention, this problem is solved by a microlens array projection device having the features of claim 1, a lighting device having the features of claim 7, a vehicle having the features of claim 8 and the use of a lighting device in a vehicle surroundings recognition system having the features of claim 9. Advantageous embodiments and developments are evident from the dependent claims.

[0012] In a microlens array projection device of the type mentioned at the beginning, according to the invention, a pattern template is formed from a microslide array having at least two microslides, at least one of which is movable by at least one actuator in a plane perpendicular to the optical axis between the field lens array and the projection lens array.

[0013] The microlens array projection device generates a light pattern with a relatively large depth of field. The microslide array allows a relatively large number of different microslides to be provided, which can generate individual light patterns. Furthermore, the microslides can be moved in a plane, so that a desired light pattern can be projected in a desired surrounding area. This allows the light pattern to be individually adapted to the current surrounding conditions. Thus, by moving one or more microslides, a desired light pattern can be formed in a specific surrounding area. Here, as in the prior art, the light pattern can include a line pattern, a stripe pattern, a dot pattern, a grid pattern, a checkerboard pattern, a pseudo-random pattern, etc. For example, the line density or dot density can be appropriately increased or decreased in a specific surrounding area. Also, for example, the direction of the lines can be adapted accordingly by moving the microslide. For example, the microslide can be moved in a plane by rotation and / or translation.

[0014] The microlens array projection device may have as a light source at least one common light emitter such as an LED, an OLED, a laser, and / or a lamp such as a halogen lamp, a light bulb, or a gas discharge lamp.

[0015] In order to generate a light pattern by the microslide array, the field lens array and the projection lens array do not have to have the same cross-sectional area in the light path as the microslide array. For example, it is sufficient that the microslide array has a smaller cross-sectional area than both lens arrays. In other words, there may be more field lenses and projection lenses than the microslides that the microslide array comprises. This ensures that the light propagation by the field lens and projection lens pair is not hindered even if the microslide is not between the field lens and the projection lens. When the microslide moves between the mentioned lenses, the light pattern generated by the microslide is projected into the peripheral area assigned to the corresponding field lens and projection lens pair. But basically, the number of field lenses and projection lenses may be the same as the number of microslides. Then, when the microslide moves, each individual microslide can move out of the lens pair. For example, recesses can be made in the lens pair to allow unhindered light propagation through the lens pair. There may be more microslides than lens pairs. This ensures that the light pattern generated by the lens pair and a special microslide can be changed by moving another microslide.

[0016] In an advantageous development of the microlens array projection device, at least two microslides are provided which are movable, in particular in mutually perpendicular intersecting rows and columns. The arrangement of the microslides in rows and columns allows a particularly flexible and simple movement of the microslides.

[0017] According to another advantageous embodiment of the microlens array projection device, at least one actuator is provided for simultaneously moving, in particular translating, at least two rows and / or columns. This allows a simplified structure of the microlens array projection device according to the invention. A smaller number of actuators are thus required for moving a large number of different rows and / or columns, which allows costs to be saved. For this purpose, for example, one actuator can be connected to several rows and / or columns at the same time. For example, the microslides can be arranged in segmented or non-segmented strips that can be translated within the microslide array by the actuator. In this case, the individual strips can also be moved at least partially out of the cross-sectional area of ​​the surface assigned to the microslide array and / or the field lens array and the projection lens array depending on their adjustment movements. In this case, the actuator can be indirectly or directly connected to at least one microslide or to the corresponding strip. By moving the microslide in the plane, the assignment of the microslides to the respective field lenses and projection lenses of the field lens array and the projection lens array changes. Thus, for example, focusing on a specific peripheral area can be achieved with a specific combination of field lenses and projection lenses. By moving a desired micro-slide between a corresponding field lens and a corresponding projection lens, the light pattern that can be generated by the corresponding micro-slide can be projected onto the desired peripheral area, as already mentioned. Essentially, different pairs of field lenses and projection lenses are aimed at the same peripheral area, but now with different focusing, and it is conceivable that the light pattern generated by the micro-slide can be distorted to different amounts and / or otherwise manipulated, for example by attenuating or polarizing the light output of the light pattern to different degrees.

[0018] Furthermore, in another advantageous embodiment of the microlens array projection device, it is provided that at least one actuator is formed by a piezoelectric actuator. This allows the construction of the microlens array projection device to be simplified and the costs reduced. In addition, the piezoelectric actuator is particularly resistant to vibrations, which allows a robust operation of the microlens array projection device in an environment with vibration loads. This allows the reliability of the microlens array projection device according to the invention to be improved.

[0019] According to a further advantageous embodiment of the microlens array projection device, the light source comprises a light emitter arranged to emit light at at least one wavelength assigned to the infrared spectrum. The light emitter can then simultaneously emit both monochromatic light with a fixed wavelength and multiple wavelengths. Here, one wavelength may be assigned to the infrared spectrum and at least one other wavelength may be assigned, for example, to visible light. However, it is also possible that all wavelengths that may be emitted by the light emitter originate from the infrared spectrum. This allows the generation of a light pattern that is invisible to humans, so that there is no risk of disturbing and / or dazzling a person. Furthermore, the risk of the light pattern being obscured by strong ambient light is also reduced. The light pattern can thus be more easily recognized by the camera system. If a light pattern generated by the microlens array projection device according to the invention is used in a surrounding recognition system for determining stereoscopic information based on active triangulation, the entire system can be further simplified. This is because the light pattern can be permanently, i.e. continuously, projected into the surroundings, so that no synchronization of the camera and the light source is required to visualize the light pattern in the camera image generated by the camera. Such synchronization is necessary, for example, when using light sources emitting visible light, as in the prior art mentioned at the outset.

[0020] Preferably, each microslide has a pattern of transparent and non-transparent parts for the light emitted by the light source, at least two microslides having different patterns. For one thing, in order to properly illuminate the surroundings, a given microslide can be moved between a specific combination of field lenses and projection lenses, whereby different field lens and projection lens pairs project the light pattern generated by the microslide into different surrounding areas and / or distort and / or focus it to different degrees. In addition, if the individual microslides of the microslide array have different patterns, the surroundings can be properly illuminated depending on the current driving situation. For example, it is possible to appropriately increase or decrease the line or dot density in a particular surrounding area. This allows changing the orientation of individual components of the pattern and / or replacing the entire or individual parts of the light pattern projected into the surroundings.

[0021] According to the present invention, an illumination device comprises at least one microlens array projection device as described above, and may comprise other components such as reflectors, mirrors, adjustment elements, filters, etc.

[0022] According to the invention, a vehicle has such a lighting device. The vehicle may be any vehicle, such as a passenger car, a truck, a transporter, a bus, etc. The lighting device may then, for example, be integrated into or form at least one front headlight and / or at least one taillight of the vehicle. This allows the light pattern projected into the periphery by the microlens array projection device according to the invention to be emitted both in the area in front of the vehicle and in the area behind the vehicle. The vehicle may also be controlled at least partially automatically. The stereoscopic information obtained using the light pattern projected into the periphery by the microlens array projection device according to the invention may then be used as an input variable for driver assistance systems, such as active suspensions, and / or as an input variable for systems for carrying out adjustment interventions in the longitudinal and / or lateral guidance of the vehicle.

[0023] According to the invention, the above-described lighting device is used in a vehicle's surroundings perception system to determine the road conditions on roads on which the vehicle can travel, in particular the roads ahead of the vehicle in the direction of travel.

[0024] In this case, the road condition is preferably determined based on active triangulation. Such a surrounding recognition system typically comprises at least one lighting device for generating a light pattern to be projected onto a road on which the vehicle can travel, at least one camera for generating a camera image of the light pattern, which is arranged at a vertical and / or horizontal distance from the lighting device of the vehicle, and a computing unit for evaluating the camera image and / or for outputting an adjustment signal for controlling the lighting device so that the lighting device can adapt the light pattern to the current driving situation. For example, when the vehicle approaches a curve, the light pattern no longer matches the curved road, so that the emission of the light pattern needs to be adjusted. In this case, for example, the change in the curve can be obtained from the analysis of the camera image generated by the camera. On this basis, the computing unit can output an adjustment signal for controlling an actuator, which in turn moves at least one microslide in the plane between the field lens array and the projection lens array. This allows the light pattern to be projected onto the road extending through the curve, so that the active suspension or the like can be adapted to the unevenness present in the curve, allowing the driver to have a comfortable driving experience. Thus, by actively lighting the surroundings, it is possible to recognize road conditions even in low light. The relatively large depth of field that can be produced in conjunction with microlens array projectors also results in less degradation of recognition accuracy with increasing distance from the vehicle.

[0025] Further advantageous embodiments of the microlens array projection device, lighting device, vehicle, and the use of the lighting device in a vehicle's surroundings recognition system for identifying road conditions based on the present invention are apparent from the examples described in detail below with reference to the figures. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram illustrating the principle of a peripheral recognition system based on active triangulation. [Diagram 2]1A and 1B are diagrams illustrating examples of light patterns projected onto a road along which a vehicle will travel. [Diagram 3] 1 is a schematic diagram of a microlens array projection device according to the present invention; [Figure 4] FIG. 4 is a detailed diagram of the configuration of the field lens array, the microlens array, and the projection lens array shown in FIG. 3. [Diagram 5] FIG. 2 is a plan view of a microslide array as viewed in the direction of the optical axis. [Figure 6] FIG. 13 is a plan view of an alternative microslide array viewed along the optical axis. [Figure 7] 1 is a schematic diagram illustrating adjusting the light pattern projected onto the road in response to changing driving conditions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] FIG. 1 shows the use of a surroundings perception system 14 based on active triangulation of a vehicle 13, here a passenger car. The surroundings perception system 14 comprises at least one lighting device 12 according to the invention, a computing unit 16 and a camera 17. The lighting device 12 comprises or is formed by at least one microlens array projection device 1 according to the invention. The lighting device 12 can in particular be integrated into a vehicle headlight or form the headlight itself. By means of the lighting device 12, a light pattern 6, shown in detail in FIG. 2, is projected in the direction of travel F onto a road 15 in front of the vehicle 13. The light pattern 6 is recorded by a camera 17. The light pattern 6 is distorted by structures 18, such as holes or reliefs, in the road 15. The camera 17 has as large a vertical and / or horizontal offset as possible with respect to the lighting device 12, so as to record the distorted light pattern 6 projected onto the road 15 as unobstructed as possible. The camera images generated by the camera 17 are evaluated in the computing unit 16. At this time, it is checked to what extent the light pattern 6 has been distorted by the structure 18. By obtaining three-dimensional information by analyzing the degree of distortion of the light pattern 6, it is possible to judge the road condition of the road 15.

[0028] Basically, it is also conceivable that the vehicle 13 has lighting devices 12 facing backwards, opposite to the direction of travel F, for example in taillights 19. Similarly, the vehicle 13 has a backup camera 20 facing backwards, for recording the light pattern 6 projected backwards.

[0029] The spatial information or road conditions calculated by the computing unit 16 can then be used as input variables for driver assistance systems, such as for example adaptive suspension.

[0030] FIG. 2 shows a plan view of an exemplary light pattern 6. In FIG. 2, the light pattern 6 is formed by a line pattern. Basically, however, the light pattern 6 may have any conceivable shape. It may be, for example, a striped pattern, a dot pattern, a grid pattern, a checkerboard pattern and / or a pseudorandom pattern. In the illustrated specification, the light pattern 6 has horizontal and vertical lines, the vertical lines in particular coinciding with the lane along which the wheels of the vehicle 13 will travel. On the left side of FIG. 2, an undistorted light pattern 6 is shown. On the right side of FIG. 2, the light pattern 6 is distorted by undulations (here, speed prevention strips). The light pattern is implemented in such a way that a higher content density of the pattern content (here, vertical stripes) is achieved, in particular for the specific peripheral area onto which the light pattern 6 is projected, which coincides with the lane trajectory of the vehicle 13.

[0031] 3 shows a schematic diagram of a microlens array projection device 1 according to the invention. The device comprises a light source 2, for example with at least one light emitter in the form of an LED, an OLED, a laser, a bulb, etc. Arranged in the light path 5 downstream of the light source 2 is an optical lens 21. The lens 21 may be of any design. For example, the lens 21 may have at least one flat, convex or concave surface.

[0032] After lens 21, the light impinges on a field lens array 3 which comprises a number of field lenses. In particular, the field lenses are arranged orthogonally in a two-dimensional matrix formed of rows Z and columns S, which are shown in detail in the example of a microslide array 7 in FIG.

[0033] A microslide array 7 is connected to the field lens array 3. The microslide array 7 comprises a number of microslides 8, each of which has a pattern 10 made up of transparent and non-transparent parts 11.1 and 11.2 for the light emitted by the light source 2. Parts 11.1 and 11.2 are shown in more detail in Figure 5. The microslide 8 or the pattern 10 made up of microslides 8 allows the generation of a light pattern 6 from the light emitted by the light source 2.

[0034] The projection lens array 4 is connected to the microslide array 7. The microslide 8 is movable within a plane E perpendicular to the optical axis OA. By moving the microslide 8, the light pattern 6 can be changed.

[0035] The light pattern 6 then impinges on a focusing plane FE, for example on a not shown reflecting surface on the road 15. The focusing plane FE does not have to be oriented parallel to the plane E, as shown in FIG. 3. In particular, the microlens array projection device 1 according to the invention is implemented in such a way that the light pattern 6 projected onto the road 15 as in FIG. 1 appears sharply in focus along the complete projection onto the road 15. For this purpose, the individual field lenses and projection lenses of the field lens array 3 and the projection lens array 4 may have different foci from each other. In particular, a given microslide 8 is assigned to a defined pair of field lenses and projection lenses. This assignment can be changed by moving the microslide 8 in the plane E.

[0036] In particular, the light source 2 is arranged to emit infrared light, which has the advantage that it is imperceptible to humans and therefore does not disturb and / or distract people from the light pattern 6. Furthermore, this ensures that the light pattern 6 is not affected in any way by ambient light reflected from the surroundings.

[0037] In addition, the microlens array projection device 1 according to the present invention may include other components not shown, such as additional lenses, filters, reflectors, mirrors, heat sinks, adjustment devices, etc.

[0038] Furthermore, Figure 3 includes detail A, which is shown in detail in Figure 4. The microslide array 7 may have a frame 22 which is completely closed or open on at least one side, for example as shown in Figure 5. The frame 22 is arranged on a base 23 on which the field lens and the projection lens are arranged. It is also conceivable that the frame 22 forms the base 23 or that the field lens and / or the projection lens rest indirectly or directly on the microslide array 7 in any manner.

[0039] FIG. 5 shows a plan view of the microslide array 7 in the direction of the optical axis OA. In the embodiment of FIG. 5, the microslides 8 are arranged in rows Z and columns S, which are now perpendicular to each other. In principle, however, the rows Z and columns S may cross each other at any angle, for example an angle of 60°. The microlens array projection device 1 or the microslide array 7 may comprise at least one actuator 9 for moving the microslides 8. The actuator 9 may be connected to the frame 22 or may for example protrude into a lateral opening of the frame 22 and be connected to at least one microslide 8 and / or to a superordinate structure suitable for supporting the microslides 8, for example a strip 24 as shown in FIG. 6. The actuator 9 may in particular be a piezoelectric actuator. The actuator 9 may for example perform a translation stroke (translation movement) in order to move the microslide 8 in the x-direction or in the y-direction. It is then particularly advantageous if the actuator 9 can move simultaneously in at least two rows Z and / or columns S of the microslides 8. This allows a simplification of the construction of the microlens array projection device 1 according to the invention and therefore costs to be saved by reducing the number of actuators 9 required, whereby it is basically also conceivable that at least one row Z and / or column S of the microslide array 7 is embodied as stationary.

[0040] Within the rows Z and / or columns S of the microslide array 7 there are a number of individual microslides 8. These microslides 8 may have a pattern 10 consisting of at least one transparent portion 11.1 and an opaque portion 11.2 to the light emitted from the light source 2. In the example of Fig. 5 only two examples of patterns 10 for two microslides 8 are shown. More microslides 8 may have the same pattern 10.

[0041] As shown in FIG. 6, the movement of a column S, or as shown, the movement of a row Z, can only take place in either the direction x or y. In FIG. 6, the individual microslides 8 are arranged in the form of strips 24, which are movable according to the x direction. A translational movement of each or all of the microslides 8 in the y direction is not possible in the example of FIG. 6. This further simplifies the structure of the microslide array 7. The individual actuators 9 can then move the strips 24 until the microslides 8, which are located at any horizontal position of the microslide array 7, can each be moved to any other horizontal position. To that end, the actuators 9 can be indirectly or directly connected to the strips 24 or the microslides 8.

[0042] The strips 24 may be segmented (not shown) to allow translational movement of the microslide 8 in both the x and y directions. Additionally, at least one strip 24 may be segmented to allow for the generation of alternative light patterns 6 and / or for unimpeded light propagation. * and / or recesses 25. In this case, the strip 24 itself also acts as a "throttle", whereby the strip 24 can interrupt the unimpeded propagation of light through the lens pair.

[0043] 7 shows a top view of a typical driving situation of a vehicle 13. When using a microlens array projection screen known from the prior art, the road 15.1 being driven on is shown by a solid line and has a number of possible light patterns 6. *Only the light pattern 6 can be generated. However, as shown by the dotted line, when driving on the road 15.2 along a curve, the relevant road area will not be sufficiently illuminated. However, with the microlens array projection device 1 according to the invention and the corresponding lighting device 12, the light pattern 6 can be modified so that it matches the curved road 15.2. This allows optimal illumination of the road 15 on which the vehicle 13 is actually driving. It is therefore possible to adapt the light pattern 6 to the current driving situation. Thus, besides the flexible adaptation of the light pattern 6 to dynamic road and / or driving situations, the microlens array projection device 1 according to the invention allows a particularly reliable recognition of the road 15, both in darkness and at any distance from the light pattern 6 to the vehicle 13, due to the large depth of field of the light pattern 6 that can be generated with the use of a microlens array projector. Thus, the decrease in recognition accuracy with increasing distance to the vehicle 13 is less. Furthermore, due to the use of an infrared light source, the corresponding surrounding recognition system 14 is robust to ambient light and has low complexity.

Claims

1. A microlens array projection device (1) for generating a light pattern (6) from light emitted from the light source (2), comprising at least one light source (2), a field lens array (3), a projection lens array (4), and a pattern template arranged between the field lens array (3) and the projection lens array (4) in a light path (5) emerging from the light source (2), the pattern template being formed from a microslide array (7) comprising at least two microslides (8); At least one micro-slide (8) is movable by at least one actuator (9) in a plane (E) perpendicular to an optical axis (OA) between said field lens array (3) and said projection lens array (4); At least two microslides (8) are movable, in particular in mutually perpendicular intersecting rows (Z) and columns (S), said at least two microslides (8) being arranged in the form of a strip (24) which is movable according to a row (Z) direction, The strip (24) is segmented to allow the microslide (8) to be translated in both row (Z) and column (S) directions. A microlens array projection device (1).

2. The at least one actuator (9) is provided for simultaneously moving, in particular translating, at least two rows (Z) and / or columns (S). A microlens array projection device (1) according to claim 1, characterised in that

3. At least one actuator (9) is formed by a piezoelectric actuator. A microlens array projection device (1) according to claim 1 or claim 2, characterized in that

4. The light source (2) comprises a light emitter arranged to emit light at at least one wavelength assigned to the infrared spectrum. A microlens array projection device (1) according to any one of claims 1 to 3, characterized in that

5. Each of the microslides (8) has a pattern (10) consisting of transparent parts (11.1) and opaque parts (11.2) to the light emitted from the light source (2), and at least two of the microslides (8) have different patterns (10). A microlens array projection device (1) according to any one of claims 1 to 4, characterized in that

6. Equipped with at least one microlens array projection device (1) according to any one of claims 1 to 5. A lighting device (12).

7. Equipped with at least one lighting device (12) according to claim 6. A vehicle (13).

8. 7. Use of a lighting device (12) according to claim 6 in a surroundings awareness system (14) of a vehicle (13) for identifying road conditions of a road (15) on which the vehicle (13) is drivable.

9. The road conditions are determined based on active triangulation. Use according to claim 8.

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