MICROLENS ARRAY PROJECTION DEVICE, LIGHTING DEVICE AND VEHICLE

Description

[0001] The invention relates to a microlens array projection device of the type defined in more detail in the preamble of claim 1, a lighting device, a vehicle and the use of such a lighting device in an environment detection system of a vehicle for determining the condition of the road.

[0002] With increasing digitalization, the level of vehicle automation is also rising. Today, vehicles are equipped with a wide range of driver assistance systems that support the driver in operating the vehicle, thus providing greater comfort and / or increased safety on the road. Some of these driver assistance systems, such as adaptive cruise control or parking assist, require environmental information, such as the presence of static and / or dynamic objects in the vehicle's vicinity and their relative distance to the vehicle. Some driver assistance systems, such as adaptive suspension, also require information about the condition of the road the vehicle will soon be traveling on.

[0003] Various sensor systems for environmental monitoring are known from the general state of the art. In particular, ultrasonic sensors, radar sensors, camera systems with a mono or stereo camera, as well as laser scanners such as lidars have already proven their worth in the automotive sector. However, the quality of depth information calculation using stereo cameras is comparatively highly dependent on the quality of the mapping algorithm used to assign image information between the two cameras. Furthermore, such a system can only be reliably used in daylight and exhibits distance-dependent accuracy. The use of dedicated "ground lidars" for recording road surface conditions is not feasible for mass production due to high costs and limited vertical angular resolution.

[0004] Another method for environmental monitoring and the acquisition of depth information utilizes active triangulation, allowing, in particular, the scanning of the road surface traversed by the vehicle to analyze its characteristics. This enables the rapid and effective detection of road irregularities such as potholes, speed bumps, or road boundaries like curbs or ditches running parallel to a highway. A projector casts a structured light pattern into the surroundings, specifically onto the road surface in front of the vehicle. Feature points of the light pattern reflected from the surroundings are then captured by a camera mounted on the vehicle. Distance determination and the acquisition of depth information are possible by taking into account the so-called epipolar geometry.By offsetting the camera and projector mounting points on the vehicle, it is possible to detect a shift in the feature points of the light pattern in the camera images generated by the camera when the light pattern is distorted due to unevenness or surrounding objects. Depending on the degree of distortion of the light pattern, depth information can then be calculated. The use of an active triangulation-based system for obtaining depth information also allows for operation in darkness due to the active illumination of the scene.

[0005] German patent DE 10 2015 008 774 A1 discloses a corresponding device and method for capturing a vehicle's surroundings based on active triangulation. A pixel headlight of the vehicle is used as the projector. This pixel headlight can be a front headlight of the vehicle or a separate headlight. The pixel headlight projects the light pattern into the surroundings within such a short time window that the light pattern cannot be perceived by a human. A camera capturing the surroundings and the pixel headlight are synchronized so that a camera image of the surroundings is captured precisely when the pixel headlight projects the light pattern into the environment.Since the light pattern is only projected into the surroundings briefly and cannot be perceived by the driver, the method disclosed in the publication can be used with particular ease. In particular, it does not distract the driver. The pixel headlight can project the light pattern into the surroundings in addition to the ambient lighting, or it can briefly deactivate or at least dim the ambient lighting while the light pattern is being emitted. The light pattern can, for example, include a line pattern, stripe pattern, dot pattern, grid pattern, checkerboard pattern, and / or a pseudo-random pattern. The pixel headlight is controlled by a brightness / dark adjustment mechanism such that the ambient lighting brightness remains constant on average during the emission of the light pattern.Using the device and method disclosed in the publication, road surface irregularities, road boundaries, and surrounding objects can be detected, and their relative position to the vehicle can be determined. The device disclosed in the publication uses a pixel spotlight to generate the light pattern; this spotlight has a complex structure and is therefore expensive.

[0006] Furthermore, so-called microlens array projectors, also known as multi-aperture projection displays, are known from the prior art. These projectors enable the emission of a structured light pattern. For this purpose, an object structure is positioned in the beam path between a light source and a projection plane onto which the light pattern is to be projected, in order to structure the light. Additionally, a field lens array and a projection lens array are arranged in the beam path in front of and behind the object structure, respectively. These arrays allow for the targeted focusing and bundling of the light rays emitted by the light source. Each lens in the field lens array and the projection lens array is assigned to a substructure of the object structure. For example, such microlens array projectors are used to create aesthetically pleasing vehicle surround lighting.The miniaturized lens array makes it possible to create a comparatively high depth of field compared to other projection systems.

[0007] A lighting device for a motor vehicle with such a microlens array projector is known, for example, from DE 10 2014 219 371 A1. This document describes the use of light patterns projected into the vehicle's surroundings by means of the lighting device as a parking assistant, distance control assistant, and / or as a narrow passage control assistant. A light pattern projected into the surroundings by means of the lighting device disclosed in the document is focused at a defined distance from the vehicle, whereby a display element encompassed by the light pattern appears sharp at a specific distance between the vehicle and the object onto which the light pattern is directed.As the vehicle approaches an object, the display content becomes sharp when the set distance is reached, thus informing the driver that the specified distance between the vehicle and the object has been reached. The lighting system can also simultaneously project multiple light patterns into the surroundings, each focused on a different focal plane representing a different distance from the vehicle. This creates a particularly simple and cost-effective device for informing the driver about the distance between the vehicle and an object in the environment. No additional displays are needed to visualize the distance between the vehicle and the object.A multi-aperture projection display can also be integrated into at least one headlight and / or one taillight of a vehicle.

[0008] Furthermore, DE 10 2015 206 936 A1 discloses a method and a device for detecting obstacles in the path of a motor vehicle using active triangulation. The document describes an arrangement consisting of a light source, a grating, and a lens as a projector for generating the light pattern. The light source is, in particular, a laser diode and is configured to emit infrared light. The grating can be formed by a filter wheel, which has a multitude of different gratings for generating various line patterns. By rotating the filter wheel, the different gratings can then be brought into a beam path between the light source and the lens. In addition, the arrangement of light source, grating, and lens can also be pivoted about a horizontal and vertical axis to project the light pattern into a desired target region.However, a disadvantage is that a filter wheel has limited space for accommodating additional gratings. This severely restricts the use of further gratings to generate different light patterns. Furthermore, a light pattern projected into the environment by the device disclosed in the publication has a comparatively shallow depth of field, which allows for only relatively low accuracy in obtaining depth information in areas far in front of the vehicle.

[0009] Furthermore, WO 2017 / 157623 A1 discloses a headlight for a motor vehicle that makes it possible to generate dynamic light in a simple manner. For this purpose, the headlight's lighting unit comprises a multi-aperture projection display and a flat digital image sensor. The digital image sensor can be an LCD display. The individual pixels of the display can be switched between transparent and opaque, allowing light emitted by the lighting unit to be selectively blocked or passed through in order to adjust the shape of the light pattern emitted by the headlight. This makes it possible to generate low beam, high beam, or glare-free high beam. In addition, a cut-off line can be dynamically shifted.

[0010] Furthermore, WO 2015 / 058227 A1 discloses a micro-projection light module for a motor vehicle headlight, comprising at least one light source, a first microlens array, a second microlens array, and a diaphragm device arranged between the microlens arrays. The microlens arrays and the diaphragm device can be multi-part. In this case, the diaphragm device is a shadow mask, line mask, grid, or the like made of metal. The microlens array following the diaphragm device in the direction of light propagation can be translationally shifted by an actuator. This allows the shape of a light pattern emitted by the motor vehicle headlight to be adjusted, for example, to generate a cornering light, adaptive headlight, highway light, low beam, and the like.

[0011] Furthermore, EP 3 486 555 A1 discloses a light module for a motor vehicle headlight. In this light module, a display is also arranged between two microlens arrays to adjust the shape of the light pattern emitted by the motor vehicle headlight. A square pixel can be divided into individually controllable subsegments, which can assume a shape deviating from the square. This allows sharp-edged light-dark boundaries to be created. However, the number of different shapes that can be stored for a pixel is small due to the limited available area within a given pixel.

[0012] Furthermore, DE 10 2010 043 829 A1 discloses an optical scanning system and method. In this system, two images of the surroundings are captured using two different image sensors. An illumination device then illuminates the captured area in the infrared spectrum. The resulting light pattern can have a predefined structure.

[0013] Furthermore, DE 10 2019 006 911 A1 discloses a device and a method for the automated detection of a destination area. The publication describes scanning the environment based on active triangulation. A projection module comprising a microlens array and a mask is used to generate the required light pattern.

[0014] Furthermore, DE 10 2018 116 511 B3 discloses a method for depth perception based on headlights arranged on both sides of a vehicle. Each headlight projects a characteristic light pattern into the surroundings. Preferably, the light patterns overlap at least partially. An image of the projection surface is recorded. Subsequently, a frequency representation of the characteristic light patterns in the captured image is calculated, and an overlap coefficient is derived from this. If the overlap is insufficient, the light patterns are shifted.

[0015] The present invention is based on the objective of providing an improved microlens array projection device for generating light patterns, which improves the accuracy of an environment detection system based on active triangulation, wherein the accuracy also remains unaffected by a current driving situation.

[0016] According to the invention, this problem is solved by a microlens array projection device with the features of claim 1, a lighting device with the features of claim 7, a vehicle with the features of claim 8, and the use of a lighting device in an environment sensing system of a vehicle with the features of claim 9. Advantageous embodiments and further developments are described in the dependent claims.

[0017] In a microlens array projection device of the type mentioned above, the pattern template is formed according to the invention from a micro-diagram array which comprises at least two different micro-diagrams which allow the generation of individual light patterns, wherein the micro-diagrams are movable in a plane perpendicular to an optical axis between the field lens array and the projection lens array by at least one actuator.

[0018] The microlens array projection device generates a light pattern with a comparatively high depth of field. The micro-slide array allows for a relatively large number of different micro-slides, which in turn enable the creation of individual light patterns. Furthermore, the micro-slides can be moved within the plane, allowing a desired light pattern to be projected into a specific area. This enables the light pattern to be individually adapted to the current environmental conditions. Thus, by moving the micro-slide(s) within a specific area, a desired light pattern can be achieved. Similar to the prior art, the light pattern can include a line pattern, stripe pattern, dot pattern, grid pattern, checkerboard pattern, pseudo-random pattern, or the like.For example, the line or point density in a specific area can be selectively increased or decreased. The orientation of lines, for instance, can also be adjusted by moving the micro-diagrams. For example, the micro-diagrams can be moved within the plane by rotation and / or translation.

[0019] The microlens array projection device can use conventional light sources such as at least one LED, OLED, laser and / or a lamp such as a halogen, incandescent or gas discharge lamp.

[0020] To generate the light pattern using the micro-diagram array, it is not strictly necessary for the field lens array and the projection lens array to have the same cross-sectional area in the light path as the micro-diagram array. It is sufficient for the micro-diagram array to have a smaller cross-sectional area than the two lens arrays. In other words, there can be more field lenses and projection lenses than there are micro-diagrams in the micro-diagram array. This allows undisturbed light propagation through a field lens and projection lens pairing when no micro-diagram is positioned between the lenses. If a micro-diagram is then moved between these lenses, the light pattern generated by the micro-diagram is projected into the area associated with the corresponding field lens and projection lens pairing. However, the number of field lenses and projection lenses can also generally be the same as the number of micro-diagrams.When the microslides are moved, individual microslides can be removed from a lens pair. For example, a recess can be created within the lens pair to allow unimpeded light propagation through it. It is also possible to have more microslides than there are lens pairs. In this way, the light pattern produced by a lens pair and a specific microslide can be changed by moving in an alternative microslide.

[0021] An advantageous further development of the microlens array projection device provides that at least two microslides are movable in intersecting, and in particular mutually perpendicular, rows and columns. Arranging the microslides in rows and columns allows for particularly flexible and easy movement of the microslides.

[0022] According to a further advantageous embodiment of the microlens array projection device, the at least one actuator is configured to move at least two rows and / or columns simultaneously, in particular translationally. This simplifies the design of the microlens array projection device according to the invention. Fewer actuators are required to move a large number of different rows and / or columns, thus saving costs. For example, one actuator can be connected to several rows and / or columns simultaneously. The microlenses can, for instance, be arranged in a segmented or non-segmented strip, which can be moved translationally within the microlens array by the actuator.It is also possible for individual strips to be at least partially displaced from the microdia array and / or a cross-sectional area of ​​the plane associated with the field lens array and projection lens array, depending on their positioning. The actuator can be connected directly or indirectly to at least one microdia or corresponding strip. By moving the microdias within the plane, the assignment of a corresponding microdia to the respective field lenses and projection lenses of the field lens array and the projection lens array is changed. For example, a specific combination of field lens and projection lens can be focused on a particular region. By moving a desired microdia between the corresponding field lens and the corresponding projection lens, the light pattern generated by the corresponding microdia can then be projected into the desired region, as already mentioned.In general, it is also conceivable that different pairings of field and projection lenses are directed into the same surrounding area, but have different focusing, distort a light pattern generated by a microdia to varying degrees and / or manipulate it in other ways, for example by attenuating its luminosity to varying degrees or polarizing it.

[0023] A further advantageous embodiment of the microlens array projection device provides that at least one actuator is a piezoelectric actuator. This simplifies the design of the microlens array projection device and reduces costs. Piezoelectric actuators are also particularly resistant to vibrations, which enables robust operation of the microlens array projection device in a vibration-prone environment. This improves the reliability of the microlens array projection device according to the invention.

[0024] According to a further advantageous embodiment of the microlens array projection device, the light source comprises a lamp configured to emit light with at least one wavelength belonging to the infrared spectrum. The lamp can emit monochromatic light with a fixed wavelength or multiple wavelengths simultaneously. One wavelength can be in the infrared spectrum, and at least one other wavelength can be, for example, in the visible spectrum. However, all wavelengths that can be generated by the lamp can also belong to the infrared spectrum. This allows for the creation of a light pattern invisible to humans, thus preventing people from being disturbed or blinded. Furthermore, this reduces the risk of the light pattern being obscured by ambient light. Consequently, the light pattern is easier for a camera system to detect.Furthermore, when using a light pattern generated by the microlens array projection device according to the invention in an environmental sensing system for determining depth information based on active triangulation, the overall system can be simplified, since the light pattern can be projected permanently, i.e., continuously, into the environment. This eliminates the need for synchronization between the camera and the light source to make the light pattern visible in the camera images. Such synchronization is necessary, analogous to the prior art mentioned above, for example, when using a light source that emits visible light.

[0025] Preferably, the microdiagrams each comprise a pattern of sections that are transparent and opaque to light emitted from the light source, with at least two microdiagrams exhibiting different patterns. To selectively illuminate an environment, a defined microdiagram can be moved between a specific combination of field lens and projection lens. Different pairs of field lenses and projection lenses, for example, project the light pattern generated by the microdiagram into different regions of the environment and / or distort and / or focus it to varying degrees. If the individual microdiagrams of the microdiagram array also comprise different patterns, the environment can be illuminated more precisely depending on the current driving situation. For example, the line or point density in a specific region of the environment can be selectively increased or decreased.This also makes it possible to change the orientation of individual components of a pattern and / or to replace the whole or individual sections of the light pattern thrown into the environment.

[0026] According to the invention, a lighting device comprises at least one microlens array projection device as described above. The lighting device may include further components such as reflectors, mirrors, actuators, filters, or the like.

[0027] According to the invention, a vehicle has such a lighting device. The vehicle can be any type of vehicle, such as a car, truck, van, bus, or the like. The lighting device can, for example, be integrated into or form at least one headlight and / or at least one taillight of the vehicle. This allows a light pattern, projected into the environment by means of a microlens array projection device according to the invention, to be emitted into both the front and rear of the vehicle. The vehicle can also be controlled at least partially automatically.Depth information obtained using the light pattern projected into the environment with the microlens array projection device according to the invention can serve as an input for driver assistance systems such as an active chassis and / or a system for performing control interventions in a vehicle's longitudinal and / or lateral guidance.

[0028] According to the invention, a lighting device described above is used in an environment detection system of a vehicle to determine the condition of a roadway that can be traveled by the vehicle, in particular a roadway located in front of the vehicle in a direction of travel.

[0029] Preferably, the road surface characteristics are determined based on active triangulation. Such an environment sensing system typically comprises at least one lighting device for generating a light pattern that is projected onto the road surface traveled by the vehicle, at least one camera for generating camera images of the light pattern, wherein the camera is arranged on the vehicle at a vertical and / or horizontal distance from the lighting device, and a processing unit for evaluating the camera images and / or for outputting control signals to actuate the lighting device so that it adapts the light pattern to the current driving situation. For example, if the vehicle is approaching a curve, the emission of the light pattern must be adjusted, otherwise the light pattern will not correspond to the road surface as it passes through the curve.For example, the curve's trajectory can be derived from an analysis of the camera images. The processing unit can then output a control signal to activate the actuators, which in turn move at least one microlens in the plane between the field lens array and the projection lens array. This allows the light pattern to be projected onto the road surface as it curves, enabling, for instance, the conditioning of an active suspension system to compensate for bumps and dips in the curve, thus providing a comfortable driving experience for the driver. Thanks to active ambient lighting, the road surface can be assessed even in darkness. Furthermore, the comparatively high depth of field achievable with microlens array projectors results in less degradation of detection accuracy with increasing distance from the vehicle.

[0030] Further advantageous embodiments of the microlens array projection device, the lighting device, the vehicle, and the use of the lighting device in an environment detection system of the vehicle for determining the condition of a roadway traveled by the vehicle are also evident from the exemplary embodiments, which are described in more detail below with reference to the figures.

[0031] This shows: Fig. 1 a schematic representation of an environment detection system based on active triangulation; Fig. 2 an exemplary light pattern projected onto a roadway to be traveled by a vehicle; Fig. 3 a schematic representation of a microlens array projection device according to the invention; Fig. 4 a detailed view of a Figure 3The arrangement shown consists of a field lens array, a micro-diagram array, and a projection lens array; Fig. 5 is a top view of the micro-diagram array from the direction of an optical axis; Fig. 6 is a top view of an alternative micro-diagram array from the direction of the optical axis; and Fig. 7 is a schematic representation of an adaptation of the light pattern projected onto the roadway depending on a changing driving situation.

[0032] Figure 1Figure 1 shows an application of an environment sensing system 14 based on active triangulation of a vehicle 13, here in the form of a passenger car. The environment sensing system 14 comprises at least one lighting device 12 according to the invention, a processing unit 16, and a camera 17. The lighting device 12 in turn has 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. With the aid of the lighting device 12, a Figure 2The light pattern 6, shown in more detail, is projected onto a roadway 15 located in the direction of travel F in front of the vehicle 13. The light pattern 6 is captured by the camera 17. The light pattern 6 is distorted by structures 18 on the roadway 15, such as potholes or bumps. The camera 17 is positioned at the greatest possible vertical and / or horizontal offset from the lighting device 12 in order to capture the distorted light pattern 6 projected onto the roadway 15 with minimal interference. Camera images generated by the camera 17 are evaluated on the processing unit 16. The degree to which the light pattern 6 is distorted by the structures 18 is analyzed. By analyzing the degree of distortion of the light pattern 6, depth information can be obtained to determine the roadway 15's condition.

[0033] In general, it is also conceivable that the vehicle 13 also has a rearward-facing lighting device 12, for example in a rear light 19. Similarly, the vehicle 13 has a rearward-facing reversing camera 20 to capture the light pattern 6 projected to the rear.

[0034] The depth information or road surface characteristics calculated by the computing unit 16 can then be used as input for driver assistance systems, for example an adaptive suspension.

[0035] Figure 2 The exemplary light pattern 6 is shown in a top view. Figure 2The light pattern 6 is formed by a line pattern. In general, however, the light pattern 6 can have any conceivable design. For example, it can also be a striped pattern, dot pattern, grid pattern, checkerboard pattern, and / or a pseudo-random pattern. In the version shown here, the light pattern 6 has horizontal and vertical lines, with the vertical lines coinciding in particular with a lane that will be traveled by the wheels of vehicle 13 in the future. In the left half of Figure 2 An undistorted light pattern 6 is shown. In the right half of Figure 2The light pattern 6 is distorted by a bump in the road, here in the form of a speed bump. The light pattern is designed in such a way that for certain areas in the surroundings where the light pattern 6 is projected, which coincide with the trajectory of the vehicle 13's lanes, a higher density of pattern elements, here the vertical stripes, is achieved.

[0036] Figure 3 Figure 1 shows a schematic representation of the microlens array projection device 1 according to the invention. This device comprises a light source 2, for example, with a light source in the form of at least one LED, OLED, laser, incandescent lamp, or the like. An optional lens 21 is arranged downstream of the light source 2 in a light beam path 5. The lens 21 can be of any design. For example, it can have at least one flat, convex, or concave side.

[0037] After passing through lens 21, the light encounters a field lens array 3, which comprises a multitude of field lenses. Specifically, the field lenses are orthogonal in one of the Figure 5 The two-dimensional matrix formed by rows Z and columns S is shown in more detail using the example of a microdia array 7.

[0038] A micro-diagram array 7 is connected to the field lens array 3. This array comprises a multitude of micro-diagrams 8, which in turn have patterns 10 consisting of sections 11.1 that are transparent to the light emitted by the light source 2 and sections 11.2 that are opaque. Sections 11.1 and 11.2 are in Figure 5 This is shown in more detail below. With the help of the micro-diagrams 8 or the patterns 10 encompassed by the micro-diagrams 8, the light pattern 6 can be generated from the light emitted by the light source 2.

[0039] A projection lens array 4 is connected to the microslide array 7. The microslides 8 are movable within a plane E orthogonal to an optical axis OA. By moving the microslides 8, the light pattern 6 can be changed.

[0040] The light pattern 6 falls in a focal plane FE onto a reflection plane not shown, for example onto the roadway 15. The focal plane FE does not necessarily have to be, as in Figure 3 depicted, oriented parallel to the plane E. In particular, the microlens array projection device 1 according to the invention is designed such that a [missing information] as shown in Figure 1The light pattern 6 projected onto a travel path 15 appears sharp along its entire projection onto the travel path 15. For this purpose, the individual field and projection lenses of the field lens array 3 and the projection lens array 4 can have different focal points relative to each other. In particular, a defined micro-diagram 8 is assigned to a defined pairing of field lens and projection lens. This assignment can be changed by moving the micro-diagrams 8 in the plane E.

[0041] In particular, light source 2 is designed to emit infrared light. Infrared light has the advantage of being invisible to humans, meaning that people cannot be disturbed or distracted by light pattern 6. Furthermore, light pattern 6 is therefore hardly, if at all, affected by ambient light reflected from the surroundings.

[0042] The microlens array projection device 1 according to the invention may also include further components not shown, such as additional lenses, filters, reflectors, mirrors, heat sinks, adjusting devices or the like.

[0043] Figure 3 It also includes a detail A, which is in Figure 4 is shown in more detail. The microslide array 7 can, for example, be used as shown in Figure 5 The frame 22 is shown to have a fully enclosed frame or one open on at least one side. A substrate 23 is located on the frame 22, on which the field lenses and projection lenses are arranged. It is also conceivable that the frame 22 forms the substrate 23 or that the field lenses and / or projection lenses rest directly or indirectly on the microdia array 7 in any way.

[0044] Figure 5 shows a top view of the microslide array 7 from the direction of the optical axis OA. In the version in Figure 5The micro-slides 8 are arranged in rows Z and columns S, which are orthogonal to each other. However, the rows Z and columns S can generally intersect at any angle, for example, at an angle of 60°. The microlens array projection device 1 or the micro-slide array 7 can include at least one actuator 9 for moving the micro-slides 8. The actuator 9 can be connected to the frame 22 or, for example, project through a lateral opening in the frame 22 and be connected to at least one micro-slide 8 and / or a higher-level structure suitable for receiving the micro-slides 8, for example, a [structure] in Figure 6The strip 24 shown is connected. The actuator 9 can, in particular, be a piezoelectric actuator. The actuator 9 can, for example, exert a translational stroke to move the micro-slides 8 in an x- or y-direction. It is particularly advantageous if, with the aid of one actuator 9, micro-slides 8 can be moved simultaneously in at least two rows Z and / or columns S. This reduces the number of required actuators 9, which simplifies the construction of the microlens array projection device 1 according to the invention, thereby saving costs. In general, it is also conceivable that at least one row Z and / or column S of the micro-slide array 7 is designed to be fixed in position.

[0045] Within a row Z and / or column S of the microslide array 7, there is a plurality of individual microslides 8. These can exhibit different patterns 10 consisting of at least one transparent 11.1 and opaque section 11.2, which is transparent to the light emitted by the light source 2. In the example in Figure 5 Only two exemplary patterns 10 for two microslides 8 are shown. Multiple microslides 8 can also exhibit the same pattern 10.

[0046] How Figure 6 As shown, a movement of columns S or, as illustrated, a movement of rows Z can only occur along one of the directions x or y. Figure 6 The individual micro-slides 8 are arranged in the form of strips 24, whereby the strips 24 can be moved along the x-direction. A translational movement of individual or all micro-slides 8 in the y-direction is shown in the example in Figure 6Not possible. This further simplifies the construction of the micro-diagram array 7. The individual actuators 9 can move the strips 24 so that a micro-diagram 8 arranged at any horizontal position in the micro-diagram array 7 can be moved to any other horizontal position. For this purpose, the actuator 9 can be connected directly or indirectly to a strip 24 or a micro-diagram 8.

[0047] The strips 24 can also be segmented, thus enabling translational displacement of the microdiagrams 8 in the x and y directions (not shown). Furthermore, at least one strip 24 can also have additional microdiagrams 8* and / or cutouts 25 to generate alternative light patterns 6 and / or to allow unimpeded light propagation. A strip 24 itself can also function as an "aperture" by preventing unimpeded light propagation through a lens pairing.

[0048] Figure 7Figure 1 shows a top view of a typical driving situation of the vehicle 13. Using a microlens array projection display known from the prior art, only a rigid light pattern 6* can be generated, which can be projected onto a straight driving path 15.1, represented by solid lines. However, if the driving path 15.2 runs along a curve, as shown by the dashed lines, a relevant section of the driving path would not be sufficiently illuminated. 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 coincides with the curved driving path 15.2. This allows for ideal illumination of the driving path 15 actually traveled by the vehicle 13. Thus, it is possible to adapt the light pattern 6 to the current driving situation.In addition to flexibly adapting the light pattern 6 to varying road and / or driving dynamics situations, the microlens array projection device 1 according to the invention thus enables particularly reliable detection of the driving path 15 even in darkness and at any distance of the light pattern 6 from the vehicle 13, thanks to the high depth of field of the generated light pattern 6 associated with the use of microlens array projectors. Thus, the degradation of detection accuracy decreases with increasing distance from the vehicle 13. Thanks to the use of an infrared light source, a corresponding environmental detection system 14 is also robust against ambient light and exhibits low complexity.

Claims

1. Microlens array projection device (1) comprising, in each case, at least one light source (2), a field lens array (3), a projection lens array (4) and a pattern template which is arranged in a light beam path (5), which emanates from the light source (2), between the field lens array (3) and the projection lens array (4) in order to generate a structured light pattern (6) for obtaining depth information based on active triangulation from the light emitted by the light source (2), characterized in that the pattern template is formed by a microslide array (7) that comprises at least two different microslides (8) which allow individual light patterns (6) to be generated, wherein the microslides (8) can be moved in a plane (E) perpendicular to an optical axis (OA) between the field lens array (3) and the projection lens array (4) by at least one actuator (9).

2. Microlens array projection device (1) according to claim 1, characterized in that at least two microslides (8) can be moved in intersecting, in particular mutually perpendicular, rows (Z) and columns (S).

3. Microlens array projection device (1) according to claim 2, characterized in that the at least one actuator (9) is configured to move at least two rows (Z) and / or columns (S) simultaneously, in particular to move them translationally.

4. Microlens array projection device (1) according to any of claims 1 to 3, characterized in that at least one actuator (9) is formed by a piezo actuator.

5. Microlens array projection device (1) according to any of claims 1 to 4, characterized in that the light source (2) comprises a lamp which is configured to emit light with at least one wavelength associated with the infrared spectrum.

6. Microlens array projection device (1) according to any of claims 1 to 5, characterized in that the microslides (8) each comprise a pattern (10) of portions that are transparent (11.1) and opaque (11.2) to light emitted by the light source (2), with at least two microslides (8) having a pattern (10) that differs from the other.

7. Lighting device (12), characterized by at least one microlens array projection device (1) according to any of claims 1 to 6.

8. Vehicle (13), comprising a camera (17), characterized by at least one lighting device (12) according to claim 7.

9. Use of a lighting device (12) according to claim 7 in an environment detection system (14) of a vehicle (13) according to claim 8 for determining a roadway condition of a roadway (15) that is traversable by the vehicle (13), in particular a roadway (15) lying in front of the vehicle (13) in a direction of travel (F).

10. Use according to claim 9, characterized in that the roadway condition is determined on the basis of active triangulation.