EP3602127A1

EP3602127A1 - Scanner having two sequential scanning units

Info

Publication number: EP3602127A1
Application number: EP18716491.8A
Authority: EP
Inventors: Florian Petit; Mathias Müller
Original assignee: Blickfeld GmbH
Current assignee: Blickfeld GmbH
Priority date: 2017-03-24
Filing date: 2018-03-22
Publication date: 2020-02-05
Also published as: JP2020515916A; WO2018171841A1; DE102017002866A1; CN110476083A; US20200110260A1

Abstract

The invention relates to a scanner (90) comprising a first mirror (150) having a reflective front side (151) and a rear side (152), a first elastic mounting (100) which extends on a side facing the rear side (152) of the first mirror (150), a second mirror (150) having a reflective front side (151) and a rear side (152), and a second elastic mounting (100) which extends on a side facing the rear side (152) of the second mirror (150). The scanner (90) is configured to deflect light (180) sequentially on the front side (151) of the first mirror (150) and on the front side (151) of the second mirror (150).

Description

Scanner with two sequential scan units

TECHNICAL AREA

Various examples generally relate to a scanner for light. In particular, various examples relate to a laser light scanner that may be used, for example, for LIDAR measurements.

BACKGROUND

The distance measurement of objects is desirable in various fields of technology. For example, in the context of autonomous driving applications, it may be desirable to detect objects around vehicles and, in particular, to determine a distance to the objects.

One technique for measuring the distance of objects is the so-called LIDAR technology (light detection and ranging, sometimes also LADAR). In doing so, e.g. pulsed laser light emitted from an emitter. The objects in the environment reflect the laser light. These reflections can then be measured. By determining the transit time of the laser light, a distance to the objects can be determined.

In order to detect the objects in the environment spatially resolved, it may be possible to scan the laser light. Depending on the beam angle of the laser light different objects in the environment can be detected.

In various examples, it may be desirable to perform a particularly large resolution LIDAR measurement. For example, it may be desirable to capture a two-dimensional (2-D) environment within the LIDAR measurement. For this purpose, a 2-D scan area is implemented. In addition, it may be desirable to radiate the laser light at well-defined angles. By such quantities, for example, a lateral resolution of the LIDAR measurement is determined. For example, reference implementations use multiple vertically spaced lasers to implement a 2-D scan area. However, such techniques are expensive and require significant space for the multiple lasers. There is also a resolution along For example, reference implementations have a resolution between 4 and 64 points in this direction. In addition, with highly integrated reference implementations, it is often impossible, or only possible to a limited extent, to monitor the emission angle of the laser light. Therefore, a lateral resolution can be comparatively small. Time drifts can occur.

BRIEF DESCRIPTION OF THE INVENTION

Therefore, there is a need for improved techniques for scanning light. In particular, there is a need for improved techniques to implement LIDAR measurements.

This object is solved by the features of the independent claims. The features of the dependent claims define embodiments.

A scanner includes a first mirror. The first mirror includes a reflective front and a back. The scanner also includes a first elastic suspension. The first elastic suspension extends on a side facing the back of the first mirror, e.g. away from the back of the first mirror. The scanner also includes a second mirror. The second mirror includes a reflective front and a back. The scanner also includes a second elastic suspension. The second elastic suspension extends on a side facing the back of the second mirror, e.g. away from the back of the second mirror. The scanner is configured to redirect light sequentially to the front of the first mirror and to the front of the second mirror.

Through the use of two mirrors, an optical path can be defined, which is sequentially deflected first at the reflective front of the first mirror and then at the reflective front of the second mirror. This can be used to implement a 2-D scan area.

Sometimes, the at least one elastic suspension may also be referred to as an elastic support element or scanning module, because thereby an elastic connection between a base - which defines a reference coordinate system, in which eg a light source for emitting the light can be arranged - and a deflection unit provided; the deflection unit may designate a moving coordinate system with respect to the reference coordinate system.

By extending the first elastic suspension and the second elastic suspension respectively from the back of the first mirror and the second mirror, a particularly high degree of integration for the scanner with the two mirrors can be achieved. In particular, compared to reference implementations in which suspensions are mounted laterally in the mirror plane, it may be possible to arrange the first game and the second mirror particularly close to each other. As a result, it can also be achieved that a particularly large detection aperture with respect to a detector is achieved by the first mirror and the second mirror. For example, at a significant scan angle of the first mirror, the optical path may no longer centrically hit the second mirror. The greater the distance between the mirrors, the greater is this eccentricity. This reduces the detection aperture.

A scanner comprises at least one elastically moved scanning unit. This is arranged to redirect light twice by means of a first degree of freedom of movement and a second degree of freedom of movement. The scanner also includes at least one actuator. The scanner also includes a controller, such as an FPGA, microcontroller or ASIC. The controller is arranged to drive the at least one actuator to excite the first degree of freedom of movement according to a periodic amplitude modulation function. The amplitude modulation function has alternately arranged rising edges and falling edges. A length of the ascending flanks is at least twice as large as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large. Alternatively, a length of the descending flanks could be at least twice as large as a length of the rising flanks, optionally at least four times as large, further optionally at least ten times as large. A scanner comprises at least one elastically moved scanning unit. This is arranged to redirect light twice by means of a first degree of freedom of movement and a second degree of freedom of movement. The scanner also includes at least one actuator. This is arranged to excite the first degree of freedom of motion according to a periodic amplitude modulation function. The amplitude modulation function has alternately arranged rising edges and falling edges. In this case, a length of the ascending flanks is preferably at least twice as long as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large. Alternatively, a length of the descending flanks could be at least twice as large as a length of the rising flanks, optionally at least four times as large, further optionally at least ten times as large.

The elastic scanning unit is sometimes called a flexure scan unit. The degrees of freedom of movement can be achieved by reversible deformation, i. Elasticity, be provided. Typically, the degrees of freedom of the motion are resonantly excited.

For example, in some examples, the scanner could include two elastically-moved scan units. Each of the two elastically moved scanning units could have a mirror with a reflective front side and a rear side, and in each case an associated elastic suspension.

By means of such techniques it can be achieved that an overlay figure of the movement according to the first degree of freedom and the movement according to the second degree of freedom for implementing a 2-D scan area is implemented. Dead times during scanning can be reduced by the particularly short descending flanks. This makes it possible to scan the 2-D scan area with a high temporal resolution. This means that a repetition rate for several consecutive LIDAR images can be particularly large. One method comprises driving at least one actuator. The at least one actuator is set up to excite a first degree of freedom of movement of at least one elastically moved scanning unit in accordance with a periodic amplitude modulation function. The periodic amplitude modulation function includes alternately arranged rising edges and falling edges. The at least one elastically moved scanning unit further comprises a second degree of freedom of the movement. The at least one elastically moved scanning unit redirects light twice by means of the first degree of freedom of the movement and by means of the second degree of freedom of the movement. A length of the rising flanks is at least twice as long as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large. Alternatively, it would also be possible for a length of the descending flanks to be at least twice as long as a length of the ascending flanks, optionally at least four times as large, further optionally at least ten times as large. A computer program product includes program code that can be executed by a controller. Running the program code causes the controller to perform a procedure. The method includes driving at least one actuator. The at least one actuator is set up to excite a first degree of freedom of movement of at least one elastically moved scanning unit in accordance with a periodic amplitude modulation function. The periodic amplitude modulation function includes alternately arranged rising edges and falling edges. The at least one elastically moved scanning unit further comprises a second degree of freedom of the movement. The at least one elastically moved scanning unit redirects light twice by means of the first degree of freedom of the movement and by means of the second degree of freedom of the movement. A length of the rising flanks is at least twice as long as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large. Alternatively, it would also be possible for a length of the descending flanks to be at least twice as long as a length of the ascending flanks, optionally at least four times as large, further optionally at least ten times as large.

A computer program includes program code that can be executed by a controller. Running the program code causes the controller to perform a procedure. The method includes driving at least one actuator. The at least one actuator is set up to excite a first degree of freedom of movement of at least one elastically moved scanning unit in accordance with a periodic amplitude modulation function. The periodic amplitude modulation function includes alternately arranged rising edges and falling edges. The at least one elastically moved scanning unit further comprises a second degree of freedom of the movement. The at least one elastically moved scanning unit redirects light twice by means of the first degree of freedom of the movement and by means of the second degree of freedom of the movement. A length of the rising flanks is at least twice as long as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large. Alternatively, it would also be possible for a length of the descending flanks to be at least twice as long as a length of the ascending flanks, optionally at least four times as large, further optionally at least ten times as large.

A scanner comprises a scanning unit with an elastic element. The elastic element extends between a base and a steering element around. The scanning unit is set up to deflect light by means of torsion of the elastic element on the deflection unit at different angles. The scanner also includes a magnet. This is set up to generate a stray magnetic field. The scanner also includes an angular magnetic field sensor disposed in the leakage magnetic field. The angular magnetic field sensor is arranged to output a signal indicative of the torsion.

The torsion can correspond to a corresponding degree of freedom of movement of the elastic element. The torsion may be provided by elastic deformation of the elastic member. By the combination of the magnet and the angular magnetic field sensor, it is possible to closely monitor the rotation of the deflection unit due to the torsion. As a result, the angle at which the light is deflected, can be closely monitored. As a result, the radiation angle of the light can be monitored closely. As a result, the lateral resolution, for example a LIDAR measurement, can be increased. This may be desirable in particular if the scanner comprises two scanning units, each with an associated elastic element and a deflection unit, at which an optical path of the light is sequentially deflected. There may be present without corresponding monitoring an increased inaccuracy in the beam angle. The features and features set out above, which are described below, can be used not only in the corresponding combinations explicitly set out, but also in other combinations or isolated, without departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 schematically illustrates a scanning unit according to various examples. FIG. 2 schematically illustrates a scanning unit according to various examples. FIG. 3 schematically illustrates a scanning unit according to various examples. FIG. 4 schematically illustrates a scanning unit according to various examples.

FIG. 5 schematically illustrates actuators for exciting degrees of freedom movement of the scanning units according to FIGs. 1 - 4. FIG. 6 schematically illustrates actuators for exciting degrees of freedom movement of the scanning units according to FIGs. 1 - 4. FIG. 7 schematically illustrates actuators for exciting degrees of freedom movement of the scanning units according to FIGS. 1 - 4.

FIG. 8 schematically illustrates the timing of the movement of actuators of a pair of actuators for exciting degrees of freedom of movement of the scanning units according to various examples.

FIG. 9 schematically illustrates the time course of the movement of actuators of a pair of actuators for exciting degrees of freedom of movement of the scanning units according to various examples.

FIG. 10 schematically illustrates the resonant excitation of a degree of freedom of movement according to various examples.

FIG. FIG. 1 schematically illustrates a degree of freedom of movement corresponding to a torsion of elastic elements according to various examples.

FIGs. Figures 12 and 13 schematically illustrate a degree of freedom of movement corresponding, according to various examples, to a transverse deflection of elastic members. FIG. 14 schematically illustrates the superimposed and resonant excitation of two degrees of freedom of motion according to various examples.

FIG. 15 schematically illustrates a scanning unit according to various examples. FIG. 16 schematically illustrates a scanner with two scan units according to various examples.

FIG. 17 schematically illustrates a scanner with two scan units according to various examples.

FIG. 18 schematically illustrates a scanner having two scan units according to various examples. FIG. 19 schematically illustrates a scanner having two scan units according to various examples. FIG. 20 schematically illustrates a scanner having two scan units according to various examples.

FIG. 21 schematically illustrates a scanner having two scan units according to various examples.

FIG. 22 schematically illustrates a scanner with two scan units according to various examples.

FIG. 23 schematically illustrates the timing of an actuator movement provided by actuators according to various examples for exciting degrees of freedom of movement of the scan units.

FIG. FIG. 24 schematically illustrates the amplitude of the movement according to a degree of freedom of the movement represented by the timing of the actuator movement according to the example of FIG. 23 is reached.

FIG. 25 schematically illustrates the timing of an actuator movement provided by actuators according to various examples for exciting degrees of freedom of movement of the scan units.

FIG. FIG. 26 schematically illustrates the amplitude of the movement according to a degree of freedom of movement caused by the timing of the actuator movement according to the example of FIG. 25 is reached. FIG. FIG. 27 schematically illustrates an overlay figure obtained by temporally superimposing the motions according to the examples of FIGS. 24 and 26 is implemented by a scanner according to various examples.

FIG. 28 schematically illustrates a scanning unit with a magnet and an angular magnetic field sensor according to various examples. FIG. FIG. 29 schematically illustrates an orientation of magnetization of the magnet according to the example of FIG. 28 upon torsion of an elastic element of the scanning unit.

FIG. 30 schematically illustrates a LIDAR system according to various examples.

FIG. 31 schematically illustrates a LIDAR system according to various examples.

FIG. 32 is a flowchart of an example method. DETAILED DESCRIPTION OF EMBODIMENTS

The above-described characteristics, features, and advantages of this invention, as well as the manner in which they will be achieved, will become clearer and more clearly understood in connection with the following description of the embodiments, which will be described in detail in conjunction with the drawings.

Hereinafter, the present invention will be described with reference to preferred embodiments with reference to the drawings. In the figures, like reference characters designate the same or similar elements. The figures are schematic representations of various embodiments of the invention. Elements shown in the figures are not necessarily drawn to scale. Rather, the various elements shown in the figures are reproduced in such a way that their function and general purpose will be understood by those skilled in the art. Connections and couplings between functional units and elements illustrated in the figures may also be implemented as an indirect connection or coupling. Functional units can be implemented as hardware, software or a combination of hardware and software.

Hereinafter, various techniques for scanning light will be described. For example, the techniques described below may allow 2-D scanning of light. Scanning may refer to repeated emission of the light at different angles of radiation. For this purpose, the light can be deflected by a deflection once or more times. The deflection unit can be formed, for example, by a mirror and optionally by an interface element which fixes the mirror to an elastic element. The diverter could also include a prism instead of the mirror. The scanning may indicate the repeated scanning of different points in the environment by means of the light. For this purpose, different emission angles can be implemented sequentially. The sequence of emission angles can be determined by a superposition figure, if, for example, two degrees of freedom of the movement are used temporally and optionally spatially superimposed for scanning. For example, the amount of different points in the environment and / or the amount of different radiation angles may define a scan area. In various examples, the scanning of light by the temporal superposition and optionally a local superposition of two movements corresponding to different degrees of freedom at least one elastic suspension can be done. Then a 2-D scan area is obtained.

Sometimes the overlay figure is also referred to as a Lissajous figure. The overlay figure can describe a sequence with which different radiation angles are converted by the movement of the support element.

In various examples, it is possible to scan laser light. In this case, for example, coherent or incoherent laser light can be used. It would be possible to use polarized or unpolarized laser light. For example, it would be possible for the laser light to be pulsed. For example, short laser pulses with pulse widths in the range of femtoseconds or picoseconds or nanoseconds can be used. For example, a pulse duration can be in the range of 0.5-3 nanoseconds. The laser light may have a wavelength in the range of 700-1800 nm. For the sake of simplicity, reference will now be made primarily to laser light; however, the various examples described herein may also be used to scan light from other light sources, for example broadband light sources or RGB light sources. RGB light sources herein generally refer to light sources in the visible spectrum, the color space being covered by superimposing several different colors, such as red, green, blue or cyan, magenta, yellow, black.

In various examples, at least one support element will be used to scan light having a shape and / or material induced elasticity. Therefore, the at least one support element could also be referred to as a spring element or elastic suspension. The support element has a movable end. Then at least one degree of freedom of movement of the at least one support element can be excited, for example a torsion and / or a transverse deflection. Different orders of transversal modes can be excited. By such Exciting a movement, a deflection unit, which is connected to the movable end of the at least one support elements, are moved. Therefore, the movable end of the at least one support element defines an interface element. For example, it would be possible to use more than a single support member, eg, two or three or four support members. These may optionally be arranged symmetrically with respect to each other.

In various examples, a movable end of a fiber or fibers is used as a support element for scanning the laser light: this means that the at least one support element can be formed by one or more fibers. Different fibers can be used as support elements. For example, optical fibers may be used, which are also referred to as glass fibers. However, it is not necessary that the fibers are made of glass. The fibers may be made of plastic, glass or other material, for example. For example, the fibers may be made of quartz glass. The fibers may, for example, have a length which is in the range of 3 mm - 10 mm, optionally in the range of 3.8 mm - 7.5 mm. For example, the fibers may have a 70 GPa elastic modulus. This means that the fibers can be elastic. For example, the fibers can allow up to 4% material expansion. In some examples, the fibers have a core in which the injected laser light is propagated and trapped at the edges by total reflection (optical fibers). The fiber does not have to have a core. In various examples, so-called single mode fibers or multimode fibers may be used. The various fibers described herein may, for example, have a circular cross-section. For example, it would be possible for the various fibers described herein to have a diameter which is not less than 50 μιτι, not optional μιτι <150, further optional not <500 μιτι, further optional not <1 mm. For example, the various fibers described herein may be bendable, ie, flexible. For this, the material of the fibers described herein may have some elasticity. The fibers may have a core. The fibers may have a protective coating. In some examples, the protective coating may be at least partially removed, eg at the ends of the fibers. In other examples, it would also be possible for elongate elements to be produced by means of MEMS techniques, ie to be produced by means of suitable lithographic process steps, for example by etching from a wafer. For example, the movable end of the support member could be moved in one or two dimensions, with temporal and spatial superposition of two degrees of freedom of movement. One or more actuators can be used for this purpose. For example, it would be possible that the movable end is tilted relative to a fixing of the at least one support element; this results in a curvature of the at least one support element. This may correspond to a first degree of freedom of the movement; this can be referred to as transversal mode (or sometimes as wiggle mode). Alternatively or additionally, it would be possible for the movable end to be rotated along a longitudinal axis of the support element (torsion mode). This may correspond to a second degree of freedom of movement. By moving the movable end can be achieved that laser light is emitted at different angles. For this purpose, a deflection unit, such as a mirror optionally with a suitable interface for fixing, can be provided. This allows an environment to be scanned with the laser light. Depending on the amount of movement of the movable end, scan areas of different sizes can be implemented.

In each of the various examples described herein, it is possible to excite the torsional mode alternatively or in addition to the transverse mode, i. a temporal and spatial superimposition of the torsional mode and the transverse mode would be possible. This temporal and local overlay can also be suppressed. In other examples, other degrees of freedom of motion could also be implemented.

For example, the deflection unit may comprise a prism or a mirror. For example, the mirror could be implemented by a wafer, such as a silicon wafer, or a glass substrate. For example, the mirror could have a thickness in the range of 0.05 μηι - 0, 1 mm. For example, the mirror could have a thickness of 25 μηι or 50 μηι. For example, the mirror could have a thickness in the range of 25 μηι to 75 μηι. For example, the mirror could be square, rectangular or circular. For example, the mirror could have a diameter of 3 mm to 12 mm, or in particular 8 mm.

In general, such techniques can be used to scan light in a wide variety of applications. Examples include endoscopes and RGB projectors and printers and laser scanning microscopes. In various examples, LIDAR techniques can be used. The LIDAR techniques can be used to perform a spatially resolved distance measurement of objects in the environment. For example, the LIDAR technique may include transit time measurements of the laser light between the mirror, the object, and a detector. In general, such techniques can be used to scan light in a wide variety of applications. Examples include endoscopes and RGB projectors and printers. In various examples, LIDAR techniques can be used. The LIDAR techniques can be used to perform a spatially resolved distance measurement of objects in the environment. For example, the LIDAR technique may include transit time measurements of the laser light. Various examples are based on the finding that it may be desirable to carry out the scanning of the laser light with a high accuracy with respect to the emission angle. For example, in the context of LIDAR techniques, spatial resolution of the distance measurement may be limited by inaccuracy of the emission angle. Typically, a higher (lower) spatial resolution is achieved the more accurate (less accurate) the radiation angle of the laser light can be determined.

Various examples are further based on the finding that it may be desirable to implement scanning of the laser light for a 2-D scan area. Often, it may be desirable to implement the 2-D scan area by overlaying two degrees of freedom of motion and a corresponding overlay figure over time. The various examples described herein make it possible to implement a high-resolution two-dimensional scan area with great accuracy, with the corresponding scanner allowing comparatively large integration into a small installation space.

FIG. 1 illustrates aspects relating to a scan unit 99. The scan unit 99 includes a scan module 100. The scan module 100 includes a base 141, two support members 101, 102, and an interface member 142. The support members 101, 102 are formed in a plane (drawing plane of FIG. 1). The scan module 100 may also be referred to as an elastic suspension.

In this case, the base 141, the support elements 101, 102, and the interface element 142 are integrally formed. For example, it would be possible for the base 141, the support members 101, 102, and the interface member 142 to be obtained by MEMS processes by etching a silicon wafer (or other semiconductor substrate). In such a case, the base 141, the support elements 101, 102, as well as the interface element 142 may be formed in particular monocrystalline. In other examples, the base 141, the However, supporting elements 101, 102, and the interface element 142 may not be formed in one piece; For example, the support elements could be implemented by fibers.

It would also be possible for the scan module 100 to have only a single support element or to have more than two support elements.

The scanning unit 99 also includes a mirror 150 implementing a deflection unit. In the example of FIG. 1 is the mirror 150, which has on the front side a mirror surface 151 with high reflectivity (for example greater than 95% at a wavelength of 950 μm, optionally> 99%, further optional> 99.999%, eg aluminum or gold in a thickness of 80 μm). 250 nm) for light 180, not integrally formed with the base 141, the support elements 101, 102, and the interface element 142. For example, the mirror 150 could be glued to the interface element 142. Namely, the interface member 142 may be configured to fix the mirror 150 and the mirror surface 151, respectively. For example, for this purpose, the interface element 142 could include an abutment surface configured to fix a corresponding abutment surface of the mirror 150. For example, to join the mirror 150 to the interface element 142, one or more of the following techniques could be used: gluing; Soldering. The mirror also has a backside 152.

By means of such techniques, large mirror surfaces can be realized, eg not smaller than 10 mm ^A 2, optionally not smaller than 15 mm ^A 2. Thereby, in connection with LIDAR techniques, which also use the mirror surface 151 as detector aperture, a high accuracy and range be achieved.

In the example of FIG. 1, the scan module 100 extends away from the backside 152 of the mirror 150, ie, on a side of the mirror 150 facing the backside 152. A 1-point suspension of the mirror is thereby implemented. In the example of FIG. 1, the support elements 101, 102 have an extension perpendicular to the mirror surface 151; this extension could be, for example, about 2 to 8 mm, in the example of FIG. 1. The support elements 101, 102 are in particular rod-shaped along corresponding longitudinal axes 11 1, 112 are formed. In FIG. 1, the surface normal 155 of the mirror surface 151 is shown; the longitudinal axes 11 1, 12 are oriented parallel to the surface normal 155, ie they enclose an angle of 0 ° with this. Therefore, the extension of the support members 101, 102 perpendicular to the mirror surface 151 is equal to the length 211 of the support members 101, 102. In general, it would be possible that the length 21 1 of the support members 101, 102 is not shorter than 2 mm, optionally not shorter than 4 mm, further optional not shorter than 6 mm. For example, it is possible that the length of the support members 101, 102 is not greater than 20 mm, optionally not greater than 12 mm, further optionally not greater than 7 mm. If multiple supports are used, they can all be the same length.

In general, the length 21 1 of the support members 101, 102 could be in the range of 20% -400% of a diameter 153 of the mirror 150. In general, the length 211 could not be less than 20% of the diameter 153, optionally not less than 200% of the diameter, further optionally not less than 400%. As a result, on the one hand a good stability can be provided, on the other hand comparatively large scan areas can be implemented.

Depending on the relative orientation of the longitudinal axes 11 1, 1 12 with respect to the mirror surface 151, it would be possible that the extension of the support elements 101, 102 perpendicular to the mirror surface 151 is shorter than the length 211 (because only the projection parallel to the surface normal 155 is taken into account). In general, it is possible that the extension of the support members 101, 102 perpendicular to the mirror surface 151 is not smaller than 0.7 mm. Such a value is larger than the typical thickness of a wafer from which the scan module 100 can be made. As a result, particularly large scanning angles for the light 180 can be implemented. The material of the support elements 101, 102 may cause a material-induced elasticity of the support elements 101, 102. Further, the elongated, rod-like shape of the support members 101, 102 may also effect a shape-indexed elasticity of the support members 101, 102. By means of such an elasticity of the support elements 101, 102, an elastic deformation to a movement of the interface element 142 and thus also of the mirror 150 can be achieved. For example, a torsional mode and / or a transversal mode of the support members 101, 102 could be used to move the interface element 142 - and thus the mirror 150 -. As a result, the scanning of light can be implemented (in FIG. 1, the resting state of the support elements 101, 102 is shown).

FIG. 2 illustrates aspects relating to a scan module 100. The scan module 100 comprises a base 141, two support elements 101, 102, and an interface element 142 Base 141, the support members 101, 102, and the interface element 142 integrally formed.

The example of FIG. 2 basically corresponds to the example of FIG. 1. However, in the example of FIG. 2, the mirror 150 is formed integrally with the interface element 142 or the support elements 101, 102 and the base 141. In order to achieve the largest possible mirror surface 151, in the example of FIG. 2, a projection is provided over a central area of the interface element 142. FIG. 3 illustrates aspects relating to a scan module 100. The scan module 100 comprises a base 141, two support elements 101, 102, and an interface element 142. The base 141, the support elements 101, 102, and the interface element 142 are integrally formed. The example of FIG. 3 basically corresponds to the example of FIG. 2. In the example of FIG. 3, mirror 150 and interface element 142 are implemented by one and the same element. The mirror surface 151 implementing the deflection unit is applied directly to the interface element 142. This allows a particularly simple structure and a simple production.

FIG. 4 illustrates aspects relating to a scan module 100. The scan module 100 comprises a base 141, two support elements 101, 102, and an interface element 142. The base 141, the support elements 101, 102, and the interface element 142 are integrally formed.

The example of FIG. 4 basically corresponds to the example of FIG. 1. In the example of FIG. 4, however, the longitudinal axes 111, 112 of the support elements 101, 102 are not oriented perpendicular to the mirror surface 151. In FIG. 4, the angle 159 between the surface normal 155 of the mirror surface 151 and the longitudinal axes 11, 12 is shown. The angle 159 is in the example of FIG. 4 45 °, but could generally be in the range of -60 ° to + 60 °.

Such tilting of the mirror surface 151 with respect to the longitudinal axes 1111, 112 may be particularly advantageous if the torsional mode of the support elements 101, 102 is used to move the mirror 150. Then, periscope-like scanning of the light 180 may be implemented by the scanning unit 99. By periscope-like scanning can be avoided that the aperture - ie in some examples, if the Light is emitted and received via the same mirror 150, in particular the detector aperture - for a single mirror 150 has a dependence on the scanning angle. In the case of two sequential mirrors 150 (see FIGS. 16 ff.) Using two scanning units (in FIG. 16: 99-1, 99-2), the aperture is dependent on the scan angle, with smaller apertures for larger scan angles and larger scan angles Distances between the mirrors 150 are obtained. Overall, however, this dependence - due to the periscope-like scanning of an individual mirror 150 - lower than in comparable systems of the prior art, in which even a single mirror

150 is scanned so that the aperture varies as a function of the scan angle. In particular, no tilting of the mirror surface occurs due to the periscope-like scanning

151 of the first mirror 150 of a first scanning unit with respect to the mirror surface 150 of the second mirror 150 of a second scanning unit.

FIG. 5 illustrates aspects relating to a scan unit 99. The scan unit 99 includes the scan module 100 which could be configured, for example, according to the various other examples described herein (however, FIG. 5A exemplifies a scan module 100 having only a single support member 101). ,

FIG. FIG. 5 particularly illustrates aspects relating to piezoactuators 310, 320. In various examples, bending piezoactuators 310, 320 may be used to excite the support member 101. The piezoactuators 310, 320 may be e.g. by a suitable control - e.g. via a driver - to be controlled.

For example, generally a first and a second bending piezoactuator may be used. It would be possible for the first bending piezoactuator and / or the second bending piezoactuator to be plate-shaped. In general, a thickness of the Biegepiezoaktuatoren eg in the range of 200 μηι - 1 mm are, optionally in the range of 300 μηι - 700 μηι. For example, it would be possible for the first bending piezoactuator and / or the second bending piezoactuator to have a layer structure comprising an alternating arrangement of a plurality of piezoelectric materials. These can have a different strength piezoelectric effect. As a result, a bending can be effected, similar to a bimetallic strip with temperature changes. For example, it is possible for the first bending piezoactuator and / or the second bending piezoactuator to be fixed at a fixing point: an end opposite the fixing point can then be moved on account of a bending or curvature of the first bending piezoactuator and / or the second bending piezoactuator. The use of Biegepiezoaktuatoren a particularly efficient and strong excitation can be achieved. Namely, the bending piezoactuators can move the base 141 and, in particular, tilt - for exciting a torsional mode of the at least one support element. In addition, it may be possible to achieve high integration of the device for excitation. This can mean that the required installation space can be dimensioned particularly small.

In particular, in the example of FIG. 5, the piezoactuators 310, 320 are designed as bending piezoactuators. This means that the application of a voltage to electrical contacts of the bending piezoactuators 310, 320 causes a bending or bending of the bending piezoactuators 310, 320 along their longitudinal axes 319, 329. For this purpose, the bending piezoactuators 310, 320 have a layer structure (not illustrated in FIG. 5 and oriented perpendicular to the plane of the drawing). In this way, one end 315, 325 of the bending piezoactuators 310, 320 is deflected perpendicular to the respective longitudinal axis 319, 329 with respect to a fixing point 311, 321 (the movement is oriented perpendicular to the plane of the drawing in the example of FIG. The movement 399 of the bending piezoactuators 310, 320 (actuator movement) due to the bending is shown in FIG. 6 shown.

FIG. 7 is a side view of the bending piezoactuators 310, 320. FIG. FIG. 7 shows the bending piezoactuators 310, 320 in a rest position of the scanning unit 99, for example without a driver signal or tension / curvature.

Referring again to FIG. 5: For example, the fixing point in 311, 321 could establish a rigid connection between the bending piezoactuators 310, 320 and a housing of the scanning unit 99 (not shown in FIG. 5) and be arranged stationarily in a reference coordinate system.

The base 141 could have a longitudinal extent of the longitudinal axes 319, 329 that is in the range of 2 to 20% of the length of the bending piezoactuators 310, 320 along the longitudinal axes 319, 329, optionally in the range of 5 to 15%. As a result, sufficient excitation can be achieved; the base 141 dampens the movement of the bending piezoactuators 310, 320 only comparatively weakly.

In the example of FIG. 5, the bending piezoactuators 310, 320 are arranged substantially parallel to each other. It would also tilting of the longitudinal axes 319, 329 to each other possible, especially as long as they are in a plane. From the example of FIG. 5, it can be seen that the connection of the bending piezoactuators 310, 320 with the support element 101 is implemented via the edge regions 146 of the base 141. Because these marginal regions 146 have elasticity, the flexure 399 can be received and results in deflection of the base 141. This allows one or more degrees of freedom of movement of the interface element 101 coupled via the base 141 to be excited. This results in a particularly efficient and space-saving excitation.

In the example of FIG. 5, bending piezoactuators 310, 320 extend away from interface element 142. However, it would also be possible for bending piezoactuators 310, 320 to extend along at least 50% of their length toward interface element 142. As a result, a particularly compact arrangement can be achieved. This is in FIG. 6 shown. The example of FIG. 6 basically corresponds to the example of FIG. 6. However, the bending piezoactuators 310, 320 extend toward the interface element 142 or toward a freely movable end of the at least one support element 101. In this way, a particularly compact design of the scanning unit 99 can be achieved. FIG. 8 schematically illustrates aspects relating to a movement 399-1, 399-2 of the bending piezoactuators 310, 320. Through a corresponding movement 399-1, 399-2, a force flow can be transmitted to the support elements 101, 102, so that one or more degrees of freedom the movement can be stimulated. In other examples, other types of actuators may be used. For example, it would be possible to use actuators which transmit a stimulus without contact by means of a magnetic field. Then, a force flow corresponding to the movement 399-1, 399-2 can also be otherwise implemented. In the example of FIG. 8, there is a sine-shaped movement 399-1, 399-2 of the bending piezoactuators 310, 320, with 180 ° phase offset between the movements 399-1, 399-2 (solid and dashed lines in FIG. As a result, the base 141 is tilted (for example with respect to the drawing plane of FIGS. 1-4), whereby a torsional mode can be stimulated particularly efficiently. In FIG. 8, the relative actuator movement 831 is also shown as the offset in the direction of the movement 399-1, 399-2 between the ends 315, 325 of the bending piezoactuators 310, 320 due to the movements 399-1, 399-2 (dotted line in FIG . 8th). FIG. 9 schematically illustrates aspects relating to a movement 399-1, 399-2 of the bending piezoactuators 310, 320. Through a corresponding movement 390-1, 399-2, a force flow can be transmitted to the support elements 101, 102, so that one or more degrees of freedom the movement can be stimulated. The example of FIG. 9 basically corresponds to the example of FIG. 8, wherein there is no phase offset between the movements 399-1, 399-2. This results in an up-down movement of the base 141 (for example, with respect to the drawing plane of FIGS. 1-4), whereby a transverse mode can be stimulated particularly efficiently. In FIG. 9, the actuator movement 831 is equal to 0.

In some examples, it would be possible for the movement of bending piezoactuators 310, 320-or otherwise designed force flow of a suitable actuator-to excite temporal and spatial superposition of multiple degrees of freedom of movement. This can be done, for example, by superimposing the movements 399-1, 399-2 according to the examples of FIGS. 8 and 9 take place. Thus, a superposition of the equal and opposite phase movements 399-1, 399-2 can be used.

FIG. 10 schematically illustrates aspects relating to a movement 399-1, 399-2 of the bending piezoactuators 310, 320. In particular, FIG. 10, the movement 399-1, 393-2 in frequency space. FIG. 10 illustrates a frequency of the movement 399-1, 399-2 with respect to a resonance curve 1302 of a torsional mode 502. The resonance curve 1302 is characterized by a half width 1322 and a maximum 1312. In the example of FIG. 10, a resonant excitation occurs because the frequency of the movement 399-1, 399-2 is located within the resonance curve 1302.

FIG. 11 illustrates aspects related to the torsional mode 502. FIG. Fig. 1 1 schematically illustrates the deflection of the torsional mode 502 for a scanning unit 99 with four support elements 101 - 1, 101-2, 102-1, 102-2 (in Fig. 1 1 the deflected state is shown with the solid lines and the rest state with the dashed lines shown). In FIG. 11, the torsion axis of the torsional mode 220 is congruent with the central axis 220 or parallel to the axes of the support elements 101-1, 101-2, 102-1, 102-2. In the example of FIG. 1 1, the support elements 101-1, 102-1, 101-2, 102-2 rotationally symmetric with respect to a central axis 220 are arranged. In particular, there is a fourfold rotational symmetry. The presence of a rotational symmetry means, for example, that the system of the support elements 101-1, 102-1, 101-2, 102-2 can be converted into themselves by rotation. The magnitude of the rotational symmetry designates how often per 360 ° rotation angle the system of the support elements 101-1, 102-1, 101-2, 102-2 can be converted into itself. In general, the rotational symmetry could be n-fold, where n denotes the number of supporting elements used.

Due to the rotationally symmetrical arrangement with high counting, the following effect can be achieved: Nonlinearities in the excitation of the torsional mode 502 can be reduced or suppressed. This can be made plausible by the following example: for example, the support elements 101-1, 102-1, 101-2, 102-2 could be arranged such that the longitudinal axes and the central axis 220 all lie in one plane. Then the rotational symmetry would be twofold (and not fourfold, as in the example of FIG. In such a case, the orthogonal transverse modes (different directions perpendicular to the central axis 220) have different frequencies - due to different moments of inertia. Thus, for example, the direction of the low-frequency transverse mode rotates together with the rotation upon excitation of the torsional mode 502. As a result, a parametric oscillator is formed because the natural frequencies vary as a function of the angle of rotation or thus as a function of time. The transfer of energy between the various states of the parametric oscillator causes nonlinearities. By using high-symmetry rotational symmetry, the formation of the parametric oscillator can be prevented. Preferably, the support elements can be arranged so that no dependence of the natural frequencies of the torsion angle occur. By avoiding non-linearities in the excitation of the torsional mode of the support elements 101-1, 102-1, 101-2, 102-2, it can be achieved that particularly large scan angles of the light through the torsional mode 502 can be achieved.

FIG. 12 illustrates aspects relating to a scan unit 99. In the example of FIG. 12, the scanning unit 99 comprises a single support element 101 with an optional balance weight 1371. Therefore, upon excitation of the transverse mode 501, a tilting of the mirror surface 151 occurs. This is shown in FIG. 13 is shown. In FIG. 13 is in particular the Transverse mode 501 lowest order shown. In other examples, it would also be possible to use a transversal mode of higher order to scan light 180, in which case the deflection of support element 101 at certain positions along length 21 1 of support element 101 would be zero (so-called node or belly of deflection) ).

FIG. Figure 14 illustrates aspects relating to resonant curves 1301, 1302 of the degrees of freedom of movement 501, 502, by means of which, for example, a heterodyne figure may be implemented for a 2-D scan area. FIG. 14 illustrates the amplitude of the excitation of the respective degree of freedom of the movement 501, 502. A resonance spectrum according to the example of FIG. 14 may be desirable in particular if a temporal and spatial superimposition of the different degrees of freedom of the movement 501, 502 of the at least one support element 101, 102 is desired for the 2-D scanning. In the example of FIG. 14, the two resonance curves 1301, 1302 could be excited temporally and spatially, e.g. by using a single scan unit 99 to implement the different degrees of freedom of movement 501, 502. However, it would also be possible that in the example of FIG. 14, the two resonance curves 1301, 1302 are superimposed over time excited, but not locally superimposed. For this purpose, it would be possible to use a first scan unit 99 to implement a degree of freedom of the movement 501, 502 according to the resonance curve 1301, and a second scan unit 99 to implement the degree of freedom of the movement 501, 502 according to the resonance curve 1302 , The resonance curve 1301 of the transverse mode 501 has a maximum 131 1 (solid line). In FIG. 14, the resonance curve 1302 of the torsional mode 502 is also shown (dashed line). The resonance curve 1302 has a maximum 1312.

The maximum 1312 of the torsional mode 502 is at a lower frequency than the maximum 1311 of the transverse mode 501, which could be, for example, the lowest order transverse mode 501. This can be achieved that the scan module is particularly robust against external disturbances such as vibrations, etc. This is the case since such external excitations typically excite transverse mode 501 most efficiently, but do not excite torsional mode 502 particularly efficiently. For example, the resonance curves 1301, 1302 could be Lorentz-shaped. This would be the case if the corresponding degrees of freedom of movement 501, 502 can be described by a harmonic oscillator. The maxima 1311, 1312 are shifted from each other in frequency. For example, the frequency spacing between the maxima 131 1, 1312 could be in the range of 5 Hz to 500 Hz, optionally in the range of 10 Hz to 200 Hz, more optionally in the range of 30 Hz to 100 Hz. 14, the half widths 1321, 1322 of the resonance curves 1301, 1302 are also shown. Typically, the half-width is defined by the attenuation of the corresponding degree of freedom of movement 501, 502. In the example of FIG. 14, the half widths 1321, 1322 are equal; however, in general, the half widths 1321, 1322 could be different from each other.

In the example of FIG. 14, the resonance curves 1301, 1302 have an overlap region 1330 (shown in dark). This means that the transverse mode 501 and the torsional mode 502 are degenerate. In the overlap region 1330, both the resonance curve 1301 has significant amplitudes and the resonance curve 1302. For example, it would be possible for the amplitudes of the resonance curves 1301, 1302 in the overlap region not to be less than 10% of the corresponding amplitudes at the respective maximum 131 1 , 1312, optionally not <5% each, optionally not <1% each further. Due to the overlap region 1330, it can be achieved that the two degrees of freedom of the movement 501, 502 can be coupled in a coupled manner, namely in each case resonantly at the same frequency. The frequency is between the two maxima 131 1, 1312 Thus, the temporal and spatial superposition can be achieved. On the other hand, nonlinear effects can be suppressed or avoided by coupling between the two degrees of freedom of movement 501, 502. Instead of using different degrees of freedom of movement 501, 502 - in the example of FIG. 14 of a torsional mode 502 and a transversal mode 501 - an overlay figure could also be achieved by double use of the same degree of freedom of movement. For example, the torsional mode 502 of a first scan unit could be excited, as well as the torsional mode 502 of a second scan unit. Thus, there is no local superposition of the two torsional modes, which may rather be assigned to different scanning units 99. Alternatively, it would also be possible, for example, to excite the transverse mode 501 of a first scan unit, as well the transverse mode 501 of a second scanning unit. Even in such cases mentioned above, the double use of the same degree of freedom of movement in different scanning unit can - for example, due to manufacturing tolerances or targeted structural variation between the scanning units, etc. - give a certain distance between the maxima of the resonance curves.

FIG. FIG. 15 illustrates aspects relating to a scan unit 99. In the example of FIG. 15, there is shown a scanning module 100 having a first pair of support members 101-1, 102-1 and a second pair of support members 102-1, 102-2. The first pair of support members 101-1, 102-1 is arranged in a plane; the second pair of support members 101-2, 102-2 is also arranged in a plane. These planes are parallel to each other and offset from one another.

In the example of FIG. 15, for example, two scan modules 100 according to the example of FIG. 4 combined. Each pair of support elements is associated with a corresponding base 141-1, 141-2, and a corresponding interface element 142-1, 142-2. Both interface elements 142-1, 142-2 make a connection with a mirror 150 here. It can thus be achieved that a particularly stable scanning module 100 can be provided, which has a large number of supporting elements. In particular, the scan module 100 may comprise support elements arranged in different planes. This can allow a particularly large robustness.

From FIG. 15, it can also be seen that the base 141-1 is not integrally formed with the base 141-2. In addition, the interface element 142-1 is not formed integrally with the interface element 142-2. Also, the support members 101-1, 102-1 are not formed integrally with the support members 102-1, 102-2. In particular, it would be possible for the various aforementioned parts to be manufactured from different regions of a wafer and then connected to one another, for example by gluing or anodic bonding. Other examples of joining techniques include: fusion bonding; Fusion or direct bonding; Eutectic bonding; Thermocompression bonding; and adhesive bonding. Corresponding connection surfaces 160 are shown in FIG. 15 marked. By means of such techniques it can be achieved that the scan module 100 can be manufactured particularly easily. In particular, it is not necessary for the complete scan module 100 to be manufactured in one piece or integrated from a wafer. Rather, the scan module 100 can be produced in a two-stage manufacturing process. At the same time, however, this can not significantly reduce the robustness: due to the large area connecting surfaces 160, a particularly stable connection between the base 141-1 and the base 141-2 and the interface element 142-1 and the interface element 142-2, respectively.

However, it is possible that the base 141-1, the support elements 101-1, 102-1, and the interface element 142-1 by mirroring on a plane of symmetry (in which also the connecting surfaces 160 are) on the base 141-2, the support elements 102-1, 102-2 and the interface element 142-2 can be imaged. As a result, a highly symmetrical structure can be achieved. In particular, a rotationally symmetrical structure can be achieved. The rotational symmetry can have a count of n = 4; i.e. equal to the number of supporting elements 101-1, 101-2, 102-1, 102-2 used. Such a symmetrical construction with respect to the central axis 220 may in particular have advantages with respect to the excitation of the torsional mode 502. Nonlinearities can be avoided. For example, a scanning unit 99 according to the example of FIG. 15 for the torsional mode 502 according to the example of FIG. 1 1 can be used.

FIG. 16 illustrates aspects relating to a scanner 90. The scanner 90 comprises two scan units 99-1, 99-2, which are each shown in the example of FIG. 15 are formed. Thus, the scanner 90 is configured to redirect light 180 sequentially on the front sides of the mirrors 150 of the scanning units 99-1, 99-2 (in Fig. 16, the corresponding optical path is shown with a dotted line). FIG. Figure 16 illustrates the scanner in an idle state, i. without actuation of the scanning units 99-1, 99-2, for example by means of the bending piezoactuators 310, 320.

For example, it would be possible for the torsional modes 502 of the two scan modules 101 of the scan units 99-1, 99-2 to be excited in order to implement different emission angles in accordance with an overlay figure defining a 2-D scan area. But it could also be used other degrees of freedom of movement.

From FIG. 16, it can be seen that the suspensions of the mirrors 150 of the scanning units 99-1, 99-2 each comprise four elastic, rod-shaped elements 101-1, 101-2, 102-1, 102-2. Thus, the scanning units 99-1, 99-2 according to the example of FIG. 15 configured. However, in other examples, it would also be possible for the suspensions of the mirrors 150 to have fewer or more rod-shaped elements (eg, only one rod-shaped elastic element as shown in FIGS. 5 and 6, and 12 and 13). From the example of FIG. 16, it can be seen that the scanning modules 100 of the scanning units 99-1, 99-2 each extend to different directions away from the backs of the mirrors 150. Rear suspensions are implemented by the scan modules 101. The scan modules 101 extend toward sides facing the backs of the mirrors 150. There are no suspensions in the mirror plane of the mirrors 150 of the scanning units 99-1, 99-2. By means of such a rear one-point suspension of the mirrors 150, it can be achieved that the mirrors 150 of the scanning units 99-1, 99-2 can be placed particularly close to one another. By such a high integration of the scanner 90, a small housing design can be achieved. This promotes the integration of the scanner 90, for example in passenger vehicles or aircraft drones, etc. In addition, it can be achieved that an effective detector aperture - if reflected light is also detected by means of the mirrors 150 - is dimensioned particularly large. This is favored because at large mirrors and large angles of rotation in reference implementations significant shifts of the mirror edges take place. Thus, it may happen that the mirrors in reference implementations abut suspensions, whereby the maximum aperture, or angle is limited.

For example, in FIG. 16 shows a distance 70 between a center of the mirror surface 151 of the scanning unit 99-1 and the mirror surface 151 of the scanning unit 99-2. This distance 70 can be particularly small dimensions. For example, this distance 70 could not be greater than four times the diameter of the mirror surface 151, optionally not more than three times the diameter, more optionally not more than one and eight times the diameter. In the example of FIG. 16, the central axis 220 of the scanning module 100 is tilted at an angle of 45 ° with respect to the surface normal 155 of the mirror surface 151 (see FIG. 4). Therefore, it may be desirable that a torsional mode 502 of both the scanning module 100 of the scanning unit 99-1 and a torsional mode 502 of the scanning module 100 of the scanning unit 99-2 be excited. These may be degenerate, but different resonance frequencies or maxima of the resonance curve are possible.

In the example of FIG. 16 is a value between the central axes 220 of the scanning units 99-1, 99-2 equal to 90 °. This angle could also vary by 90 °, for example 90 ° ± 25 °. By such an arrangement, a particularly large scan area can be implemented. For example, if transverse modes 501 are used to scan light, it may be desirable that the central axis 220 of scan units 99-1, 99-2 enclose an angle of substantially 180 ° (not shown in FIG. 16), ie, a linear one Arrangement of scan units 99-1, 99-2 is selected (English, face-to-face).

FIGs. 17-22 are different representations of the scanner 90 according to the example of FIG. 16. Different perspectives are shown.

FIG. FIG. 23 illustrates aspects related to the actuation of a scan module 100. For example, a scan module 100 of the scanner 90 according to the examples of FIGS. 16-22 be actuated accordingly.

FIG. 23 illustrates a timing of the actuator movement 831. In FIG. In particular, the relative deflection of the bending piezoactuators 310, 320 relative to each other is shown as actuator movement 831 (see FIG. For example, FIG. 23 thus a distance of the ends 315, 325 of the Biegepiezoaktuatoren 310, 320 of the examples of FIGs. 5 and 6 illustrate. However, other characteristics of the actuator movement 831 could also be taken into account - for example the movement 399-1 of the bending piezoactuator 310 or the movement 399-2 of the bending piezoactuator 399-2: the actuator movement 831 is proportional to a force flow provided by the bending piezoactuators 310, 320 , In that regard, FIG. 23, an example using bending piezoactuators 310, 320; however, in other examples, other actuators, such as actuators that use magnetic fields, etc., could be used if a corresponding power flow is provided.

The frequency of the actuator movement 831 is tuned to the resonance curve 1301, 1302 of the selected degree of freedom of the movement 501, 502 (cf. FIGS. 10 and 14): The actuator movement excites one degree of freedom of the movement 501, 502. In the example of FIG. 24, the torsional mode 502 is excited because the actuator movement 831 causes a tilting of the base 141 of the scanning module 100. This is the case because the actuator movement 831 causes a time-variable distance of the ends 315, 325 of the Biegepiezoaktuatoren 310, 320 to each other. In other examples, the transverse mode 501 could also be excited by a suitable actuator movement. In the example of FIG. 23, the actuator movement 831 has a constant amplitude. As a result, the torsional mode 502 with constant amplitude 832 is excited. This is shown in FIG. 24 (in Fig. 24, the instantaneous deflection of the torsional mode is not shown). FIGs. FIGS. 25 and 26 basically correspond to FIGS. 23 and 24. In the example of FIGS. 25 and 26, however, the bending piezo actuators 310, 320 are configured to excite the torsional mode 502 in accordance with a periodic amplitude modulation function 842 having alternately rising edges 848 and descending edges 849. For this purpose, a suitable actuator movement 831 is implemented.

From FIG. In particular, it can be seen that the length 848A of the rising flanks 848 is substantially greater than the length 849A of the descending flanks 849. For example, the length of the rising flanks 848 could be at least twice the size of the length of the descending flanks 849, optionally at least four times as large, further optionally at least ten times as large.

In the example of FIG. 25, the descending flanks 849 are dimensioned so short that their lengths are not greater than two periods of the frequency of the resonantly actuated torsional mode 502 and the frequency of the actuator 831 movement. In general, the length of the falling edges 849 of the amplitude modulation function 842 could not be greater than ten durations of the frequency of the torsional mode 502, optionally not greater than three period lengths, further optionally not greater than two period lengths.

Due to a particularly short dimensioning of the length 849A of the descending flanks 849, it can be achieved that the scanning module 100 can be converted to the resting state 844 very quickly with respect to the corresponding degree of freedom of the movement 501, 502 after actuation has taken place up to the maximum amplitude 843 - whereupon a renewed actuation can take place. This means that a reset of the movement according to the corresponding degree of freedom of the movement 501, 502 can be done quickly. This may be particularly useful when implementing a superposition figure by means of the corresponding degree of freedom of movement. For example, it would be possible for LI DAR measurements to be performed for imaging only during ascending edges 848. The amount of all LIDAR measurements recorded during the 848A period can correspond to a LIDAR image for a specific environment. The same surrounding area can be scanned again after the reset so that LIDAR images are provided at a specific refresh rate. The shorter the length 849A, the higher the refresh rate. The short dimensioning of the length of the descending flanks 849 may be achieved by slowing down the movement in accordance with the torsional mode 502 during the descending flanks 849. In other words, this means that the movement according to the torsional mode 502 is actively attenuated, ie, attenuated more, than given by an intrinsic damping or the mass moment of inertia. For this purpose, a suitable actuator movement 831 of the bending piezoactuators 310, 320 is used.

Such slowing down of the movement of the torsional mode 502 is achieved in particular by increasing the amplitude 835 of the actuator movement 831 during the descending flanks 849. This can be achieved, for example, by increasing the individual movements 399-1, 399-2 of the bending piezoactuators 310, 320. For example, an average amplitude of actuator motion 831 during descending flanks 849 could be twice as large as an average amplitude of actuator motion 831 during rising flanks 848, optionally at least four times as large, and optionally at least ten times as large. By increasing the amplitude of the actuator movement 831 during the descending flanks 849, a particularly fast deceleration of the movement according to the torsional mode 502 can be achieved. This is the case because the power flow to the scan module 100 can be increased. The deceleration of the movement of the torsional mode 502 can also be achieved by a phase jump 849 in the actuator movement 831. Again, this can be achieved by a phase jump in the individual movements 399-1, 399-2 of the bending piezoactuators 310, 320. In the example of FIG. For example, the individual motion 399-1 of the bending piezoactuator 310 has a phase offset of 180 ° between the rising edge 848 and the descending edge 849. The phase shift 849 implements a phase offset in the displacement of each of the two bending piezoactuators 310, 320. Similarly, the individual movement 399-2 of the bending piezoactuator 320 also has a phase offset of 180 ° between the rising edge 848 and the falling edge 849. Thereby, the phase jump 849 in the in FIG. 25 resulting actuator movement 831 achieved as a distance between the ends 315, 325. This also achieves antiphase excitation of the torsional mode 502 in the descending edge 849 period from the rising edge period 848 resulting in the deceleration of the movement according to the torsional mode 502 during the descending edges 849.

While in the example of FIG. 25, the actuator movement 831 during the rising flanks 848 has a constant amplitude 835, respectively, and during the descending Flanks 849 each have a constant amplitude 835, it would also be possible in other examples that the actuator 831 movement during the rising flanks 848 has a time-varying amplitude and / or during the descending flanks 849 has a time-varying amplitude (not shown in FIG 25) ,

In some examples, a first scan unit 99-1 of a scanner 90 according to the examples of FIGS. 23 and 24, and a second scanning unit 99-2 of a scanner 90 could be constructed according to the examples of FIGS. 25 and 26 are operated. In other words, this means that differently actuated degrees of freedom of the movement-for example, two torsional modes 502 or two transverse modes 501-can be associated with different scanning units 99-1, 99-2. From this an overlay figure can be obtained, which allows a two-dimensional scan area. This is shown in FIG. 27 shown. FIG. FIG. 27 illustrates aspects relating to an overlay figure 900. FIG. FIG. 27 particularly illustrates aspects related to a 2-D scan area 915 (dashed line in FIG. 27) defined by the overlay figure 900. FIG. 27 shows the scan angle 901 that can be achieved by the constant amplitude 832 actuated torsional mode 502 (see FIGs 23 and 24), e.g. by means of the scanning unit 99-1. FIG. Figure 27 also shows a scan angle 902 that can be achieved by the torsional mode 502 actuated by the amplitude modulation function 842 (see Figures 25 and 26), e.g. by means of the scanning unit 99-2. By using the two scan angles 901, 902, a radiation angle can be obtained which varies in two orthogonal spatial directions, whereby a 2-D environment region can be scanned.

For example, the scanning unit 99-2 can be arranged in the beam path of the light 180 between (i) the scanning unit 99-1 and (ii) a detector and a light source. This means that smaller maximum amplitudes of the torsional mode 502 are converted by the inner scanning unit 99-2 and the inner mirror 150, respectively; and larger maximum amplitude of the torsional mode 502 are converted by the outer scanning unit 99-1 and the outer mirror 150, respectively.

However, in other examples, a constant amplitude transversal mode 501 and a modulated amplitude transverse mode 501 could be used. In still other examples, a transverse mode 501 and a torsional mode 502 could be used. It would also be possible to use transversal modes 501 of different order. It would also be possible to use torsional modes 502 of different order. The overlay figure 900 according to the example of FIG. 27 is obtained when the torsional modes 502 of the scanning units 99-1, 99-2 have the same frequency. This avoids nodes in the overlay figure 900, which are otherwise typical for Lissajous scanning. In addition, the overlay figure 900 according to the example of FIG. 27 is then obtained when the amplitude of the torsional mode during the rising edges 848 of the amplitude modulation function 842 is increased. That is, it is achieved that the overlay figure 900 is obtained as an "opening eye", that is, larger scanning angles 901 are obtained with increasing amplitude of the transverse mode 501 (represented by the vertical dotted arrows in FIG.).) Thus, scan lines can be obtained (horizontal 27), with which the surroundings of the laser scanner 99 can be scanned, by repeated emission of light pulses, different pixels 951 can be obtained avoided that certain areas between the nodes are not scanned.

Due to the fast deceleration during the descending edges 849, "the opening eye" can be quickly repeated, i.e., the overlay figure 900 can be implemented quickly in a row.

In the foregoing, techniques were explained using an "opening eye", i.e., implementing a reset of the overlay figure 900 by the descending edges 849. In other examples, a "closing eye" could also be used. There, the descending flanks 849 may have a length 849A that is greater than the length 848A of the rising flanks 848. The LIDAR imaging may then be primarily or exclusively during the descending flanks 849.

In the various examples described herein, it may be desirable to particularly well determine the scan angle 901, 902 of the scan units 99, 99-1, 99-2 used. For this purpose, techniques according to the example of FIG. 28 are used.

The example of FIG. 28 basically corresponds to the example of FIG. 1. In the example of FIG. 29, a magnet 660 is further applied to the interface element 142. In the example of FIG. 28, the magnet 660 is formed as a ferromagnetic coating. In other examples, it would also be possible for the magnet 660 to be formed, for example, as a bulk material or ferromagnetic pill. In the example of FIG. 28 is also an angular magnetic field sensor 662 is provided, which is arranged in the stray magnetic field of the magnet 660. The angular magnetic field sensor 662 outputs a signal which is indicative of the torsion 502 of the scanning module 100. For example, the signal may be analog and have a signal level that varies depending on the orientation of the stray magnetic field in the range of, for example, 0 ° to 360 ° between a minimum and a maximum. A digital signal could also be output which digitally codes the orientation of the stray magnetic field. For example, the signal may be received by a controller and used to appropriately drive the bending piezo actuators 310, 320. For example, a loop may be implemented to accurately reproduce the overlay figure 900.

This allows the movement of the torsion 502 to be closely monitored. As a result, it is possible in turn to deduce the exact angle 901, 902 that is implemented by the respective scanning unit 99. As a result, a particularly high lateral resolution can be provided for a LIDAR measurement.

In the example of FIG. 28, the backside 152 of the mirror 150 is disposed between the mirror surface 151 and the magnet 660 and the angular magnetic field sensor 162. This means that both the magnet 660 and the angular magnetic field sensor 662 are arranged rearwardly with respect to the mirror surface 151. This means that both the magnet 660 and the angular magnetic field sensor 662 are arranged on a side of the mirror 150 facing the back 152. This allows a particularly high integration can be achieved. In addition, the angular magnetic field sensor 162 can be placed particularly close to the magnet 660, so that a high signal-to-noise ratio can be achieved. As a result, the corresponding angle 901, 902 can also be determined particularly accurately. In particular, a physical separation between the optical path of the light 180 and the angular magnetic field sensor 662 can be achieved particularly easily because the optical path of the light 180 extends on a side of the mirror 150 facing the front side 151. Because the magnet 660 and the magnetic field sensor 662 are arranged rearwardly with respect to the mirror 150, the distance 70 in a scanner 90 comprising a plurality of scan units 99 can also be dimensioned particularly small. In the example of FIG. 28, the magnetic moment 661 of the magnet 660 is arranged perpendicular to the central axis 220 and to the torsional axis of the torsional mode 502 (see FIG. In general, the magnet 660 may have a magnetic moment 661 that has at least one component perpendicular to the torsion axis. As a result, for example, an in-plane angle magnetic field sensor 662, which has a sensitivity in the plane of the drawing of FIG. 29, are used. In other examples, a magnetic field sensor 662 with out-of-plane sensitivity could also be used.

In the example of FIGs. 28 and 29, the magnetic moment 661 is further arranged symmetrically to the central axis 220 and to the torsion axis of the torsion 502, respectively. At the same time, however, the angular magnetic field sensor 662 is disposed eccentrically with respect to the central axis 220. This may, for example, reduce the measured signal, but allows a more flexible choice with respect to the attachment of the angular magnetic field sensor 662. For example, the angular magnetic field sensor 662 may be mounted radially adjacent the base 141.

In the example of FIG. 28, the magnet 660 is rigidly connected to the mirror 150, i. is arranged in the moving coordinate system; while the angular magnetic field sensor 662 is disposed in the reference coordinate system of the base 141. In this way, signals of the angular magnetic field sensor 662 can be read out particularly easily because no transfer from the moving coordinate system into the reference coordinate system-in which the control is typically arranged-must take place. In other examples, however, it would also be possible to have a reverse arrangement, i. the angular magnetic field sensor 662 is arranged in the moving coordinate system and the magnet 660 is arranged in the reference coordinate system of the base 141. For example, then the signal of the angular magnetic field sensor 662 could be transmitted wirelessly, for example by light modulation. Alternatively, it would also be possible along the elastic elements 101, 102 for electrical conductor tracks - e.g. by metallic coating or doping - be provided that allow transmission of the signals of the angular magnetic field sensor 662. Such an implementation may be helpful, for example, if one and the same magnet 660 provides a stray magnetic field for a plurality of angular magnetic field sensors 662 associated with different scan units 99, 99-1, 99-2 of a scanner 90 or in the moving coordinate systems of different scan units 99, 99-1, 99-2 are arranged. The different magnetic field sensors 662 can therefore be rigidly connected to the deflecting units of different scanning units 99, 99-1, 99-2. For example, the magnet 660 can be made particularly strong, so that a large leakage magnetic field is available.

In an example according to FIG. 28 - in which the magnets 660 are mounted in the moving coordinate system - can be a simple separation of the stray magnetic fields Magnets 660 associated with different scanning units 99-1, 99-2 are made as follows: with an in-plane sensitivity, the angular magnetic field sensor 662 and a vertical arrangement of the torsion axes 220 (see FIG. 99-2 associated angular magnetic field sensors 662 no or only a small cross-sensitivity. This is the case because the corresponding stray magnetic fields rotate in planes oriented perpendicular to one another.

FIG. 30 illustrates aspects related to a LIDAR system 80. The LIDAR system 80 includes a laser scanner 90 that may be configured, for example, according to the various implementations described herein. The LIDAR system also includes a light source 81. For example, the light source 81 could be formed as a laser diode that emits pulsed laser light 180 in the near infrared region with a pulse length in the nanosecond range. The light 180 of the light source 81 may then impinge on one or more mirror surfaces 151 of the scanner 90. Depending on the orientation of the deflection unit, the light is deflected under different angles 901, 902. The light emitted by the light source 81 and deflected by the mirror surface of the scanner 90 is often referred to as the primary light.

The primary light may then hit an environment object of the LIDAR system 80. That such reflected primary light is called secondary light. The secondary light may be detected by a detector 82 of the LIDAR system 80. Based on a transit time - which can be determined as a time offset between the emission of the primary light by the light source 81 and the detection of the secondary light by the detector 82 -, by means of a controller 4001, a distance between the light source 81 and the detector 82 and the environment object be determined.

In some examples, the emitter aperture may be equal to the detector aperture. This means that the same scanner can be used to scan the detector aperture. For example, the same mirrors can be used to emit primary light and detect secondary light. Then, a beam splitter may be provided to separate primary and secondary light. Such techniques can make it possible to achieve a particularly high sensitivity. This is because the detector aperture can be aligned and confined to the direction from which the secondary light arrives. Ambient light is reduced by the spatial filtering, because the detector aperture can be made smaller. Such an example may have advantages particularly in the context of periscope-like scanning. It is then possible to dimension the detector aperture particularly large - even for large scanning angles. This will be explained in detail below for detected secondary light.

In periscope-like scanning, the detector aperture defined by a single mirror-as described above-has no dependence on the scanning angle. By using the torsional mode with a torsion axis tilted at about 45 ° to the mirror axis (see Figures 4 and 16 et seq.), The effective area of the mirror is collected from the light and then scanned in the mirror Direction detector is forwarded - not changed. This is different with reference implementations where a mirror is tilted, see for example US 5614706 A: FIG. 2.

If two mirrors are arranged one behind the other for deflecting the secondary light (cf., FIG. 16 ff), this combination results in a dependence of the detector aperture on the scan angle-in particular compared to the reference implementations according to US Pat. No. 5,614,706. This in turn can be motivated as follows: the outer mirror, which is located farther from the detector with respect to the beam path of the secondary light, collects secondary light from a certain direction and deflects it in the direction of the inner mirror, which is located closer to the detector, as the outer mirror. The inner mirror is thus arranged in the beam path of the secondary light between the outer mirror and the detector. The inner mirror is also scanned. At a large torsion angle, i. the inner mirror is rotated with respect to the outer mirror and has - according to a corresponding projection in the direction of the outer mirror - a smaller effective area, described by a Cos function. Therefore, the larger the scanning angle of the inner mirror, the more the detector aperture is reduced. The detector aperture shows no or only a small dependence on the scan angle of the outer mirror. The result is a comparatively small dependence of the detector aperture on the scanning angle, because essentially only the scanning angle of the inner mirror contributes to the reduction of the detector aperture, but not the scanning angle of the outer mirror.

This dependence can be further reduced if the maximum scanning amplitudes of the outer mirror and the inner mirror are suitably adjusted. By limiting the maximum scan amplitude of the inner mirror - for example, compared to the maximum scan amplitude of the outer mirror - an elliptical overlay figure 900 can be obtained (see Fig. 27, where the maximum scan amplitude of the mirror 150 of FIG vertical scanning unit 99-2 is smaller than that of the mirror 150 of the horizontal scanning unit 99-1), but which has a comparatively large detector aperture throughout. In particular, the dependence of the detector aperture on the scan angle of the inner mirror is well described by a cosine function, so that even at small scanning angles no strong decrease of the detector aperture is observed ("flat top" of the Cos function) Torsional mode of the degree of freedom of movement with which the outer mirror is excited to excite with a greater maximum amplitude than the torsional mode of the degree of freedom of movement with which the inner mirror is excited.

Thus, in a typical application, the heavily scanned outer mirror could scan for proper mounting of the scanner, such as in a vehicle, in a horizontal direction (see Fig. 27: angle 901), and the weakly scanned inner scanner could scan in the vertical direction (see Figure 27: angle 902). Typically, a comparatively large scan angle in the horizontal direction is needed, for example, to detect objects also laterally from the vehicle; while in the vertical direction no large scan angle is needed, because no objects of interest need to be detected in the sky and in the ground. In addition, in addition to this distance measurement, a lateral position of the environment object can also be determined, for example by the controller 4001. This can be done by monitoring the position or orientation of the one or more deflection units of the laser scanner 99. In this case, the position or orientation of one or more deflection units at the moment of impact of the light 180 correspond to a deflection angle 901, 902; From this it is possible to draw conclusions about the lateral position of the environment object. For example, it may be possible to determine the position or orientation of the deflection unit based on a signal of the angular magnetic field sensor 662.

By taking into account the signal of the angular magnetic field sensor 662 in determining the lateral position of the environment objects, it may be possible to determine the lateral position of the environment objects with a particularly high accuracy. In particular, in comparison to techniques which only consider a drive signal for driving actuators of the movement in determining the lateral position of the environment objects, such increased accuracy can be achieved.

FIG. 31 illustrates aspects relating to a LIDAR system 80. The LIDAR system 80 includes a control unit 4001 that may be, for example, a microprocessor or application-specific integrated circuit (ASIC) could be implemented. The controller 4001 could also be implemented as a Field Programmable Array (FPGA). The control unit 4001 is configured to output control signals to a driver 4002. For example, the control signals could be output in digital or analog form.

The driver 4002 is in turn configured to generate one or more voltage signals and to output them to corresponding electrical contacts of the piezoactuators 310, 320. Typical amplitudes of the voltage signals are in the range of 50 V to 250 V.

The piezoactuators 310, 320 are in turn coupled to the scan module 100, such as the above reference to FIGS. 5 and 6 described. As a result, one or more degrees of freedom of the movement of the scanning module 100, in particular of one or more supporting elements 101, 102 of the scanning module 100, can be excited. As a result, the deflection is deflected. As a result, the surrounding area of the laser scanner 99 can be scanned with light 180. In particular, the torsional mode 502 can be excited.

The controller 4001 may be configured to suitably excite the piezoactuators 310, 320 to implement a heterodyne figure for scanning a 2-D environment. For this purpose, techniques relating to the amplitude modulation function 842 can be implemented. In the example of FIG. 31, the control unit 4001 may be configured in particular to control the driver 4002 or the bending piezoactuators 310, 320 in accordance with the actuator movements 831 of the examples of FIGS. 23 and 25 to drive. Then, the overlay figure 900 can be implemented.

In FIG. 31 is further illustrated as having a coupling between the control unit 4001 and the angular magnetic field sensor 662. The control unit 4001 may be configured to drive the piezoactuator (s) 310, 320 based on the angular magnetic field sensor 662 signal. By such techniques, monitoring of the movement of mirror surface 151 by controller 4001 may occur. If needed, the controller 4001 may adjust the drive of the driver 4002 to reduce variations between a desired movement of the mirror surface 151 and an observed movement of the mirror surface 151.

For example, it would be possible for a closed-loop control to be implemented. For example, the control loop could be the target amplitude of the movement as a reference. For example, the control loop could include the actual amplitude of the movement as a controlled variable. In this case, the actual amplitude of the movement could be determined based on the signal of the angular magnetic field sensor 662. FIG. 32 is a flowchart of an example method. In 8001, an actuator, such as a bending piezoactuator, is driven to excite a first degree of freedom of movement of an elastically-moved scan unit in accordance with a periodic amplitude modulation function. In this case, the periodic amplitude modulation function alternately arranged rising edges and falling edges. A length of the ascending flanks can be at least twice as large as a length of the descending flanks, optionally at least four times as large, further optionally at least ten times as large.

In summary, the following examples have been described above:

Example 1. Scanner (90) comprising:

a first mirror (150) having a reflective front (151) and a back (152),

a first elastic suspension (100) extending on a side facing the rear side (152) of the first mirror (150),

a second mirror (150) having a reflective front (151) and a back (152), and

a second elastic suspension (100) extending on a side facing the rear side (152) of the second mirror (150),

wherein the scanner (90) is arranged to sequentially light (180) at the front

(151) of the first mirror (150) and on the front side (151) of the second mirror (150).

Example 2. Scanner (90) according to Example 1,

wherein the first elastic suspension (100) has at least one elastic,

rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2), and / or

wherein the second elastic suspension (100) comprises at least one elastic rod-shaped member (101, 101-1, 101-2, 102, 102-1, 102-2).

Example 3. Scanner (90) according to Example 2,

wherein a longitudinal axis (11 1, 112) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the first elastic suspension (100) includes an angle (159) of 45 ° ± 15 ° with a surface normal of the reflective front surface (151) of the first mirror (150), and / or

wherein a longitudinal axis (11 1, 112) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the second elastic suspension (100) comprises a wedge (159) of 45 ° ± 15 ° with a surface normal of the reflective front side (151) of the second mirror (150).

Example 4. Scanner (90) according to one of the preceding examples,

wherein the first elastic suspension (100) is in a resting state of

Scanners (90) along a first axis (220),

wherein the second elastic suspension (100) in the resting state of the

Scanners (90) along a second axis (220),

wherein the first axis includes an angle of 90 ° ± 25 ° with the second axis, optionally of 90 ° ± 1 °, further optionally of 90 ° ± 0, 1 °.

Example 5. Scanner (90) according to one of Examples 1 - 4,

wherein the first elastic suspension (100) is in a resting state of

Scanners (90) along a first axis (220),

wherein the second elastic suspension (100) in the resting state of the

Scanners (90) along a second axis (220),

wherein the first axis with the second axis at an angle of 180 ° ± 25 °

optional, from 180 ° ± 1 °, further optional from 180 ° ± 0, 1 °.

Example 6. Scanner (90) according to one of the preceding examples,

wherein a length of the first elastic suspension (100) is in the range of 20% - 400% of a diameter of the reflective front surface (151) of the first mirror (150), and / or

wherein a length of the second elastic suspension (100) is in the range of 20% - 400% of a diameter of the reflective front surface (151) of the second mirror (150).

Example 7. Scanner (90) according to one of the preceding examples,

wherein a distance (70) between a center of the reflective front side (151) of the first mirror (150) and a center of the reflective front side (151) of the second mirror (150) in a resting state of the scanner (90) is not greater than the 4- times the diameter (153) of the reflective front (151) of the first mirror (150) is optionally not greater than 3 times the diameter, further optionally not greater than 1, 8 times the diameter.

Example 8. The scanner (90) of any one of the preceding examples, further comprising:

a first actuator (310, 320) arranged to excite a degree of freedom of movement of the first elastic suspension (100), and

a second actuator (310, 320) arranged to excite a degree of freedom of movement of the second elastic suspension (100),

wherein the degree of freedom of movement of the first elastic suspension (100) is a

Torsion mode (502) comprises

wherein the degree of freedom of movement of the second elastic suspension (100) comprises a torsional mode (502). Example 9. The scanner (90) of any one of the preceding examples, further comprising:

a first pair of piezoactuators (310, 320) mounted on an end (141) of the first elastic suspension (100) facing away from the rear side (152) of the first mirror (150), and / or

a second pair of piezoactuators (310, 320) mounted on an end (141) of the second elastic suspension (100) facing away from the rear side (152) of the second mirror (150).

Example 10. Scanner (90) according to one of the preceding examples,

wherein the first elastic suspension (100) comprises the first mirror (150) as a 1-point

Suspension attached to a base, and / or

wherein the second elastic suspension (100) secures the second mirror (150) as a 1-point suspension to the base. Of course, the features of the previously described embodiments and aspects of the invention may be combined. In particular, the features may be used not only in the described combinations but also in other combinations or per se, without departing from the scope of the invention. For example, techniques have been described above in which an overlay figure is implemented with short descending flanks and long ascending flanks. Accordingly, it would also be possible, for example, that comparatively long descending flanks and comparatively short ascending flanks are used; For example, in such an example, it may be possible for LIDAR imaging to occur substantially during the comparatively long descending edges. In some examples, it would also be possible to use equally long rising and falling edges; Even in such cases, an efficient scanning can be ensured by a suitable implementation of the overlay figure, for example, with or without a few nodes.

Furthermore, techniques have been described above in which two time-overlapping two degrees of freedom of motion are excited at the same frequency. However, in some examples, it would also be possible for a first degree of freedom of motion to be excited at a first frequency and for a second degree of freedom of motion to be excited at a second frequency different from the first frequency, for example, greater by a factor of two. As a result, an overlay figure, for example, may have a node, which may decrease the efficiency of scanning the surrounding area, but at the same time make the choice of degrees of freedom of movement more flexible.

Furthermore, various examples have been described above with respect to an overlay figure described by temporally superimposing a first torsional mode associated with a first scan unit and a second torsional mode associated with a second scan unit. However, corresponding techniques can also be implemented if, for example, two transverse modes associated with different scan units are used. Furthermore, various techniques have been described above relating to the movement of scanning units in conjunction with LIDAR measurements. However, corresponding techniques can also be used in other applications, e.g. for projectors or laser scanning microscopes, etc ..

Claims

1. Scanner (90) comprising:

a first mirror (150) having a reflective front (151) and a back (152),

a first elastic suspension (100) extending away from a rear side (152) of the first mirror (150) and on a side facing the rear side (152) of the first mirror (150),

a second mirror (150) having a reflective front (151) and a back (152),

a second elastic suspension (100) extending away from a rear side (152) of the second mirror (150) and on a side facing the rear side (152) of the second mirror (150),

wherein the degree of freedom of movement of the first elastic suspension (100) comprises a torsional mode (502),

wherein the degree of freedom of movement of the second elastic suspension (100) comprises a torsional mode (502),

wherein the scanner (90) is arranged to sequentially redirect light (180) at the front (151) of the first mirror (150) and at the front (151) of the second mirror (150).

2. Scanner (90) according to claim 1,

wherein the first elastic suspension (100) comprises at least one elastic, rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2), and / or

3. scanner (90) according to claim 2,

wherein a longitudinal axis (11 1, 112) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the first elastic suspension (100) forms an angle (159) of 45 ° ± 15 ° with a surface normal of the reflective front face (151) of the first mirror (150), and / or wherein a longitudinal axis (11 1, 112) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the second elastic suspension (100) forms an angle (159) of 45 ° ± 15 ° with a surface normal of the reflective front side (151) of the second mirror (150).

4. scanner (90) according to claim 2 or 3,

wherein a first torsion axis of the torsional mode (502) of the first elastic suspension is parallel to a central axis (220, 11, 12) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the first elastic suspension (100),

wherein a second torsion axis of the torsional mode (502) of the second elastic suspension is parallel to a central axis (220, 11, 12) of the at least one elastic rod-shaped element (101, 101-1, 101-2, 102, 102-1, 102-2) of the second elastic suspension (100).

5. Scanner (90) according to one of the preceding claims,

wherein the first mirror (150) is scanned periscope-like, and

wherein the second mirror (150) is scanned periscope-like.

The scanner (90) of any one of the preceding claims, further comprising:

a light source (81),

a detector (82),

wherein the light (180) comprises primary light from the light source (81) and further comprises secondary light for a detector (82),

wherein the first mirror and the second mirror are arranged to both the

To emit primary light, as well as to detect the secondary light.

7. scanner (90) according to claim 6,

wherein an emitter aperture defined by the first mirror (150) and the second mirror (150) associated with the light source (81) is equal to a detector aperture defined by the first mirror (150) and the second mirror (150) is associated with the detector (82).

8. scanner (90) according to claim 6 or 7,

wherein the first mirror (150) is disposed in the beam path of the secondary light between the second mirror (150) and the detector (82), wherein the first actuator (310, 320) is arranged to excite the torsional mode (502) of the first degree of freedom of movement at a first maximum amplitude, the second actuator (310, 320) being arranged to rotate the torsional mode (502) of the second Degree of freedom to excite the movement with a second maximum amplitude, wherein the first amplitude is smaller than the second amplitude.

9. scanner (90) according to one of the preceding claims,

wherein the scanner (90) is arranged to enter by means of the first mirror (150)

To scan the scanner (90) environment vertically (902),

wherein the scanner (90) is adapted to use the second mirror (150)

Scanning the scanner (90) environment horizontally (901).

10. scanner (90) according to any one of the preceding claims,

wherein the first elastic suspension (100) is in a resting state of

Scanners (90) along a first axis (220),

wherein the second elastic suspension (100) in the resting state of the

Scanners (90) along a second axis (220),

1 1. A scanner (90) according to any one of claims 1 - 9,

wherein the first elastic suspension (100) is in a resting state of

Scanners (90) along a first axis (220),

wherein the second elastic suspension (100) in the resting state of the

Scanners (90) along a second axis (220),

wherein the first axis with the second axis at an angle of 180 ° ± 25 °

optional, from 180 ° ± 1 °, further optional from 180 ° ± 0, 1 °.

12. Scanner (90) according to one of the preceding claims,

wherein a length of the first elastic suspension (100) in the range of 20% -

Is 400% of a diameter of the reflective front side (151) of the first mirror (150), and / or

Scanner (90) according to one of the preceding claims, wherein a distance (70) between a center of the reflective front side (151) of the first mirror (150) and a center of the reflective front side (151) of the second mirror (150) in a resting state of the scanner (90) is not greater than the 4- times the diameter (153) of the reflective front surface (151) of the first mirror (150) is optionally not greater than 3 times the diameter, further optionally not greater than 1, 8 times the diameter.

The scanner (90) of any one of the preceding claims, further comprising:

15. Scanner (90) according to one of the preceding claims,

wherein the first elastic suspension (100) fixes the first mirror (150) as a 1-point suspension to a base, and / or

wherein the second elastic suspension (100) secures the second mirror (150) as a 1-point suspension to the base.

16. Scanner (90) according to one of the preceding claims,

wherein the first actuator (310, 320) is arranged to adjust the degree of freedom of the

Movement of the first elastic suspension (100) resonantly stimulate

wherein the second actuator (310, 320) is arranged to adjust the degree of freedom of the

Movement of the second elastic suspension (100) resonantly stimulate.