# US 11,029,145 B2 · Projection device and projection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,145 B2 - Document ID: US11029145B2 - Status: Granted - Kind: B2 - Application number: 16/423,814 - Filed: 2019-05-28 - Published: 2019-11-28 - Granted: 2021-06-08 - Earliest claimed: 2018-05-28 - Assignees: Fraunhofer-Gasellschaft zur Forderung der angewandten Forschung e.V. - Applicants: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. - Inventors: Anika Brahm; Claudia Reinlein; Ingo Gebhart - Web page: https://patentgrep.com/patent/US11029145B2 ## CPC - G01B 11/2518: {Projection by scanning of the object} - G01B 11/2513: {with several lines being projected in more than one direction, e.g. grids, patterns} - G01B 11/2545: {with one projection direction and several detection directions, e.g. stereo} - G02B 26/0833: {the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B)} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A projection device can include: an illuminating unit for emitting light; and a projection unit having a mirror surface, the projection unit being designed to project the light emitted by the illuminating device by means of the mirror surface into an object space and to shape it into different spatially structured light patterns in the object space. The projection device is distinguished in that the mirror surface is deformable, at least in regions, and in that the projection unit, for forming the different spatially structured light patterns in the object space, has at least one actuator for deforming the mirror surface, at least in regions. The present subject matter furthermore relates to a projection method, to a device, and to a method for detecting a three-dimensional contour. ## Claims ### Claim 1 A projection device comprising: an illuminating unit for emitting light; and, a projection unit having a mirror surface, the projection unit configured to project the light emitted by the illuminating unit using the mirror surface into an object space and to shape it into different spatially structured light patterns in the object space; wherein the mirror surface is deformable, at least in regions, and in that the projection unit, for shaping the different spatially structured light patterns in the object space, has at least one actuator for deforming the mirror surface, at least in regions; and wherein the mirror surface has a fixed microstructure configured for shaping high-frequency spatial structures of the spatially structured light patterns, and wherein the fixed microstructure is formed on the mirror surface separately from the deforming caused by the at least one actuator. ### Claim 2 (depends on 1) The projection device according to claim 1, wherein the mirror surface for shaping the spatially structured light patterns includes a freeform mirror surface. ### Claim 3 (depends on 1) The projection device according to claim 1, wherein a direction perpendicular to the mirror surface the fixed microstructure comprises local height variations having an amplitude of one of: up to 10 μm, up to 20 μm, up to 50 μm, up to 100 μm, up to 200 μm, or up to 500 μm. ### Claim 4 (depends on 3) The projection device according to claim 3, wherein a direction parallel to the mirror surface the height variations or the local height variations of the fixed microstructure extend over one of: up to 100 μm, up to 200 μm, up to 500 μm, up to 1 mm, up to 5 mm, or up to 10 mm. ### Claim 5 (depends on 1) The projection device according to claim 1, wherein a direction perpendicular to the mirror surface the fixed microstructure comprises local height variations having an amplitude of one of: at least 0.5 μm, at least 1 μm, at least 2 μm, at least 5 μm, at least 10 μm, at least 20 μm, at least 50 μm, or at least 100 μm. ### Claim 6 (depends on 1) The projection device according to claim 1, wherein, for configuring the mirror surface, the projection unit has a substrate layer, in particular a metal substrate layer, having a thickness of at most 1 mm. ### Claim 7 (depends on 6) The projection device according to claim 6, wherein, on a back side of the substrate layer facing away from the mirror surface, the projection unit has at least one connecting element or at least one connecting layer, the at least one connecting element or the at least one connecting layer being arranged for transmitting a deforming force from the at least one actuator to the substrate layer between the at least one actuator and the substrate layer. ### Claim 8 (depends on 7) The projection device according to claim 7, wherein the at least one connecting layer comprises at least one adhesive layer or at least one metal layer. ### Claim 9 (depends on 1) The projection device according to claim 1, wherein the at least one actuator comprises at least one piezo element, at least one linear motor, or at least one actuating unit that is capable of being driven by a linear motor. ### Claim 10 A device for contactless detection of a three-dimensional contour, comprising: a projection device comprising an illuminating unit for emitting light; and, a projection unit having a mirror surface, the projection unit configured to project the light emitted by the illuminating unit using the mirror surface into an object space and to shape it into different spatially structured light patterns in the object space, wherein the mirror surface is deformable, at least in regions, and in that the projection unit, for shaping the different spatially structured light patterns in the object space, has at least one actuator for deforming the mirror surface, at least in regions and wherein the mirror surface has a fixed microstructure configured for shaping high-frequency spatial structures of the spatially structured light patterns, and wherein the fixed microstructure is formed on the mirror surface separately from the deforming caused by the at least one actuator; at least one camera, for recording images of an object arranged in the object space with the different spatially structured light patterns projected onto the object by means of the mirror surface; and, an evaluation unit for determining a three-dimensional contour of an object arranged in the object space based on image data from images of the object recorded using the at least one camera, with the different spatially structured light patterns projected onto the object using the mirror surface. ### Claim 11 (depends on 10) The device according to claim 10, further comprising: a control unit for controlling the at least one actuator and for controlling the at least one camera; the control unit being configured to control the at least one actuator and the at least one camera, such that the at least one camera, for each spatially structured light pattern of the different spatially structured light patterns that is projected by means of the mirror surface onto the object arranged in the object space, records at least one image of the object with the spatially structured light pattern projected onto the object. ### Claim 12 (depends on 10) The device according to claim 10, wherein, for detecting the three-dimensional contour of the object arranged in the object space, the evaluation unit is configured, for a plurality of object points of the object, based on the image data of the images recorded using the at least one camera, to identify pairs of points corresponding to one another and to a specific object point in an image plane of the camera or of a first camera and in another plane, wherein the other plane a) is an image plane of a second camera, or, b) is a virtual projection plane associated with the mirror surface, and to determine depth information using triangulation depending on positions of the points corresponding to one another and to the specific object point in the image plane and in the other plane. ### Claim 13 A projection method comprising the steps of: shaping a first spatially structured light pattern in an object space by reflecting light on a mirror surface having a first surface shape, wherein the mirror surface has a fixed microstructure configured for shaping high-frequency spatial structures of the spatially structured light patterns; deforming, at least region-wise, the mirror surface so that the mirror surface assumes a second surface shape different from the first surface shape; and, shaping a second spatially structured light pattern in the object space that is different from the first spatially structured light pattern by reflecting light on the mirror surface having the second surface shape, wherein the mirror surface contains the fixed microstructure for shaping high-frequency structures of the spatially structured light patterns, and wherein the fixed microstructure are formed on the mirror surface separately from the deforming caused by the at least one actuator. ### Claim 14 (depends on 13) The projection method according to claim 13, wherein deforming the mirror surface is accomplished by means of at least one actuator, by changing a piezo voltage of a piezo element or by adjusting a linear motor. ### Claim 15 (depends on 13) The projection method according to claim 13, wherein the mirror surface is deformed at different positions of the mirror surface simultaneously. ### Claim 16 (depends on 15) The projection method according to claim 15, wherein the mirror surface is deformed at different positions of the mirror surface arranged rotationally symmetrical to one another. ### Claim 17 (depends on 13) A method for contactless detection of a three-dimensional contour, comprising the steps: projecting different spatially structured light patterns onto an object arranged in an object space in accordance with the method according to claim 13; recording images of the object with the different spatially structured light patterns projected onto the object using at least one camera; and, determining a three-dimensional contour of the object based on image data of the images recorded by means of the at least one camera. ### Claim 18 (depends on 17) The method according to claim 17, wherein the deforming of the mirror surface for shaping the different spatially structured light patterns and the recording of the images of the object by means of the at least one camera, are accomplished synchronously in that the at least one camera, for each of the different spatially structured light patterns that is projected onto the object, records or record at least one image of the object with the spatially structured light pattern projected onto the object. ### Claim 19 (depends on 17) The method according to claim 17, wherein, for a plurality of object points of the object, based on the image data of the images recorded by means of the at least one camera, pairs of points corresponding to one another and to a specific object point in an image plane of the camera or of a first camera and in another plane are identified, wherein the other plane a) is an image plane of a second camera, or, b) is a virtual projection plane associated with the mirror surface, and depth information is determined using triangulation depending on positions of the points corresponding to one another and to the specific object point in the image plane and in the other plane.