# US 12,601,910 B2 · Rotation angle correction method, device of rotary mirror, and scanning method and system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,910 B2 - Document ID: US12601910B2 - Status: Granted - Kind: B2 - Application number: 18/517,289 - Filed: 2023-11-22 - Published: 2025-04-24 - Granted: 2026-04-14 - Earliest claimed: 2023-10-23 - Assignees: Beijing Xunheng Technology Co., Ltd. - Applicants: Beijing Xunheng Technology Co., Ltd. - Inventors: Hongde Zhu - Web page: https://patentgrep.com/patent/US12601910B2 ## CPC - G02B 27/0025: {for optical correction, e.g. distorsion, aberration} - G02B 26/101: {with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129)} - G02B 26/105: {with one or more pivoting mirrors or galvano-mirrors (G02B26/101 takes precedence)} - G02B 27/14: operating by reflection only - G06T 15/06: Ray-tracing - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract A rotation angle correction method comprises: obtaining a plurality of light stripe images cast to a reference target screen under different graduations and corresponding rotation graduation information; based on the light stripe images and corresponding rotation graduation information, obtaining a first mapping relationship; based on the first mapping relationship and the rotation graduation information, correcting coordinate information of the structured light. Based on the corrected coordinate information of the structured light and the rotation graduation information, one may cast the structured light to irradiate a scanned target and collect images, so as to complete the scanning and thus optimize a scanning result and improve a scanning analysis accuracy. ## Claims ### Claim 1 A rotation angle correction method of a rotary mirror, applied to an optical scanning device, wherein the optical scanning device is based on line laser irradiated onto a rotating multi-faceted reflector and then reflected to a scanned target so as to generate structured light, and the correction method comprises the following steps: obtaining a plurality of light stripe images cast to a reference target screen under different graduations and corresponding rotation graduation information; based on the light stripe images and corresponding rotation graduation information, obtaining a first mapping relationship; based on the first mapping relationship and the rotation graduation information, correcting coordinate information of the structured light. ### Claim 2 (depends on 1) The rotation angle correction method of claim 1, wherein, the step of obtaining the first mapping relationship based on the light stripe images and corresponding rotation graduation information comprises: based on the light stripe images, obtaining position information of each light stripe; based on the position information of the light stripe of each light stripe image and corresponding rotation graduation information, establishing the first mapping relationship. ### Claim 3 (depends on 2) The rotation angle correction method of claim 2, wherein there are a plurality of first mapping relationships that match mirror surface number information of different mirror surfaces; the step of establishing the first mapping relationship based on the position information of the light stripe of each light stripe image and corresponding rotation graduation information comprises: based on the rotation graduation information, obtaining, by guidance, change information of the position information; based on increase and decrease of the change information, distinguishing as a plurality of segments of change relationships; based on each segment of change relationship, determining the mirror surface number information and corresponding first mapping relationship. ### Claim 4 (depends on 1) The rotation angle correction method of claim 1, wherein each mirror surface of the multi-faceted reflector correspondingly generates a plurality of light stripe images. ### Claim 5 (depends on 1) The rotation angle correction method of claim 1, wherein the step of obtaining a plurality of light stripe images cast to the reference target screen under different graduations and corresponding rotation graduation information comprises: based on a plurality of pieces of different preset rotation graduation information, enabling the line laser to generate light stripes in the reference target screen and obtain the light stripe images. ### Claim 6 (depends on 5) The rotation angle correction method of claim 5, wherein the line laser is enabled briefly based on a preset time window period; the light stripe images perform image integral acquisition based on a line laser enabling time. ### Claim 7 (depends on 1) The rotation angle correction method of claim 1, wherein the step of correcting the coordinate information of the structured light based on the first mapping relationship and the rotation graduation information comprises: based on the first mapping relationship and the rotation graduation information, determining the rotation graduation information corresponding to the coordinate information of all structured light. ### Claim 8 (depends on 1) A scanning system, comprising a controller, wherein the controller is configured to perform the rotation angle correction method of the rotary mirror of claim 1 to correct the coordinate information of the structured light. ### Claim 9 A scanning method, applied to an optical scanning device, wherein the optical scanning device is based on line laser irradiated onto a rotating multi-faceted reflector and then reflected to a scanned target so as to generate structured light, and the scanning method comprises the following steps: based on corrected coordinate information of the structured light, generating structure information of to-be-cast structured light; based on the structure information, performing structured light casting; during the structured light casting process, collecting image information of a scanned target irradiated by the structured light; and based on the image information, performing three-dimensional reconstruction on the scanned target; the coordinate information of the structured light is corrected based on the following steps: obtaining a plurality of light stripe images cast to a reference target screen under different graduations and corresponding rotation graduation information; based on the light stripe images and corresponding rotation graduation information, obtaining a first mapping relationship; and based on the first mapping relationship and the rotation graduation information, correcting the coordinate information of the structured light. ### Claim 10 (depends on 9) The method of claim 9 wherein the optical scanning device comprises a rotary mirror, and the method comprises rotating the rotary mirror at a speed of at least 1,000 rpm during the structured light casting process. ### Claim 11 (depends on 9) A scanning system, comprising a controller, wherein the controller is configured to perform the scanning method of claim 9 to generate a scanning result. ### Claim 12 A rotation angle correction device of a rotary mirror, applied to an optical scanning device, wherein the optical scanning device is based on line laser irradiated onto a rotating multi-faceted reflector and then reflected to a scanned target so as to generate structured light, and the correction device comprises the following modules: an obtaining module, configured to obtain a plurality of light stripe images cast to a reference target screen under different graduations and corresponding rotation graduation information; a mapping module, configured to, based on the light stripe images and corresponding rotation graduation information, obtain a first mapping relationship; and a correcting module, configured to, based on the first mapping relationship and the rotation graduation information, correct coordinate information of the structured light.