# US 12,761,016 B2 · Optical displacement meter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,016 B2 - Document ID: US12761016B2 - Status: Granted - Kind: B2 - Application number: 18/780,601 - Filed: 2024-07-23 - Published: 2025-03-06 - Granted: 2026-10-13 - Earliest claimed: 2023-08-30 - Assignees: Keyence Corporation - Applicants: Keyence Corporation - Inventors: Akira Fuyuno; Tatsuro Homma; Kaoru Kanayama - Web page: https://patentgrep.com/patent/US12761016B2 ## CPC - G01B 11/2518: {Projection by scanning of the object} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract An optical displacement meter that measures a cross-sectional profile of a workpiece, and includes: a light projecting/receiving module including a light projecting unit that emits slit light extending in an X direction, a light receiving lens that collects reflected light of the slit light reflected by the workpiece, and an imaging unit that receives light collected by the light receiving lens; a motor that integrally rotates the light projecting/receiving module; and a control unit that controls the motor to scan the slit light in a direction orthogonal to the X direction. A rotation angle is limited to prevent specularly reflected light reflected from a specular reflection surface from being captured by the imaging unit when the light projecting unit irradiates the workpiece having the specular reflection surface parallel to an X-Y plane extending in the X direction and a Y direction with the slit light. ## Claims ### Claim 1 An optical displacement meter of a light sectioning method that measures a cross-sectional profile of a workpiece having a height in a Z direction based on a principle of triangulation, the optical displacement meter comprising: a light projecting/receiving module including a light projecting unit that emits slit light extending in an X direction, a light receiving lens that collects reflected light of the slit light reflected by the workpiece, and an imaging unit that receives light collected by the light receiving lens; a motor that integrally rotates the light projecting/receiving module; and a control unit that controls the motor to scan the slit light during a first measurement operation in a direction orthogonal to the X direction, wherein an angle range of the light projecting/receiving module during the first measurement operation is limited to prevent specularly reflected light reflected from a specular reflection surface from being captured by the imaging unit when the light projecting unit irradiates the workpiece having the specular reflection surface, parallel to an X-Y plane extending in the X direction and a Y direction, with the slit light. ### Claim 2 (depends on 1) The optical displacement meter according to claim 1, wherein a measurement range in the Y direction is eccentrically located closer to a side of the light projecting unit side than a light receiving unit side including the light receiving lens and the imaging unit with respect to a light projection axis of the light projecting unit in a state of being parallel to the Z direction. ### Claim 3 (depends on 1) The optical displacement meter according to claim 1, wherein the angle range includes a first angle range and a second angle range, and when the light projecting unit is viewed to be located on a left side of the light receiving lens in a Y-Z plane extending in the Y direction and the Z direction, the control unit rotates the light projecting/receiving module in a first angle range to execute the first measurement operation on a left side of a light projection axis of the light projecting unit in a state of being parallel to the Z direction, and rotates the light projecting/receiving module in the second angle range, which is smaller than the first angle range and does not include a predetermined angle at which the specularly reflected light is collected on the light receiving lens, to execute the first measurement operation on a right side of the light projection axis in the state of being parallel to the Z direction. ### Claim 4 (depends on 3) The optical displacement meter according to claim 3, wherein the control unit causes the motor to rotate the light projecting/receiving module in a third angle range including a rotation angle at which the light projection axis and an optical axis of the light receiving lens are symmetrical with respect to a perpendicular line of the X-Y plane in a non-measurement period in which a rotation direction of the light projecting/receiving module is switched and the first measurement operation is not executed. ### Claim 5 (depends on 3) The optical displacement meter according to claim 3, the optical displacement meter receiving selection of one mode from a first mode in which the first measurement operation is limited within the second angle range, and a second mode in which a second measurement operation is executed in an angle range obtained by combining the second angle range and a third angle range including the predetermined angle, on the right side of the light projection axis in the state of being parallel to the Z direction. ### Claim 6 (depends on 3) The optical displacement meter according to claim 3, wherein the control unit controls the motor to satisfy a relational expression of (θTR−θT−θR)/2>θM, where OM is the second angle range; θTR: θTR is an angle formed by a main light beam of the slit light and a main light beam of the reflected light accepted to the light receiving lens; θT: θT is a light collection angle (half angle) of the slit light; and θR: θR is a light acceptance angle (half angle) of the light receiving lens. ### Claim 7 (depends on 6) The optical displacement meter according to claim 6, wherein as the imaging unit includes an image sensor that outputs a distribution of light receiving amounts of the reflected light from the workpiece by a plurality of pixels arranged two-dimensionally, the light projecting/receiving module has a predetermined measurement range in a direction of the light projection axis, the θTR has a minimum angle at a position farthest from the light projecting unit in the predetermined measurement range, and the control unit controls the motor to satisfy the relational expression at the minimum angle of the θTR. ### Claim 8 An optical displacement meter of a light sectioning method that measures a cross-sectional profile of a workpiece having a height in a Z direction based on a principle of triangulation, the optical displacement meter comprising: a light projecting/receiving module including a light projecting unit that emits slit light extending in an X direction, a light receiving lens that collects reflected light of the slit light reflected by the workpiece, and an imaging unit that receives light collected by the light receiving lens; a motor that integrally rotates the light projecting/receiving module; and a control unit that controls the motor to scan the slit light during a first measurement operation in a direction orthogonal to the X direction, wherein the control unit controls, during the first measurement operation, the motor to rotate the light projecting/receiving module in an angle range which does not include a predetermined angle at which the light receiving lens collects specularly reflected light reflected from a specular reflection surface when the light projecting unit irradiates the workpiece having the specular reflection surface, parallel to an X-Y plane extending in the X direction and a Y direction, and the control unit controls, during the first measurement operation, the motor not to rotate the light projecting/receiving module in another angle range which includes the predetermined angle. ### Claim 9 (depends on 8) The optical displacement meter according to claim 8, wherein a measurement range in the Y direction is eccentrically located closer to a side of the light projecting unit side than a light receiving unit side including the light receiving lens and the imaging unit with respect to a light projection axis of the light projecting unit in a state of being parallel to the Z direction. ### Claim 10 (depends on 8) The optical displacement meter according to claim 8, wherein the angle range includes a first angle range and a second angle range, and when the light projecting unit is viewed to be located on a left side of the light receiving lens in a Y-Z plane extending in the Y direction and the Z direction, the control unit rotates the light projecting/receiving module in the first angle range to execute the first measurement operation on a left side of a light projection axis of the light projecting unit in a state of being parallel to the Z direction, and rotates the light projecting/receiving module in the second angle range, which is smaller than the first angle range and does not include the predetermined angle, to execute the first measurement operation on a right side of the light projection axis in the state of being parallel to the Z direction. ### Claim 11 (depends on 10) The optical displacement meter according to claim 10, wherein the control unit causes the motor to rotate the light projecting/receiving module in the another angle range during a non-measurement period in which a rotation direction of the light projecting/receiving module is switched and the first measurement operation is not executed. ### Claim 12 (depends on 10) The optical displacement meter according to claim 10, the optical displacement meter receiving selection of one mode from a first mode in which the first measurement operation is limited within the second angle range, and a second mode in which a second measurement operation is executed in the second angle range and the another angle range, on the right side of the light projection axis in the state of being parallel to the Z direction. ### Claim 13 (depends on 10) The optical displacement meter according to claim 10, wherein the control unit controls the motor to satisfy a relational expression of (θTR−θT−θR)/2>θM, where OM is the second angle range; θTR: θTR is an angle formed by a main light beam of the slit light and a main light beam of the reflected light accepted to the light receiving lens; θT: θT is a light collection angle (half angle) of the slit light; and θR: θR is a light acceptance angle (half angle) of the light receiving lens. ### Claim 14 (depends on 13) The optical displacement meter according to claim 13, wherein as the imaging unit includes an image sensor that outputs a distribution of light receiving amounts of the reflected light from the workpiece by a plurality of pixels arranged two-dimensionally, the light projecting/receiving module has a predetermined measurement range in a direction of the light projection axis, the θTR has a minimum angle at a position farthest from the light projecting unit in the predetermined measurement range, and the control unit controls the motor to satisfy the relational expression at the minimum angle of the θTR.