US 11,927,435 B2
Three-dimensional measurement device and three-dimensional measurement method
Manabu Okuda, Aichi (JP); Tsuyoshi Ohyama, Aichi (JP); and Norihiko Sakaida, Aichi (JP)
Assigned to CKD CORPORATION, Aichi (JP)
Filed by CKD CORPORATION, Aichi (JP)
Filed on Nov. 24, 2021, as Appl. No. 17/534,539.
Application 17/534,539 is a continuation of application No. PCT/JP2020/017212, filed on Apr. 21, 2020.
Claims priority of application No. 2019-109740 (JP), filed on Jun. 12, 2019.
Prior Publication US 2022/0082374 A1, Mar. 17, 2022
Int. Cl. G01B 11/25 (2006.01)
CPC G01B 11/2527 (2013.01) [G01B 11/2513 (2013.01); G01B 11/254 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A three-dimensional measurement device that performs three-dimensional measurement of a measured object using a phase shift method, the three-dimensional measurement device comprising:
an irradiator that irradiates the measured object with a predetermined light pattern having a light intensity distribution in a fringe shape;
a control device that shifts a phase of the light pattern radiated from the irradiator in N different ways, where N is a natural number of not less than 3; and
an imaging device that takes an image of the measured object irradiated with the light pattern, wherein
the control device executes three-dimensional measurement of the measured object by the phase shift method based on N different image data taken under the light pattern having the phase shifted in the N different ways,
the control device executes the three-dimensional measurement by:
obtaining N luminance values with respect to a predetermined coordinate position on the image data based on the N different image data;
extracting luminance values of not less than two but less than N from among the N luminance values, wherein the extracted luminance values are neither overexposed nor underexposed; and
executing height measurement at the predetermined coordinate position based on the luminance values of not less than two but less than N.