公开(公告)号：US11170572B2

公开(公告)日：2021-11-09

申请号：US16676943

申请日：2019-11-07

Applicant: THE UNIVERSITY OF TOKYO ,  MITUTOYO CORPORATION

Inventor： Yutaka Ohtake ,  Yukie Nagai ,  Tomonori Goto ,  Seiji Sasaki ,  Masato Kon

IPC: G06T17/20

Abstract: An isosurface mesh M is generated by extracting voxels having a certain CT value from volume data obtained by X-ray CT. A gradient vector g of a CT value is calculated at each vertex p of the isosurface mesh M. A plurality of sample points S are generated in positive and negative directions of the calculated gradient vector g. Gradient norms N of CT values at the respective generated sample points S are calculated. The vertex p of the isosurface mesh is moved and corrected to a sample point Sm having the maximum norm Nm calculated.

公开(公告)号：US11573190B2

公开(公告)日：2023-02-07

申请号：US17360304

申请日：2021-06-28

Applicant: MITUTOYO CORPORATION

Inventor： Masato Kon ,  Hiromu Maie ,  Seiji Sasaki ,  Jyota Miyakura

IPC: G01N23/083 ,  G01N23/18

Abstract: A calibration method for an X-ray measuring device includes mounting a calibration tool on a rotating table, identifying centroid positions from an output of an X-ray image detector, calculating projection transformation matrixes from the centroid positions and known relative positional intervals, repeating to identify the centroid positions from the output of the X-ray image detector and to calculate the projection transformation matrixes from the centroid positions and known relative positional intervals while the rotating table is rotated twice or more by a predetermined angle, and calculating a rotation center position of the rotating table on the basis of the projection transformation matrixes. The calibration method thereby allows easy calculation of the rotation center position of the rotating table on which an object to be measured is mounted in a rotatable manner, with the simple process.

公开(公告)号：US11346660B2

公开(公告)日：2022-05-31

申请号：US17014308

申请日：2020-09-08

Applicant: MITUTOYO CORPORATION

Inventor： Masato Kon ,  Hiromu Maie ,  Seiji Sasaki ,  Jyota Miyakura

IPC: G01B15/04

Abstract: A calibration method of an X-ray measuring device includes: a front-stage feature position calculation step of parallelly moving spheres disposed in N places a plurality of times, and identifying centroid positions ImPos(1 to Q)_Dis(1 to M)_Sphr_(1 to N) of projected images of the spheres in the N places; an individual matrix calculation step of calculating an individual projection matrix PPj (j=1 to Q) for each of the spheres; an individual position calculation step of calculating moving positions Xb of the spheres on the basis of the individual projection matrix PPj (j=1 to Q); a coordinate integration step of calculating specific relative position intervals X(1 to N) of the spheres; a rear-stage feature position calculation step; a transformation matrix calculation step of calculating a projective transformation matrix Hk (k=1 to Q); a rotation detection step; a position calculation step; and a center position calculation step.

公开(公告)号：US11344276B2

公开(公告)日：2022-05-31

申请号：US17015618

申请日：2020-09-09

Applicant: MITUTOYO CORPORATION

Inventor： Masato Kon ,  Hiromu Maie ,  Seiji Sasaki ,  Jyota Miyakura

IPC: A61B6/00 ,  A61B6/03 ,  A61B6/04

Abstract: A calibration method of an X-ray measuring device includes: mounting a calibration tool 102 on a rotating table 120; a moving position acquisition step of parallelly moving a position of an j-th sphere 106 with respect to a position of a first sphere 106, irradiating the calibration tool 102 with an X-ray 118, and acquiring, form an output of an X-ray image detector 124, a moving position Mj where the magnitude of a differential position Erjofa centroid position ImDisjh_Sphr_j of a projected image of the j(2£j£N)-th sphere 106 with respect to a centroid position ImDis1_Sphr_1 of a projected image of the first sphere 106 becomes equal to or less than a specified value Vx; a relative position calculation step of performing the moving position acquisition step on the remaining spheres; a feature position calculation step; a transformation matrix calculation step; a rotation detection step; a position calculation step; and a center position calculation step.

公开(公告)号：US11333619B2

公开(公告)日：2022-05-17

申请号：US17011411

申请日：2020-09-03

Applicant: MITUTOYO CORPORATION

Inventor： Seiji Sasaki ,  Nobuyuki Nakazawa ,  Hisayoshi Sakai ,  Masato Kon ,  Hidemitsu Asano

IPC: G01N23/00 ,  G01N23/046 ,  G06T7/00

Abstract: A measurement X-ray CT apparatus calibrates a geometrical positional relationship between a focus of an X-ray source, an X-ray detector, and a rotation center of a rotating table in advance. The measurement X-ray CT apparatus then obtains projection images by irradiating the object to be measured with X-rays to perform a CT scan, and generates a three-dimensional image of the object to be measured by CT reconstruction of the projection images. The measurement X-ray CT apparatus further includes a reference frame that is made of a material and has a structure less susceptible to environmental changes, and sensors that are located on the reference frame and intended to successively obtain calibration values of the geometrical positional relationship between the focus of the X-ray source and the X-ray detector during the CT scan. The calibration values are used as parameters of the CT reconstruction.

公开(公告)号：US10545102B2

公开(公告)日：2020-01-28

申请号：US15800408

申请日：2017-11-01

Applicant: MITUTOYO CORPORATION

Inventor： Akihito Takahashi ,  Seiji Sasaki

IPC: G01N23/046

Abstract: A coordinate alignment tool includes a base having at least two ground faces to hold an attitude suitable for measurement by a coordinate measuring device and an attitude suitable for measurement by a measuring X-ray CT apparatus, and a fixer to fixate a measured object to the base; and at least three master balls arranged on the base.