| 摘要 |
<P>PROBLEM TO BE SOLVED: To simultaneously detect an irregular flaw and a flaw in a pattern shape that may occur on an internal surface of a tubular body. <P>SOLUTION: A defect detecting device according to the present invention comprises: a tubular body imaging device irradiating annular laser beams with respect to an internal surface of a tubular body while moving along an axis direction of the tubular body so as to generate a plurality of annular beam images; and an arithmetic processor executing image processing with respect to the plurality of annular beam images having been generated so as to determine whether or not a defect exists on the internal surface of the tubular body. The arithmetic processor includes: an annular beam center calculating section for calculating a center of gravity position of an annular laser beam irradiation portion in each of the plurality of annular beam images; a coordinate converting section for converting coordinate systems of the annular beam images so as to generate a plurality of optical cut images; an image calculating section for calculating a depth image representing an unevenness state on the internal surface of the tubular body and a luminance image representing luminance distribution of the laser beams on the internal surface of the tubular body based on a fringe image frame formed from each of the plurality of optical cut images; and a defect detecting section for detecting a defect existing on the internal surface thereof based on the depth image and the luminance image having been calculated. <P>COPYRIGHT: (C)2012,JPO&INPIT |
