Patent ID: 9247213
Filing Date: 2016-01-26
CPC Classification: G01N,H04N

Claim Text:
1. An apparatus for detecting a defect in an outer surface of a work, comprising: a jig for supporting the work and holding the work rotated at predetermined angles; an image pickup device for taking images of the outer surface of the work which is held at each of the predetermined rotation angles by the jig; and a controller for processing the images obtained by the image pickup device and detecting the defect, wherein the controller stores information about a shape of the outer surface of the work and about a positional relationship between the image pickup device and an imaging area of the work taken by the image pickup device at each of the predetermined rotation angles, and compares a longitudinal dimension of the defect included in the image taken by the image pickup device with a threshold to determine the defect, and wherein the threshold for the use of the determination is changed in response to an image distortion caused by a position of the defect in the image and by a shape of the outer surface of the work in each of the predetermined rotation angles of the work, by using the information about the shape of the outer surface of the work and about the positional relationship between the image pickup device and the imaging area of the work taken by the image pickup device at each of the predetermined rotation angles.