| 摘要 |
PURPOSE: To discriminate a printed pattern to be inspected without overlooking defects by extracting the border line of the pattern and acquiring the information on the bending state of the border line at each point of observation provided at every picture element, and then, comparing the information with reference information. CONSTITUTION: The picture processing section 15a of a CPU 15 binarizes picture information taken with a CCD camera 13 and the acceptance/rejection discrimination processing section 15b of the CPU 15 extracts a picture element point row constituting the border line of a printed pattern to be inspected by extracting black picture elements at the white-black inverting boundary of a binarized picture in the scanning unit of 3×3 picture element matrix, finds the angle (corresponding to the curvature) between line segment by forming the line segments between each fifth picture element and a point of observation in the clockwise and counterclockwise directions from the point of observation by using a border line tracking starting point as the point of observation, and finds the curvature by shifting the point of observation by one picture element in the clockwise direction based on the data and program stored in a memory 15c. Thus the section 15b measure the whole periphery of the pattern to be inspected. Then the CPU 15 discriminates the acceptance/rejection of the pattern by reading out reference data registered in the memory 15c and comparing measured data with the characteristic point of the reference data. |
