PURPOSE: To simplify an image signal to be led out, to differentiate only a fault part in the form of binary-coded information, and to automate inspection by setting the direction of stripes of a striped pattern in parallel to the direction of scanning lines of a photoelectric converter for the inspection.
CONSTITUTION: A body 5 to be inspected which has a striped pattern is placed on a movable stage 7, which is provided with two lighting systems 19 for inspection using transmitted light and reflected light; and one visual field of the body 5 to be inspected is enlarged through an enlarging lens system 8 and image pickup operation is performed by a photoelectric converter 9 for inspection to supply an image signal 10 to a floating threshold value generating circuit 12 after amplification 11. Then, a slice level signal 13 generated by the circuit 12 is compared with the original image signal by a comparator 14 to obtain a binary-coded signal, thereby obtaining the binary-coded signal 13 of a different part which is a fault part of the pattern of the image signal. In this case, the direction of stripes of the body 5 to be inspected is set nearly in parallel to the direction of scanning lines of the converter 9 to facilitate the differentiation of the different part.
IWASAKI MITSUHIRO
OZAWA TATSUROU
| JPS4866886A | 1973-09-13 | |||
| JPS5318387A | 1978-02-20 |