| 摘要 |
PROBLEM TO BE SOLVED: To improve the setting accuracy of a detecting position by electrically enlarging and detecting an image obtained by photographing a cross ligament mark, displaying the mark on a monitor and matching the alignment mark with a registered reference line. SOLUTION: A differentiation circuit 7 extracts the differential component from a video signal obtained from the whole image of an object photographed by a TV camera 4 and a CPU 11 controls a motor driving circuit 12 and drives a focal distance moving mechanism part 13 through an absolute value obtaining circuit 8, an integration circuit 9 and an A/D conversion circuit 10 to move the object 1 to a position on which the differential component becomes a peak. Thus an image 30 is extracted. Then the extracted image 30 is enlarged and displayed so as to indicate an enlarging range 33. In this case, positional relation among a cross alignment mark 322 and cross reference patterns 311 to 314 is extremely cleared. Thereby the position of the object 1 can be simply adjusted and alignment can be precisely executed. |
