| 摘要 |
PURPOSE:To cut down processing time and simplify hardware, by binarizing an image signal with a level based on the greatest value of the image signal from an image pickup means developing on image of a body provided with a position detecting mark and detecting the position of the mark based on the up-rising position of the binarizing signal. CONSTITUTION:An image signal fed out from an image pick-up tube 13 is amplified by an amplifier 1 ad at the first scanning, it is transferred to a peak hold 3 by a multiplexer 2 for holding the maximum value. At the scanning beginning with 2nd one, it is transmitted to a comparator 4 to be binarized by a slide level based on the maximum value. Counter and register 5, 6 count horizontal synchronous signal and clock pulse phi respectively. And, for the horizontal position, the counted value is registered in the memory 8 at the up-rising time of the binarized signal and for the vertical position, the counted value is registered in the memory 7 at the up-rising time of the binarized signal. These counted values stored in the memories 7, 8 are taken in by a computer 9 and averaging of the mark positions is performed. |
