| 摘要 |
<p>PURPOSE:To detect the pattern, which needs detecting of the position of a material to be treated, accurately even when there are a scar, a break, the adhesion of other patterns, etc. in the pattern by detecting the points of variation in the rise and fall of a pattern signal being projected. CONSTITUTION:When the break is generated in a projection pattern to an X axis, the points of variation of all of the rise and fall of the projection pattern are detected. The points of variation are detected so that the data of the points of variation of each rise are memorized to a rise counter 14 and a rise address memory 15 in response to starting signals from the contdrol circuit 10, slice level signals, scan counter signals and scan address signals regarding rise. The satisfaction of conditions by a specific formula of distances among the pairs of the points of variation in the sequence previously determined is checked from the data of these points of variation.</p> |
