| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a position measuring apparatus capable of simply retrieving a position measuring mark and measuring an accurate position. SOLUTION: A position measuring apparatus has a coaxial type binocular two-magnification projection optical system 60 for focusing an alignment mark on a work W, first and second photographing units 71, 72 for converting a low one-magnification image and a high two-magnification image projected by the system 60 into image signals, and an image processor 80 for suitably signal processing the image signals output from the units 71, 72. First, the work W is conveyed to a stage 30, a large global mark is searched and aligned by the unit 71, and a fine mark disposed at a center of the global mark is guided to an image filed of the unit 72. Thus, the work W can be accurately measured only by moving the work W in the case of the searching and aligning, and the position of the work W can be rapidly measured.</p> |
