| 摘要 |
PURPOSE:To make it feasible to automatically carry a photomask for alignment by means of aligning a circular body in the rotating direction in terms of fluctuations in light quantity. CONSTITUTION:This aligning device is composed of a light source for illuminating the peripheral part of photomask, a light receiving element 12 to detect the light transmitting peripheral part of photomask, an amplifier 14 to amplify the electric signals photoelectric-converted by another light receiving element 13, a bright-dark discriminating circuit 15 detecting that a photoelectric conversion output changes from an output level at opaque part to another output level at transmitting part (pattern part) a motor 10 to rotate the photomask and a control circuit 18 to control the driving operation of mask rotating motor 10. An output 17 stops the motor 10 when a photomask etching pattern 8 approaches to a specified position. Through these procedures, any position of photomask in the rotating direction may be arbitrarily selected. |
