| 摘要 |
PURPOSE:To draw a pattern in high accuracy by generating a drawing beam scan start signal in response to a variation in a distance to the reference surface of a reference block detected by a displacement sensor. CONSTITUTION:A distance from the reference surface 7 of a reference block 8 to a displacement sensor 10 is D. When a feed screw 5 is rotated by a motor 6, a table 2 is fluctuated rightward or leftward at D due to the error of the linearity of a linear guide 4 as a table 2 is moved. As a result, the sensor 10 outputs a distance signal (a), and a signal processor 11 outputs an output signal (b) by delaying (advancing) a time corresponding to D at the timing of the scan start signal of a drawing beam 9. Thus, the scan starting point A on a film 1 of the beam 9 is not displaced in the rightward or leftward direction. |
