| 摘要 |
PURPOSE:To eliminate the vibration when a pulse motor reaches a constant velocity and to reduce the region of acceleration, by controlling the duration of a pulse which is applied to the pulse motor in the acceleration mode. CONSTITUTION:A pulse duration Ti is set so as to obtain a speed Vi which is slightly higher than the real velocity (curve D shown by a broken line) at the initial stage of driving as shown by a curve C (theta1>theta2 to be obtained for the slope of the graph in the figure). The velocity Vi is reduced at a time point when the velocity Vi is approximate to a constant velocity Vc. In other words, the pulse duration Ti is increased more than the pulse duration Tc obtained with the velocity Vc. As a result, the overshoot of an optical system, i.e., the vibration caused at the speed Vc is eliminated. Thus the time tc2 from the initial stage of driving to the velocity Vc is reduced to decrease the region of acceleration. |
