| 摘要 |
A method and a device for adjusting an original plane (8), an objective plane (6), and an image plane (4) in an image-reproducing apparatus by means of one or more D.C. motors with a great torque. The motors are controlled by means of voltage pulses each motor (1) being braked after each pulse supply. The planes are adjusted to approximately the desired magnifying percentage by known means. Final adjustment is determined by giving one of the motors a pulse and sensing the displacement of its associated plane. From this the pulse width of a given number of pulses or the number of given pulses is determined which will result in the final positioning of the said plane. <IMAGE> |
