Servo control arrangement utilizing alternately energized light source.

摘要

A servo control arrangement for a position control system to control the accurate positioning of a movable controlled member to each of a predetermined plurality of controlled positions. The position control system includes a drive arrangement responsive to a drive input signal for moving the controlled member. The position control system also includes a coded array device that moves in a predetermined path correlated to the controlled member and defines an array of energy transmissive members. The servo control arrangement includes two energy generation sources and means for alternately energizing the sources. The sources are arranged side by side at a detection station along the predetermined path of the coded array device. The servo control arrangement also includes energy detection means for generating an output signal corresponding to the relative level of energy received from each of the sources. The coded array device is positioned intermediate the detection means and the sources such that the relative energy received by the detection means is dependent on the position of the energy transmissive member at the detection station. The servo control arrangement further includes control means responsive to the energy detection means for generating the drive input signal.