| 摘要 |
<p>-22- RCA 74,789 Video Disc Stylus Position Sensor System A stylus position sensor for a video disc player apparatus. An electrode secured in fixed relation to a movable stylus is disposed between first and second electrodes to form first and second variable capacitors therewith. The capacitance of the variable capacitors change in accordance with the motion of the stylus related electrode between the first and second electrodes. A time varying signal is applied through fixed impedances to the first and second electrodes, the amplitude of the signal being modulated by voltage variable impedances connected between the first and second electrodes and a point of fixed potential. The modulated signals at said first and second electrodes are coupled to the stylus related electrode and the time average of the summed signal is indicative of the position of the stylus related electrode and thereby the stylus with respect to the first and second electrodes.</p> |
