| 摘要 |
<p>A video disc playback system includes a pickup stylus which is adapted to track in a groove in a disc record. The record comprises a molded thermoplastic substrate supporting a conductive surface with a dielectric coating disposed over the conductive surface. When relative motion is established between the disc record and the pickup, the pickup stylus cooperates with the disc record to establish capacitance variations between the stylus and the record due to geometrical variations in the bottom of the groove. The stylus includes a support element having an irregular surface with a conductive element disposed on the irregular surface. The support element is shaped in a manner such that when it engages the record medium groove, an edge of the conductive element is adjacent the dielectric coating.</p> |
