| 摘要 |
1392201 Recording and playback RCA CORPORATION 21 March 1972 [22 March 1971] 13073/72 Heading G5R The sidewalls of a groove 15 in a disc record 30 are engaged by the insulating sides of a stylus 10 which carries a playback electrode 20. As shown, television signals are recorded as hill- and-dale undulations 75 in the bottom of a groove 15 in a disc 30 of dielectric material which rests on an electrically conductive turntable (31), Fig. 3 (not shown). The capacitance between the electrode. 20 and the turntable (31) varies with the undulations 75 and is connected in a resonant circuit, Fig. 4 (not shown), to which radio-frequency oscillations are applied so that the output amplitude varies with this capacitance and hence with the recorded signals. |
