| 摘要 |
<p>1391342 Recording and play back of magnetic tapes; control circuits MATSUSHITA ELECTRIC INDUSTRIAL CO Ltd 7 June 1972 [18 June 1971 (5)] 26573/72 Heading G5R A circuit for the control of head track-changing, head switching and cartridge ejection from a holder in the playback of two or four channels simultaneously from an endless, multi-track tape having a conductive foil, or in the recording of two channels simultaneously thereon, includes a relay 18 for switching heads 33 L , 33 R , 34 L , 34 R , a track-change solenoid 19, and a cartridge-eject solenoid 31, which may all be energized from a transformer T. In the apparatus shown, the heads have four positions I-IV, and there are eight tape tracks. Switch 16 is closed during recording, and switch 17 is closed during two-channel operation, so that all four heads are utilized only in four-channel playback, when relay 18 is de-energized and switches 39, 40 are disposed as shown. Otherwise, heads 34 L , 34 R are not utilized. Track;change solenoid 19 is energized by the tape foil bridging contacts 22; also by manual switch 20 during playback only (switch 21 then being closed); and also in four-channel playback (switch 23 linked to relay 18 is in the position shown) whenever the heads take up track positions III, IV (rotary switch 25 in grounded position III or IV), since each four-channel programme spans four tracks. Cartridge-eject solenoid 31 may be energized by manual switch 32; also at the end of recording (switch 30 closed) on the last track (rotary switch 28 in position IV) when the tape foil bridges contacts 22. A further manual switch (41), Fig. 2 (not shown), may be provided which, if closed, causes cartridge ejection at the end of playback (switch 30 open) of the last track (i.e. track IV for two-channel playback, track II for four-channel playback), when the foil bridges contacts 22.</p> |
