| 摘要 |
1,200,882. Associated working; tape recorders. CITY OF COVENTRY CORP. 20 Oct., 1967 [23 July, 1966], No. 33227/66. Heading G5R. A separate control track on a tape in a tape recorder is used to control and synchronize a projector in normal forward mode and in backspacing for recapitulation. As described, a slide projector is controlled by a three-or fourtrack tape recorder, three tracks containing master, student and control information respectively for teaching languages, for example. The system functions are selected by pushbuttons 1-4, 16 and 37 operating relays connected to solenoids (not illustrated). Operation-loading tape.-A "load tape" button 16 is depressed to close the circuit of a photo-cell 40 associated with a continuously illuminated lamp 41 and to energize a "forward drive" relay 12 until a window in the tape passes the photo-cell 40 whereupon a "stop" relay 14 terminates drive. "Forward drive" button 2 is depressed to engage pinch rollers with a capstan to drive the tape, the control signals being fed to a relay 30 controlling slide-change mechanism. Backspacing is effected by holding down pushbutton 1 (recap button) during which time the tape and projector are back-spaced in synchronism, a further motor 46, which normally provides back tension, being energized to rewind the tape. A microswitch 32, located at the projector gate, operates relay 31 to allow backspacing only during forward drive and when a slide is located at the gate. Rewinding is effected by depressing pushbutton 3 whereupon the tape is fast wound and the slide-change mechanism reversed although not necessarily in sync. To ensure correspondence when forward drive is re-engaged after rewind, relays 20, 23 and 24 are arranged to complete the photo-cell circuit so that when the tape window first passes the photo-cell the rewind relays 13, 13a are de-energized to terminate rewind and spool brakes are applied. Delay capacitors 20a, 24a are provided so that the forward drive relay 12 is then energized until the window is opposite the photo-cell again, whereupon forward drive is terminated and the spool brakes reapplied. Meanwhile, a microswitch 36 is operated by the slide magazine 49 to stop the projector when reverse operation is completed. Unloading.-"Unload" button 37 is depressed to open the photo-cell circuit and override rewind switch 3 to energize rewind relay- 13, 13a so that the tape may be completely rewound on to the feed spool. Modifications.-The slides may be mounted in succession on the face of a rotatable disc instead of in a magazine. |
