Recording and reproducing system using time division multiplexing
First Claim
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1. A recording and reproducing system comprising,a plurality of individual input channels for receiving respective input signals having respective levels;
- time division multiplexing means for sampling the respective input signals cyclically, according to a predetermined sequence of the input channels and for outputting a succession of samples occupying respective time slots, each sample representing a level of an input signal received in a respective input channel during a respective time slot, the samples derived from one of the input channels being used as synchronisation signals;
frequency modulation means for frequency modulating the succession of samples output by said time division multiplexing means to produce frequency-modulated samples;
means for recording the frequency-modulated samples, as an analogue signal, on magnetic recording tape;
means for reading the frequency-modulated samples from the magnetic recording tape;
frequency demodulation means for demodulating the frequency modulated samples read by the reading means to produce a succession of frequency-demodulated samples,a plurality of output channels, each output channel corresponding to a respective input channel;
time division demultiplexing means for distributing the frequency-demodulated samples output by said frequency-demodulation means to respective output channels; and
synchronisation signal detection means for detecting the frequency-demodulated samples that are used as synchronisation signals, the time division demultiplexing distributing the frequency-demodulated samples output by said frequency demodulation means to respective output channels in accordance with the timing of the detected synchronisation signals.
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Abstract
A system for recording analogue and/or digital signals (especially analogue voice signals) on magnetic tape has a plurality of individual input channels and a time division multiplexing circuit which samples the analogue signals in the input channels cyclically, in a pre-arranged sequence. The samples are output to a single output channel for recording on a standard VHS magnetic tape. In the replay mode, recorded signals are distributed to respective output channels by a demultiplexing circuit.
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3 Claims
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1. A recording and reproducing system comprising,
a plurality of individual input channels for receiving respective input signals having respective levels; -
time division multiplexing means for sampling the respective input signals cyclically, according to a predetermined sequence of the input channels and for outputting a succession of samples occupying respective time slots, each sample representing a level of an input signal received in a respective input channel during a respective time slot, the samples derived from one of the input channels being used as synchronisation signals; frequency modulation means for frequency modulating the succession of samples output by said time division multiplexing means to produce frequency-modulated samples; means for recording the frequency-modulated samples, as an analogue signal, on magnetic recording tape; means for reading the frequency-modulated samples from the magnetic recording tape; frequency demodulation means for demodulating the frequency modulated samples read by the reading means to produce a succession of frequency-demodulated samples, a plurality of output channels, each output channel corresponding to a respective input channel; time division demultiplexing means for distributing the frequency-demodulated samples output by said frequency-demodulation means to respective output channels; and synchronisation signal detection means for detecting the frequency-demodulated samples that are used as synchronisation signals, the time division demultiplexing distributing the frequency-demodulated samples output by said frequency demodulation means to respective output channels in accordance with the timing of the detected synchronisation signals. - View Dependent Claims (2, 3)
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Specification