| 摘要 |
A system for recording a plurality of marking signals on a record carrier track during scanning thereof, and for detecting from the track during scanning thereof the marking signals recorded thereon. The system includes recording apparatus which generates the marking signals (M1, M2, M3) as different combinations of first and second recording signals (S1, S2) of different frequencies and of durations which are selected by respective time-control stages (Z1, Z2). The first marking signal (M1) may consist of only the first recording signal (S1) having a predetermined duration T; the second marking signal (M2) may consist of the combination of the first marking signal (S1) of duration T and the second marking (S2) of the same duration T; and the third marking signal (M3) may consist of the combination of the first recording signal (S1) of duration (P) and the second marking signals (S2) of a duration between T and zero such as T/2. The system also includes reproducing apparatus for detecting during scanning of the track detection signals (S1', S2') corresponding to the recording signals (S1, S2) recorded thereon, the reproducing apparatus including time-measurement stages (Z3, Z4) for determing the duration at least the detection signal (S2') corresponding to the recording signal (S2) which may have various different durations, and a logic circuit which combines the detection signals in accordance with the determined durations so as to derive the marking signal represented thereby.
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