| 摘要 |
PURPOSE:To discriminate intervals of recording tracks, namely, a medium transporting speed for recording by using effectively four kinds of pilot signal superposed successively onto each recording track. CONSTITUTION:A tape speed detecting circuit 8 consists of a pilot detecting circuit 16 which detects four kinds of pilot signal independently one another, the first speed error detecting circuit 17 which detects it in accordance with the detection signal of the pilot detecting circuit 16 that four kinds of pilot signal are reproduced in a one-field time, the second speed error detecting circuit 18 which detects it in accordance with the detection signal of the pilot detecting circuit 16 that two or more kinds of pilot signal are not reproduced in a two-field time, and a control circuit 19 which generates a reproducing mode switching signal in accordance with output signals of velocity error detecting circuits 17 and 18. Individual parts of a device are so controlled that the SP mode is set if said reproducing mode switching signal 19a is in the high level and the LP mode is set if this signal 19a is in the low level, and a capstan motor is controlled to switch the transporting speed of a tape, and a switch is changed over to switch the head used for reproducing, thus switching the reproducing mode to/from the SP mode from/to the LP mode.
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