MAGNETIC RECORDER AND REPRODUCING DEVICE

摘要

PURPOSE:To simplify the circuit of a rotation controlling system in a device equipped with plural magnetic disks, by using the detecting pulse of the rotational phase detecting device of a reference servo system as the reference clock for controlling the rotational phase of the rotational phase detecting devices from the next stage. CONSTITUTION:At a reference servo system, the rotational phase of a disk 1 is controlled by a servo controlling circuit 9 so that a detecting pulse by a rotational phase detecting device 8 which detects the rotational phase of the magnetic disk 1 can be synchronized to a reference clock. The detecting pulse from the device 8 which becomes stable and highly accurate at the time of normal operation is impressed upon similar servo controlling circuits 31 and 32 for disks 23 and 24 to be used for dubbing the disk 1 and so forth, as reference clocks and the disks 23 and 24 are accurately controlled in rotational phase synchronously to the disk 1. With this constitution which does not need any circuits for synchronizing, the circuit of a rotation controlling system in a device equipped with plural disks can be simplified.