Magnetic disk device


PURPOSE: To evade the occurrence of a read error when the burst quantity of a magnetic head becomes excessive by measuring the time up to the detection of a servo signal after detecting a physical index, and then comparing the time with a set value. CONSTITUTION: When physical index information {2548/60} recorded on a mag netic disk is read by a sensor 8, the timer 91 in a control part 9' starts and counts the time. Then, the control part 9' monitors a servo signal from the magnetic head 1 through a peak holding circuit 7 and when, for example, '1' is detected, the counting value of the timer 91 is stopped. A decision part 92 compares the current value of the timer 91 with a preset control value and when the counted value is within the range, it is recognized that the operation is performed normally, and reading operation is carried on; when not, it is decided that abnormality occurs, and a fault FF is set to send out a trouble signal, thereby interrupting reading/writing operation. COPYRIGHT: (C)1987,JPO&Japio




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Cited By (4)

    Publication numberPublication dateAssigneeTitle
    EP-0665535-A2August 02, 1995Fujitsu LimitedVorrichtung und Verfahren zur Steuerung einer magnetischen Platteneinheit
    EP-0665535-A3July 03, 1996Fujitsu LtdVorrichtung und Verfahren zur Steuerung einer magnetischen Platteneinheit.
    US-5831782-ANovember 03, 1998Fujitsu LimitedMethod and apparatus for supplying optimal bias current to a magnetic head
    US-5956200-ASeptember 21, 1999Fujitsu LimitedMethod of and apparatus for controlling magnetic disc drive