Fujitsu Corporation

Shuko Watanabe

Makoto Sasaki

Ryuuichi Miyaguchi

A cartridge of a single reel is inserted and information is recorded and reproduced by a helical scan type using a rotary head. A control pulse is reproduced from a recording signal of a control track of a magnetic tape by a fixed head. A repositioning operation and a high speed search are controlled on the basis of the control pulse. A torque ripple of a capstan motor is previously measured. When the tape runs, a motor drive current is corrected so as to reduce a torque change of one rotation on the basis of the measurement result, thereby improving a wow and flutter. A switching timing of motor coils by Hall sensors is set to an early timing, thereby suppressing a torque fluctuation. A regenerative braking circuit is formed by an OFF timing of a PWM control and a tape back tension is formed by a decrease in torque by the regenerative braking circuit. A tape thread and a tape wrap at the time of the insertion of the cartridge are simultaneously executed.

Magnetic tape apparatus

In a current supply circuit for supplying a current to a reel-drive motor in a magnetic tape apparatus, the circuit includes: a conversion table storing a relationship between a radius of the magnetic tape wound on a reel and a target current to be supplied to the reel-drive motor, and the target current being converted to a digital command; a correction table storing a relationship between the digital command and an actual current flowing in the motor when the digital command is applied to the motor, the actual current being converted to a digital value; a command unit for outputting the digital command corresponding to the target current in accordance with the conversion table; a supply current control unit for supplying an analog current corresponding to the digital command to the motor; a first correction unit for applying first correction signal to the supply current control unit in response to the actual current flowing in the motor; and a second correction unit for supplying a second correction signal to the supply current control unit in accordance with an error to be corrected from the correction table with reference to the digital command.

Current supply circuit and control method for supply current in a

A recording medium library system retaining up to a predetermined number of cartridge type recording media for recording/reproducing data on the recording medium is disclosed. The recording media are stored in a plurality of cells provided in a cell drum. The cell drum is rotatably driven such that a desired cell is brought to a target position. In the driving, an accelerating current, a braking current, and a positioning current are supplied to the motor in order of mention. At least the braking current is determined according to an input value of the inertia of the cell drum.

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Kawasaki, Japan

Shuko Watanabe