The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 1998
Filed:
May. 12, 1995
Shuko Watanabe, Kawasaki, JP;
Makoto Sasaki, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
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.