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:
Jan. 30, 1990
Filed:
Jul. 11, 1988
Hiroshi Suzuki, Monroeville, PA (US);
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A data separator system has a PLL circuit for out-putting data pulses and clock pulses on the basis of the read data from a magnetic recording medium. The system also includes an external synchronization detection circuit which detects the synchronization data (predetermined zero pattern data) recorded in the synchronization area of the magnetic recording medium, on the basis of the read data. When detecting the synchronization data, the synchronization detection circuit enables the PLL circuit to oscillate in synchronism with the read data. The data pulses and clock pulses output from the PLL circuit are also supplied to an internal synchronization detection circuit. On the basis of the data pulses and the clock pulses, the internal synchronization detection circuit detects the synchronization data, and upon detection thereof, a floppy disk controller performs the data readout operation. The system further comprises a preventing circuit which prevents the PLL circuit from performing the synchronizing operation to the read data, which is read out from the overwritten area in the magnetic recording medium by the preceding-erase type magnetic head.