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:
Mar. 15, 1977
Filed:
Feb. 13, 1976
David L MacDougall, Jr, San Jose, CA (US);
Shugart Associates, Inc., Sunnyvale, CA (US);
Abstract
A playback circuit for use with a magnetic recording transducer, in a magnetic recording apparatus, the transducer developing an alternating current readback signal having alternating positive and negative peaks, the playback circuit comprising a differentiator responsive to the readback signal and operative to produce a differentiated signal having first and second polarities and having zero crossings in time coincidence with the positive and negative peaks, a bidirectional one-shot device responsive to the differentiated signal and operative to produce a first bistate signal having transitions in time coincidence with the zero crossings and to produce a second signal comprising a sequence of pulses having leading edges that correspond in time to the zero crossings and having trailing edges that lag the leading edges by a predetermined time interval, a latch for producing a third signal having transitions that correspond in time to the trailing edges and having a level that corresponds to the level of the first signal at such time, and for producing a fourth signal that is the complement of the third signal, two one-shot devices responsive to the third and fourth signals and operative to produce fifth and sixth signals including pulses corresponding to the positive going transitions of the third and fourth signals, and an OR gate operative to conduct the pulses to an output terminal, the conducted pulses corresponding to the positive and negative peaks of the readback signal.