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:
Oct. 01, 1985
Filed:
Sep. 01, 1983
Chao S Chi, Cupertino, CA (US);
Sperry Corporation, New York, NY (US);
Abstract
A quaternary saturated digital magnetic recording system for enhancing information entropy provides an effective bit density increase of 100% or more over the MFM code. In the simplest implementation, groups of two input binary bits are mapped into one data cell, preferably into four combinations of long or short breaks and positive or negative polarity, with the break optionally centralized within the data cell for self-clocking. A system for reproducing the recorded information provides a peak detector, responsive to the recorded signal, coupled to pulse polarity and break width detector circuitry, with an internally synchronized clock, for remapping the recorded data into binary format.