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:
Jul. 09, 1996
Filed:
Dec. 15, 1993
Constantin M Melas, Los Gatos, CA (US);
Daniel Rugar, Los Altos, CA (US);
Pantas Sutardja, San Jose, CA (US);
Roger W Wood, Gilroy, CA (US);
Intenational Business Machines Corporation, Armonk, NY (US);
Abstract
A system for encoding and decoding binary data in a data transmission system, such as a magnetic or optical data storage channel. The encoding process is implemented as a two-step RLL coding procedure wherein the original user bit data are first encoded as an asymmetric RLL code signal at a reduced clock rate and then translated to a second even-spaced RLL code signal suitable for recording to a data storage medium at a full-speed clock rate. The system also provides for recovering suitable even-spaced RLL codes recorded at a full-speed clock rate, translating the recovered even-spaced RLL code signal to an asymmetric RLL code signal at a reduced clock rate, and then decoding the asymmetric RLL code signal to recover the original user bit data. A preferred embodiment uses a rate 2/5 (2, 16, 2) even-spaced RLL code at a full-speed clock rate and a rate 4/5 (0,7; 1,8) asymmetric RLL code at a half-speed clock rate. The rate 4/5 asymmetric RLL code has a high capacity and the rate 2/5 even-spaced RLL code has a wide detection window. The intercode translation procedure requires only simple time-delay circuitry.