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:
Jun. 13, 1995
Filed:
Feb. 18, 1994
Norman L Koren, Encinitas, CA (US);
Eastman Kodak Company, Rochester, NJ (US);
Abstract
In a magnetic playback system using an unshielded MR head and a d.c. free charge constrained recording code, the present invention discloses a playback equalizer and the method of making the equalizer whose response to an isolated pulse, unlike the narrow unidirectional pulse response known in the prior art, is a bidirectional signal having a steep zero crossing corresponding to the peak of an isolated pulse. The bidirectional signal is further characterized by skirts resulting from the excellent low frequency of the unshielded MR head, and, unlike the teaching of the prior art, these skirts overlap contiguous pulse periods without causing intersymbol interference. In combination with the characteristics of the patterns of the d.c. free charge constrained code, the presence of the skirts eliminates false zero crossings by maintaining the signal level above the system base line except at the time of a true signal crossing. This allows signal detection by means of a single zero crossing detection channel, and obviates the necessity for a second channel serving as an amplitude qualifier.