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:
Apr. 26, 1994
Filed:
Nov. 27, 1991
Nobumasa Nishiyama, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A system which records and reproduces a digital signal in the form of a magnetic reversal on and from a recording medium includes a magnetic head for reproducing data recorded on the recording medium; an automatic gain control unit for controlling the reproduced signal so as to have a constant amplitude; an equalizer for processing the output waveform from the automatic gain control unit; a differentiator for changing the output from the equalizer to a differentiated waveform; a low pass filter for limiting the signal band of the differentiated waveform; a low pass filter for limiting the signal band of the equalizer output; a pulser for receiving the equalizer output, the band of which is limited by the low pass filter and the differentiated waveform, the band of which is limited; a differentiator for receiving the output from the automatic gain control unit and producing a differentiated signal from the output signal; an attenuator for attenuating the differentiator output; and a waveform processor for adding the attenuated differentiated signal to the band-limited differentiated waveform and inputting the resulting signal to the pulser.