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:
Dec. 31, 2002
Filed:
Feb. 05, 1996
Takao Sugawara, Kawasaki, JP;
Umeo Oshio, Kawasaki, JP;
Takenori Ohshima, Kawasaki, JP;
Yoshifumi Mizoshita, Kawasaki, JP;
Keiji Aruga, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A detection circuit in a magnetic recording and playback apparatus which uses partial response and the maximum likelihood method, in which neither the size of the detection circuit nor the power consumption increase when the partial response order n increases. In this detection circuit, in the circuit that detects a signal read out from a head, either a plurality of equalizers for different target equalization waveforms, or a single variable target equalizer is provided. A detector for the waveform output from an equalizer is connected in series with the detector. A plurality of combinations, each formed by an equalizer and a detector, is connected in parallel to the output of a filter, the outputs of the combinations of equalizers and detectors being input to a switching circuit, which is controlled by a switching control means. The switching control means controls the switching circuit so that just one of the combinations of equalizer and detectors is selected as the detector output. If a variable target equalizer, which is capable of generating two or more different types of equalization waveforms, is used as the equalizer, it is possible to reduce the number of equalizers to one.