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. 14, 1998
Filed:
Apr. 21, 1997
Masato Shiokawa, Tokyo, JP;
Hiromi Honma, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A PRML (Partial Response Maximum Likelihood) signal processing apparatus for both MP (Mark Position) recorded medium and ME (Mark Edge) recorded medium. The apparatus has a PR (Partial Response) equalizer to which the reproduction signal from the medium is inputted, a folded back value calculation circuit for folding back an input signal thereto with a predetermined level, and a Viterbi detector having a path memory and performing a Viterbi detection. The path memory is constructed based on a structure of a trellis for a signal recorded by the MP recording. In case of the MP recorded medium, the equalizer transfer characteristics and the reference amplitude both for the MP recording are set to the PR equalizer and the Viterbi detector, respectively, and the output of the PR equalizer is directly supplied to the Viterbi detector. On the other hand, in case of the MP recorded medium, the equalizer transfer characteristics and the reference amplitude both for the ME recording are set, and the output of the PR equalizer is supplied to the Viterbi detector via the folded back value calculation circuit.