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:
Nov. 20, 2001
Filed:
Jan. 29, 1999
Manabu Tsukamoto, Tokyo, JP;
Masayoshi Shimamoto, Tokyo, JP;
Kenji Goto, Tokyo, JP;
Takehiko Umeyama, Tokyo, JP;
Yoshiji Inoue, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In an optical information reproduction device for reproducing information from an optical disk medium on which an identification information area including first identification information shifted radially outward with respect to the center of a recording track by a specified distance and second identification information shifted radially inward with respect to the center of a recording track by a specified distance, and a user information area disposed along the center of a recording track are disposed, information is reproduced using a sum signal and a difference signal of the outputs from a split photodetector having at least two light-receiving parts disposed on opposite sides of a track tangential line. The first or second identification information signal is inverted and the direct-current component in the identification information signal and the user information signal are removed.