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:
Jan. 13, 1998
Filed:
May. 30, 1996
Hiroyuki Takahashi, Tokorozawa, JP;
Shinichi Nagahara, Tokorozawa, JP;
Fumikazu Tahata, Tokorozawa, JP;
Hidehiro Ishii, Tokorozawa, JP;
Eiji Muramatsu, Tokorozawa, JP;
Akiyoshi Inoue, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo-to, JP;
Abstract
A tracking error signal generation device is used for an optical pickup device capable of reproducing and/or recording an information signal on a spiral or coaxial signal track of a disk shaped optical record medium of one type among a plurality of optical record media of different types which track pitches are different from each other. The optical pickup device has a light beam irradiation device for irradiating the optical record medium with three light beams; and light detection devices for receiving a reflection light of each light beam. The tracking error signal generation device is provided with: a first operation device for calculating a first tracking error signal according to the three beams method; a second operation device for calculating a second tracking error signal according to a DPP (Differential Push Pull) method; and a selecting device for selecting one of the first tracking error signal and the second tracking error signal on the basis of an instruction from the external.