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. 07, 1998
Filed:
Oct. 02, 1996
Hiroyuki Fueki, Tokorozawa, JP;
Wataru Hasegawa, Tokorozawa, JP;
Pioneer Electronic Corporation, Tokyo-to, JP;
Abstract
A servo control device for controlling operation of tracking servo loop includes: on-track signal generating unit for generating on-track signal indicating whether a light beam irradiated on an optical disk is positioned on track of the optical disk or not, on the basis of the light beam reflected by the optical disk; tracking error signal generating unit for generating tracking error signal on the basis of the light beam reflected by the optical disk; discriminating unit for discriminating whether the light beam irradiated on the optical disk is positioned in pre-pit area or not; holding unit for holding value of the on-track signal immediately before entrance of the light beam to the pre-pit area on the basis of discrimination result of the discriminating unit; and control unit for opening and closing the tracking servo loop in accordance with the value of the on-track signal held by the holding unit and the tracking error signal.