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:
May. 17, 2011
Filed:
Jun. 26, 2006
Toru Kawashima, Mito, JP;
Hiroharu Sakai, Tokyo, JP;
Takeyoshi Kataoka, Yokohama, JP;
Motoyuki Suzuki, Yokohama, JP;
Toru Kawashima, Mito, JP;
Hiroharu Sakai, Tokyo, JP;
Takeyoshi Kataoka, Yokohama, JP;
Motoyuki Suzuki, Yokohama, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Abstract
A focus-servo control method of an optical disc recording/reproducing apparatus, for recording or reproducing information onto/from an optical disc having a track with a land and a groove, which are formed in a spiral manner on an information recording surface thereof, the optical disc recording/reproducing apparatus including an objective lens, the method comprising steps of: moving an optical spot from the land to the groove or from the groove to the land through a L/G exchange portion therebetween and moving a position of the objective lens from a land position to a groove position by gradually changing a focus offset value for the land to a focus offset value for the groove from a position located before the L/G exchange portion, when the optical spot moves from the land to the groove.