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. 29, 2012
Filed:
Feb. 24, 2011
Hiroharu Sakai, Tokyo, JP;
Hajime Nishimura, Tokyo, JP;
Shuichi Minamiguchi, Tokyo, JP;
Hitachi-LG Data Storage, Inc., Tokyo, JP;
Abstract
An optical disc drive for reading or writing information on a multilayer optical disc having three or more recording layers by irradiating the disc with a light beam includes an optical pickup for irradiating the disc with the light beam, a recording state detector for detecting data recording states at a start point of a focus jump, a transit point or transit points on a recording layer or recording layers to be passed through, and an expected landing point of a focal point of the light beam in a focus jump, and a controller for moving the optical pickup to a position where the recording states are the same at all of the start point, the transit point(s) on the recording layer(s) to be passed through, and the expected landing point if the recording states are different among those points, before starting the focus jump.