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:
Sep. 27, 2011
Filed:
Mar. 19, 2007
Takuya Asano, Ehime, JP;
Takuya Asano, Ehime, JP;
Panasonic Corporation, Osaka, JP;
Abstract
In a device for controlling a focus to an optical disc having a land section and a groove section, the control is performed so as to avoid a focus step difference at a land-area/groove-area switching point. When performing write-in or readout of data to an optical disc on which a land area and a groove area are continuously formed, using an optical pickup, there are provided a land learning unit () for determining a focus position in the land area, a groove learning unit () for determining a focus position in the groove area, and a focus position calculation unit () for determining a focus position in an area where the land area and the groove area are switched, and the focus position of the optical pickup is moved so that it is located at the third focus position when the switching signal is inverted according to the switching between the land area and the groove area.