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. 15, 2008
Filed:
Jan. 28, 2004
Jeong Chae Youn, Pyungtaek-si, KR;
Jeong Chae Youn, Pyungtaek-si, KR;
Hitachi-LG Data Storage Korea, Inc., Seoul, KR;
Abstract
Disclosed is a method for adjusting focus bias in an optical disk device. When a focus bias adjustment operation for an optical disk such as a DVD-RAM is performed, a focus bias offset value at which the smallest jitter value of a high frequency signal is detected is set as an optimum focus bias offset value. A physical information data area, which has an embossed form and is recorded in a data area of the disk in a dispersed manner, is detected so that the jitter value of the high frequency signal is measured only for areas other than the detected physical information data area. This achieves a focus bias adjustment operation optimal for an optical disk such as a DVD-RAM, thereby enabling a secure focusing servo operation thereof.