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:
Nov. 24, 2009
Filed:
Mar. 22, 2006
Keuk Young Bahng, Osan-si, KR;
Keuk Young Bahng, Osan-si, KR;
Hitachi-LG Data Storage Korea, Inc., Seoul, KR;
Abstract
A focus servo control method for an optical disc device is provided which compensates for variations present on the disc while printing a label on a label surface of the disc. The label surface of the disc is radially divided into a plurality of areas arranged about the center of the disc, and a focus swing operation is performed for each of the radially divided areas to detect an RF signal. Respective center points of pulses in the detected RF signal are regarded as optimal focus points, and focus driving voltages corresponding respectively to the center points are detected and stored in association with the corresponding areas. When a label is printed on the label surface, feed-forward focus servo control is performed based on the stored focus driving voltages. Accordingly, feed-forward focus servo control can be performed while compensating for variations the disc, thereby improving the label printing operation and quality of the resulting label.