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:
Dec. 02, 2008
Filed:
Dec. 01, 2004
Hung-hsiang Chang, Taipei-Hsien, TW;
Fu-shan Wang, Tai-Nan, TW;
Hung-Hsiang Chang, Taipei-Hsien, TW;
Fu-Shan Wang, Tai-Nan, TW;
Mediatek Incorporation, Science-Based Industrial Park, Hsin-Chu Hsien, TW;
Abstract
A method used in an optical storage device having a pickup head. The pickup head includes an object lens, a first and a second light source. The object lens focuses the laser light generated by the first or the second light source onto a first or a second focal point. A driving control effort is used to change the location of the object lens. The method includes the following steps: providing the driving control effort to move the object lens; measuring a first parameter when the first focal point passes through a predetermined layer of an optical disc; measuring a second parameter when the second focal point passes through the predetermined layer of the optical disc; and (d) determining the relationship between the difference of object lens location and the driving control effort according to the predetermined distance, the first parameter, and the second parameter.