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:
Jul. 08, 2008
Filed:
May. 31, 2005
Jeng-jiun Chen, Hsinchu, TW;
Bor-ruey Chen, Hsinchu, TW;
Chao-jen Chen, Hsinchu, TW;
Lite-On It Corporation, Taipei, TW;
Abstract
A method and system for measuring the signal deviation are applied to an optical recording/reproducing apparatus. The optical recording/reproducing apparatus comprises an optical pickup head for receiving Differential Push Pull (DPP) signals reflected from an optical recording medium to trace the tracks on the surface of the optical recording medium. The DPP signal comprises a Main beam Push Pull (MPP) signal and a Sub-beam Push Pull (SPP) signal. The method firstly receives the MPP signal and the SPP signal to generate an MPP waveform and an SPP waveform separately. Then, the MPP waveform and the SPP waveform are combined to generate an amplitude waveform function. Finally, according to the amplitude waveform function, a phase difference between the MPP signal and the SPP signal is estimated. An adjusting direction can be further determined according to a relative position between the SPP waveform and the MPP waveform.