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. 27, 2005
Filed:
Jul. 31, 2002
Shinichi Nagahara, Tokorozawa, JP;
Ryo Sato, Tokorozawa, JP;
Ko Ishii, Tokorozawa, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
An information recording/reproducing apparatus includes an optical device, a photo-detector and a calculation unit. The optical device irradiates light beams, including one main beam and at least two sub-beams with respect to an information recording medium. The photo-detector receives return lights of the main beam and sub-beams to output light detection signals. The calculation unit produces a tracking error signal and a position information signal based on the light detection signals. The optical device irradiates the at least two sub-beams onto positions shifted to opposite sides of a center of the guide track, respectively, when the main beam is being irradiated onto a center of the information recording track. Thus, the apparatus produces the tracking error signal and the position information signal by utilizing a common optical system and a common signal processing system and thereby executes tracking servo control and random access processing with high accuracy.