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:
Oct. 26, 2010
Filed:
Jul. 03, 2006
Takuma Yanagisawa, Tsurugashima, JP;
Masakazu Ogasawara, Tsurugashima, JP;
Takuma Yanagisawa, Tsurugashima, JP;
Masakazu Ogasawara, Tsurugashima, JP;
Pioneer Corporation, Tokyo, JP;
Abstract
The present invention provides an optical pickup device requiring no position adjustment of a diffraction grating at the time of assembling the optical pickup device, and capable of suppressing fluctuations in a differential push-pull signal amplitude and cancelling a push-pull offset. An optical pickup deviceof an embodiment of the present invention has a diffraction gratingof a special shape including predetermined grooves and two kinds of lattice grooves arranged at a pitch determined on the basis of a pitch of grooves formed in the surface of an optical disk, numerical aperture, wavelength of a light beam, and effective diameter of the light beam applied on the optical disk To suppress push-pull signals generated in the ± first-order diffraction rays, reflection rays from the optical diskof a zeroth-order diffraction ray and ± first-order diffraction rays are detected, and signals corresponding to light reception results are output to a reproduction unit, a control unit, and an actuator servo circuit