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:
Jan. 24, 2012
Filed:
Dec. 07, 2010
Kazumasa Kaneda, Kanagawa, JP;
Yoshito Asoma, Saitama, JP;
Toshifumi Yasui, Saitama, JP;
Kazuyuki Takahashi, Kanagawa, JP;
Kazumasa Kaneda, Kanagawa, JP;
Yoshito Asoma, Saitama, JP;
Toshifumi Yasui, Saitama, JP;
Kazuyuki Takahashi, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
An optical pickup includes: a first emitting unit to emit an optical beam of a first wavelength; a second emitting unit to emit an optical beam of a second wavelength; a third emitting unit to emit an optical beam of a third wavelength; an object lens to condense optical beams emitted from the first through third emitting units onto a signal recording face of an optical disc; and a diffraction unit provided on one face of an optical element or the object lens positioned on the optical path of the optical beams of the first through third wavelengths; wherein the diffraction unit includes a generally circular first diffraction region provided on the innermost perimeter, a ring zone shaped second diffraction region provided on the outer side of the first diffraction region, and a ring zone shaped third diffraction region provided on the outer side of the second diffraction region.