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. 14, 2004
Tetsuo Ueyama, Nara, JP;
Kohji Minami, Gose, JP;
Tomoyuki Miyake, Nara, JP;
Yasuo Nakata, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A pickup for a magneto-optical recording medium is provided, which improves quality of reproduced signals by eliminating a phase difference between the polarizations and is capable of coping with magneto-optical recording media of different recording/reproducing systems. A return light beam of light reflected by a magneto-optical recording medium is polarized and separated into ± first-order diffracted lights through a light-branching diffraction element provided between a light source and an objective lens. The ± first-order diffracted lights are compensated for their phases through first and second phase compensation elements so that there is no phase difference between the polarizations, and are, further, polarized and separated through the first and second polarization/separation elements, and are received by first and second light detectors. Use of the first and second phase compensation elements having different phase compensation amounts makes it possible to cope with the magneto-optical recording media of different recording/reproducing systems.