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:
Apr. 14, 1998
Filed:
Jul. 22, 1996
Toshiyuki Kase, Tokyo, JP;
Hiroshi Nishikawa, Tokyo, JP;
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A laser beam emitted from a laser diode passes through a first polarization beam splitter to form a spot on a magnetic film of a magneto-optic disk. The plane of polarization of the laser beam reflected at the magneto-optic disk rotates, due to the Kerr effect, in a fixed direction in accordance with the direction of magnetization of the magnetic film. The laser beam then passes through a half-wave plate. The half-wave plate is attached on a base plate and tilted with respect to the optical axis of the laser beam so that its phase difference along the optical axis compensates the phase difference of the entire optic system. The laser beam passed through the half-wave plate is separated by the second beam splitter into a P polarization component and S polarization component, which are respectively detected by photodiodes.