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:
Mar. 28, 2006
Filed:
Apr. 21, 2003
Tadashi Adachi, Yamagata, JP;
Hirokazu Furuse, Yamagata, JP;
Masayoshi Sugawara, Yamagata, JP;
Mitsumi Electric Co., Ltd., Tokyo, JP;
Abstract
An optical pickup comprising: a diffraction grating, a beam splitter and laser beam guiding optical components that change direction of laser beams, which are placed on a light path constituted by a semiconductor laser that emits dual wavelength laser beams and an information recording surface of an optical disk, wherein a wavelength plate is provided on a light path between said diffraction grating and said semiconductor laser so that a laser beam irradiated on the recording surface of said optical disk becomes an elliptically polarized (including circularly polarized) beam or a beam having a polarizing plane that produces an angle of 30–60 degrees relative to a radius direction.