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:
Sep. 20, 2005
Filed:
Mar. 02, 2001
Shigeru Nakamura, Tachikawa, JP;
Kouji Arikawa, Hitachinaka, JP;
Kazuko Shigematsu, Yoshikawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A low-profile optical disk device which performs recording and reproducing using a plurality of laser light sources with different wavelengths, without thug need for additional components. It is used as a DVD-Ram, CD-R or the like. It comprises a plurality of neighboring laser light sources with different wavelengths: a beam-shaping prism for expanding the width of laser beams in a direction in which the plural laser light sources are arranged; and a focus lens which forms an optical spot on an optical disk, where laser light sources with longer wavelengths are positioned closer to an extension line of a refracted beam created by the beam-shaping prism. The above arrangement enables correction of optical spot coma aberrations caused by a laser light source positioned out of the optical axis of the focus lens, thereby realizing a low-profile optical disk device with high optical performance.