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. 13, 1990
Filed:
Dec. 02, 1987
Masahiro Ojima, Tokyo, JP;
Motoyasu Terao, Tokyo, JP;
Yoshio Taniguchi, Hino, JP;
Shuji Imazeki, Kodaira, JP;
Yasushi Tomioka, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Disclosed is a wavelength multiplexing optical recording apparatus comprising laser sources radiating a plurality of laser beams of different wavelengths, an optical system for focusing the laser beams, and an optical recording medium having a plurality of optical recording layers with wavelength sensitivities for selective recording by said laser beams focused by said optical system. The optical recording layers of recording medium are laminated with distances between adjacent layers being made consistent with biased focal positions of the laser beams attributable to the chromatic aberration of the optical system, so that the laser beams are focused on the optical recording layers of corresponding wavelength sensitivities.