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:
Nov. 16, 1993
Filed:
Nov. 21, 1991
Toshio Niihara, Sayama, JP;
Harukazu Miyamoto, Hachioji, JP;
Makoto Miyamoto, Yokohama, JP;
Keikichi Andoo, Musashino, JP;
Tsuyoshi Toda, Kodaira, JP;
Atsushi Saito, Ichikawa, JP;
Masahiro Ojima, Tokyo, JP;
Yoshio Suzuki, Eindhoven, NL;
Hiroyuki Awano, Nagareyama, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Maxwell, Ltd., Osaka, JP;
Abstract
According to this invention, since the range of power necessary for erasing an overwritable magneto-optical recording medium is set to 2.5 mW or above, overwriting is possible without erase residue due to mark (magnetic domain) diameter difference, tracking offset, ambient temperature variation and characteristic dispersion between magneto-optical recording media and thus the magneto-optical recording medium has high reliability. Moreover, the rate of change, K of the switching field of the memory layer relative to temperature at around an erase start temperature can be controlled to be a constant value so that an erase power margin can be increased and that the tolerance to the reading light when the ambient temperature rises can be improved.