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:
May. 14, 2002
Filed:
Mar. 30, 1999
Hiroyuki Awano, Noda, JP;
Katsusuke Shimazaki, Toride, JP;
Hiroki Takao, Ibaraki, JP;
Norio Ohta, Ibaraki, JP;
Akiyoshi Itou, Matsudo, JP;
Katsuji Nakagawa, Tokyo, JP;
Manabu Tani, Ibaraki, JP;
Masafumi Yoshihiro, Ibaraki, JP;
Masaki Sekine, Ibaraki, JP;
Hitachi Maxell, Ltd., Ibaraki, JP;
Abstract
The magneto-optical recording medium has a magnetic domain magnification reproducing layer and an information recording layer. Clock marks are formed on the information recording layer, making it possible to generate a reproducing clock on the basis of these. The clock marks are detected either by irradiating directly with light of wavelength &lgr; (&lgr; ≠&lgr; ), being different from the light of wavelength &lgr; which is used for reproducing the recording marks, or by applying a direct-current magnetic field, transferring and enlarging the clock marks on to the magnetic domain magnification reproducing layer, and detecting the reproduction signals from this magnetic domain magnification reproducing layer. Since the reproducing clock is in exact synchronisation with the recording marks, it is eminently suitable as a clock for pulse-modulated reproducing light and reproducing magnetic fields used when reproducing the reproducing layer.