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:
Dec. 12, 2000
Filed:
Aug. 07, 1998
Satoru Ohnuki, Toride, JP;
Toshinori Sugiyama, Tsukuba, JP;
Masafumi Yoshihiro, Kitasouma-gun, JP;
Tsuyoshi Maro, Otokuni-gun, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
A magneto-optical recording medium comprises a protective layer having a self-lubricating property formed at an uppermost layer on a side opposite to a substrate wherein a recording or reproducing light beam comes into a side of the protective layer. The thickness and the refractive index of the protective layer are selected under predetermined conditions depending on whether or not evanescent light is transmitted through the protective layer. It is possible to perform high density recording and reproduction thereof by utilizing the evanescent light. A protective layer having a self-lubricating property may be also formed on a bottom surface of an optical head opposing to the optical recording medium. Even when the optical head contacts with the surface of the optical recording medium, the sliding scratch scarcely occurs, because the optical head smoothly glides on the recording medium surface. It is possible to reduce the influence of multiple interference of light which would be otherwise caused in an air layer existing between the optical recording medium and the optical head, and it is possible to suppress variation in reproduced signal intensity.