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. 30, 1995
Filed:
Feb. 23, 1993
Hisataka Sugiyama, Kodaira, JP;
Akira Arimoto, Kodaira, JP;
Motoyasu Terao, Tokyo, JP;
Norio Murase, Kokubunji, JP;
Kimio Tatsuno, Kodaira, JP;
Masahiko Takahashi, Kodaira, JP;
Fumiyoshi Kirino, Tokyo, JP;
Fumio Kugiya, Hachioji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An information recording medium includes an information recording layer on which at least information is to be recorded by irradiating light, and a light transmission restricting layer which has a plurality of nonlinear transmission characteristics or nonlinear reflection characteristics for the intensity of the light irradiated and which has an optical material for restricting the transmission or reflection of the light according to the respective characteristics when the light is irradiated onto the information recording layer. An information recording and reproducing unit uses the information recording medium and includes an information recording position setting unit for deciding a position at which information is to be recorded on the information recording medium by detecting a direction of an easy magnetization axis. With the above arrangement, the spot diameter of the light can be distinguished between the one when information is reproduced and the one when information is recorded on the information recording medium respectively, to thereby ensure an accurate positioning of the head on the tracks of the recording medium.