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:
Jun. 12, 2001
Filed:
Aug. 05, 1998
Katsusuke Shimazaki, Ibaraki, JP;
Masafumi Yoshihiro, Ibaraki, JP;
Akito Sakemoto, Ibaraki, JP;
Norio Ohta, Ibaraki, JP;
Osamu Ishizaki, Ibaraki, JP;
Satoru Ohnuki, Ibaraki, JP;
Toshinori Sugiyama, Tsukuba, JP;
Kazuko Ishitsuka, Iwai, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
On a surface of a transparent substrate,having a preformat pattern,formed thereon are laminated a first recording layer,in which a recording state exists in one different magnetic field region of an applied external magnetic field and a second recording layer,in which two recording states exist in magnetic field regions different from that for the first recording layer. As required, dielectric layers,and,, a reflecting layer,and a protection layer,can be laminated. The 4-valued recording of information becomes possible by assigning information signals “1”, “0”, “3”, and “2” to H,, H,, H,and H,, respectively.