公开(公告)号：EP0762410A1

公开(公告)日：1997-03-12

申请号：EP95918157.9

申请日：1995-05-10

申请人： HITACHI MAXELL, LTD.

发明人： SHIMAZAKI, Katsusuke ,  YOSHIHIRO, Masafumi ,  SAKEMOTO, Akito ,  OHTA, Norio ,  ISHIZAKI, Osamu ,  OHNUKI, Satoru ,  SUGIYAMA, Toshinori ,  ISHITSUKA, Kazuko

IPC分类号： G11B11/10

CPC分类号： G11B11/10515 ,  G11B11/10502 ,  G11B11/10508 ,  G11B11/1051 ,  G11B11/10521 ,  G11B11/10528 ,  G11B11/1053 ,  G11B11/10534 ,  G11B11/10554 ,  G11B11/10586 ,  G11B11/10595

摘要： On a surface of a transparent substrate 1 having a preformat pattern 2 formed thereon are laminated a first recording layer 4 in which a recording state exists in one different magnetic field region of an applied external magnetic field and a second recording layer 6 in which two recording states exist in magnetic field regions different from that for the first recording layer. As required, dielectric layers 3, 5 and 7, a reflecting layer 8 and a protection layer 9 can be laminated. The 4-valued recording of information becomes possible by assigning information signals "1", "0", "3" and "2" to H 0 , H 1 , H 2 and H 3 , respectively.