公开(公告)号：US5208797A

公开(公告)日：1993-05-04

申请号：US612798

申请日：1990-11-14

申请人： Yoshiyuki Nakaki ,  Takashi Tokunaga ,  Tatsuya Fukami ,  Motohisa Taguchi ,  Kazuhiko Tsutsumi

发明人： Yoshiyuki Nakaki ,  Takashi Tokunaga ,  Tatsuya Fukami ,  Motohisa Taguchi ,  Kazuhiko Tsutsumi

IPC分类号： G11B11/10 ,  G11B11/105 ,  G11B13/00

CPC分类号： G11B11/10586 ,  G11B11/10506 ,  G11B11/10521

摘要： In a magneto-optical recording system for recording information with bits having upward magnetization and having downward magnetization on a recording layer of a magneto-optical recording medium, having four magnetic layers exchange-coupled with each other. A laser beam directed onto the medium is modulated to heat the magneto-optical recording medium to two values, for "High" writing and for "Low" writing. During "High" writing, the first to third layers lose magnetization because their Curie temperatures are exceeded, and the direction of the magnetization of the first layer, which is the recording layer is determined mainly by the magnetostatic coupling from the the fourth layer. During "Low" writing, the first and the third layers lose their magnetization as their Curie temperatures are exceeded, and the direction of the magnetization of the first layer is determined by the exchange coupling from the second layer, which in turn is dependent on the exchange coupling from the fourth layer.