发明授权
- 专利标题： Perpendicular magnetic recording medium
- 专利标题（中）： 垂直磁记录介质
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申请号： US372307申请日： 1989-06-27
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公开(公告)号： US4966821A公开(公告)日： 1990-10-30
- 发明人: Ikue Kawashima , Futoyoshi Koh , Masafumi Kumano , Shinei Ryu
- 申请人： Ikue Kawashima , Futoyoshi Koh , Masafumi Kumano , Shinei Ryu
- 申请人地址： JPX Tokyo JPX Miyagi
- 专利权人： Ricoh Company, Ltd.,Ricoh Research Institute of General Electronics Co., Ltd.
- 当前专利权人： Ricoh Company, Ltd.,Ricoh Research Institute of General Electronics Co., Ltd.
- 当前专利权人地址： JPX Tokyo JPX Miyagi
- 优先权： JPX61-168915 19860717; JPX62-73762 19870326
- 主分类号： G11B5/00
- IPC分类号： G11B5/00 ; G11B5/66 ; G11B5/73
摘要：
A perpendicular magnetic recording medium is disclosed, which comprises a substrate, a soft magnetic layer formed on the substrate, a lower recording layer having a coercive force of Hcl formed on the soft magnetic layer, and an upper recording layer having a coercive force of Hcu, with the coercive ratio of Hcu/Hcl being in the range of 1.4 to 3.3, that is, 1.4.ltoreq.Hcu/Hcl.ltoreq.3.3.
公开/授权文献
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