发明名称 |
Bias magnetic field abnormality detecting apparatus which controls recording and erasing of information |
摘要 |
The bias magnetic field abnormality detecting apparatus is used in a photomagnetic recording and reproducing apparatus for recording information on a recording medium or for reproducing and erasing the information from the recording medium and is provided with a field magnetic coil generating a magnetic field in the reverse direction at the time of recording and erasing information but generating no magnetic field at the time of reproducing information. A magnetic field detecting circuit detects the polarity of at least the magnetic field of the field magnetic coil and detects whether the magnetic field is abnormal or not. A writing in protecting circuit prohibits the recording and erasing operations by the output of the magnetic field detecting circuit.
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申请公布号 |
US4979158(A) |
申请公布日期 |
1990.12.18 |
申请号 |
US19880161590 |
申请日期 |
1988.02.29 |
申请人 |
OLYMPUS OPTICAL CO., LTD. |
发明人 |
YODA, YOSHIRO |
分类号 |
G11B5/02;G11B11/10;G11B11/105;G11B19/04 |
主分类号 |
G11B5/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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