| 摘要 |
PURPOSE:To increase the recording and erasure speed and to attain long range stability of a data by using a magnetic flux generator comprising a core, a coil and an AC power supply so as to generate an eddy current to a specific part of an optical recording medium being an optical disk so as to heat the part. CONSTITUTION:A magnetic head 20 is formed by the core 22, the coil 26 and the AC power supply 28. In giving an AC current to the coil 26, an alternate magnetic flux phi is generated and an eddy current is produced to a recording material 14 being a conductor of the disk 10. A core B24 is opposed via the disk 10 to a core A22, most of the magnetic flux phi passes through the core B24 and penetrates a recording film 14. Further, the eddy current flows around magnetic poles N, S, the current density is lower around the magnetic pole and high among the magnetic poles. The temperature of the recording film 14 rises by Joule's heat by the eddy current and the temperature is higher especially among the magnetic poles. Thus, the preheat for erasure and recording is applied from the internal side of the disk 10. Thus, the speed of erasure and recording rises and the long range stability of data is attained.
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