| 摘要 |
PURPOSE:To prevent a track jump, a miserasing, and a misrecording, by providing a photosensor means which receives reflecting light, or transmitting light from a recording medium for an erasing beam, and obtaining a recording control signal from the photosensor means. CONSTITUTION:A control beam B3 is made incident on photosensors 12 and 15, and a focus error signal can be obtained from a four-sected photosensor 12, and a tracking error signal can be obtained from a bisected photosensor 15. And since an address signal can be obtained as the sum signal of the bisected photosensor 15, and the reflecting light of a recording beam B2 is not made incident on the photosensors 12 and 15, an accurate address signal can be obtained. According to the address signal, the direction of a current impressed on a coil 17 at every recording track is switched, then the polarity of a bias magnetic field is switched, and the recording of new information by the recording beam B2 can be performed, while erasing recorded information by an erasing beam B1. Thus, the miserasing, the misrecording, or the track, jump can be prevented from occurring.
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