| 摘要 |
PURPOSE:To simplify and scale down a device by irradiating a laser beam, switching an impressed magnetic field at a high speed corresponding to recorded information so as to form a magnetic domain, reproducing information from the rotation of the deflected surface of a laser reflected light beam corresponding to the magnetization direction of the magnetic domain and returning it to the degaussed state by impressing a magnetic field and irradiating the laser beam. CONSTITUTION:When information is recorded on an optical magnetic disk 1, a laser power Pw at a constant level is irradiated on a disk track, and simultaneously a magnetic field (amplitude+ or - Hw and bias HB) modulated by recorded information is offered. It is adjustable by a current source 20, and at this time the magnetic domain corresponding to the recorded information having Kerr rotational angle of + or -thetak is formed on the disk track. When erasure is continuously carried out, a laser power PE at a constant level is irradiated on the track of the disk, where information has been recorded, and sumultanously a magnetic field HE at a constant level is supplied. At this time the disk track is returned to its degaussed state. |
