| 摘要 |
PURPOSE:To reduce an area where a magnetizing direction is uncertain which causes a noise and to enable a recording by which a satisfactory regenerative signal can be obtain by setting the temperature of a magnetic thin film to less than a recording threshold value during the switching period of a recording magnetic field. CONSTITUTION:At the time of driving a semiconductor laser 5, and an electro- magnet 7, a timing signal by which the irradiation of a light beam is stopped or the intensity of the light beam is decreased in advance of the start of the inversion of the magnetic field, and the irradiation of the light beam is started or the intensity of the light beam is increased in advance of the completion of the inversion of the magnetic field, is supplied from a timing signal generating circuit 15 to a magnetic field modulation circuit 8 and an optical modulation circuit 11. |
