OVERWRITABLE MAGNETO-OPTICAL RECORDING METHOD, MAGNETO-OPTICAL RECORDING MEDIUM USED BY SAME AND MAGNETO-OPTICAL REPRODUCING METHOD

PURPOSE:To cast a narrowed laser beam on the front of a track and to set a recording width below a prescribed one by exploiting laser's cohesive property excellent in terms of space and hour and narrowing a beam to a spot almost the same as a diffraction limit determined by the wavelength of a laser beam. CONSTITUTION:The laser beam L is narrowed and heated on the recording layer of a substrate 20a in an optical magnetic recording body. A recording magnetic field Hb with a direction opposite to an initialized field during the heating is impressed on the heated part from the outside. By impressing the recording magnetic field Hb, the coercive force Hc of the heated part is partially decreased to minimize the recording magnetic field Hb. As a result, the magnetization of the part is in the direction of the recording magnetic field Hb to form a magnetized bit conversely. The cohesive property of the laser is exploited to project a small spot narrowed to the same level of the diffraction limit determined by the laser beam on the track, and a bit with a width narrower than a prescribed one is formed on the recording layer accordingly.