The overwriting characteristics of magneto-optical disk by magnetic field modulation method

To achieve a direct overwriting on magnetooptical disk, we investigated the magnetic field modulation recording. Several cylindrical magnetic heads were prepared as magnetic field modulation recording heads and recording characteristics were measured using those heads. It was found that the inductance of a head is the chief source of limiting recording frequency. A C/N of 50 dB was obtained at a modulating frequency of 1 MHz. Former recorded signals (hereafter said to be pre-signals) were completely overwritten when the overwriting laser power was the same as the recording power at the former recording process.