摘要 |
A method for erasing and recording information on an optical recording member of the type wherein a new signal is overwritten on a previously recorded track by means of a single laser spot passing only once thereon. The method comprises the steps of modulating a recording laser power to a recording power level (PW): maintaining the laser power at the recording power level (PW) for a time corresponding to data to be recorded: lowering the laser power to a cooling power level (PC) which is lower than the recording power level (PW); and maintaining the laser power level at the cooling power level (PC) for a predetermined period, to thereby record information. By modulating the recording laser power at three power levels, the irradiation power becomes small immediately after the recording power level and thus the irradiated parts can be cooled quickly. Therefore, a large amorphous area can be formed or a large difference between complex refractive indexes can be obtained, since the microcrystals are hardly included in the recording part, and the complex refractive index of the recording bit becomes small. Therefore, a large reproduced signal is obtainable. PAT 11595-1 |