| 摘要 |
PURPOSE:To enable overwriting without executing erasing operation by deciding the direction of an externally impressed magnetic field and whether a clock of recording data is to be delayed or not on the basis of sector information recorded in a data management area. CONSTITUTION:Sector information recorded in the data management area of a magneto-optical recording medium is read out to decide each sector recording method corresponding to the constitution of a file. Then, a preformat part is read out to decide whether the read address is an objective address or not, and in case of a correct address, the recording magnetization polarity is set up in accordance with the decided recording method. Whether the clock is to be delayed or not is decided so that the trailing edge of a recording pulse is positioned on the center of a data cell in accordance with the preceding recording state and the clock is delayed in accordance with necessity. Consequently, the recording state is erased by switching the polarity of an external magnetic field and radiating a recording waveform and then data can be recorded and overwritten only by one head without using an erasing head by successively recording data in a user area. |
