| 摘要 |
PROBLEM TO BE SOLVED: To perform the further more multi-valued recording by controlling the size of a mark with a single pulse. SOLUTION: Power levels of laser beams 19 are arranged to be three steps P1, P2, P3, and the sizes of the power levels P1, P2, P3 are settled to have the relation P1>P2>P3, and the power level P2 is formed to the constant level among each recording unit, and the laser beams 19 are modulated by changing the power levels in order of P2, P1, P3, P2 and in order of P2, P1, P2, and also changing pulse widths T1, T2 which are the times to hold the power levels P1, P3, then the multi-valued information is recorded on the information recording medium 1 with the single pulse by changing the lengths of the recording mark 201 in the tangential direction and the radial direction of the disk. |
