Patent ID: 7193950

Claim:
An optical recording method which records a data signal indicating a sequence of data blocks in a recording layer of an optical recording medium by emitting light to the recording layer of the medium and changing a phase of a recording material of the recording layer, comprising the steps of: setting a linear velocity of rotation of the medium substantially in a speed range from 5 m/s to 28 m/s; converting each data block in the data signal into a power level and a pulse width by using eight-to-fourteen modulation EFM; applying a light source driving power to a light source to control emission of a light beam to the recording layer of the medium, the driving power including a sequence of mark and space portions according to the modulated data signal, each mark portion having a pulse width that corresponds to a multiple of a period T of a write clock based on the EFM; setting a multi-pulse waveform of each mark portion of the driving power that includes a front-end portion, a multi-pulse portion and a tail-end portion, the front-end portion having a first pulse width t 1 with a high-power write level Pw and starting from a middle-power erase level Pe, the multi-pulse portion including a sequence of write pulses each having a second pulse width t 2 with the write level Pw and a third pulse width t 3 with a low-power base level Pb, the multi-pulse portion having a given duty ratio z=t 2 /(t 2 +t 3 ), and the tail-end portion having a fourth pulse width t 4 with the base level Pb and ending at the erase level Pe; and controlling the waveform such that the first pulse width t 1 of the front-end portion ranges from 0.1T to 1T and the fourth pulse width t 4 of the tail-end portion ranges from 0.2T to 1.3T.