Patent ID: 7349315

Claim:
An information recording method, comprising: first irradiating an optical information recording medium comprising a phase change recording layer on a substrate having a guide groove with continuous light of a laser beam having an erase power level Pe to determine a transition linear velocity Vo defined as a minimum linear velocity, above which the following relationship is satisfied: Rr=Ra/Rb< 1, wherein Rr represents a reflection light intensity ratio, and Ra and Rb represent a reflection light intensity measured after and before the irradiation of the optical information recording medium with the continuous light, respectively; and then second irradiating the optical information recording medium with a laser beam, which is modulated by a pulse width modulation (PWM) system so as to have at least a recording power level Pw and the erase power level Pe, to form marks and spaces therebetween having a length of nT in the optical information recording medium by causing a phase change in the phase change recording layer, wherein n represents a natural number and T represents a basic clock cycle, wherein the erase power level Pe of the continuous light of the laser beam with which the medium is irradiated to determine the transition linear velocity Vo satisfies the following relationships: ( Pwo/ 2)≦ Pe ≦( Pwo/ 2)×1.5, wherein Pwo is an optimum recording power level for use in recording information with intensity modulated pulse patterns.