Patent ID: 8050158

Claim:
A method for adjusting write power when irradiating an information write medium with light by conducting trial writing of a signal in the information write medium with write power of a plurality of kinds and adjusting write power on the basis of read signal qualities of the signal, the method comprising the steps of: finding a modulation M,m from read signal amplitude of a signal subjected to trial writing by using write power Pw,m of a plurality of kinds; fitting a modulation characteristic formula M,m=Msat(1−(Pws−Pasy)/(Pw,m−Pasy)) having a saturated modulation Msat, write start power Pws, and asymptotic power Pasy as parameters to a relation between the write power Pw,m and the modulation M,m, and thereby determining optimum write start power Pws-opt which is an optimum value of the write start power Pws; and calculating optimum write power Pw-opt by performing predetermined computation using the optimum write start power Pws-opt.