Patent ID: 7751288

Claim:
A write power adjustment method that is used to test-write a signal onto an information recording medium at a plurality of different power levels and adjust write power in accordance with read signal quality of the signal when the information recording medium is irradiated with light to write information onto the information recording medium and/or read information from the information recording medium, the write power adjustment method comprising the steps of: determining a modulation Mm from a read signal amplitude of the signal that is test-written at the plurality of different levels of write power Pwm; setting a write power compensated value Pcn; determining an evaluated value Smn=Mm×(Pwm−Pcn) from the modulation Mm and compensated write power (Pwm−Pcn), which is obtained from the write power compensated value Pcn and the write power Pwm; determining an optimum write power compensated value PcO in accordance with the relationship between the compensated write power (Pwm−Pcn) and the evaluated value Smn; determining compensated write power PthO that provides an evaluated value SmO of zero when the relationship between compensated write power (Pwm−PcO) for the optimum write power compensated value PcO and the evaluated value SmO is subjected to linear approximation; determining a write power threshold Pth by using the compensated write power PthO and the optimum write power compensated value PcO; and determining optimum write power Popt in accordance with the write power threshold Pth.