Patent ID: 7085211

Claim:
A method of determining an optimum recording power based on a relationship between modulation parameters and recording powers which are provided through a test writing in which writing a pattern of marks and spaces to an optical storage medium with a recording power p is repeated by sequentially changing the recording power p with increments of a predetermined power, a test reading in which reading the pattern from the storage medium is repeated so that data signals are reproduced from the respective patterns on the storage medium, and a calculation of a modulation parameter m for each of the reproduced data signals, each modulation parameter m corresponding to one of the respective recording powers p, the method comprising the steps of: selecting a sequence of pairs of the modulation parameter m and the corresponding recording power p from all of the modulation parameters and the recording powers; calculating a gamma=(Δm/m)/(Δp/p) for each of the selected pairs of the modulation parameter m and the recording power p, the gamma defining a ratio of a change of the modulation parameter m, normalized by a modulation parameter value, to a change of the recording power p, normalized by a recording power value; and finding a target recording power corresponding to the optimum recording power based on a function derived from a relationship between the calculated gammas and the respective recording power, the target recording power causing a value of the function to be equal to zero, wherein a pair of the modulation parameter m and the recording power p is omitted in the selecting step if a value of the modulation parameter of the pair is not larger than a threshold value, and wherein the threshold value used in the selecting step is set to a predetermined value in order to determine the optimum recording power without being affected by noise.