| 摘要 |
<p>In write power adjustment for an optical disc having a plurality of information storage layers, data of trial writing is varied by the influence of layers other than a target layer. It is difficult, therefore, to determine optimal write power. A modulation M[m] is obtained from a reproduction signal amplitude of a signal subjected to the trial writing performed with use of write powers Pw[m] (m being an integer) of a plurality of kinds. At least an optimum write power intercept Pint - opt is determined by fitting a relation between the Pw[m] and the M[m] by a modulation characteristic formula M = Masy x (1-(Pint-Pasy)/(Pw-Pasy)) having an asymptotic modulation Masy, a write power intercept Pint, and an asymptotic write power Pasy as parameters. Approximation accuracy by the fitting andfor quality of the trial writing signal are evaluated with use of at least the M[m], the modulation characteristic formula, and the Pint-opt. An optimum write power Pw-opt is calculated by performing a specified operation at least with use of the Pint - opt.</p> |
