| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem that when a scoop phenomenon occurs, in which the quantity of emission light of a laser is varied due to light and darkness (level) of the quantity of reflection light of a recording mark and a space portion, and furthermore variation of the quantity of emission light of the laser due to the scoop phenomenon is different for each of disks or each of positions in a radial direction of the same disk, and still furthermore stray light from other layers occurs in a multilayer recording medium, a β value is shifted from the original β value obtained from a peak value and a bottom value of the quantity of reflection light at a constant quantity of emission light of the laser, and consequently wrong power correction may be performed. <P>SOLUTION: A means for measuring a level of stray light from other layers; a scoop correction means that calculates a variation level of the quantity of emission light of a laser in a recording mark and a space portion due to scoop, and calculates the scoop correction coefficient for correcting variation of the quantity of emission light using the variation level; a peak value correction means and bottom value correction means for correcting the peak value and the bottom value using the scoop correction coefficient and the level of stray light from other layers; and a β value calculation means for calculating the β value using the corrected peak and bottom values are provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
