| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical disk initializing apparatus in which a light quantity of a laser beam to be radiated on a multi-layer optical disk is made proper without being affected by a inter-layer crosstalk of the multi-layer optical disk. <P>SOLUTION: The optical disk initializing apparatus initializes each recording layer of the optical disk DK having two recording layers by an elliptic light spot, and is provided with: quadrant photodetectors 21, 22 which are divided into four rhombic regions having light receiving areas equal to each other and are arranged before and behind the converging point of a reflection light, respectively; computing devices 31, 32 for producing a SUM signal from detected signals A1-D1, A2-D2 coming from the quadrant photodetectors 21, 22; and SUM signal producing circuit 37. The SUM signal is calculated by (A1+B1-(C1+D1))+(A2+B2-(C2+D2)), and by this SUM signal, a reflected light quantity from each recording layer is detected, and the light quantity of the outgoing laser beam is set. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
