| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an information recording medium wherein one surface is provided with a plurality of recording layers, and recording and reproduction are performed with high accuracy even in any recording layer. <P>SOLUTION: In this disk-shaped information recording medium having a plurality of laminated recording layers (214, 215), each of the recording layer has a spiral track (14) consisting of a plurality of circumferences and at least one index header (12) aligned in the radial direction of a disk so as to disconnect a portion of the spiral track. The index header has the address data of each track recorded with embossed pits, and portions of or all of the index header of each of the recording layers are arranged so as to overlap from the viewpoint of an incident face of a light beam. <P>COPYRIGHT: (C)2004,JPO |
