Information recording disk.

摘要

An information recording disk having a recording layer for recording information, two bonded disk substrates (11, 12), and a hub (14) for clamping the disk. Holes formed in the central portion of the disk substrates have different diameters, or a hole formed in one of the disk substrates is stepped. With this structure part of or the entire hub is received in the disk substrates, so that the hub projects only partially or does not project at all.