Disk-shaped information recording medium, disk cartridge, and information recording/reproducing apparatus

摘要

The disk-shaped information recording medium having an outer diameter and an inner diameter comprises a substrate having a predetermined thickness, a first side that is one side of the substrate, a second side that is the other side of the substrate, a cylindrical portion forming a through hole formed at a center of the substrate, and a thin portion formed so as to surround an outer diameter of the cylindrical portion. The thin portion is thinner than the predetermined thickness and includes a non-inclined surface and an inclined surface formed on an outer diameter side of the non-inclined surface. The inclined surface is inclined at a predetermined angle to the non-inclined surface and is larger than the non-inclined surface in the thin portion.

主权项

1. A disk-shaped information recording medium having an outer diameter and an inner diameter, the information recording medium comprising:
a substrate having a predetermined thickness; a first side that is one side of the substrate; a second side that is the other side of the substrate; a cylindrical portion forming a through hole formed at a center of the substrate; a thin portion formed so as to surround an outer diameter of the cylindrical portion, the thin portion being thinner than the predetermined thickness; a non-inclined surface formed at the thin portion; an inclined surface formed on an outer diameter side of the non-inclined surface at the thin portion, the inclined surface being inclined at a predetermined angle to the non-inclined surface and being larger than the non-inclined surface in the thin portion; and a curvature portion formed between the non-inclined surface and the inclined surface.