Disc cartridge having a shutter that includes a convex portion protruding into a center hole of the disc

A disc cartridge comprising:

• a cartridge body including a disc storage portion, a chucking opening and a head opening, wherein the disc storage portion stores a disc, having first and second sides, therein so that the disc is rotatable in the disc storage portion;
• the chucking opening is formed on the bottom of the disc storage portion so as to get the disc chucked externally;
• and the head opening is also formed on the bottom of the disc storage portion so as to allow a head, which reads and/or writes a signal from/on the second side of the disc, to access the second side of the disc;
• and
• a shutter, which is supported to, and movable with respect to, the cartridge body between the disc and the bottom of the disc storage portion so as to expose or cover the chucking opening and the head opening,
• wherein the shutter includes a convex portion that is provided for the shutter so as to protrude into a center hole of the disc while the shutter covers the chucking opening and the head opening, and wherein as the shutter is going to be opened, the convex portion lifts the disc in a thickness direction of the cartridge while contacting with the second side of the disc.