A disk cartridge in which a pair of shutter members can be opened and closed
smoothly
and reliably, and a dust-proof property and an airtightness of a large opening
portion can be increased by reducing a space between a pair of shutter members
and a cartridge housing as much as possible. The disk cartridge comprises a cartridge
housing in which a disk compartment is formed-between an upper shell and a middle
shell by overlapping the upper shell, the middle shell and the lower shell and
the middle shell is supported by the upper shell and the lower shell so as to become
freely rotatable, an optical disk rotatably stored within the disk compartment
and a pair of shutter members attached to the middle shell in such a manner that
they can be moved in the plane direction on the same plane. A shutter opening and
closing mechanism for opening and closing opening portions by moving the pair of
shutter members based rotation of the middle shell.
