Patent ID: 8108885

Claim:
A disk cartridge comprising: first and second disk housing portions, each of which defines a space to house a portion of a disk with an information storage layer on at least one side thereof and which house the disk in its entirety when put together; a supporting base member that has a disk housing rotating and supporting portion for rotating and supporting the first and second disk housing portions so as to open or shut a window with respect to the disk such that the disk gets chucked externally, and a head is able to access the disk and read and write information from/on the information storage layer thereof, though the window; and a locking unit, which includes first and second locking lever portions for keeping the first and second disk housing portions closed from rotating and a locking lever supporting portion that supports the first and second locking lever portions rotatably and that is attached to the supporting base member, wherein the supporting base member has an insertion port to insert the locking unit, and wherein while the locking unit is yet to be inserted into the supporting base member through the insertion port, the first and second disk housing portions open the window to such an angle of rotation that is wide enough to remove the disk easily, and wherein with the locking lever supporting portion inserted into the supporting base member through the insertion port, the first and second disk housing portions contact with the locking unit and have their angle of rotation limited, thereby controlling a size of the window such that the disk is unremovable.