Disk cartridge

摘要

The present invention relates to an improved disc cartridge 203 comprising first and second disc housing portions 920, 930 each of which defines a space to house a portion of a disk 910 with an information storage layer on at least one side thereof and which house the disk 910 in its entirety when put together; a supporting base member 940 that has a disk housing rotating and supporting portion for rotating and supporting the first and second disk housing portions 920, 930 so as to open or shut a window 900A with respect to the disk 910 such that the disk 910 gets chucked externally, and a head is able to access the disk 910 and read and write information from/on the information storage layer thereof, through the window 900A; and a locking member 950, 960 for keeping the first and second disk housing portions 920, 930 closed from rotating, wherein the supporting base member 940 has at least one side surface that crosses, at right angles, a line segment that connects together the respective centers of rotation of the first and second disk housing portions 920, 930, and wherein the side surface runs parallel to the disk 910 housed in the first and second disk housing portions 920, 930 and has a main groove 940AL, 940AR that includes a bottom, an opening on the bottom, and a protrusion 947L, 947R on the bottom, and wherein the locking member 950, 960 includes a locking/unlocking portion 952, 962 for unlocking the first and second disk housing portions 920, 930 externally, and wherein the locking/unlocking portion 952, 962 protrudes through the opening of the main groove 940AL, 940AR to first and second levels C1, C2, C3, C4 when the first and second disc housing portions 920, 930 are locked and when the first and second disk housing portions 920, 930 are unlocked, respectively, the second level C1, C2 being lower than the first level C3, C4, a level B5, B6 reached by the protrusion 947L, 947R on the bottom of the main groove 940AL, 940AR being lower than the first level C3, C4 but higher than the second level C1, C2.