Disk cartridge

摘要

A disk cartridge has a spindle insertion hole (8) and a head insertion hole (9). A pair of projections (800,800) project inwardly from adjacent portion between the two holes (8,9).
Each of the projections (800,800) has a triangle which comprises a straight side (801) extending almost perpendicularly to a lateral side of the head insertion hole and an arched side (802) forming part of edge of the spindle insertion hole (8). An almost annular projection (85) being formed on an inner wall of the case of the disk cartridge along peripheral edge of the spindle insertion hole (8) or at a position separated outwardly in radius direction of the spindle insertion hole (8) from a peripheral edge of the spindle insertion hole (8) in such a manner that opposite ends of the annular projection are extended on each of the triangle projections in arched shape. The annular protection has a small width to be opposed to a non-recording surface of the disk so as to surround the spindle insertion hole.