Magnetic or optical disk cartridge

A cartridge accommodating a disk therein, wherein:

• the cartridge has a rectangular shape having first to fourth corners;
• at least three mis-insertion protection mechanisms are provided each at a position which is on a side surface section of the cartridge and which is spaced apart from each of the first to fourth corners, the at least three mis-insertion protection mechanisms being provided for preventing the cartridge from being inserted into a cartridge holder in a wrong direction;
• a first concave-shaped auto-loading slot and a second concave-shaped auto-loading slot are provided in the side surface section;
• each of the first to fourth corners is shaped so as to allow for the cartridge to be inserted into the cartridge holder;
• the side surface section has a first side surface and a second side surface each being formed in a direction which is substantially perpendicular to a surface of the disk and substantially parallel to a direction in which the cartridge is inserted into the cartridge holder;
• the at least three mis-insertion protection mechanisms include a first mis-insertion protection mechanism provided in the first side surface, a second mis-insertion protection mechanism provided in the second side surface, and a third mis-insertion protection mechanism provided in the first side surface;
• the first auto-loading slot is provided in the first side surface and the second auto-loading slot is provided in the second side surface;
• the first auto-loading slot is provided on an opposite side of the first mis-insertion protection mechanism with respect to the third mis-insertion protection mechanism;
• the cartridge holder has a mis-insertion protection member located within an insertion path along which the cartridge is inserted into the cartridge holder;
• each of the first to fourth corners is shaped so as to abut the mis-insertion protection member to move the mis-insertion protection member out of the insertion path;
• each of the first, second and third mis-insertion protection mechanisms is shaped so as to engage with the mis-insertion protection member;
• and
• the first auto-loading slot is located such that the mis-insertion protection member engages with the third mis-insertion protection mechanism after the mis-insertion protection member passes over the first auto-loading slot.