Disc cartridge and dust-proofing system in disc drive system

摘要

A disc cartridge which includes a dust-proofing mechanism having a dust-proofing panel, a dust-proofing arm and a dust-proofing plate which are arranged facing the major surface, bottom surface and both lateral surfaces of the disc cartridge loaded in position to prohibit intrusion of dust and dirt into the inside of the device via a cartridge insertion and/or removal opening. The disc cartridge includes a main cartridge body unit having a detection hole for detecting a second disc housed in the disc cartridge on insertion of a detection switch provided on the device. The detection hole is formed so that its one end in the depth-wise direction is closed. The detection hole is formed to a depth such that an actuator of the detection switch is not abutted on the hole bottom. This prohibits dust and dirt from being intruded into the main body unit of the disc drive device.