Disc cartridge with thick portion surrounding head insertion hole

摘要

A disc cartridge capable of preventing entering of dust into a casing and ensuring a stable and positive operation without damaging a disc while satisfactorily exhibiting a cleaning effect and keeping proper contact between a recording head and the disc. A casing is provided thereon with a slide area which is formed by a slide area defining section of the casing. The slide area is formed with at least one head inserting hole. The slide area defining section is provided on an inner surface thereof with at least one thick-walled portion in a manner to extend along a whole periphery of a portion of the head inserting hole overlapping a sheet-like liner and inwardly project from the inner surface of the casing, so that the liner may be pressed against the disc at a force of a constant level over a wide area of the disc and block a communication between an exterior of the cartridge and its interior through the head inserting hole.