A disc cartridge contains an optical disc with data to be processed by an information processing device. The device has a turntable for holding the optical disc. The optical disc held on the turntable is turned by a motor. The device also has a first optical head for focussing a light beam onto a surface of the optical disc at one location and a second optical head for focussing a light beam onto a surface of the disc at another location, which lies opposite the first location with respect to the axis of rotation of the disc. The disc cartridge includes a casing for rotatably accommodating the optical disc and a closure, which is fitted movably on the casing. The casing has openings for exposing surfaces of the optical disc onto which the light beams of the optical heads are focussed. The closure device is used in order to open and close the openings.
