A disc cartridge can be loaded stably in the disc recorder/player, whether
it is provided with a shutter member or not. The present invention
provides a disc recording and/or playback apparatus including a cartridge
holder in which there is to be held a first disc cartridge including a
body and a shutter member, or a second disc cartridge including a body, a
shutter member supporting mechanism to support, by pressing, the shutter
member of the first disc cartridge to limit the movement of the shutter
member, a pressing mechanism to press the second disc cartridge, and a
pressing controlling mechanism which is moved due to displacement of the
shutter member supporting mechanism by the first disc cartridge to
displace the pressing mechanism for removing the pressure applied to the
first disc cartridge and has the pressing mechanism press the second disc
cartridge inserted in the cartridge holder.