A disc drive apparatus includes a tray member, on which a bare disc, or a
cartridge accommodating a disc therein is placed, and a disc drive
device, into or from which the tray member is loaded or ejected by a
drive unit. A medium detection system includes detection holes provided
on the tray member to detect a disc or a cartridge. In addition, provided
on the disc drive device is a detection unit to optically detect a state
including a type of a disc or a cartridge placed on the tray member based
on whether the detection holes are shaded in the course of loading of the
tray member.