Disc changer, method of detecting mode thereof, and method of selecting disc ejection

A disc changer capable of selecting a disc set on a desired subtray among a plurality of subtrays and recording and reproducing the disc, comprising:

• a device frame;
• the plurality of subtrays;
• a main tray for accommodating said subtrays, accommodated in said device frame;
• a first motor for driving said main tray;
• a second motor for driving said subtrays;
• and
• a mode-detecting mechanism including means for identifying an operation, cams respectively operated by powers supplied from said first and second motors, each cam provided with said identifying means, sensors for detecting said identifying means moving according to the operation of said cam, each composed of a set of a light-emitting element and a light-receiving element, a control section for receiving operation signals detected by said sensors to control the operation of the disc changer, and transmission gears for driving said cams, said transmission gears interlocking with a transporting gear meshing with a rack of said main tray for carrying the main tray out with the subtray put thereon.