Protecting a disc cartridge from inadvertent actuation during nonuse

A disc cartridge, comprising:

• a casing comprising an upper cover plate and a lower cover plate joined together to define a space therewithin and having a front end at which said cartridge is inserted into a disc player;
• a disc rotatably housed in said casing;
• a shutter for operating at least one window provided in said casing for insertion of a disc driving element of the disc player therethrough into said casing, and for closing said window during non-use of said disc cartridge;
• a pair of actuators arranged in said casing;
• a shutte lock element for releasably locking said shutter, said shutter lock element comprising at least one of said actuators;
• a pair of disc receivers, each arranged in said casing and operatively connected to one of said actuators to selectively receive a part of a peripheral portion of said disc to hold said disc at a substantially central position in said casing in a thickness direction of said casing, by pivotal movement of said disc receivers;
• connection means for operatively connecting each of said actuators to the corresponding disc receiver;
• said connection means comprising a guide groove provided in one of said actuator and corresponding disc receiver, and a guide pin provided on the other of said actuator and said corresponding disc receiver, said guide pin being positioned within said guide groove and being selectively engagable with said guide groove;
• said actuator or disc receiver provided with said guide groove additionally being formed with a depression situated at a distall end of a surface of said guide groove on a side thereof toward the front end of the casing, said depression enlarging said guide groove to position said surface of said guide groove outside of a locus of pivotal movement of said guide pin during non-use of said disc cartridge, and to carry out delayed actuation of said disc receiver with respect to said actuator, at the time of starting of the disc cartridge;
• elastic means for forcing said actuator and corresponding disc receiver toward said front end of said casing;
• and
• a position regulating element for stopping movement of said corresponding disc receiver during non-use of said disc cartridge.