Disk drive apparatus with shutter locking mechanism which is preventive of play of disk cartridge in loading condition

A disk drive apparatus for driving a recording medium disk housed within a disk cartridge having a disk access window and a sliding shutter, comprising:

• a chassis;
• a disk driving mechanism including disk chucking means for chucking the disk on a turn table and for rotatingly driving the disk, said disk driving mechanism being mounted on the chassis;
• cartridge holder for receiving the disk cartridge and for carrying the disk cartridge between a predetermined unloading position at which said disk cartridge is externally accessible for insertion and extraction and a predetermined loading position at which the disk is chucked by the disk chucking means;
• a cartridge holder lifting mechanism for shifting said cartridge holder between said unloading and loading positions;
• shutter operating means incorporated in said cartridge holder for shifting said sliding shutter between an open position in which said disk access window is exposed for reading and/or writing information on the disk and a closed position in which said disk access window is blocked, said shutter operating means including a pivotal arm for carrying said sliding shutter between said open and closed positions according to the relative positions of said disk cartridge and said cartridge holder;
• arm lock means incorporated in said cartridge holder for locking said pivotal arm at a position corresponding to the fully open position of said shutter;
• and,
• cartridge lock means incorporated in said cartridge holder for locking said disk cartridge within said cartridge holder, said cartridge lock means being engaged when said disk cartridge is fully inserted within said cartridge holder,
• wherein said cartridge lock means comprises a slide plate movable within said cartridge holder in the direction of motion of said disk cartridge, said movement depending upon the relative position of said disk cartridge and said cartridge holder, and a pivotal lever carrying a cartridge locking pin, said pivotal lever being cooperated with said slide plate to engage said cartridge locking pin into a locking pin receptacle in said disk cartridge at the fully inserted position of said disk cartridge;
• and,
• wherein said side plate is biased by said pivotal arm of said shutter operating means to a position for establishing locking engagement between said cartridge locking pin and said locking pin receptacle at the locked position of said pivotal arm by said arm lock means.