Playback mechanism of recording medium

A playback mechanism of a recording medium comprising:

• a pair of nipping devices for nipping the recording medium and conveying the recording medium into an instrument body;
• a clamp playback device for clamping the recording medium conveyed into the instrument body and reading out information recorded in the recording medium;
• a locking device for locking the clamp playback device relatively to the instrument body, the locking device being movable within a range between a locking position where the clamp playback device is fixed relatively to the instrument body and a lock-releasing position where the clamp playback device is movable relatively to the instrument body;
• and
• a cooperation device for gradually parting each of the pair of the nipping devices from the recording medium when the clamp playback device clamps the recording medium conveyed by the pair of the nipping devices, and for gradually shifting the locking device from the locking position to the lock-releasing position so that the clamp playback device becomes movable relatively to the instrument body in response to a movable range of the recording medium, the movable range being formed due to that each of the pair of the nipping devices gradually parts from the recording medium.