Patent ID: 7199976

Claim:
A reel lock mechanism of a tape cassette for locking tape reels of the tape cassette having the tape reels upon which a tape-shaped recording medium is wound rotatably supported inside a cassette shell, the reel lock mechanism comprising: a slider which is disposed in a space between the two tape reels and the inside surface of a back wall of the cassette shell, the slider being supported so as to be movable forward and backward; two lock portions which are rotatably supported at both the left and right sides of the slider; a slide spring for pushing the slider forward; and a lock spring for biasing the lock portions in directions in which the lock portions engage the respective tape reels; wherein loading of the tape cassette into a tape drive device causes the slider to withdraw and the lock portions to rotate in directions in which the lock portions move away from the respective tape reels in order to unlock the tape reels; wherein each lock portion has a front portion including an anchoring pawl which engages the tape reel and a back portion extending in a direction substantially opposite to the front portion with a support portion supported by the slider serving as center; and wherein, when the slider withdraws, the slider moves rectilinearly from a first position to an intermediate position and then to a second position, and when the slider is in the intermediate position, the back portion of each lock portion comes into contact with the inside surface of the back wall of the cassette shell, and when the slider moves from the intermediate position to the second position, the back portion of each lock portion slides along the inside surface of the back wall of the cassette shell causing each lock portion to rotate in an unlocking direction, so that each anchoring pawl separates from the tape reel.