Patent attributes
A thermal activation device includes a platen lock mechanism for locking a platen roller of a platen unit and a heating unit or printing unit into press contact with each other. The platen lock mechanism has a lock arm mounted to undergo rotation about a rotational axis, a shaft member provided in one of the platen unit and the lock arm, an engagement recess for engagingly receiving the shaft member and provided in the other of the platen unit and the lock arm, and an urging member for urging the lock arm in a direction for bringing the shaft member into engagement with the engagement recess. In a state in which the heating unit or printing unit is in press contact with the platen roller, a distance between the rotational axis of the lock arm and an axis of the shaft member is greater than a distance between the rotational axis of the lock arm and the rotational axis of the platen roller.
