Patent ID: 7537402

Claim:
A thermal activation device, comprising: heating means for thermally activating a heat-sensitive adhesive layer of a sheet material having the heat-sensitive adhesive layer; a platen unit having a platen roller mounted to undergo rotation about a rotational axis for conveying the sheet material, the platen unit being movable in a direction for bringing the platen roller into and out of press contact with the heating means; and a platen lock mechanism for locking the platen roller and the heating means into press contact with each other, the platen lock mechanism having a lock arm engaged with the platen unit and 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; wherein in a state in which the heating means 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.