Patent ID: 7556445

Claim:
A thermal activation device comprising: heating means for thermally activating a heat-sensitive adhesive layer of a sheet material having a printing layer on one surface of a sheet-like base material and the heat-sensitive adhesive layer on the other surface thereof; a platen roller that conveys the sheet material, the platen roller being disposed in pressure contact with the heating means so that the platen roller and the heating means apply a holding force on the sheet material; a pair of conveyor rollers that hold and convey the sheet material, the pair of conveyor rollers being disposed on an upstream side of the heating means in a conveying direction of the sheet material and applying a holding force on the sheet material larger than the holding force applied on the sheet material by the platen roller and the heating means; and drive force shielding means for shielding a rotational drive force of the platen roller in response to a tension applied to the sheet material held between the pair of conveyor rollers and between the platen roller and the heating means; wherein when the heating means thermally activates the heat-sensitive adhesive layer asymmetrically with respect to a centerline in a width direction perpendicular to the conveying direction of the sheet material, a conveying speed of the sheet material conveyed by the pair of conveyor rollers is slower than a conveying speed of the sheet material conveyed by the platen roller.