US Patent 7556445 Thermal activation device and method of conveying sheet material

A thermal activation device has a thermal activation head that thermally activates 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 formed on the other surface thereof. A platen roller conveys the sheet material and is disposed in pressure contact with the thermal activation head so that the platen roller and the thermal activation head apply a holding force on the sheet material. A pair of conveyor rollers hold and convey the sheet material and are disposed on a downstream side of the thermal activation head in a conveying direction of the sheet material. A holding force applied on the sheet material by the pair of conveyor rollers being larger than a holding force applied on the sheet material by the platen roller and the thermal activation head.