Patent ID: 6850262

Claim:
A thermal activation device for heat-sensitive self-adhesive sheet comprising: a thermally-activating thermal head for thermally activating a heat-sensitive adhesive layer of a heat-sensitive self-adhesive sheet including a sheet-like substrate formed with a printable surface on one side thereof and with the heat-sensitive adhesive layer on the other side thereof; and a platen roller for conveying the heat-sensitive self-adhesive sheet in a predetermined direction; wherein the platen roller comprises adhesive-mass removing means for removing an adhesive mass of the heat-sensitive adhesive adhered to a periphery of the platen roller, and the adhesive-mass removing means comprises a transfer roller slidably contacting the periphery of the platen roller as located near an exit of the heat-sensitive self-adhesive sheet, thereby allowing the adhesive mass adhered to the periphery of the platen roller to be transferred thereto and a cleaning sheet inserted through space between the transfer roller and the platen roller thereby removing the adhesive mass adhered to a periphery of the transfer roller by allowing the adhesive mass to be transferred thereto.