Patent ID: 6875955

Claim:
A thermal activation device for a heat-sensitive self-adhesive sheet, the thermal activation device comprising: thermally-activating heating means including a thermal head having an array of individually and controllably energized heat generating elements for thermally activating a heat-sensitive adhesive layer of a heat-sensitive self-adhesive sheet comprised of a sheet-like substrate having a printable surface on a first side thereof and the heat-sensitive adhesive layer on a second side thereof; and energy control means for controlling the thermally-activating heating means by applying one or more voltage pulses to the heat generating elements of the thermal head for energizing the heat generating elements to thereby thermally activate an area of the heat-sensitive self-adhesive layer of the heat-sensitive self-adhesive sheet in one step; wherein when a plurality of the voltage pulses are applied to the heat generating elements by the energy control means to thermally activate the area of the heat-sensitive self-adhesive layer, the energy control means selectively switches between the heat generating elements to be energized by the voltage pulses each time one of the voltage pulses is applied.