Thermal transfer printer with improved adhesion of colored material spots to the record medium

Claim 1

A thermal transfer printing apparatus comprising: a stationary printhead having a plurality of individually energizable thermal elements corresponding to one line of information to be recorded arranged in a primary scanning direction; a carrier sheet supported for movement across said printhead in a direction substantially perpendicular to said primary scanning direction or in a subsidiary scanning direction with one face of the sheet being maintained in heat transfer relation with the thermal elements, said sheet bearing a plurality of different color record-forming materials arranged in a plurality of separate areas located in end-to-end relation in said subsidiary scanning direction; means for feeding and supporting a record medium on the opposite surface of said carrier sheet for movement in the subsidiary scanning direction; means for driving said carrier sheet and record medium for movement across said printhead in timed relation while pressing them together so as to perform recording of the information of one line on the record medium in different colors by successively transferring spots of the color record-forming materials from the carrier sheet onto the record medium as the thermal elements are selectively energized; and means for pressing, into the record medium, spots of one of the color record-forming materials after thermal transfer thereof from the carrier sheet to the record medium but before thermal transfer of spots of another color from the carrier sheet to the record medium, to thereby reduce surface irregularities of the record medium before the last-recited thermal transfer; wherein the means for pressing includes means for forming miniscule irregularities in the surface of the spots being pressed into the record medium, said miniscule irregularities being small in size as compared with the size of the spots, to thereby improve adhesion to the spots pressed into the record medium of spots subsequently transferred from the carrier sheet to the record medium.