THERMAL HEAD FOR ROTARY PRINTING AND ROTARY PRINTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To realize an image of high image quality by eliminating the mutual overlap of pixels or the gap between them or by correcting density irregularity caused by the inner and outer peripheral speed difference of a disc printing medium. SOLUTION: A thermal head has a plurality of heating elements 11a arranged in a line form and performs printing in the main scanning direction along the radius direction of a disc printing medium M. The dimension in the sub-scanning direction of each of the heating elements 11a changes so as to become small from the outer peripheral side of the medium to the inner peripheral side thereof. The electric resistance value of the heating elements changes so as to become high from the outer peripheral side of the medium to the inner peripheral side thereof.