| 摘要 |
<p>PURPOSE:To prevent a missing of a recording part and a deformation of a dot shape caused by irregularities of recording paper and improve a trackability of a high to low density to an increasing or decreasing heating value by a method wherein in a thermal head, a plurality of heating units each formed by connecting the both ends of a heating resistor to electrodes are arranged in a line, and an electric conduction to each heating unit is independently controlled. CONSTITUTION:In a thermal head 1, a plurality of heating units 11... are arranged in a line. Each heating unit 11 is formed by connecting the both ends of a heating resistor 13 to electrodes 12, 12. The heating resistor 13 is longitudinally divided by opening a hole 13a in an intermediate part. For example, a staggered heating pattern is used, in which the heating units are alternately electrically conducted, and the heating units to be conducted are changed over per pitch in a main scanning direction. In this manner, at a low density, a small part corresponding to a heating part 14 is used for printing, and with increasing heating value, two heating parts 14 are synthesized to one heating part 15. At this time, the area of the heating part 15 is large, but the temperature of the center part is not raised. Thus, the printing densities of the center part and the peripheral part are uniformized.</p> |
