| 摘要 |
PROBLEM TO BE SOLVED: To provide a thermal head unit capable of performing the fine radiation control corresponding to a heat generating part in spite of simple constitution not requiring a complicated control system individually controlling heating elements composed of resistance elements. SOLUTION: A line thermal head unit 10 is equipped with a line thermal head 11 having a plurality of resistance elements 11a and developing the color of thermal paper by operating the resistance elements 11a to record data on the thermal paper. The thermal head unit is further equipped with the substrate 14 supporting the line thermal head 11 and a plurality of the radiation fins 12 arranged corresponding to a plurality of the resistance elements 11a in the vicinity of the line thermal head 11 of the substrate 14 and the radiation fins 12 are composed of a shape memory alloy having parts coming into contact with the substrate 14 when the circumferential temp. is printing proper temp. or lower and separated from the substrate 14 when the circumferential temp. exceeds the printing proper temp. |
