| 摘要 |
PURPOSE:To improve a yield and to make it possible to ensure an unvaried printing density, by controlling electrification so that an energy applied to heating resistors being opposite to each other and positioned in a joint portion of a thermal head or in the vicinity thereof may be the same. CONSTITUTION:Input printing data are stored in a shift register 4, and based thereon, each heater of a thermal head unit 1 is driven through the intermediary of a latch circuit 3 and a gate group 2. Now, given that resistors RL and RR in the heater unit 1 are positioned on the right and left sides of a joint portion, electrification is controlled so that an energy impressed on said resistors, i.e. time lengths of electrification TRL and TRR, be TRL/RL=TRR/RR. This method makes it unnecessary to select a resistance value of the joint portion of the thermal head, thus improving the operability of assembly, as well as yield of heaters, and enabling the elimination of a recording density difference in the joint portion. |
