| 摘要 |
PURPOSE:To obtain uniform recording density, by estimating the degree of the effect on the heat accumulation of a thermal head from a recording cycle and a printing ratio and calculating the correction quantity of heat accumulation from the cumulative value thereof at every row and the circumferential temp. before the heat accumulation of the thermal head and setting the recording time of the thermal head from said correction quantity and an optimum recording time in a heat not-accumulated state. CONSTITUTION:A recording cycle 9 calculating a recording cycle from a data source 6 and a printing ratio counter 8 similarly calculating a printing ratio therefrom at every one line are mounted. Further, a heat accumulation correcting circuit 10 for estimating the heat accumulation quantity of a thermal head 7 from the recording cycle and the printing ratio to set an optimum recording time to be applied on the basis of the obtained correction value and a thermal head driver 11 supplying a current to the thermal head 7 on the basis of the output of said circuit 10 are mounted. By setting the optimum recording time based on the correction quantity of heat accumulation by this constitution, uniform recording density not affected by the circumferential temp. and heat accumulation of the thermal head 7 can be obtained. |
