| 摘要 |
PURPOSE:To prevent thermal accumulation of a thermal head and enable recording with stable density to be performed by subdividing recording data of each line into plural data per single dot, supplying each of subdivided data to a shift register while updating it and controlling the drive pulse width of a thermal element through variation of a high-level signal count. CONSTITUTION:Recording data transmitted serially from a circuit is converted to a parallel data by a series/parallel conversion part 6 of CPU5 to constitute a gradation matrix 7. Further it is converted to a serial data by a parallel/series conversion part 8 and a subdivision data is created referring to a table in ROM10. The data is transmitted to a thermal head drive circuit 11, thus subdividing recording data of a single dot to be given to a single thermal element into plural data segments. After this, these segments are updated and the number of high-level signals in the segments is made variable in accordance with the output of a temperature sensor. Then the drive pulse width of the corresponding thermal element is controlled to prevent heat accumulation of the thermal head. |
