| 摘要 |
<p>PURPOSE:To prevent abnormal heat generation, to reduce nonuniform print density, and to prolong the life of a thermal head, by controlling the electrically conducting time to a thermal head heat generating element according to a print pattern and keeping the temperature of the heat generating element constant. CONSTITUTION:Print data is inputted to the arithmetic processing unit CPU of a thermal printer and the CPU controls the processing of the input data to output electric conduction data from terminals 1-7 to the heat generating element of a thermal head TH. Further, the 1st data on the stating of a print scan is outputted from a terminal 8 and when the same print pattern from a terminal 9 is continuously repeated >10 times, a state signal is outputted. The feeding data from the terminals 1-7, on the other hand, are stored in a shift register R1. When conducting to the same elements of the header TH continues, a conduction compensating register R2, etc., shortens the conducting time to the same elements and the time is supplied to a conducting register R3. When the same print pattern is repeated continuously >=10 times, the conducting time is further shortened by the outputs of pulse oscillators OS1-OS3 to reduce nonuniform print density.</p> |
