| 摘要 |
<p>PURPOSE:To improve printing quality by providing voltage switching means for switching a voltage to be applied to a printing heat in normal and reverse directions to readily prevent the print from becoming irregular in density by one power source. CONSTITUTION:Voltage switching means 12 for switching a voltage of a power source 11 to be supplied to at least two print heads 1 in normal and reverse directions are provided, and constructed to supply different voltages to the two heads 1a, 1b. A printing head controller 9a has a function for sharing the printing in the heads 1a, 1b in normal and reverse directions by switching voltage setters 12a, 12b by a normal/reverse direction signal. The setter 12a has a transistor Tr1 and resistors R1, R3, and the setter 12b has a transistor Tr2 and resistors R2, R3. Thus, the difference of the density of the prints in normal and reverse direction can be eliminated, a power source can be reduced, a circuit is simplified to improve the cost.</p> |
