| 摘要 |
PURPOSE:To make electric power supplied to a resistor always constant even though the number of ink heating resistors to which electricity is conducted concurrently in printing is varied. CONSTITUTION:A voltage level applied to a resistor RH heating individually each of a plurality of nozzles 51 jetting ink in printing is monitored at a point A. Fluctuation in a voltage level is outputted to a differential amplifier circuit 40, converted to a digital quantity with an A/D converter 23, and outputted to a CPU 22. A reference value corresponding to each output value of the A/D converter 23 is preliminarily corresponded to each output value and stored in the CPU 22. The reference value corresponding to the output value of the A/D converter 23 which is inputted, is outputted to a register 27. Then, an enable signal is outputted to a gate 31 from a comparator 26 until a counter value is equalized to the reference value with the comparator 26. When an output voltage level from the A/D converter 23 is lowered, a value of the reference value inputted to the register 27 is increased according thereto. Then, electric power supplied to the resistor RH in printing is kept always constant. |
