| 摘要 |
PURPOSE:To control the electrolysis of ink by providing an electric current direction selection device which selects the direction of an electric current every time the residual amount of ink is detected and detecting the residual amount of ink in a state where the direction of an electric current is changed. CONSTITUTION:Paired electrodes for detection of a residual ink amount 1A, 1B are exposed in an ink tank 2. An arithmetic/logic operation device(CPU) 8 controls the direction of an electric current for detection of a residual ink amount, and at the same time, reads a resistance value between the electrodes to interpret a residual ink amount. In addition, output terminals 00, 01 which output a signal for control of an electric current direction and an A/D input terminal A/D which reads a voltage obtained via a divided voltage resistor 3 and electrodes 1A, 1B in terms of analog value, are provided. Non-volatile memory 9 stores the changed direction of an electric current each time it is changed by switching elements 4A, 4B and 6A, 6B between the electrodes 1A, 1B. Thus the residual amount of ink is interpreted by CPU 8 in accordance with an electric current value between the detection electrodes 1A, 1B in a residual ink amount detection circuit. |
