| 摘要 |
PURPOSE:To enhance the charge detecting accuracy of ink particles by altering at least one of reference values for obtaining binary signals of integrated voltage of charge detecting voltage and adequate charge and non-charge in esponse to temperature with a temperature sensor. CONSTITUTION:A switch SW is disposed at a retrieving charge voltage generator 21 side at phase retrieving time, a deflection voltage power source circuit 22 is turned ON, a charge electrode is energized through a terminal D, ink particles are separated by the period and phase of an excitation pulse VP. When the separation is synchronized with the pulse PP, the particles are negatively charged and collided to platelike charge detecting electrode, fed through a terminal A to a charge detector 23, sinusoidal voltage variation is inverted, amplified and integrated, and flattened, but since positive temperature coefficient thermistor is connected through terminals G, H to an operational amplifier, the ink temperature becomes, even if altered, substantially constant level. This level is compared with a reference voltage, L when charged, and H when non-charged or incompletely charged, and applied to a print control unit 25. Accordingly, error detection due to temperature change can be prevented. |
