At the control section of the printer itself, being digital reference level entry manner of the head driver IC

摘要

PROBLEM TO BE SOLVED: To correctly detect junction temperature by highly precisely correcting fluctuation in characteristics of a diode for detecting temperature of a head driver IC. ;SOLUTION: A thermistor for temperature measurement is installed in the neighborhood of a head on a head substrate to perform precise measurements. Although their temperature are different during printing operation, solid variation of anode voltage of a diode is corrected by using a temperature measured by a thermistor, since both temperatures are conceivably conincident immediately after the power is turned on. A volume of each nozzle line is preliminarily stored before a prescribed number of a driving wave shape pulses of voltage that does not jet ink is charged for the measurement of a variation of anode voltage. The value thus obtained is compared with the variation of voltage due to an increase of temperature in calculation, thereby correcting the solid variation of the temperature coefficient of the anode voltage. The junction temperature is then determined by using the coefficient obtained by A/D conversion of the anode voltage. The anode voltage of an upper limit of the junction temperature is obtained from the coefficient as above, and a protective measure to stop printing or the like is taken when the anode voltage reaches the value.;COPYRIGHT: (C)2004,JPO