Patent ID: 7438376

Claim:
A device for detecting a temperature of a head drive based on an output value of a diode which is provided in the head driver, the device comprising: a setting unit, operable to set a reference value corresponding to a reference temperature for temperature detection; a controller, operable to determine a characteristics of temperature changes in the output value of the diode; a comparator, operable to input the reference value into the setting unit based on the characteristics of temperature changes in the output value of the diode, and compares the output value with the reference value; and a detector, operable to detect whether the temperature of the head driver is larger than the reference temperature based on a comparison result of the comparator; wherein the controller the characteristics of temperature changes in the output value of the diode based on a magnitude of change between an output value of the diode at an ambient temperature and an output value of the diode after a drive waveform pulse having a voltage at which no ink is to be ejected is applied to a head a specific number of times.