Patent ID: 7806503

Claim:
A printing apparatus adapted to print on a printing medium by discharging ink from a plurality of nozzles using an inkjet printhead having the plurality of nozzles for discharging ink, a plurality of electrothermal transducers arranged in correspondence with the respective nozzles, and a plurality of sensors for detecting temperatures in correspondence with the respective electrothermal transducers, the printing apparatus comprising: a measurement unit configured to measure temperatures of the respective electrothermal transducers on the basis of outputs from the plurality of sensors; a prediction unit configured to predict temperatures of the sensors at a predetermined timing during a printing operation on the basis of temperature change profiles of the sensors that are generated by energizing the respective electrothermal transducers; a generation unit configured to generate a plurality of thresholds corresponding to states of the nozzles on the basis of the temperatures predicted by the prediction unit and a driving condition of the inkjet printhead; a measurement control unit configured to control and to execute temperature measurement by the measurement unit at the predetermined timing; a comparison unit configured to compare a temperature measured by the measurement unit under the control of the measurement control unit with the respective thresholds generated by the generation unit; and an identifying unit configured to identify the states of the nozzles on the basis of comparison results by the comparison unit.