Printing apparatus and method of determining minimum discharge energy

A printing apparatus that performs printing by discharging ink onto a print medium from a printhead which includes a plurality of electrothermal transducers, a plurality of temperature detection elements configured to detect temperatures of corresponding electrothermal transducers, and a plurality of orifices arranged in correspondence with the plurality of electrothermal transducers, comprising:

• a measurement unit configured to use a corresponding temperature detection element to measure a temperature, which changes due to heat generated by supplying energy, of an electrothermal transducer selected from the plurality of electrothermal transducers;
• a detection unit configured to detect, based on the temperature measured by the measurement unit, a peak voltage which indicates a point of change, from a state in which the ink is discharged normally from the printhead to a state in which the ink is not discharged from the printhead, and which is based on an output signal from the temperature detection element reflecting temperature change of the electrothermal transducer;
• a comparison unit configured to compare the peak voltage detected by the detection unit with a threshold value;
• a change unit configured to change the energy to be supplied to the selected electrothermal transducer;
• a repetition unit configured to repeat the measurement by the measurement unit, the detection by the detection unit, and the comparison by the comparison unit, by supplying the energy changed by the change unit, until the peak voltage is determined not to be less than the threshold value in the comparison by the comparison unit;
• and
• a determination unit configured to determine the energy supplied at a time in which the peak voltage is determined not to be less than the threshold to be minimum discharge energy.