Printing apparatus and ink discharge failure detection method

An ink discharge failure detection method for an inkjet printhead configured to print on a printing medium by discharging ink from a plurality of nozzles, the inkjet printhead including the plurality of nozzles for discharging ink, a plurality of electrothermal transducers arranged in correspondence with the respective nozzles, for generating thermal energy used for discharging ink from the respective nozzles, and a plurality of sensors for detecting temperatures in correspondence with the respective electrothermal transducers, the method comprising:

• measuring temperatures of the respective electrothermal transducers based on outputs from the plurality of sensors at a first timing after a predetermined period of time from a start of applying a voltage pulse to the respective electrothermal transducers;
• and
• identifying statuses of the respective nozzles by comparing the respective temperatures detected by the plurality of sensors with a plurality of threshold values indicating a plurality of nozzle statuses,
• the plurality of threshold values are determined based on an initial temperature of the ink printhead at a second timing before applying the voltage pulse and a driving condition of the inkjet printhead.