Inkjet printing apparatus and determination method of driving pulse applied to inkjet printing apparatus

A method of determining a driving pulse applied in an inkjet printing apparatus including a printhead including a temperature sensor and an element array formed by arraying a plurality of heat generation elements, each of which generates thermal energy required to discharge ink in response to application of a driving pulse, the printhead being configured such that a portion of the element array used for printing is changeable, the method comprising:

• obtaining information relating to the portion of the element array to be used for printing;
• sensing a temperature of the printhead using the temperature sensor;
• and
• determining a driving pulse, to be applied to the respective heat generation elements, for discharging the ink for printing, according to the temperature of the printhead sensed in the sensing and according to the portion of the element array used for the printing determined based on the information obtained in the obtaining.

An inkjet printing apparatus comprising:

• a printhead including a temperature sensor and an element array formed by arraying a plurality of heat generation elements, each of which generates thermal energy required to discharge ink in response to application of a driving pulse;
• a mode setting unit configured to set an executing print mode from among a plurality of print modes which include a first print mode and a second print mode, wherein a number of heat generation elements used for printing in the element array is a first number when the first print mode is executed, and a number of heat generation elements used for printing in the element array is a second number greater than the first number when the second print mode is executed;
• and
• a determination unit configured to determine a driving pulse, to be applied to respective heat generation elements, for discharging the ink for printing, according to a temperature of the printhead sensed by the temperature sensor and the print mode set by the mode setting unit.

An inkjet printing apparatus comprising:

• a printhead including a temperature sensor and an element array formed by arraying a plurality of heat generation elements, each of which generates thermal energy required to discharge ink in response to application of a driving pulse;
• a mode setting unit configured to set an executing print mode from among a plurality of print modes which include a first print mode and a second print mode, wherein a number of heat generation elements used for printing in the element array is a first number when the first print mode is executed, and a number of heat generation elements used for printing in the element array is a second number greater than the first number when the second print mode is executed;
• a determination unit configured to determine a driving pulse, to be applied to respective heat generation elements, for discharging the ink for printing, according to a temperature of the printhead sensed by the temperature sensor and the print mode set by the mode setting unit;
• and
• a storage unit configured to store a plurality of driving pulse tables required to define a plurality of driving pulses,
• wherein the determination unit selects one driving pulse table from among the plurality of driving pulse tables stored in the storage unit based on the executing print mode set by the mode setting unit, and determines the driving pulse to be applied to the respective heat generation elements from the selected driving pulse table based on the temperature of the printhead sensed by the temperature sensor, and
• wherein the plurality of driving pulses in a first driving pulse table selected when the first print mode is set as the executing print mode is defined so that a ratio of an increase in target ink discharge amount according to an increase in a temperature of the printhead is higher than that for the plurality of driving pulses in a second driving pulse table selected when the second print mode is set as the executing print mode.