Recording head driving method and recording apparatus

A method for driving a recording head including a plurality of electrothermal transducers associated with temperature sensing elements disposed above or below the electrothermal transducers, the method comprising:

• supplying driving energy to the electrothermal transducer;
• acquiring temperature information from the temperature sensing element;
• acquiring gradient change timing occurring in a normal discharge operation, in a temperature fall interval occurring after supplying of driving energy to the electrothermal transducer, based on the temperature information acquired from the temperature sensing element;
• evaluating a temperature change in the temperature fall interval based on temperature information obtained when a predetermined period of time has elapsed after the acquired change timing, and a temperature threshold;
• changing a amount of the driving energy supplied to the electrothermal transducer;
• determining an energy value for driving the electrothermal conversion element based on the evaluated temperature change and an energy value supplied to the electrothermal transducer;
• and
• recording data on a recording medium by driving the electrothermal transducer according to the determined energy value.

A method for driving a recording head including a plurality of electrothermal transducers associated with temperature sensing elements disposed above or below the electrothermal conversion elements, the method comprising:

• supplying driving energy to the electrothermal transducer;
• acquiring temperature information from the temperature sensing element;
• acquiring gradient change timing occurring in a normal discharge operation, in a temperature fall interval occurring after supplying of driving energy to the electrothermal transducer, based on the temperature information acquired from the temperature sensing element;
• evaluating a temperature change in the temperature fall interval based on an integrated value of temperature information during a predetermined period of time after the acquired change timing, and a temperature threshold;
• changing an amount of the driving energy supplied to the electrothermal transducer;
• determining an energy value for driving the electrothermal conversion element based on the evaluated temperature change and an energy value supplied to the electrothermal transducer;
• and
• recording data on a recording medium by driving the electrothermal transducer according to the determined energy value.

A recording apparatus capable of performing recording with a recording head including a plurality of electrothermal transducers associated with temperature sensing elements disposed above or below the electrothermal transducers, the recording apparatus comprising:

• a driving unit configured to drive the electrothermal transducer;
• an acquisition unit configured to acquire temperature information from the temperature sensing element;
• a calculation unit configured to calculate a second-order differential value based on the temperature information acquired by the acquisition unit;
• an evaluation unit configured to evaluate a temperature change in a temperature fall interval, occurring after supplying of driving energy to the electrothermal transducer, based on a calculation result of calculating the second-order differential value based on the temperature information;
• a control unit configured to change a setting value of the driving energy supplied to the electrothermal transducer to cause the driving unit to perform driving, when the evaluation unit evaluates the temperature change;
• a determination unit configured to determine an energy value for driving the electrothermal transducer based on the temperature change evaluated by the evaluation unit;
• and
• a recording control unit configured to record data on a recording medium by driving the electrothermal transducer according to the energy value determined by the determination unit.