Inkjet printhead and inkjet image apparatus

An inkjet printhead wherein electrical energy is supplied to at least one piezoelectric member making up at least one wall of at least one ink chamber, causing deformation of the at least one piezoelectric member and permitting a plurality of consecutively jetted ink droplets to be made to combine to form a single dot on recording medium, comprising:

• the inkjet printhead that has at least one rate of change with respect to temperature, of at least one electromechanical coupling coefficients of the piezoelectric member, said rate of change exhibits negative characteristics, wherein the inkjet printhead is constructed so as to permit control of at least a portion of the electrical energy supplied to the at least one piezoelectric member and the electric energy supplied is based solely on the change of temperature.

An inkjet printhead wherein electrical energy is supplied to at least one piezoelectric member making up at least one wall of one ink chamber, causing deformation of the at least one piezoelectric member, as a result of which at least a portion of the ink within at least one of the ink chamber is jetted toward at least one recording medium, including

• an inkjet printhead that is constructed such that, taking ink viscosities at ink temperatures Ta (° C.) and Tb (° C.) to respectively be ηa and ηb, taking electrical capacitances of the at least one piezoelectric member at those temperatures to respectively be Ca and Cb, taking electromechanical coupling coefficients of the piezoelectric member at those temperatures to respectively be Ka and Kb, and taking voltages supplied so as to cause deformation of at least one of the piezoelectric member at those temperatures to respectively be Va and Vb, the supplied voltages are set so as to satisfy
• (Va/Vb)2=α2×(Cb×Kb2×ηa)/(Ca×Ka2×ηb)
• where 0.93≦α≦1.14.

An inkjet image forming apparatus equipped with one or more inkjet printheads wherein electrical energy is supplied to one or more piezoelectric members making up at least one wall of one or more ink chambers, causing deformation of at least one of the piezoelectric member or members, as a result of which at least a portion of the ink within the at least one or more of the ink chamber or chambers is jetted toward one or more recording media,

• the inkjet image forming apparatus including one or more means for controlling at least a portion of the electrical energy supplied to at least one of the piezoelectric member or members based on image data and ink temperature;
• and
• one or more rates of change with respect to temperature, of one or more electromechanical coupling coefficients of the piezoelectric member or members, exhibits positive characteristics.

An inkjet image forming apparatus equipped with one or more inkjet printheads wherein electrical energy is supplied to one or more piezoelectric members making up at least one wall of one or more ink chambers, causing deformation of at least one of the piezoelectric member or members, as a result of which at least a portion of the ink within at least one of the ink chamber or chambers is jetted toward one or more recording media, comprising:

• the inkjet image forming apparatus that has one or more controllers for controlling at least a portion of the electrical energy supplied to at least one of the piezoelectric member or members based on image data and ink temperature;
• and
• one or more rates of change with respect to temperature, of one or more electromechanical coupling coefficients of the piezoelectric member or members, exhibiting positive characteristics.