US Patent 7866781 Method and apparatus to check piezoelectric inkjet head

A method and apparatus to check an operation of a piezoelectric inkjet head includes a first current detection unit to detect a first current output from a piezoelectric element of the piezoelectric inkjet head when a predetermined voltage is applied, a second current detection unit to detect a second current from a capacitor having a capacitance with the same magnitude as a capacitor component of the piezoelectric element when the voltage is applied to the capacitor, and a third current detection unit to detect a third current corresponding to a difference between the first current and the second current, as the amount of deformation of the piezoelectric element according to the application of the voltage.