Patent ID: 8857939

Claim:
A liquid ejection apparatus comprising: a plurality of piezoelectric element units comprising piezoelectric elements, the piezoelectric element units configured to be driven to eject liquid by changing a drive voltage; a power supply configured to output a predetermined main voltage; a plurality of linear regulators provided in correspondence with the piezoelectric element units, the linear regulators configured to supply drive voltages to the respective piezoelectric element units by reducing the main voltage output from the power supply; and a control device configured to: calculate an accumulated time, for each of the piezoelectric element units, that the respective piezoelectric element unit is in a driven state, wherein a piezoelectric element unit is in the driven state when the corresponding drive voltage is not reduced or when liquid is ejected; identify a first piezoelectric element unit having a maximum accumulated time and a second piezoelectric element unit having a minimum accumulated time from among the plurality of piezoelectric element units; determine whether a difference between the maximum accumulated time and the minimum accumulated time is less than a predetermined time; and reduce the drive voltage applied to one or more of the piezoelectric element units that are not in the driven state to a lower voltage, when the control device determines that the difference is less than the predetermined time.