Patent ID: 7938499

Claim:
A liquid discharge device, comprising: (A) a pressure chamber to be filled with a liquid; (B) a nozzle communicating with the pressure chamber; (C) a piezoelectric actuator vibrated by application of a drive voltage and ON/OFF control of the drive voltage for discharging the liquid within the pressure chamber through the nozzle as a liquid drop; (D) a drive circuit for applying the drive voltage to the piezoelectric actuator; and (E) a control unit for carrying out the ON/OFF control of the drive voltage, wherein the control unit carries out discharge movement which turns the drive voltage off from a waiting state in which the drive voltage is on, and then turns the drive voltage on again to vibrate the piezoelectric actuator, thereby to discharge the liquid within the pressure chamber as the liquid drop through the nozzle, and the control unit includes a micro vibration control section for controlling the driving of the drive circuit periodically repeats fall and rise of the drive voltage in a range, in which the drive voltage is not turned off and having a cycle shorter than a discharging cycle of liquid drop, immediately after the drive voltage is turned on again as part of the discharge movement for every discharge movement, in order to micro-vibrate the piezoelectric actuator in a range in which no liquid drop is discharged from the nozzle.