In a sensor sheet, first electrodes each covered with a pressure-sensitive resistive member and second electrodes each covered with a pressure-sensitive resistive member are disposed to extend perpendicularly to each other in a plan view. In an ink jet head configured by linking multiple head modules together, each head modules is mounted on a base frame supported by a head module support unit provided on the base frame. A control unit controls a drive current supplied to the assist actuator based on the operating angle and the assist angle.