Patent ID: 7997694

Claim:
An inkjet recording apparatus, including: an ink holding chamber having an opening portion so as to hold the ink inside thereof; and a head unit ejecting the ink held in the ink holding chamber from the opening portion, wherein the head unit comprises: an ultrasonic wave generation member to generate ultrasonic waves; a focusing member to focus the ultrasonic waves in a vicinity of the opening portion; an ultrasonic wave propagation portion propagating the ultrasonic waves leaving the focusing member; and a container portion containing the ultrasonic wave generation member, the focusing member, and the ultrasonic wave propagation portion, and wherein the container portion comprises: a sidewall portion disposed approximately in parallel with a traveling direction in which the ultrasonic waves leaving the focusing member travels; and an isolation film positioned on a traveling path of the ultrasonic waves focused by the focusing member, disposed to face the opening portion, and of which shape is changeable, wherein the ultrasonic wave propagation portion is composed of a liquid ultrasonic wave propagation material and includes an ultrasonic wave propagation material circulation member to circulate the ultrasonic wave propagation material, and wherein the ultrasonic wave propagation material circulation member has a hydraulic pressure adjusting member to adjust hydraulic pressure inside of the ultrasonic wave propagation portion, and to vary a position to focus the ultrasonic waves generated at the ultrasonic wave generation member by changing a shape of the isolation film by the hydraulic pressure adjusting member.