Patent ID: 7712679

Claim:
A mist ejection head, comprising: a nozzle plate in which a nozzle hole for ejecting liquid is formed; a liquid chamber connected to the nozzle hole; an ultrasonic wave generating device which applies an ultrasonic wave to the liquid in the liquid chamber, wherein the ultrasonic wave generating device abuts the nozzle plate; and a reflective wall which reflects the ultrasonic wave applied to the liquid, wherein: the reflective wall is disposed so as to oppose the nozzle plate and has an axially symmetrical shape comprising a portion of a parabolic surface, the portion including an apex of the parabolic surface and being on an apex side with respect to a focal point of the parabolic surface; an axis of the parabolic surface passes through the nozzle hole; and the focal point of the parabolic surface is positioned in a vicinity of the nozzle hole, wherein the ultrasonic wave generating device is disposed in a vicinity of the nozzle hole on an opposite side of the nozzle plate from the liquid chamber, in such a manner that the ultrasonic wave generated by the ultrasonic wave generating device is applied to the liquid in the liquid chamber via the nozzle plate, travels in parallel to the axis toward the reflective wall, is reflected by the reflective wall and focuses at the focal point.