Patent ID: 7963634

Claim:
A liquid ejection head, comprising: an ejection port through which liquid is ejected; a liquid chamber which is connected to the ejection port, the liquid chamber being filled with the liquid; a heating device which is arranged on a wall of the liquid chamber, the heating device heating the liquid in the liquid chamber so as to generate a bubble in the liquid and to cause growth of the bubble; and a movable member which has a free end on a side of the ejection port and a fixed end on a side opposite to the ejection port, the free end being arranged at a prescribed distance from the wall of the liquid chamber so as to face the wall of the liquid chamber and to be moved by pressure applied by the growth of the bubble, the movable member including a first layer that is an internal layer, and second and third layers that are respectively arranged on both surfaces of the first layer, the second and third layers having a stress lower than the first layer.