Patent ID: 6910760

Claim:
A liquid discharge head comprising: a discharge energy generating element for generating energy for discharging a liquid droplet; an element base plate provided with said discharge energy generating element on a main surface thereof; and an orifice base plate bonded to the main surface of said element base plate, being provided with a nozzle having a discharge port portion with a discharge port for discharging the liquid droplet, a bubbling chamber for generating a bubble in liquid therein by said discharge energy generating element, and a supply path for supplying liquid to said bubbling chamber, and a supply chamber for supplying liquid to said nozzle, wherein said bubbling chamber is formed by a first bubbling chamber communicated with said supply path with the main surface of said element base plate as the bottom face thereof for generating the bubble in liquid therein by said discharge energy generating element, and also, a second bubbling chamber communicated with said first bubbling chamber, and the central axis of the lower face of said second bubbling chamber and the central axis of the upper face of said second bubbling chamber are in agreement in the direction perpendicular to said base plate, and the sectional area of the upper face with respect to the central axis of said second bubbling chamber is smaller than the sectional area of the lower face with respect to the central axis of said second bubbling chamber, and the sectional area in the direction toward the central axis is continuously changed from the lower face to the upper face of said second bubbling chamber, and on the circumferential portion of the upper face of said first bubbling chamber in parallel with the main surface of said element base plate, and in contact with the opening communicated with said second bubbling chamber, an extrusion is formed continuously to surround said opening in the direction toward the main face of said element base plate.