Patent ID: 6926392

Claim:
A liquid ejection head comprising: a liquid flow path; an ejection outlet-forming member, which comprises a part of a wall of said liquid flow path and which forms an ejection outlet for ejecting a droplet of liquid, the ejection outlet having a recessed portion recessed from a plane in which the ejection outlet is formed; a heat generating element, provided at a position opposed to the ejection outlet, for generating a bubble in the liquid by application of heat to the liquid; a restrictor portion provided at the recessed portion of the ejection outlet, wherein the liquid forms a meniscus and is retained in the ejection outlet such that said restrictor portion is within the liquid, wherein said restrictor portion has an opening and defines an entirety of a closed periphery of the opening, and wherein an area So of the opening of said restrictor portion and a surface area Sh of said heat generating element satisfy the following inequality: So≦Sh.