Patent ID: 6935723

Claim:
An ink jet recording head comprising: an element base plate provided with plural discharge energy-generating elements for generating bubbles in liquid by thermal energy, and a through-opening becoming a supply chamber for leading liquid to said discharge energy-generating elements; and a flow-path-forming base plate (i) for forming (a) plural bubbling chambers containing said discharge energy-generating elements, respectively, on a surface of said element base plate having said discharge energy-generating elements formed thereon, and (b) plural supply paths for leading liquid to said bubbling chambers, respectively, and (ii) having plural nozzles provided therefor corresponding to said bubbling chambers, respectively, to enable said bubbling chambers to be communicated with the outside of the head, wherein a diameter of each of said nozzles is not greater than a distance between the surface of said element base plate on which said discharge energy-generating elements are formed and a surface of said flow-path-forming base plate opposed to the surface on which said discharge energy-generating elements are formed in said respective supply path, said ink jet recording head is provided with a flow path structure so configured that, for each of said supply paths, a cross-sectional area thereof perpendicular to a liquid flow direction is smallest between said respective bubbling chamber and the through-opening, and said flow path structure is provided with (i) a first structure for closing a part of each of said supply paths, said first structure being formed on the surface of said element base plate having said discharge energy-generating elements formed thereon, and (ii) a second structure formed on said flow-path-forming base plate to be a columnar structure extending from said first structure, said second structure also being for closing a part of each of said supply paths.