Patent ID: 7172264

Claim:
An ink jet recording head comprising: a substrate having heat generating members provided on a surface thereof to generate bubbles in ink; a ceiling wall facing said substrate, having plural discharge ports formed thereof to discharge ink; plural partition walls for forming plural ink flow paths communicating with said discharge ports, respectively, for supplying ink to said discharge ports; and a flow path formation member provided on the surface of said substrate, ink being discharged from said discharge ports by pressure exerted by the generation of the bubbles, wherein for each of said ink flow paths two of said heat generating members, each having a rectangular shape, are provided therein, and said discharge port is arranged on an extended line extending in a normal direction from a center of a region including said two heat generating members and a portion between said two heat generating members, a non-bubbling region is provided between said two heat generating members and a portion of said non-bubbling region is provided in a projected area of said discharge port projected on the surface of said substrate, and portions of said two rectangular heat generating members overlap with the projected area of the discharge port projected on the surface of the substrate, and wherein the bubble generated by said heat generating members communicates with the outside for the first time during the stage in which the volume of the bubble is reduced after the volume of the bubble has grown to a maximum value.