Patent ID: 7635176

Claim:
An ink-jet head comprising: a first passage component having an ink ejection face in which ink ejection ports for ejecting ink are formed and a first surface opposite to the ink ejection face and composed of metal; a second passage component composed of resin and having a second surface contacting the first surface of the first passage component and a third surface opposite to the second surface, the second surface having an outlet through which the ink to be supplied to the first passage component is discharged; and a screw that fixes the first passage component and the second passage component each other, wherein the second passage component is formed with a through-hole connecting the second surface and the third surface, wherein the first surface of the first passage component is formed with a female screw hole smaller in diameter than the through-hole and an inlet into which the ink discharged through the outlet is introduced, wherein the screw is a stepped screw having a head larger in diameter than that of the through-hole, a cylinder part connected to the head and having a diameter capable of being inserted into the through-hole, and a male screw part extending from the leading end of the cylinder part in the axial direction of the cylinder part and having a diameter smaller than the through-hole, wherein the first passage component and the second passage component are fixed with each other as the male screw part is screw-engaged with the female screw hole while the cylinder part of the stepped screw is inserted into the through-hole, wherein the second passage component has a convex contacting the head and a spaced surface spaced apart from the head in the axial direction, both in a first annular confronting area confronting the head of the stepped screw, with respect to the axial direction, at a surrounding of the through-hole of the third surface, and wherein the axial length of the cylinder part is same as the length of a line segment extending to the second surface from the leading end of the convex in the axial direction, while the axial length of the cylinder part is smaller than the length of the line segment until the male screw part is screw-engaged with the female screw hole.