Patent ID: 8585182

Claim:
A liquid jet head, comprising: a nozzle plate having a plurality of nozzles arranged in a reference direction for jetting a liquid onto a recording medium; a piezoelectric plate having a first surface, a plurality of elongated grooves formed in the first surface and arranged in the reference direction orthogonal to a longitudinal direction of the piezoelectric plate, and having a second surface connected to the nozzle plate; and a cover plate having at least one liquid supply hole for supplying the liquid into the plurality of elongated grooves of the piezoelectric plate, and having at least one liquid discharge hole for discharging the liquid through the plurality of elongated grooves, the cover plate having one surface disposed on the first surface of the piezoelectric plate so as to cover the plurality of elongated grooves of the piezoelectric plate; wherein the plurality of elongated grooves of the piezoelectric plate comprise deep grooves and shallow grooves alternately and adjacently arranged in the reference direction, the shallow grooves having a smaller depth than the deep grooves; wherein a cross-section of each of the deep grooves in the depth direction thereof has a convex shape; wherein each of the deep grooves and each of the plurality of nozzles are communicated to each other at a tip of the convex shape; and wherein the cover plate covers the piezoelectric plate in such a manner that opening portions of the shallow grooves opened to the first surface of the piezoelectric plate are closed, and that the deep grooves opened to the first surface of the piezoelectric plate are communicated to the liquid supply hole and the liquid discharge hole.