Patent ID: 7585059

Claim:
An ink jet head comprising: a piezoelectric board having a plurality of elongated channels arranged parallel to each other and isolated from each other by channel walls; and a nozzle plate having a plurality of nozzle holes provided in association with the channels, and bonded onto the piezoelectric board with the nozzle holes located at generally longitudinally middle positions of the respective channels; wherein the nozzle plate has trench-like recesses each having a predetermined width and a predetermined depth and extending perpendicularly to the channels as being spaced equidistantly from the nozzle holes longitudinally of the channels; gaps for communication between adjacent channels are defined by the recesses between a surface of the nozzle plate and upper face portions of the channel walls located equidistantly from the nozzle holes; and active areas contributable to ink ejection are defined in each of the channels on opposite sides of the corresponding nozzle hole along the channel.