US Patent 7699439 Droplet ejection head and droplet ejection apparatus

A droplet ejection head includes: a first laminate having plural nozzles; a second laminate bonded to the first laminate and internally having plural pressure generating chambers communicating with the plurality of nozzles; plural piezoelectric devices having individual electrodes and common electrodes, the plural piezoelectric devices being provided in the second laminate correspondingly to the plural pressure generating chambers, the plural piezoelectric devices changing volumes of the plural pressure generating chambers in accordance with driving signal supplied to the individual electrodes so that fluid reserved in the pressure generating chambers is ejected as droplet from the nozzles; a first wiring board connected to the individual electrodes and supplying the driving signal to the individual electrodes; and a second wiring board connected to the common electrodes in common.