DROP ON DEMAND INK JET PRINTING APPARATUS

摘要

A droplet on demand inkjet apparatus utilizing a piezoelectric actuator arranged so as to deflect in shear mode, a method of ink jet printing, and a method of manufacturing an ink jet printing apparatus are disclosed. The apparatus is formed of a plurality of laminated plates arranged so as to define an ink chamber. The actuator forms one side of the chamber and deflects towards a nozzle formed in a nozzle plate which provides the opposite side of the chamber. An interconnect layer acts as the substrate and has orifices to allow the tracks to the drive chip to pass through. On the opposite side of the interconnect layer is the piezoelectric sheet. Electrodes are provided between the interconnect layer and the piezoelectric sheet. The piezoelectric sheet is carved, drilled or molded so as to provide parallel ink channels and a circular depression with a raised central reservation. The piezoelectric sheet is bonded to the interposer plate or ground electrode which in turn is bonded to the nozzle plate. When a charge is applied between the two electrodes, a selected actuator of the piezoelectric sheet deflects in shear mode towards the nozzle plate. This movement provides sufficient energy to eject a droplet from the nozzle. A number of short pulses could be applied so as to increase the size of the droplet ejected. A number of distinct pressure chambers connected only by the parallel ink channels are arranged in a two dimensional matrix which allows for increased distances between the actuators allowing for less densely packed electrical connection than are required in a linear array.