Printer head for an ink-on-demand type ink-jet printer

Claim 1

A printer head for an ink-on-demand type ink-jet printer for squirting ink droplets onto a printing medium, said printer head comprising: an ink chamber filled with ink; a nozzle for squirting said ink droplets; an ink supply passageway extending from an ink tank to said ink chamber; an ink delivery passageway extending from said ink chamber to said nozzle; ink supplying pressure means responsive to an electrical signal for exerting a pressure on said ink in said ink chamber in order to squirt said ink droplets; one-way fluid control means disposed in both said supply and delivery passageways and having a peripherally clamped elastic and deformable flat member and a valve seat, said deformable member resting on said valve seat and forming at least one open portion through which ink may flow, said open portion being opened and closed by deformation of said deformable member, said deformable member being deformed solely in response to the on demand ink supplying pressure means responding to sdid electrical signal in order to pass said ink in said one-way therethrough, at least one of said deformable member and said valve seat being a solid central disc connected by spokes to the periphery thereof; and the other of said deformable member and said valve seat being a solid ring shaped member with a center hole positioned over said central disc, whereby said open portion extends through space between said spokes and said center hole, and further whereby the flow resistance may become low under the action of the pressure of the ink in response to the ink stream flow in the direction from the supply side toward the nozzle side and the flow resistance may become high in the opposite direction.