Patent ID: 6874867

Claim:
An emission device for ejecting a liquid drop, said device comprising: a first chamber of variable volume adapted to receive a liquid and having a nozzle orifice through which a drop of received liquid can be emitted; an electrically addressable, deformable electrode associated with the first chamber such that movement of the deformable electrode in a first direction increases the first chamber's volume to draw liquid into the first chamber and movement of the deformable electrode in a second direction decreases the first chamber's volume to emit a drop of liquid from the first chamber through the nozzle orifice; and a fixed electrode, of predetermined perimeter, opposed to the deformable electrode and defining a second chamber there between such that control of relative voltage differences between the movable and the fixed electrodes selectively moves the deformable electrode in one of said first and second directions, said variable volume containing a dielectric material and being vented to a source of such dielectric material through an opening of predetermined area in the fixed electrode, the ratio of the area of said opening to the perimeter of said opening being greater than 0.5 μm.