Abstract: A coincidence ink jet array system is disclosed wherein each ink jet has two inlet passages communicated to an outlet orifice. An ink droplet is expressed from the orifice only when pressure pulses applied to the inlet passages coincide at the orifice. Two main fluid supply passages are provided, one of which traverses across the jets at the upper portion of a housing and the other which traverses across the jets at the lower portion of the housing. A plurality of separate fluid rectifier passages interconnect the supply passages with a respective one of the jets to provide a fluid layer at a location between its respective outlet orifice and its respective inlet passages. This connection of the jets with separate fluid rectifier passages isolates each jet from another to either prevent or substantially limit "cross-coupling" (pressure communication) between the jets.

Abstract: A first pressure increase is effected in liquid in a pressure chamber to express liquid droplets therefrom. A time-delayed second pressure increase is effected in liquid in the same pressure chamber to effect a pressure front timed to arrive within an effective meniscus dampening vicinity of a droplet orifice at substantially the same instant that the droplet leaves the orifice to dampen substantially the full period of meniscus vibration.

Abstract: An ink jet assembly comprises a magnetic driver and a liquid droplet instrument. The driver includes a plurality of magnets, which may be selectively energized. The instrument includes a diaphragm means, which forms an outer wall of each of a plurality of chambers and when exposed to a magnetic field, deforms to decrease the volume of a chamber to increase the pressure therein to express a liquid droplet therefrom. The driver and instrument are releasably secured to each other to permit replacement of the instrument without disposing the driver.

Abstract: A high density linear array ink jet assembly is provided wherein a multiple chamber unit comprises a chamber housing and at least one flexible diaphragm spanning and sealing the chambers from each other and forming one wall of each chamber. A plurality of actuators for deforming the diaphragm are secured to the diaphragm at each chamber. The actuators are independently activated to deform the diaphragm for a particular chamber thereby decreasing the volume thereof to create a pressure on liquid ink therein. In one embodiment, a pair of elongated coextensive ribbon members are located opposite each other and are separated by a plurality of spaced ferrite walls secured thereto. At least one of the ribbon members comprises a deformable laminate of two layers of different material which have significantly different strain characteristics in the presence of a magnetic field. The ribbon members and each pair of ferrite walls form a deformable chamber whereby a plurality of deformable chambers are formed.

Abstract: An ink jet includes a meniscus dampening passage, which carries a pressure front timed to arrive within an effective meniscus dampening vicinity of a droplet outlet orifice at substantially the same instant that a droplet leaves the orifice to dampen substantially the full period of meniscus vibration.DESCRIPTION OF THE INVENTIONWhen an ink droplet is expressed from a droplet outlet orifice, the new meniscus formed in the orifice, after the droplet leaves the same, vibrates until it reaches a stable condition. Since the meniscus must be stabilized in order to express controlled droplets, this period of vibration affects the frequency in which the droplets can be expressed through the orifice. The longer the period of vibration, the lower the frequency or the shorter the period of vibration, the higher the frequency.