Abstract

An ink jet printing apparatus for ejecting fluids from a nozzle chamber has at least two fluid ejection apertures defined in the walls of the chamber; a moveable paddle vane located in a plane adjacent the rim of a first one of the fluid ejection apertures; and an actuator mechanism attached to the moveable paddle vane and adapted to move the paddle vane in a first direction so as to cause the ejection of fluid drops out of the first fluid ejection aperture and to further move the paddle vane in a second alternative direction so as to cause the ejection of fluid drops out of a second fluid ejection aperture. The apparatus can include a baffle located between the first and second fluid ejection apertures such that the paddle vane moving in the first direction causes an increase in pressure of the fluid in the volume adjacent the first aperture and a simultaneous decrease in pressure of the fluid in the volume adjacent the second aperture. Further, the paddle vane moving in the second direction can cause an increase in pressure of the fluid in the volume adjacent the second aperture and a simultaneous decrease in pressure of the fluid in the volume adjacent the first aperture.