24-05-2005 дата публикации
Номер: US6896346B2
An apparatus and method of operating a liquid drop emitter, such as an ink jet device, for emitting liquid drops of different volumes. The liquid drop emitter comprises a chamber, filled with a liquid, having a nozzle for emitting drops of the liquid, a thermo-mechanical actuator having a moveable portion within the chamber for applying pressure to the liquid at the nozzle, and apparatus adapted to apply heat pulses to the thermo-mechanical actuator. The method for operating comprises applying a first heat pulse having a first power P 1 , first pulse duration τ p1 , and first energy E 1 =P 1 ×τ p1 , displacing the movable portion of the actuator so that a drop is emitted having a first drop volume V d1 , and traveling substantially at the target velocity v 0 ; and applying a second heat pulse having a second power P 2 , second pulse duration τ p2 , and second energy E 2 =P 2 ×τ p2 , displacing the movable portion of the actuator so that a drop is emitted having a second drop volume V d2 and traveling substantially at the target velocity v 0 , wherein V d2 >V d1 , E 2 >E 1 , τ p2 >τ p1 , and P 2 <P 1 . An alternate method for operating causes the emission of drops having different volumes traveling at different velocities wherein all velocities are within a pre-determined drop velocity range, v d min to v d max . Further methods for operating an ink jet printhead cause the emission of drops having different volumes and velocities wherein the triggering of the drop emission is delayed so as to result in synchronized arrival times at a print plane.
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