| 摘要 |
An apparatus (110) and method of operating a liquid drop emitter, such as an ink jet device (100), for emitting liquid drops of different volumes. The liquid drop emitter comprises a chamber (11, 42), filled with a liquid, having a nozzle (30) for emitting drops of the liquid, a thermo-mechanical actuator (15) having a moveable portion within the chamber for applying pressure to the liquid at the nozzle, and apparatus (42; 44; 200) adapted to apply heat pulses to the thermo-mechanical actuator. The method for operating comprises applying a first heat pulse having a first power P1, first pulse duration tau p1, and first energy E1 = P1 x tau p1, displacing the movable portion of the actuator so that a drop is emitted having a first drop volume Vd1 and traveling substantially at the target velocity v0; and applying a second heat pulse having a second power P2, second pulse duration tau p2, and second energy E2 = P2 x tau p2, displacing the movable portion of the actuator so that a drop is emitted having a second drop volume Vd2 and traveling substantially at the target velocity v0, wherein Vd2 > Vd1, E2 > E1, tau p2 > tau p1 and P2 < P1. 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, vd min to vd 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. <IMAGE>
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