Patent ID: 6029896
Filing Date: 2000-02-29
Classification: B05B,B41J

Abstract:
A method for producing in demand mode a series of drops of a jettable liquid which exceed the diameter of an exit orifice, comprising,providing an operable demand mode jetting device comprising a chamber having an exit orifice in front, an intermediate section including a voltage operated transducer and a jetting fluid supply behind, which define an acoustic fluid chamber having a resonant frequency and acoustic period;operating the jetting device in demand mode by applying a drive voltage at a selected frequency;applying said drive voltage by increasing in magnitude the drive voltage from an initial rest voltage to a first rest voltage over a first transition time about equal to or greater than the acoustic period;holding the drive voltage at the first rest voltage for a first dwell time selected to reinforce the energy input applied to the fluid by the transducer;returning the drive voltage from the first rest voltage to the initial rest voltage; andwhereby a series of individual drops-on-demand of a diameter which substantially exceed the diameter of the exit orifice are produced in response to delayed application of the drive voltage.