PURPOSE: To widen the variable range of the dot diameter of recording liquid droplets by a method in which plural electrical and mechanical conversion means are provided to a liquid jet head device, meniscus of recording liquid is controlled by a part of the means, and the recording liquid is discharged by the rest of the means.
CONSTITUTION: According to input tonal signals 21, voltage V0 and V1 to be applied to piezo-electric elements 11 and 12 are set up by DA converters 22 and 24 and amplifiers 23 and 25, and pulse signals for driving a piezo-electric element 12 for controlling meniscus are sent out from a mono-stable multi vibrator 33 by input trigger signals 32. When the signal 21 is greater than intermediate value, signal 2 is output from a multiplexer 36 but when it is smaller, signal 3 is output. By the signal 2, voltage pulse in the direction of polarization is applied to the piezo-electric element 12 through switching elements 28 and 29, and also by the signal 3, voltage pulse in the opposite direction is applied to control the meniscus. Signal 1 is sent out from monostable multi vibrator 35 through a delay circuit 34, and recording liquid droplets are sent out by the piezo-electric element 11 for discharging. The amount of recording liquid to be discharged, or the dot diameter of recording liquid droplets, can be widened with respect to variable ranges.
WATABE KUNIO
SHIMODA JIYUNJI
