PURPOSE: To enable the printer to operate in a wider temperature range by a method wherein a combined controller-driver capable of controlling the amplitude of an electrical signal accordingly to the changes of the ambient temperature is provided as a source of electrical signal for an electromechanical vibration transducer.
CONSTITUTION: A nozzle 2 is vibrated by the electromechanical vibration transducer 3, thereby producing ink droplets 4 from ink. The time tb required for breaking the ink into droplets, i.e. the so-called dropletizing, is inversely proportional to lnδo, where δo is the excitation amplitude which in turn is proportional to the input voltage Vus. Therefore, increasing the input voltage Vus increases the excitation amplutude δo and shortens the breaking time tb. In order to control the excitation amplitude according to the change of the ambient temperature while maintaining the breaking time tb at a constant value, the input voltage Vus is changed along the center line C of the stable region (i.e., the shaded area in the figure) where satellite droplets are seldom generated.
SHIMASAWA YOUICHI
KAWAMOTO TOSHIAKI
