Patent ID: 7556327
Filing Date: 2009-07-07
Classification: B41J

Abstract:
1. A method of controlling a droplet ejection device comprising at least two switches that selectively couple at least one waveform input signal to at least one of a plurality of piezoelectric actuators, the method comprising: during a droplet firing period, controlling the at least two switches to selectively drive at least one of the piezoelectric actuators with the at least one waveform input signal; during a non-firing period, controlling the at least two switches to drive at least one of the piezoelectric actuators with a constant voltage level for substantially all of the non-firing period; using a channel control signal to control the at least two switches to drive at least one of the piezoelectric actuators with the at least one waveform input signal and using a clamp control signal to control the at least two switches to drive at least one of the piezoelectric actuators with the constant voltage level; logically combining the channel control signal and the clamp control signal to generate a single drive signal for controlling the two or more switches; and connecting the channel control signal and the clamp control signal to input terminals of an OR gate.