Method, apparatus and circuit for trimming droplet ejection signals

A droplet ejection apparatus comprising one or more droplet ejection heads wherein each droplet ejection head comprising a plurality of actuators, each actuator associated with at least one fluid chamber, and a circuit for controlling a plurality of actuators, the circuit comprising:

• inputs for receiving a first common drive waveform, a second common drive waveform, and a trimming signal;
• an output for supplying an individual drive waveform to an actuator;
• and
• a waveform select configured to couple to the first common drive waveform and to the output for connection to a first electrode of the actuator;
• the waveform select is configured to provide the individual drive waveform to a selected one of the actuators based on the first common drive waveform, the second common drive waveform and the trimming signal;
• wherein
• the waveform select is further configured to cause a transition from the first common drive waveform to the second common drive waveform by decoupling the first common drive waveform from the output and coupling the second common drive waveform to the output, the transition occurring at a time determined by the trimming signal.

A method of controlling a plurality of actuators, each actuator associated with at least one fluid chamber in a droplet ejection apparatus, the method comprising:

• receiving first and second common drive waveforms;
• receiving a trimming signal;
• and
• outputting an individual drive waveform during a print cycle by:
• coupling the first common drive waveform to a first electrode of a first actuator;
• in response to the trimming signal, decoupling the first common drive waveform from the first electrode of the first actuator;
• and
• coupling the second common drive waveform to the first electrode of the first actuator, the transition occurring at a time determined by the trimming signal.