Operation of droplet deposition apparatus
AssigneeXaar Technology Limited
InventorsRobert Mark Pulman, Stephen Temple, Laura Ann Webb
Life of this patent
Estimating the term…
Abstract
In droplet deposition apparatus comprising one or more independently actuable ink ejection chambers, electrical signals are applied to reduce variation in the temperature of the droplet fluid between chambers and with variations in droplet ejection input data. Short potential difference pulses, suitable for influencing the temperature of the droplet fluid in a chamber, can be generated by application of longer duration voltages to ink chamber actuation means.
Claims34
Method of operation of droplet deposition apparatus, said method comprising the steps of:
- providing an apparatus comprising first and second chambers each supplied with droplet fluid and communicating with a respective nozzle for ejection of droplets therefrom and each having an actuator comprised of piezoelectric material actuable by electrical signals to vary the volume of that chamber, volume variation sufficient to effect droplet ejection being effected in accordance with droplet ejection input data;
- applying a first electrical signal to the actuator of said first chamber to effect droplet ejection from said first chamber;
- and
- applying a second electrical signal to the actuator of said second chamber to selectively electrically heat the fluid in the second chamber without effecting droplet ejection from said second chamber to reduce the difference in temperature between the fluid in the second chamber and the fluid in the first chamber, wherein said second signal generates hysteresis losses in said piezoelectric material.
Droplet deposition apparatus comprising first and second chambers each supplied with droplet fluid and communicating with a respective nozzle for ejection of droplets therefrom and having an actuator comprised of piezoelectric material actuable by electrical signals to vary the volume of that chamber, volume variation sufficient to effect droplet ejection being effected in accordance with droplet ejection input data;
- and a signal processor configured to apply a first electrical signal to the actuator of said first chamber to effect droplet ejection from said first chamber, and configured to apply a second electrical signal to the actuator of said second chamber to selectively electrically heat the fluid in the second chamber without effecting droplet ejection from said second chamber to reduce the difference in temperature between the fluid in the second chamber and the fluid in the first chamber, wherein said second signal generates hysteresis losses in said piezoelectric material.
Dependencies are inferred from the claim text.