Method of determining thermal turn on energy
AssigneeHewlett-Packard Company
InventorsNaoto Kawamura, Erik D Ness
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Abstract
A method of determining thermal turn on energy is disclosed. The method comprises heating a fluid ejection device to a predetermined temperature that is below a fluid ejection temperature; applying firing pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets; and incrementally varying the drop count from said predetermined count while sampling the temperature of the fluid ejection device after said pulse bursts are applied.
Claims39
A method of determining thermal turn on energy comprising:
- heating a fluid ejection device to a predetermined temperature that is below a fluid ejection temperature;
- applying firing pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- and
- incrementally varying the drop count from said predetermined count while sampling the temperature of the fluid ejection device after said pulse bursts are applied.
A method of determining thermal turn on energy comprising:
- heating a fluid ejection device to a predetermined temperature;
- applying firing pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- and
- incrementally varying the drop count from said predetermined count while incrementally varying the pulse energies.
A method of determining thermal turn on energy comprising:
- heating a fluid ejection device to a predetermined temperature before ejecting fluid therefrom;
- applying firing pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- and
- sampling the temperature of the fluid ejection device after said pulse bursts are applied,
- wherein a net energy input to said fluid ejection device remains substantially constant during each burst.
A method of determining thermal turn on energy comprising:
- heating a fluid ejection device to a predetermined temperature before ejecting fluid therefrom;
- applying firing pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- incrementally varying the pulse energies;
- producing a set of temperature samples of the fluid ejection device respectively associated with the varying pulse energies;
- locating a point of minimum temperature and lowest energy on a temperature curve fitted to said set of temperature samples in a region of said set of temperature samples that changes from decreasing to increasing pursuant to incrementally increasing pulse energy;
- and
- determining the lowest turn on energy which occurs at the minimum value of temperature samples to define said thermal turn on energy.
A method of operating a fluid ejection device comprising:
- heating a resistor of a fluid ejection device to a predetermined temperature before ejecting fluid;
- applying firing pulse bursts to said resistor, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to fire a predetermined count of fluid droplets;
- incrementally varying the drop count from said predetermined count;
- sampling the temperature of the resistor after said pulse bursts are applied to said resistor to produce a set of temperature samples respectively associated with the varying drop count;
- determining a minimum value of the temperature samples;
- determining the lowest turn on energy which occurs at the minimum value of temperature samples to define said thermal turn on energy;
- and
- operating the printhead at a pulse energy above said thermal turn on energy.
A system to determine thermal turn on energy of a fluid ejection device comprising:
- a means for applying pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- a means for incrementally varying the drop count from said predetermined count;
- and
- a means for sampling a temperature of the fluid ejection device after said pulse bursts are applied.
An apparatus used to determine thermal turn on energy of a fluid ejection device comprises:
- a driver that applies pulse bursts to a resistor of said fluid ejection device, the pulses in each of said bursts having a predetermined reference pulse energy and a predetermined pulse frequency to eject a predetermined count of fluid droplets;
- a controller that incrementally varies the drop count from said predetermined count and gathers temperature samples after said pulse energies are applied for each drop count amount;
- a software application that applies a smoothing algorithm to the temperature samples to determine a minimum temperature on a temperature curve, wherein the minimum temperature is at a point at which both minimum temperature and minimum energy are located on the temperature curve.
Dependencies are inferred from the claim text.