Method and apparatus for firing nozzles in an ink jet printer

1. A method of firing a plurality of jetting heaters in an ink jet printer, said method comprising:

identifying a first of the jetting heaters to be fired in a first firing cycle;

identifying a second of the jetting heaters to be fired in a second firing cycle, said second of the jetting heaters being fired immediately after the firing of the first jetting heater, said first firing cycle overlapping said second firing cycle; and

simultaneously applying power to each of the first jetting heater and the second jetting heater.

2. The method of claim 1 , wherein power is applied to the first jetting heater before power is applied to the second jetting heater.

3. The method of claim 2 , wherein the power to the first jetting heater causes an associated first ink emitting orifice to emit ink, the power to the second jetting heater being insufficient to cause an associated second ink emitting orifice to emit ink.

4. The method of claim 2 , comprising the further step of providing a clock pulse, power being applied to the first jetting heater before and after the clock pulse, power being applied to the second jetting heater after the clock pulse.

5. The method of claim 1 , wherein said step of simultaneously applying power includes supplying a cyclical fire signal.

6. The method of claim 1 , wherein said step of simultaneously applying power includes using a fire hold circuit.

7. A method of operating an ink jet printer, said method comprising:

identifying at least one first jetting heater to be fired during a first firing cycle;

identifying at least one second jetting heater to be fired immediately after the firing of the at least one first jetting heater, said second jetting heaters being fired during a second firing cycle, said first firing cycle overlapping said second firing cycle; and

simultaneously applying a fire pulse to each of the at least one first jetting heater and the at least one second jetting heater.

8. The method of claim 7 , wherein the fire pulse is applied to the at least one first jetting heater before the fire pulse is applied to the at least one second jetting heater.

9. The method of claim 8 , wherein the fire pulse to the at least one first jetting heater causes nucleation of ink, the fire pulse to the at least one second jetting heater being insufficient to cause nucleation of ink.

10. The method of claim 8 , comprising the further step of providing a clock pulse, the fire pulse being applied to the at least one first jetting heater before and after the clock pulse, the fire pulse being applied to the at least one second jetting heater after the clock pulse.

11. The method of claim 7 , wherein said step of simultaneously applying the fire pulse includes supplying a cyclical fire signal.

12. The method of claim 7 , wherein said step of simultaneously applying the fire pulse includes using a fire hold circuit.

13. A method of operating an ink jet printer, said method comprising:

at least one of repetitively loading external input data into a shift register and repetitively latching the data onto a printhead chip, said loading and latching steps occurring at a selected frequency defining a data cycle; and

controlling a plurality of jetting heaters with a fire signal defining a fire cycle, the fire cycle being longer than the data cycle, the data cycle being reinitiated prior to the end of the firing cycle.

14. The method of claim 13 , wherein the fire signal includes a series of fire pulses, each jetting heater being warmed to a first level insufficient to cause ink nucleation by a corresponding leading one of the fire pulses and warmed to a second level sufficient to cause ink nucleation by a trailing one of the fire pulses immediately after the leading fire pulse.

15. The method of claim 14 , wherein each said fire pulse serves as a leading fire pulse to at least one of the jetting heaters and as a trailing fire pulse to at least one other one of the jetting heaters.

16. The method of claim 14 , wherein each said leading fire pulse comprises a prefire pulse.

17. The method of claim 13 , comprising the further step of supplying a clock signal having the selected frequency.