| 摘要 |
In thermal inkjet printing, an energy source supplies voltage pulses to a set of resistors in a printhead. The resistors are not necessarily equal-valued. The subset of energized resistors changes from pulse to pulse as a function of the printable data. As the subsets vary, resulting in a varying load on the energy source, this causes undesirable variations in the energy supplied to individual resistors, even when a regulated source is used, because of residual impedances in the source and wiring. The invention compensates for such energy variations, using information about which subset of resistors is to be energized during a pulse. By determining the electrical load presented by the subset, and by referring to a predetermined relation between the load value and the voltage drop in the residual impedances, the invention maintains nominally constant energy in individual pulsed resistors by an appropriate adjustment of the pulse width.
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