Printhead IC with open actuator test

摘要

A printhead IC comprising: an array of nozzles; an ejection actuator corresponding to each of the nozzles respectively, the ejection actuator having a resistive heater that is activated when the actuator ejects ink through the corresponding nozzle; drive circuitry for receiving print data and activating the actuators with drive signals in accordance with the print data; and, open actuator test circuitry for selectively disabling the actuators when they receive a drive signal while comparing the resistance of the resistive heater to a predetermined threshold to assess whether the actuator is defective.