US Patent 7669955 Inkjet printhead with temperature zones

A printhead IC is provided having an array of nozzles, drive circuitry for receiving print data and sending drive pulses of electrical energy to the array of nozzles in accordance with the print data, and a temperature sensor connected to the drive circuitry to adjust the drive pulse profile in response to the temperature sensor output. During use, the temperature sensor can be de-activated after a period of use. The drive circuitry is programmed with a series of temperature thresholds defining a set of temperature zones, each of the zones having a different pulse profile for the drive pulses sent to the nozzles in the region currently operating in that temperature zone.