US Patent 7591523 Printhead IC with de-activatable temperature sensor and maintenance mode

A printhead IC is provided which has 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 configured to operate in two modes, a printing mode in which the drive pulses it generates are printing pulses, and a maintenance mode in which the drive pulses are de-clog pulses, such that, the de-clog pulse has a longer duration than the printing pulse.