Patent ID: 7938500
Filing Date: 2011-05-10
Classification: B41J

Abstract:
1. A printhead IC comprising: an array of nozzles having a plurality of adjacent regions; drive circuitry for sending an electrical pulse to each of the nozzles individually such that the respective nozzles eject a drop of printing fluid; and, a plurality of temperature sensors, each associated with a respective region, for sensing the temperature of the printhead IC within each of the regions respectively; wherein, the drive circuitry is programmed with a series of temperature thresholds defining a set of temperature zones, each of the zones having a different duration for the electrical pulses sent to the nozzles in the region currently operating in that temperature zone and the temperature sensors are configured to deactivate after a predetermined period of operation, and wherein every second temperature sensor in the plurality of temperature sensors is deactivated such that the drive circuitry adjusts a drive pulse profile for the region corresponding to each activated temperature sensor and applies the same adjustment to the adjacent region where the temperature sensor is deactivated.