Patent ID: 6676246
Filing Date: 2004-01-13
Classification: B41J

Abstract:
An ink jet printer for forming printed images by ejecting droplets of ink onto a print medium, the printer comprising:a power supply; and an ink jet print head powered by the power supply and in communication with an ink supply, the print head including: a plurality of nozzles through which the droplets of ink are ejected; and a heater chip having a plurality of heating elements, each heating element including a heating resistor in electrical communication with the power supply and having an area and a thickness, and a protective layer having a thickness of less than about 7200 Angstroms overlying the heating resistor, each heating element having a volume and associated with a corresponding one of the plurality of nozzles, for transferring heat into adjacent ink for a period of time corresponding to a pulse time of less than about 0.73 microseconds to achieve ejection of the ink through the nozzle in response to energy being supplied to the heater resistor by the power supply, wherein the energy supplied to each of the heater resistor ranges from about 2.9 GJ/m3 to about 4.0 GJ/m3 based on the volume of the heating element, and wherein the volume of the heating element is determined by the area of the heater resistor multiplied by the sum of the thickness of the heater resistor and the thickness of the protective layer.