Method and apparatus for predicting and limiting maximum printhead chip temperature in an ink jet printer

A method of controlling a temperature of a print chip of a printhead in an ink jet printer, said method comprising the steps of:

• providing the printer with a memory device for storing at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead;
• estimating a temperature of the print chip at a future point in time, said estimating step being based upon:
• a number of ink drops to be emitted by the printhead before the future point in time;
• and
• the at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead;
• comparing the estimated temperature to a predetermined limit temperature;
• and
• if the estimated temperature exceeds the predetermined limit temperature, reducing the number of ink drops to be emitted by the printhead before the future point in time.

A method of controlling a temperature of a print chip of a printhead in an ink jet printer, said method comprising the steps of:

• dividing a swath of print data into a plurality of groups;
• estimating a plurality of maximum temperatures of the print chip in printing the swath in a predetermined number of passes of the printhead, each of said maximum temperatures being associated with a respective one of said groups;
• and
• if at least one of the maximum temperatures exceeds a predetermined limit temperature, increasing the predetermined number of passes of the printhead for printing the swath.

A method of controlling a temperature of a print chip of a printhead in an ink jet printer, said method comprising the steps of:

• dividing a swath of print data into a plurality of groups;
• estimating a plurality of maximum temperatures of the print chip in printing the swath in a predetermined number of passes of the printhead, each of said maximum temperatures being associated with a respective one of said groups;
• if at least one of the maximum temperatures exceeds a predetermined limit temperature, increasing the predetermined number of passes of the printhead for printing the swath;
• and
• providing a memory device in the printer for storing at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead.

An ink jet printer comprising:

• a printhead including a print chip;
• a memory device storing at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead;
• and
• a controller configured to:
• retrieve the at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead from said memory device;
• and
• calculate a maximum temperature of said print chip during printing based upon the at least one of a thermal resistance value associated with the printhead and a thermal capacitance value associated with the printhead.