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

摘要

A method of controlling a temperature of a print chip of a printhead in an ink jet printer includes providing a memory device within the printer. Ink is emitted from the printhead. Temperature data associated with the print chip during the emitting step is recorded. A thermal resistance value associated with the printhead and/or a thermal capacitance value associated with the printhead is calculated. The calculating is dependent upon the recorded temperature data. The thermal resistance value associated with the printhead and/or the thermal capacitance value associated with the printhead is stored in the memory device. A temperature of the print chip at a future point in time is estimated based upon a number of ink drops to be emitted by the printhead before the future point in time, and the thermal resistance value associated with the printhead and/or the thermal capacitance value associated with the printhead. The thermal resistance and/or the thermal capacitance values vary with the print power, target temperature, and heatsink temperatures. The estimated temperature is compared to a predetermined limit temperature. If the estimated temperature exceeds the predetermined limit temperature, the number of ink drops to be emitted by the printhead before the future point in time is reduced.