Hewlett-Packard Company

Nancy Leigh Herald

Donald L Michael

Brian L Helterline

John M Skene

Karsten N Wilson

Marilyn Louise Zuber

Susan A Chavez

A method and apparatus for calibrating color in an inkjet printing system initiates a calibration procedure by instructing an inkjet printer to print a color calibration sample. From the color calibration sample, an analysis is performed to select a color calibration based on the sample. Based on the characteristics of the selected color calibration, the color of the inkjet printer is calibrated.

Color calibration in an inkjet printer

A method and apparatus for detecting the end of life of a print cartridge for a thermal ink jet printer determines the status of the print cartridge and warns the user if the print cartridge is at or near the end of its useful life. In a first mode of operation, an initial temperature of a printhead contained in the print cartridge is checked after a threshold amount of ink is expelled from the printhead, such as for a high density print swath or during a service routine. This initial temperature is then compared with a maximum initial temperature. If the initial temperature exceeds the maximum initial temperature, a warning about the status of the print cartridge is sent to a user. If the initial temperature does not exceed the maximum initial temperature, the user is informed of the remaining life portion of the print cartridge. In a second mode of operation, a final temperature is checked after a period of time elapses since the threshold amount of ink is expelled from the printhead. This final temperature is then compared to a maximum final temperature. If the final temperature exceeds the maximum final temperature, a warning about the status of the print cartridge is sent to a user. If the final temperature is less than the maximum final temperature, the user is informed of the remaining life portion of the print cartridge. In a third mode of operation, the heat transfer efficiency of the print cartridge is calculated. If the heat transfer efficiency of the print cartridge is below a minimum heat transfer efficiency, a warning about the status of the print cartridge is sent to a user. If the heat transfer efficiency exceeds a minimum heat transfer efficiency, the user is informed of the remaining life portion of the print cartridge.

Method and apparatus for detecting the end of life of a print cartridge for a thermal ink jet printer

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Corvallis, OR, United States of America

Nancy Leigh Herald