Test-based advance optimization in incremental printing: median, sensitivity-weighted mean, normal random variation

A method of determining optimum printing-medium advance in an incremental printer that uses image-marking devices which print in respective different colors or color dilutions;

• said method comprising the steps of:
• printing a test pattern that includes a set of representative image patches at each of plural printing-medium advance settings in turn;
• each set comprising at least one representative image patch for each of the different colors or color dilutions;
• and
• performing optical measurements of the test pattern to ascertain a relationship between said printing-medium advance settings and resulting image quality of said patches.

An incremental printer for using image-marking devices to form images on a printing medium;

• said printer comprising:
• a support for such printing medium;
• a carriage for holding such marking devices and scanning such marking devices relative to such medium, to form such images on such medium;
• a printing-medium advance mechanism for progressively moving such medium relative to the carriage at right angles to the scanning;
• a sensor for measuring test-pattern image quality;
• and
• programmed processor means for:
• controlling the carriage, the advance mechanism, and such marking devices to print a test pattern comprising a set of representative image patches at each of plural printing-medium advance settings in turn, each set comprising at least one representative image patch for each of plural different colors, and
• operating the sensor and interpreting resulting signals from the sensor to determine optimum printing-medium advance.

An incremental printer for using image-marking devices to form an image on a printing medium;

• said printer comprising:
• a support for such printing medium;
• a carriage for holding such marking devices and scanning such marking devices relative to such medium, to form such image on such medium;
• a printing-medium advance mechanism for progressively moving such medium relative to the carriage at right angles to the scanning;
• a sensor for measuring test-pattern image quality;
• and
• programmed processor means for:
• operating the sensor and interpreting resulting signals from the sensor to determine optimum printing-medium advance;
• thereafter controlling the carriage, the advance mechanism, and such marking devices to employ particular printing-medium advance values while printing such image;
• and
• selecting the particular advance values to provide a sequence of values that varies about the determined optimum advance.

An incremental printer for using image-marking devices to form an image on a printing medium;

• said printer comprising:
• a support for such printing medium;
• a carriage for holding such marking devices and scanning such marking devices relative to such medium, to form such image on such medium;
• a printing-medium advance mechanism for progressively moving such medium relative to the carriage at right angles to the scanning;
• a sensor for measuring test-pattern image quality;
• and
• programmed processor means for:
• operating the sensor and interpreting resulting signals from the sensor to determine an optimum printing-medium advance for each marking device respectively;
• and
• thereafter controlling the carriage, the advance mechanism, and such marking devices to employ a particular printing-medium advance value that is substantially the median of the optimum advances for the image-marking devices respectively.

An incremental printer for using image-marking devices to form an image on a printing medium;

• said printer comprising:
• a support for such printing medium;
• a carriage for holding such marking devices and scanning such marking devices relative to such medium, to form such image on such medium;
• a printing-medium advance mechanism for progressively moving such medium relative to the carriage at right angles to the scanning;
• a sensor for measuring test-pattern image quality;
• and
• programmed processor means for:
• operating the sensor and interpreting resulting signals from the sensor to determine an optimum printing-medium advance for each marking device respectively;
• thereafter determining, for a specific image swath, the image density contributed by each marking device respectively;
• and
• thereafter controlling the carriage, the advance mechanism, and such marking devices to employ a particular printing-medium advance value that is substantially a sensitivity-weighted mean of the optimum advances for the image-marking devices respectively;
• wherein the sensitivity-weighted mean is calculated substantially by weighting an optimum advance value for each marking device by the sensitivity of banding to printing density for a color in that image-marking device respectively.

An incremental printer for using image-marking devices to form an image on a printing medium;

• said printer comprising:
• a support for such printing medium;
• a carriage for holding such marking devices and scanning such marking devices relative to such medium, to form such image on such medium;
• a printing-medium advance mechanism for progressively moving such medium relative to the carriage at right angles to the scanning;
• a sensor for measuring test-pattern image quality;
• and
• programmed processor means for:
• operating the sensor and interpreting resulting signals from the sensor to determine an optimum printing-medium advance for each marking device respectively;
• thereafter determining, for a specific image swath that is prospectively to be printed, a characteristic of the image components to be contributed by each marking device respectively;
• and
• thereafter, for said specific image swath that is prospectively to be printed, controlling the carriage, the advance mechanism, and such marking devices to employ a particular printing-medium advance value that is a function of the said determined characteristic of image components to be contributed by each marking device respectively.