Abstract: A method for calibrating a printhead includes printing a test pattern, scanning the test pattern to obtain calibration data, performing an ink drop velocity optimization for the printhead using the calibration data, and determining a bi-directional offset based on the calibration data.

Abstract: A method for use with an ink jet printhead having a plurality of nozzles, each of the plurality of nozzles having associated therewith a respective heating element, includes printing with the plurality of nozzles a test pattern while varying an energy of a respective heater pulse used to energize each respective heating element at each of a plurality of printhead carrier positions; scanning the test pattern with a reflectance sensor to generate reflectance data associated with the energy of the respective heater pulse used to energize each respective heating element at each of the plurality of printhead carrier positions; and determining an optimal non-nucleating heater pulse for use with the ink jet printhead based on the reflectance data.

Abstract: An image sensor has two or three rows of imaging elements, all the imaging elements being of the same size. This provides the rows with a native resolution. The image sensor is also provided with three shift registers. First and second shift register elements receive information from respective corresponding imaging element in a first and second row of imagining elements while shift register elements of the third shift register receive information from four imaging elements. The four imaging elements form a super-pixel, allowing the sensor to output information in a low resolution mode, as well a native and a high resolution mode.

Abstract: A method for determining ink drop velocity of a printhead located at a gap above a print medium. A first ink mark is printed at a first printhead velocity. A second ink mark is printed at a different (in magnitude and/or direction) second printhead velocity. The ink for the second ink mark is ejected from the printhead at the same print ejection position used for the first ink mark plus an offset distance (if any). An optical scan of at least a portion of the print medium is generated using a non-printhead-carrier-mounted optical scanner. The distance between the ink marks is measured using the optical scan. The ink drop velocity is calculated using the measured distance, the offset distance, the first and second printhead velocities, and the gap.

Abstract: A printhead having improved performance is provided. The printhead includes a housing having an array of nozzles and a printhead memory incorporated on the housing and containing data pertaining to malfunctioning or missing nozzles of the array.

Abstract: A method of correcting for sensitivity variation of media sensors includes determining a first signal level corresponding to a first calibration media having a first glossiness; determining a second signal level corresponding to a second calibration media having a second glossiness, the second glossiness being greater than the first glossiness; and determining a corrected normalized signal level ratio of an unknown media based on the first signal level of the first calibration media and the second signal level of the second calibration media.

Abstract: A method of reducing printing defects in an ink jet printer including at least one printhead mounted to a printhead carrier for printing on a print media sheet, includes the steps of determining a vertical alignment error for at least one printhead and adjusting a sheet feed increment for the print media sheet based on the vertical alignment error.