Printhead alignment test pattern and method for determining printhead misalignment

A method for determining a printhead misalignment of a printer comprising the steps of:

• a) printing a printhead alignment test pattern including a plurality of spaced-apart images at least partially aligned substantially along a printhead scan axis, wherein each image includes leading and trailing edge portions having respective image-outermost leading and trailing edges spaced apart along the printhead scan axis and includes an intervening portion disposed between the leading and trailing edge portions, and wherein the leading and trailing edge portions are printed at a higher print density than the intervening portion;
• b) moving a sensor along the printhead scan axis over the plurality of images;
• c) obtaining data from the sensor;
• d) determining the locations along the printhead scan axis of the leading and/or trailing edges of the plurality of images using the data;
• and
• e) calculating the printhead misalignment from the determined locations of the leading and/or trailing edges of the plurality of images,
• wherein the leading and trailing edge portions of each image are printed at a substantially uniform and substantially identical print density,
• wherein the intervening portion of each of the images is printed at a substantially uniform print density,
• wherein the intervening portion of each of the images is printed to extend along the printhead scan axis to the leading and trailing edge portions, and
• wherein step a) prints each of the leading and trailing edge portions of each of the images at a print density in the range of substantially 75% to substantially 100% and prints the intervening portion of each of the images at a print density in the range of substantially 25% to substantially 50%.

A printhead alignment test pattern comprising a plurality of spaced-apart printed images at least partially aligned substantially along an axis, wherein each image includes leading and trailing edge portions having respective image-outermost leading and trailing edges spaced apart along the axis and includes an intervening portion disposed between the leading and trailing edge portions, and wherein the leading and trailing edge portions have a higher print density than the intervening portion,

• wherein the leading and trailing edge portions of each of the images have a substantially uniform and substantially identical print density,
• wherein the intervening portion of each of the images has a substantially uniform print density,
• wherein the intervening portion of each of the images extends along the axis to the leading and trailing edge portions,
• wherein each of the leading and trailing edge portions of each of the images has a print density in the range of substantially 75% to substantially 100% and the intervening portion of each of the images has a print density in the range of substantially 25% to substantially 50%, and
• wherein the images are substantially identical block images.