Inkjet printing with uniform wear of ink ejection elements and nozzles

摘要

In one embodiment of the invention, an inkjet printer selectively energizes ink ejection elements in a scanning printhead such that the top nozzles of the printhead do not always print the first line of text in a scan. In one embodiment, this is accomplished by occasionally aligning the bottommost nozzle in the printhead with the bottom of the last full line of text to be printed during the scan. The alignment of the printhead with respect to the lines of text to be printed is varied from page to page or varied at other intervals so that the top nozzles and bottom nozzles are used about equally. This will also cause more uniform wear of the middle nozzles. The more uniform wearing of the nozzles and ink ejection elements extends the life of the printhead. In inkjet printers using a black ink printhead which has a wider printing swath than one or more color ink printheads in the same scanning carriage, a new printing technique makes use of the nozzles in the wider printhead which extend beyond the shorter printhead when both printheads are being used during color printing.