Ink jet printer with non-uniform rectangular pattern of print positions

Claim 1

An ink jet printer for printing a print image on a moving print medium by selectively depositing ink drops at a plurality of print positions arranged in a rectangular grid on the medium such that a plurality of print lines are formed on said medium, comprising: means for generating a plurality of jet drop streams directed toward the print medium, said streams arranged in a jet row which is skewed with respect to the direction of movement of the moving print medium, means for selectively deflecting drops from each jet drop stream perpendicular to said jet row to a plurality of print positions in an associated band of print positions, thereby printing along a band of print lines, with drops deposited along adjacent print lines by adjacent jets overlapping more than drops deposited along adjacent print lines by the same jet, said rectangular grid arranged such that: S.sub.H /S.sub.V =K(n±1/M)(S.sub.V /C), and S.sub.V ≠S.sub.H, where S H =horizontal displacement between adjacent print positions in a band; S V =vertical displacement between adjacent print positions in a print line; M=number of print positions serviced by each jet drop stream; n=number of rows of print positions between print positions successively serviced by each jet, plus 1; K=vertical displacement between adjacent jet drop streams divided by S V ; and C=horizontal displacement between adjacent jet drop streams.