Ink drop compensation based on dynamic, print-data blocks

Abstract

The invention relates to an ink jet printer and in particular to correcting the flight path of drops from the printer to reduce print position error on the print media. Compensation values can be stored and retrieved for use by the printer to correct the flight of a drop to the print media. The compensation values are based on the pattern of print data representing the drops in the ink stream with the drop being compensated. To reduce the number of variables that must be dealt with, one or more portions of the print data can be grouped into one or more blocks and each block treated as having a single effect on the drop being compensated. However, basing the compensation value on one predetermined treatment of print drops as having individual effects or as having individual effects in combination with one or more group effects on the drop being compensated does not produce the optimum print appearance for all combinations of print data. Disclosed herein is a method and apparatus for selecting one of a plurality of treatments of the print data based upon the pattern of print data representing drops in the ink stream. Depending on the number of drops in the flight path with the drop being compensated, the drops may be treated as each having an individual effect, an individual effect by some drops and a single group effect by the remaining drops or an individual effect by some drops and group effects by multiple groups of the remaining drops. Also more storage space may be allotted for compensation values based on the combinations treated as multiple groups because these combinations produce the most visible print error.