Bidirectional black and color pass print method for ink-jet printers

摘要

Bidirectional interleaving of tri-color and black ink-jet pen print pass carriage retrace periods by the invention are utilized whenever possible for black printing. Preferably, printer controller logic used to determine next print direction monitors and records a most recent, or last, black print direction indicium such as a flag stored in memory. If certain predetermined last black print direction criteria are met, the next black print pass is performed in the opposite direction from that of the most recent color print pass, thereby increasing printer throughput. In accordance with the invention, typical tricolor and black printed swaths require up to three color print passes, one black print pass during retrace and only two non-printing retraces, thereby saving time and motion that otherwise would be wasted performing two additional, non- printing retraces.