Registration of paper location for multiple printing

摘要

A laser printer (3) can initiate a line of printing only when the sweep of the laser light reaches a point in its cycle. An inkjet printer (5) moves paper by stepper motor in increments. Switch (9) senses the paper (15) to determine the location of paper in path (6) with respect to nominal printing locations of the laser printer. The closest nominal position is selected for printing. The paper may lead or lag the selected position. Switch (11) senses the paper to determine the location of paper in the path with respect to nominal printing locations of the inkjet printer. Two leads are added to reach a net greater lead, a lag is subtracted from a lead, and two lags are added to reach a net greater lag. The closest nominal position is then selected. This assures that registration does not vary by more than one half of the spacing between nominal locations of the second printer.