Automatic Left Margin Adjustment Procedure
Original Publication Date: 1983-Feb-01
Included in the Prior Art Database: 2005-Feb-06
In conventional wire matrix printers, the printer tracks position by the utilization of three print emitter signals which occur every .01" of printhead travel. These emitter signals occur in a sequence of 1,2,3,1,2,3... in the forward direction and 3,2,1,3,2,1... in the reverse direction. When power is first applied to the printer, it must initialize its position with respect to another signal referred to as the left margin signal. During the course of a printing task, the printhead may recalibrate several times and this recalibration must always occur on the same print emitter pulse to prevent registration errors. This could be done by calibrating on the first emitter pulse after the left margin signal switches. However, a problem arises if the left margin signal switches on the edge of a print emitter signal.