Compensation for Gear and Stepper Motor Errors
Original Publication Date: 1986-Mar-01
Included in the Prior Art Database: 2005-Mar-08
In a printer, inaccurate paper advance is a problem and, generally, it can be attributed to the gear tolerance or the stepper motor. In some printers, a stepper motor, which is coupled to the paper advance mechanism with a set of gears, advances the paper. A knob is also attached to the mechanism for manual paper advance. The stepper motor, upon receiving an appropriate signal, advances the paper 1/144 inch. There is a certain amount of tolerance built into the gears. The tolerance can vary from a fraction of a step to as high as a few steps. The gear tolerance does not cause any problem as long as the paper in the printer is advanced in the same direction. When the paper direction is changed, then the first line increment, following a direction change, will be off by the amount of the gear tolerance.