Patent ID: 6454474
Filing Date: 2002-09-24
Classification: B41J

Abstract:
A method of determining calibration values for a media advance system of a printer that uses a drive roller for advancing the media and that employs an encoder that is connected to the roller and that provides as output encoder position signals that correlate to the position of the media as the media is advanced in the printer, the method comprising the steps of:rotating the drive roller out of a first position and to move a sheet of calibration media that has targets thereon so that a set of at least three targets are moved past a sensor for detecting spacing among the set of targets and correlating that spacing to encoder position signals; rotating the drive roller out of a second position that is different from the first position and to move the sheet of calibration media so that the set of targets are moved past the sensor for detecting spacing among the set of targets and correlating that spacing to encoder position signals; identifying sinusoidally varying errors between the encoder position signals and the set of targets on the calibration sheet; and calculating calibration values based on the identified errors.