Compensation for alignment errors in an optical sensor

摘要

A method of operating a printer to detect errors in an optical sensor includes forming a printed line across a first side of a print medium and generating first image data corresponding to the printed line with the optical sensor. The optical sensor generates second image data of the second side of the print medium as the print medium passes the optical sensor a second time. A detect in the optical sensor is identified with reference to a difference between process direction alignments of the line in the first image data and the second image data.

主权项

1. A method of operating a printer comprising:
moving a print medium through a printer a first time in a process direction; ejecting ink drops from a plurality of inkjets in the printer to form a line extending in a cross-process direction on a first side of the print medium; moving the print medium through the printer a second time with a second side of the print medium facing an optical sensor; generating image data corresponding to the line on the first side of the print medium with the optical sensor facing the second side of the print medium; and identifying a difference in a process direction between the line in the image data and another line extending in the cross-process direction to enable a controller to compensate for the difference during processing of image data generated by the optical sensor.