Translatable scanner calibration target

A method of calibrating a document scanner without a calibration document, comprising:

• controllably moving a flat translatable calibration target built into the scanner a predetermined distance relative to a fixed-position scan bar of the scanner;
• during the moving, repeatedly imaging the calibration target with the fixed-position scan bar such that each imaging element of the fixed-position scan bar captures signals for a zone of a flat uniform color surface of the calibration target;
• and
• processing the captured signals from each imaging element to calibrate the scanner.

A document scanner, comprising:

• a scan bar array of overlapping staggered fixed-position scan bars each having a linear array of imaging elements;
• an array of overlapping staggered translatable calibration targets spaced apart from and parallel to the scan bar array, each target having a planar surface that spans a length of a corresponding imaging element array and is imageable by the imaging elements of the corresponding linear array;
• and
• a single drive system coupled to all the calibration targets to controllably translate the calibration targets relative to the scan bars during a calibration operation.