Method and apparatus to compensate for imperfect scanner motion
AssigneeLexmark International, Inc.
InventorsAaron Ray Crooker, Noah Jonathon Gawlik, Marc Alan Herwald, Michael Anthony Marra, III, Donald Norman Spitz
Life of this patent
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Abstract
A method to compensate for imperfect scanner motion in a scanning apparatus having a moveable scanner includes generating an error array by measuring errors in a scanner position at each of a plurality of spaced positions along a direction of travel of the scanner; generating an error compensation array from the error array based on a low frequency component of the error array; and using the error compensation array to adjust at least one parameter associated with the scanning apparatus during a document scanning operation.
Claims41
A method to compensate for imperfect scanner motion in a scanning apparatus having a moveable scanner, comprising:
- generating an error array by measuring errors in a scanner position at each of a plurality of spaced positions along a direction of travel of said scanner;
- generating an error compensation array from said error array based on a low frequency component of said error array;
- interpolating data contained in said error compensation array to provide continuous error correction of said scanner along a scanning range of said scanner,
- wherein a scan motor is coupled to said scanner via a drive train, said low frequency error component being associated with errors in said scan position occurring within about one revolution of gear in said drive train, and
- wherein said drive train includes a toothed drive belt which engages a toothed pulley associated with said scanner, said scanning apparatus including a belt guard to prevent said toothed pulley from jumping teeth with respect to said toothed drive belt.
A method to compensate for imperfect scanner motion in a scanning apparatus having a moveable scanner, comprising:
- generating an error array by measuring errors in a scanner position at each of a plurality of spaced positions along a direction of travel of said scanner;
- generating an error compensation array from said error array based on a low frequency component of said error array;
- wherein the act of generating said error array is effected by scanning a calibration sheet having a plurality of equally spaced lines positioned at a predefined resolution in said direction of travel of said scanner;
- and
- using said error compensation array to adjust at least one parameter associated with said scanning apparatus during a document scanning operation.
A scanning apparatus, comprising:
- a scanning unit including a scanner;
- a drive unit connected to said scanning unit, said drive unit including a scan motor;
- and
- a controller communicatively coupled to said drive unit, said controller being configured to execute program steps to compensate for imperfect scanner motion of said scanner, said program steps including:
- generating an error array by measuring errors in a scanner position at each of a plurality of spaced positions along a direction of travel of said scanner, said error array being generated by scanning a calibration sheet having a plurality of equally spaced lines positioned at a predefined resolution in said direction of travel of said scanner;
- generating an error compensation array from said error array based on a low frequency component of said error array;
- and
- using said error compensation array to adjust at least one parameter associated with said scanning apparatus during a document scanning operation.
Dependencies are inferred from the claim text.