Sheet advancement control system detecting fiber pattern of sheet
AssigneeHewlett-Packard Company
InventorWilliam D. Holland
Life of this patent
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Abstract
A sheet advancement control system for use in printers such as inkjet printers includes a light source for directing a beam of light onto a localized area of a sheet, a photosensitive detector for providing output signals that vary according to microscopic patterns that are illuminated within the sheet by the directed light, a correlator for determining cross-correlations between pairs of detected patterns as the sheet is advanced in a printer and for computing displacements between matching patterns to, thereby, detect the displacement of a sheet within the printer.
Claims12
A sheet advancement control system for use in printers such as inkjet printers, comprising:
- light source means for directing a beam of light onto a localized area of a sheet;
- magnifier means for magnifying the light is incident on the localized area of the sheet;
- photosensitive fiber pattern detecting means for detecting the magnified light and for providing output signals that vary according to fiber patterns within the localized area of the sheet;
- correlator means for determining cross-correlations between pairs of detected fiber patterns as the sheet is advanced in a printer;
- and
- displacement detecting means connected to the correlator means for detecting displacement between correlated patterns, thereby, to detect displacements of a sheet as it advances within the printer.
Dependencies are inferred from the claim text.