Patent ID: 6809855
Filing Date: 2004-10-26
Classification: G01J

Abstract:
A color correction system for a color printer having an output path for moving printed color sheets, including printed test sheets with printed color test patches, in which a spectrophotometer is mounted adjacent to said printer output path for sensing the colors printed on said printed color test patches on said printed test sheets as said printed test sheets are moving past said spectrophotometer in said output path, said color correction system including plural illumination sources for sequentially illuminating said color test patches with different illumination spectra in a substantially circular illumination pattern, and a plural photodetectors system for providing electrical output signals in response to the color of said test patches from said sequential illumination of said test patches by reflection of said illumination of said color test patches in said substantially circular illumination pattern by said illumination sources, and a lens system for transmitting said reflected illumination from said color test patches to said plural photodetectors system, so as to provide improved angular displacement insensitivity of said spectrophotometer relative to said printed test sheets wherein said plural photodetectors system comprises a plurality of photodetectors angularly spaced around said substantially circular illumination pattern to receive reflected illumination therefrom at substantially the same angle from substantially opposing directions.