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AssigneeXerox Corporation
InventorsFred F. Hubble, III, Tonya L. Love, Daniel A. Robbins
Estimating the term…
An improved and lower cost color spectrophotometer, especially suitable for an on-line color printer color control system, in which plural different spectra LEDs sequentially perpendicularly illuminate a common and substantially circularly illuminated color test area, which may be variably spaced and variably oriented relative to the spectrophotometer, through a common central lens system, and also the reflected illumination therefrom may be measured at 45 degrees thereto by averaging the outputs of photodetectors spaced around that circularly illuminated color test area, to provide reduced sensitivity to the variable angular or azimuthal orientation of the color test area relative to the spectrophotometer, and which photodetectors may be so illuminated by 1:1 optics for spatial insensitivity.
A low cost broad spectrum spectrophotometer for measuring the colors of test target areas which may be variably displaced and variably angularly oriented relative to said spectrophotometer, comprising plural illumination sources and a common lens system for sequentially projecting plural different spectral illuminations from said plural illumination sources substantially perpendicular to the color test target area to illuminate a substantially circular illumination area of the color test target area, a sequential actuation circuit for sequential actuation of said plural illumination sources, and at least one photodetector spaced from said common lens system and spaced from said substantially circular illumination area of the color test target area to angularly receive reflected light from said substantially circular illumination area, so as to provide reduced angular displacement sensitivity of said spectrophotometer relative to said color test target area.
A method of broad spectrum color measurement of a color test area comprising substantially perpendicularly sequentially illuminating a substantially circular area of said color test area with a limited plural number of different spectra illuminations through a common lens system and sequentially non-contact measuring a portion of the reflected illumination from said sequentially illuminated substantially circular area of said color test area at approximately 45 degrees thereto with at least one photodetector spaced from said color test area to provide reduced angular sensitivity of said photodetector relative to said color test area.
A low cost broad spectrum spectrophotometer comprising means for sequentially perpendicularly illuminating a common substantially circularly illuminated color test area with a limited plural number of different spectra illuminations, and means for sequentially measuring the angularly reflected illumination from said sequentially illuminated substantially circularly illuminated color test area by applying said reflected illumination simultaneously to plural photodetectors spaced around said common color test area and summing the outputs of said photodetectors to provide an averaged output.
A system for more accurately measuring the color of a material, comprising:
A system for more accurately measuring the color of a material, comprising:
A system for more accurately measuring the color of a material, comprising:
A system for more accurately measuring the color of a material, comprising:
Dependencies are inferred from the claim text.