Abstract: A marking engine forms one or more toned patches and/or images on a photoreceptor transfer device such as a photoreceptor belt or drum, either within or outside a main image area. A sensor illuminates the tones patches and/or images on the photoreceptor transfer device using wavelengths outside the photo response range of the photoreceptor transfer device, thereby allowing reflectance values for each toned patch and/or image to be measured without generating ghost images on the photoreceptor transfer device. The sensor supports collection of measured reflectance values from single-color, mixed-color; and multi-separation image-on-image toned patches and/or images directly from the photoreceptor transfer device at rates as high as one or more times per revolution of the photoreceptor transfer device. The measured reflectance values may be used to generate and/or update color stabilization tone reproduction curves.

Abstract: An algorithmic method is identified for compensating for thermochromaticity errors in insitu spectral color measurements of a color printing device. A difference is mapped between spectral measurements of a printed color generated by the color printing device measured at a first or hot temperature and at a second or cool ambient temperature where the mapping comprises a referenceable characteristic of the color printing device. The spectrophotometric measurement of a hot color is compared with colors obtained with thermochromaticity compensation matrix to assess if the measured color corresponds to the desired color which will result when cooled to ambient temperature.

Abstract: An alogrithmic method is identified for compensating for thermochromaticity errors in insitu spectral color measurements of a color printing device. A difference is mapped between spectral measurements of a printed color generated by the color printing device measured at a first or hot temperature and at a second or cool ambient temperature where the mapping comprises a referenceable characteristic of the color printing device. The spectrophotometric measurement of a hot color is compared with colors obtained with thermochromaticity compensation matrix to assess if the measured color corresponds to the desired color which will result when cooled to ambient temperature.

Abstract: A marking engine forms one ore more toned patches and/or images on a photoreceptor transfer device such as a photoreceptor belt or drum, either within or outside a main image area. A sensor illuminates the tones patches and/or images on the photoreceptor transfer device using wavelegths outside the photo response range of the photoreceptor transfer device, thereby allowing reflectance values for each toned patch and/or image to be measured without generating ghost images on the photoreceptor transfer device. The sensor supports collection of measured reflectance values from single-color, mixed-color; and multi-separation image-on-image toned patches and/or images directly from the photoreceptor transfer device at rates as high as one or more times per revolution of the photoreceptor transfer device. The measured reflectance values may be used to generate and/or update color stabilization tone reproduction curves.

Abstract: An LED spectrophtometer device for determining an aspect of the color of an object may include: a visible spectrophotometer comprising a plurality of light emitting diodes that emit light in the visible spectrum onto the object; at least one detector for detecting said light after being directed onto the object and for generating an output; and a UV light emitting diode assembly that emits light in the near ultraviolet spectrum and communicates with at least one detector for generating an output. The device may further include a processor that combines the outputs of the at least one detector of the visible spectrophotometer and the at least one detector in communication with the UV light emitting diode assembly.

Abstract: 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.

Abstract: A sheet curl measurement system and method and an automatic sheet decurling system controlled thereby for the printed paper sheets output of printer. The sheet curl may be remotely sensed without contacting or interfering with the motion of the sheets in their normal sheet path, using a simple but accurate optical sheet curl sensor operating on a portion of the moving sheet at an angle thereto and perpendicularly thereto, with displacement insensitive optics, in both an angular direction substantially parallel to the sheet movement direction and an angular direction substantially transverse to the sheet movement direction, with ratioing of the two output signals.

Abstract: 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.

Abstract: A method is provided for measuring the color of irregular surface materials, including textiles which may provide dissimilar color measurements from different viewing angles, by illuminating a sampling area of the irregular surface material approximately perpendicularly thereto and measuring the color reflected from that area at a substantial angle, preferably about 45 degrees, with a plurality of separate photodetectors arrayed circularly around the illuminated sampling area of irregular surface material to receive the reflected illumination from substantially opposing directions and at a substantial angle to the illuminated area, for providing a more accurate yet lower cost color measurement system for textiles that can be used easily, quickly, and uncritically in terms of the handling, positioning and orientation of the textile material being tested.

Abstract: 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.

Abstract: 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.

Abstract: A method is provided for measuring the color of irregular surface materials, including textiles which may provide dissimilar color measurements from different viewing angles, by illuminating a sampling area of the irregular surface material approximately perpendicularly thereto and measuring the color reflected from that area at a substantial angle, preferably about 45 degrees, with a plurality of separate photodetectors arrayed circularly around the illuminated sampling area of irregular surface material to receive the reflected illumination from substantially opposing directions and at a substantial angle to the illuminated area, for providing a more accurate yet lower cost color measurement system for textiles that can be used easily, quickly, and uncritically in terms of the handling, positioning and orientation of the textile material being tested.