Abstract: To determine the spectra of objects that have different degrees of fluorescence, a plurality of reference databases are provided, each reference database being suited to a different degree of fluorescence. A most appropriate one of the reference databases is selected based on a predicted degree of fluorescence of an object for which a reflectance spectrum is to be determined. The prediction of the degree of fluorescence may be based on user input, or may be predicted by using a priori information, such as a priori knowledge of media types.

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: An electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including a probe; a support for supporting the probe in spaced relationship with the surface, the probe having a plurality of spacing element sites thereon for measuring a distance between each of the plurality of spacing element sites and a corresponding area on the surface opposite of each of the plurality of spacing element sites; a plurality of electrostatic element sites, intermixed and adjacent to the plurality of spacing element sites on the probe, for measuring a voltage between each of the plurality of spacing element sites and an area on the surface adjacent to the corresponding area opposite of each of the plurality of spacing element sites. A processor for compensating an output signal of the probe in response to the measurements received from the plurality of spacing element sites and the plurality of electrostatic element sites.

Abstract: A device independent color control server and control methods provide color consistency services and improve consistent color document appearance between any number of connected color image forming devices and/or color display monitors on a distributed network.

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: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

Abstract: In a color analysis method in which sheets with multiple different color printed test patches are moved relative to a color analyzing spectrophotometer, and in which fiducial marks are printed adjacent to respective test patches and optically detected by a fiducial mark detector to provide a triggering system for the respective test patch analysis, there is provided automatic diagnostic testing of the spectrophotometer and the fiducial mark triggering system, including automatically generating special test sheets, some of which may include test areas of varying density black.

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 apparatus for correcting beam-to-beam spacing error on an image plane of a photoreceptor includes a controller which generates beam-to-beam spacing error corrections signals, a plurality of optical elements, each of which is adjustable and responsive to beam-to-beam spacing error correction signal and a gray level measurement device. The controller performs the beam-to-beam spacing error correction analysis, determining whether or not a correction is necessary, and if so, which optical element to adjust and the magnitude of adjustment. Enhanced toner area coverage sensors are used to detect the gray level of a toned area of raster scan line patterns at various locations across the photoreceptor image plane. By repeatedly evaluating the beam-to-beam spacing error during operation, the apparatus of the invention is able to correct beam-to-beam spacing errors that may develop during operation and does not permit residual errors to persist even after an initial correction has been implemented.

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 apparatus for correcting beam-to-beam spacing error on an image plane of a photoreceptor includes a controller which generates beam-to-beam spacing error correction signals, a plurality of optical elements, each of which is adjustable and responsive to beam-to-beam spacing error correction signal and a gray level measurement device. The controller performs the beam-to-beam spacing error correction analysis, determining whether or not a correction is necessary, and if so, which optical element to adjust and the magnitude of adjustment. Enhanced toner area coverage sensors are used to detect the gray level of a toned area of raster scan line patterns at various locations across the photoreceptor image plane. By repeatedly evaluating the beam-to-beam spacing error during operation, the apparatus of the invention is able to correct beam-to-beam spacing errors that may develop during operation and does not permit residual errors to persist even after an initial correction has been implemented.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

Abstract: By using a reconstruction algorithm, based on the spectral characteristics of the illumination source and a color sensing system, a spectral curve reconstruction device converts measurements from a non-fully illuminant populated color sensor into a fully populated spectral curve. This is done using a spectral measurement system model, which may use basis vectors.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

Abstract: In a color analysis system in which sheets with multiple different color printed test patches are moved relative to a color analyzing spectrophotometer, and in which fiducial marks are printed adjacent to respective test patches and optically detected by a fiducial mark detector to provide a triggering system for the respective test patch analysis, there is provided automatic diagnostic testing of the spectrophotometer and the fiducial mark triggering system, including automatically generating special test sheets, some of which may include test areas of varying density black.

Abstract: An electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including a probe; a support for supporting the probe in spaced relationship with the surface, the probe having a plurality of spacing element sites thereon for measuring a distance between each of the plurality of spacing element sites and a corresponding area on the surface opposite of each of the plurality of spacing element sites; a plurality of electrostatic element sites, intermixed and adjacent to the plurality of spacing element sites on the probe, for measuring a voltage between each of the plurality of spacing element sites and an area on the surface adjacent to the corresponding area opposite of each of the plurality of spacing element sites. A processor for compensating an output signal of the probe in response to the measurements received from the plurality of spacing element sites and the plurality of electrostatic element sites.

Abstract: A color spectrophotometer incorporating a low cost commercial imaging chip, which normally forms part of a document imaging bar used for imaging documents in scanners, etc., having multiple photo-sites with three different rows of color filters. Each chip is mounted on the optical axis of an imaging lens system, in the image plane of that lens system, to image the reflected illumination from an illuminated color test target area on the chip. The optical axis of the imaging lens system is oriented at 45° to the illuminated color test patches, and the photodetector chip is physically mounted perpendicular to the plane of the illuminated color test patches. Respective photo-sensor chips and associated 1:1 optics may be mounted on opposing sides of the spectrophotometer physically oriented at 90° to the test target area plane receiving the reflected light from the test target optically oriented at 45° to the illuminated test target.

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.