Measurex Corporation

Honeywell-measurex Corporation

Daniel A Gordon

Mark J Alguard

Gunnar Wennerberg

Harriss T King

Disclosed is an apparatus for measuring on-line the color and color-related properties of a moving sheet. Contrast ratio reflectance measurements are made for providing opacity corrections substantially in real time for a full color spectrum. An optical color sensor in accordance with the invention includes a pair of synchronized spectrometers, the first spectrometer being aligned to view a region of the sheet backed with a highly reflective ('white') material and the second spectrometer being aligned to view a region of the sheet backed with a highly absorptive ('black') material. The use of two spectrometers permits substantially simultaneous 'black' and 'white' measurements for a full color spectrum. The optical color sensing system further includes two light sources, a flashlamp and a continuously energized tungsten filament lamp. Light beams from the two sources are combined to form a sheet-illuminating third beam approximating the D65 standard source. The intensity of the flashlamp is electronically controlled to maintain the balance of UV to visible light that characterizes the standard source. The color sensor further includes a sheet backing system including a rotatable standard wheel carrying a white standard tile. Provision is made to permit rotation of the standard wheel and to standardize the sensor off-sheet while maintaining isolation of the white standard tile from the paper mill environment. The sheet backing system includes a paper guide plate defining an annular vortex space into which air is introduced from a pressurized source. A low pressure region thereby produced in the vortex space draws the paper sheet toward the guide plate. At the same time, circulating air spirals outwardly from the vortex space to form a thin air film or air bearing between the sheet and the paper guide. Sheet flutter is thereby minimized and damage to the sheet is prevented.

Dual spectrometer color sensor

Disclosed is an apparatus for measuring on-line the color and color-related properties of a moving sheet. Contrast ratio reflectance measurements are made for providing opacity corrections substantially in real time for a full color spectrum. An optical color sensor in accordance with the invention includes a pair of synchronized spectrometers, the first spectrometer being aligned to view a region of the sheet backed with a highly reflective ('white') material and the second spectrometer being aligned to view a region of the sheet backed with a highly absorptive ('black') material. The use of two spectrometers permits substantially simultaneous 'black' and 'white' measurements for a full color spectrum. The optical color sensing system further includes two light sources, a flashlamp and a continuously energized tungsten filament lamp. The color sensor further includes a sheet backing system including a rotatable standard wheel carrying a white standard tile. Provision is made to permit rotation of the standard wheel and to standardize the sensor off-sheet while maintaining isolation of the white standard tile from the paper mill environment. The sheet backing system includes a paper guide plate defining an annular vortex space into which air is introduced from a pressurized source. A low pressure region thereby produced in the vortex space draws the paper sheet toward the guide plate. At the same time, circulating air spirals outwardly from the vortex space to form a thin air film or air bearing between the sheet and the paper guide.

A system for detecting optically-sensitive properties of sheet materials during manufacture includes a first group of bundles of optical fibers that convey light to selected transmitting locations adjacent one face of the sheet material. The system further includes a second group of bundles of optical fibers that collect and convey light transmitted through the sheet material to a light detector. The light detector measures the intensity of light received from each of the bundles of the second group to provide measurements of optically-sensitive properties of the sheet material at selected cross-directional locations.

Optical system for detecting properties of traveling sheet materials

A gas measuring device has a source capable of emitting a beam of radiation aligned to impinge a detector. A housing means encloses the beam. The housing means has a plurality of apertures permitting the gas to enter the housing means, to intercept the beam, and to exit from the housing means. The device further comprises means to control the amount of thermal radiation reaching the detector.

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Cupertino, CA, United States of America

Daniel A Gordon