Abstract: A patterned sample is analyzed by traversing a light spot across the sample and analyzing detected color at several sites to spatially resolve the pattern. A pattern analyzer includes a holder for supporting the sample which is illuminated by projecting the light spot onto the sample. A color sensor receives light reflected by the sample at the light spot and analyzes color of the sample at the spot. The spot is traversed across the sample surface to obtain a plurality of color readings across the surface to spatially resolve the pattern.

Abstract: An apparatus for sensing blend segregation in a mixture comprises a light transmissive window disposed within a feed connection between a hopper and an extruder for example, a light source for emitting a light beam, and a light sensor to perform spectrum analysis of any incident light supplied thereto. An illumination assembly has a first end optically coupled to the light source and a second end optically coupled to the light transmissive window to illuminate a portion of the internal path provided by the feed connection. At least one detection assembly is provided, having a first end disposed adjacent to the light transmissive window so as to detect the reflection from any illuminated polymer blend passing therethrough. The light sensor collects the diffuse reflecting light from the polymer blend and transforms the diffuse reflecting light into tri-color signals, reflection curves or the like, for comparison with other diffuse reflecting light so as to determine if a particular blend is segregating.

Abstract: A chip sorting apparatus is disclosed. The apparatus includes an article transport mechanism, a light source positioned to direct light across surfaces of transported articles, and a detector positioned to detect light reflected from such surfaces and emit signals each indicative of a spectrum of light reflected by one such article as such articles are transported. A signal analyzer compares detector signals with stored data representative of the colors of articles of a set of articles being sorted. The analyzer emits article identifying signals reflective of such comparison. The apparatus also includes a sorter which is responsive to such identifying signals and directs identified articles from the transport mechanism into appropriate ones of a set of collection stations. A method of sorting a set of articles according to color is also disclosed.

Abstract: A method for the continual, real-time, in-situ generation of a Kappa number used by a process control system to control the delignification of papermaking pulps is disclosed. The method converts a plurality of analog output signals representing the intensities of spectral bands of light energy reflected by the pulp, and feedback analog output signals representing the intensities of spectral bands of light energy before they are injected into the pulp, into digital output values. The digital output values are then normalized in accordance to a normalization algorithm and stored with a time marker. The normalized values are used along with previously-stored coefficient values that represent a model of the delignification process for any particular point in time, and in accordance to the time marker and configuration data from a configuration computer, a Kappa number representation is calculated in accordance to a Kappa number-generating algorithm.

Abstract: Methods and apparatus for determining accurate hair color classificatinos and appropriate coloring agents to bring about a selected change of color include a table of hair color classifications, a color measuring instrument to arrive at Hunter L, a and b values for use in identifying a particular classification from the table and a database that identifies appropriate coloring agents based on a selection of coloring actions from a menu and the classifications of hair color.

Abstract: A method and apparatus for controlling the color of an article such as a paper web includes performing a comparison between target and measured reflectance values in numerous wavelength bands spanning the visible spectrum. The comparison quantifies correspondingly numerous errors that are modified by a non-linear operation, such as squaring, and then added together. The resulting sum is minimized by individually adjusting the application of a number of colorants to the article. The number of wavelength bands is greater than the number of colorants. This avoids metameric effects which are common in conventional systems that rely on three color space coordinates such as Hunter Laboratories L, a, b; C.I.E. L*, a*, b*; chromaticity x, y, z; and tristimulus X, Y, Z. Colorant response simulators enable the effects of changes in application of colorants to be tested while the actual application of colorants to the article is unchanged.

Abstract: An apparatus is disclosed that develops output signals representing the degree of finished state of a processed medium during a process operation, such as the lignin content of wood pulp during delignification or, alternatively, the brightness during the bleaching process. Broad spectrum light energy from a light energy source is injected into the processed medium and the resultant reflected light energy is collected from a first light collector located near the point of injection and a second light collector located far from the point of injection. The light energy collected by each light collector is conveyed to a respective light analyzer associated with each light collector. Each light analyzer divides the detected light into distinct spectral wavelengths and generates output signals representing the intensity of light energy received in each wavelength. A feedback arrangement conducts the light energy emitted by the source to a location proximate the point of injection and then to a light analyzer.

Abstract: A method of mixing colorants to achieve a target color includes combining individual colorants, detecting an output color of the combined colorants with a color sensing device and automatically adjusting the output color based on comparison between the detected output color and the target color. An apparatus for mixing colorants according to this method is also disclosed.

Abstract: A method for maintaining substantial reliability of color measurements obtained by a number of color measuring instruments includes by measuring color values of a set of master color standards on a master color measuring instrument at a master color lab, and measuring color values of sets of working color standards on the same instrument to determine calibration values. The working sets are provided to remote locations for use on remote color measuring instruments and the working sets are measured on the remote color measuring instruments to obtain color value measurements which are transmitted to the master color lab. The measurements from the remote instruments are compared with the calibration values obtained from measurements on the master instrument to generate profiles which are provided to the remote color labs. The profiles are applied to measured color values for the set of working color standards to obtain corrected color values.

Abstract: In order to determine the color stimulus specification of a translucent object under test, it is suggested to illuminate the object under test with light having different wave length bandwidth portions, or, alternatively, to subdivide the light reflected by the object under test into different wave length bandwidth portions before it is captured by an image sensor. To exactly approach a probe head to the object under test, the object under test is visualized with the help of a further image sensor. Preferably, two image sensors are used, whereby the one image sensor is used for visualizing the object under test and the other image sensor is used for determining the colorimetric data of the object under test. In this way, the color stimulus specification of the object under test can be determined very exactly. Moreover, such a method including an apparatus suitable for performing the method can be practically realized very easily.

Abstract: A method and apparatus for detecting the presence of specific substances, such as contaminates, in milk from individual animals obtained at consecutive milkings. With the aid of a color sensor measuring system, the intensity of frequency bands of selected colors (red, yellow and blue) are determined and stored as data for each animal being milked in a computer for each milking. In the course of each milking of each animal, the animal's intensity values are compared both mutually and with corresponding intensity values recorded during one or more previous milkings. The results of the comparison are displayed on a computer monitor and/or in a printed record. The milk line system includes a diversion valve disclosed between the receptacle receiving milk from the teat cups and a bulk milk tank for diverting contaminated milk as sensed by the color sensor measuring system and detected by comparisons in the computer before that milk is conveyed to the bulk milk tank.

Abstract: In a printer, periodic testing of printer ink density occurs once the number of print operations exceeds a particular threshold. The threshold is either determined from use or from statistics which summarize the performance of a particular manufacturer and ink supply. Testing results are reported to a maintenance facility and to an MIS application over a network or over a point to point link. Local warnings may be given that the ink supply is low and double printing may be used to darken the printed product until the ink supply is changed.

Abstract: A sensor for measuring reflective, transmissive, or self-luminous samples, comprises a plurality of light sources, where each of the light sources emit light of a substantially different wavelength band spaced in the visible spectrum; a reference channel photodetector; a sample channel photodetector; an optical cap adapted to direct a first portion of the light emitted by each of the light sources to the reference channel photodetector; a reflector cone for directing a second portion of the light emitted by each of the light sources to the sample; and a receptor piece for directing the diffuse portion of the light reflected from the sample to the sample channel photodetector. Preferably, the reference channel and sample channel photodetectors are identical devices and are mounted back-to-back to share environmental characteristics, and in turn, minimize the variation between their respective responses.

Abstract: A method and associated apparatus for the standardized grading of gemstones is provided. The system gauges the spectral response of a gemstone subject to a plurality of incident light sources within an imaging apparatus. The operation of the imaging apparatus is controlled by an instruction set of a local station control data processor. Light energy data is captured in the form of pixel data sets via a charge coupled device of the imaging apparatus of the local station. The control data processor of the local station is operably linked to an analysis station, the station includes an analysis data processor and mass storage memory device. The memory device provides storage space for the instruction set of the analysis data processor as well as database records. The analysis station employs a data processor and model database for assessing the aesthetic and/or monetary value of gemstones by way of the communicated pixel data sets.

Abstract: A color-sorting machine for granular materials optically detects raw material grains falling along a substantially fixed path and sorts out no-good grains by color. An optical detection unit to this end comprises a condenser lens, a plurality of optical filters and a plurality of light-receiving sensors corresponding to the filters and can detect a plurality of wavelengths. The light-receiving sensors lie side by side on the same plane, are formed in a unit body, require no positioning adjustment among the light-receiving sensors, and make it possible to reduce the size of the optical system. A prism is provided between the condenser lens and the light-receiving sensors. The prism has light path diffraction surfaces of the same number as the light-receiving sensors, so that the light-receiving sensors receive light of the same point of view and can perform color sorting.

Abstract: A method for determining the appearance of an object to be replicated and an apparatus therefor are described herein. The method consists in providing a controlled illumination to illuminate a surface of the object, measuring the object with a CCD camera to collect an image map of a plurality of points on the surface and processing that information to produce an appearance mapping of the object. Calibration of the apparatus is done by measuring calibration patches illuminated with the same illumination. When the apparatus is made in view of replicating the appearance of an object, a comparison can be done by similarly producing an appearance mapping of the replicate and by comparing it to the appearance mapping of the object.

Abstract: A hand-manipulatable device includes a sensor for gathering reflective, densitometric, spectrophotometric, colorimetric, self-luminous or radiometric readings from a sample surface. The device includes a housing having a substantially flat bottom surface and a top surface contoured to fit comfortably in the fingers and palm of the human hand. The housing also includes area on its top surface for seating an index finger of the human hand. Positioned within this area is a pressure-activated switch that is operatively coupled to the sensor circuitry for performing the readings. Preferably, the sensor is mounted into the device such that the focal aperture of the sensor is in axial alignment with the pressure-activated switch. Accordingly, a user will be able to use the device to "point" with his or her index finger to an area of the sample surface, and will then simply press the switch to initiate the readings, using the same index finger.

Abstract: A color measuring apparatus is provided with a radial illumination unit for projecting illumination light to a measurement object at a first illumination angle in a plurality of directions, a unidirectional illumination unit for projecting illumination light to the measurement object at a second illumination angle in a single direction, a unidirectional light receiving unit for receiving a light ray reflected at a first angle .theta.1 from the direction of regular reflection out of illumination light projected from the radial illumination unit and reflected by the measurement object, and a light ray reflected at a second angle .theta.2 from the direction of regular reflection out of illumination light projected from the unidirectional illumination unit and reflected by the measurement object, the second angle .theta.2 being larger than the first angle .theta.1, and a processing unit for calculating a color value at the first angle .theta.1 and a color value at the second angle .theta.

Abstract: A probe is configured for measuring color in a sample of material having a refractive index. The probe includes a light source that emits a light beam toward the sample. A color sensor is disposed at an oblique angle with the light source and directed toward a common probe zone for containing the sample. The light source and sensor are optically aligned with a reference plane in the probe zone to effect angles of incidence and reflection relative to the zone having a magnitude substantially equal to Brewster's maximum polarization angle for the refractive index of the sample, for measuring interior color of the sample.

Abstract: A system for the continual, real-time, in-situ generation of a Kappa number used by a process control system to control the delignification of papermaking pulps that includes injecting broad-spectrum light energy from a light energy source into the pulp and collecting the resultant reflected light energy from a near-and a far-light collector. The reflected light energy collected by the light collectors is analyzed by associated near- and far-light analyzers that generate analog output signals representing the intensity of selected wavelengths of light energy received by the light collectors. An included feedback arrangement conducts the light energy emitted by the light source to a location proximate the point of injection and then to an associated light analyzer that generates analog output signals representing the intensity of the light energy emitted by the light source in selected wavelengths.

Abstract: A colorimeter for measuring colour of process medium comprising two light sources and two detectors both light sources being arranged to emit a beam through the process medium and the windows adjoining the process medium to both detectors. In order to achieve a solution functioning reliably the windows adjoining the process medium at both light sources are formed from a triangular prism, the two surfaces of which being at an angle to each other, are arranged to divide the beam arriving from the light source into two beams travelling in different directions so that both beams proceed to the process medium through the same part of the window surface formed by a third surface of the prism. Mirror surfaces arranged to gather radiation arriving form both light sources to a sensor of the detector are formed at both detectors.

Abstract: An image reading method and apparatus enable a high-speed, efficient reading of a multicolor image and a monochromatic image. The image reading apparatus has a color image pickup unit, a first light source and a second light source. An output switching unit selectively switches to either a first output state, where plural kinds of read information from the color image pickup unit are all output as a result of an image reading, or a second output state, where only one kind of read information among the plural kinds of read information from the color image pickup unit is selected to be output as a result of an image reading. A lighting control unit controls lighting conditions of the first light source and the second light source. A switching control unit controls a switching condition of the output switching unit.

Abstract: This invention relates to a method for matching a color formulation to a color shade model in the field of a color- and/or effect-imparting surface coating. The reflecting surface of a color shade, which is to be rematched, of a colored surface coating is determined metrologically over the visible spectral region using a goniometric spectral photometer with variation of the angle of measurement. The associated standard tristimulus values and/or the vectors in the CIELAB color solid which are derived therefrom are calculated from the measured reflection factors or spectral energy factors. Those formulations and/or color shades which exhibit reflection properties or properties derived therefrom which are the most similar to the measured color shade model are subsequently identified from a formulation database by means of the reflection spectra or the calorimetric dimensional numbers derived therefrom.

Abstract: A multispectral sensor device comprises a plurality of optoelectrical conters. Each optoelectrical converter generates wavelength selectively from an optical signal an electrical measurement signal in a respective measurement channel. A processing circuit processes the generated electrical measurement signals to the respective measurement signal values. A fuzzy logic circuit performs a comparison of the generated measurement signal values with reference values and, on the basis of the comparison, assigns the measurement signal values to a number of channels, this number exceeding the number of measurement channels.

Abstract: According to the method the intensity of at least one pressure-independent (impurity detection) or pressure-dependent (gas pressure determination) spectral line is measured selectively. Indirect detection utilizes the intensity of spectral lines whose wavelengths correspond to higher levels of excitation energy than those of the impurities. The intensity of these spectral lines is a measure of the impurities. Alternatively, the intensity of at least one spectral line of the respective impurity is measured directly. In order to eliminate co-phasal interference, two spectral lines are measured and the ratio is formed therefrom. The intensity ratio of argon lines of wavelengths .lambda..sub.1 =772.4 nm and .lambda..sub.2 =738.4 nm has in particular proved acceptable for the indirect detection of impurities in argon and the intensity ratio V of the argon lines of wavelengths .lambda..sub.1 =763.5 nm and .lambda..sub.2 =738.4 nm has proved acceptable for determining the argon pressure.

Abstract: The present invention provides methods and devices for the quantitative analysis of pesticides with fluorescent pigments. The methods include dry mode, fluid mode, and in-field quantitative pesticide analysis. The methods also include dry mode and fluid mode data acquisition procedure by which linear relationships between spectral data and quantity of pesticide may be determined. The devices include a first and a second pesticide analysis device. The first pesticide analysis device includes a spectrophotometer and logic for determining the amount of pesticide present in a sample. The second pesticide analysis device also includes a spectrophotometer and logic for determining the amount of pesticide present in a sample. The second pesticide analysis device is further configured for in-field quantitative pesticide analysis of samples.

Abstract: This disclosure relates to a page identification system for multiple page processing systems which operates by measuring color. Detected color is compared to a look-up table that stores color characteristics for at least one known page. If a match is detected, within a tolerance selected in response to expected measurement variance, then the system produces a page identification code used in page processing. Preferably, the system is embodied in a clipboard device that automatically associates electronic data with a corresponding one of multiple pages. A stylus can be used to write on each page, and each time the stylus is used, the system automatically optically scans the page, produces a page identification code, and associates electronic data with the current page. If no match is detected in the lookup table, then the system enters a learn mode corresponding to presumed detection of a new page.

Abstract: A system and method of operation performing automated optical inspection to remove peel-bearing defective potato pieces from a random mixture of peel-bearing defective and acceptable potato pieces use near infrared light as a source of illumination. The system implements a method of illuminating the mixture with near infrared light, detecting light reflected by the potato pieces under inspection, identifying defective potato piece surface regions based on the detected reflections, and removing the defective items from the mixture. The system and method the system implements permit the inspection of peel bearing potato pieces for the presence of peel covered defects.

Abstract: An apparatus for sensing color blend homogeneity in a mixture having a first and second blend portion includes a light transmissive plate for holding the mixture, a light source for emitting a light beam, and a color sensor optically coupled to the light source. An illumination assembly has a first end optically coupled to the light source and a second end optically coupled to and disposed normal to the light transmissive plate so as to illuminate the mixture disposed on the plate with the light beam. At least one detection assembly is provided, having a first end disposed adjacent the light transmissive plate so as to detect the diffuse reflection from the illuminated mixture. Next, the color sensor collects the diffuse reflecting light from the first and second material blends and transforms the diffuse reflecting light into tri-color signals so as to determine the local and global homogeneity of the first and second material blend portions.

Abstract: A description is given of a photoelectric measuring device by means of which the light reflected from a measuring point on a printed product is detected, and the corresponding measured signals are processed for the purpose of indicating quality data. A measuring instrument of this type, having at least one illumination device and measuring channels, is an improvement over the prior art in order to expand its possible uses, with a construction which is cost-effective and stable when handled. In accordance with the invention, this is achieved with an illumination device which has a spectral intensity distribution which corresponds to the number of spectral ranges provided for the irradiation of the measuring point. The light from the sequentially drivable illumination devices irradiates the measuring point. The light reflected from the measuring point is detected and converted into a reflective signal which is processed to determine ink density values.

Abstract: The present invention discloses a method and system for selecting a previously used color match from a plurality of previously used color matches that best matches a color standard. In the present invention, each of the plurality of previously used matches are identified with a spectral reflectance and a color formula. The present invention includes measuring a color spectrum and spectral reflectance of the color standard. The spectral reflectance of each of the plurality of the previously used color matches are then processed. The processed plurality of previously used color matches are searched for a set of previous color matches that have a high probability of being adapted to attain the color spectrum and spectral reflectance of the color standard. Next, a color match that provides the best match with the color of the standard is determined from the set of previous color matches. The formula of the best match is used to reproduce the color of the standard.

Abstract: Two detectors are effectively positioned at a predetermined lateral position in a rectangular illumination field at a wafer plane. The ratio of the signals from the two detectors is calculated. This ratio is indicative of the quality of the illumination field and any lamp instability which may effect the illumination field, and therefore image quality. In a photolithographic device, a short arc mercury xenon lamp provides illumination for projecting the image of a reticle onto a photosensitive resist covered substrate or wafer. The desired illumination intensity profile is sensitive to lamp instability. This instability may alter the desired illumination intensity profile which may adversely effect image quality, and therefore the resulting product. The ratio of the signals received from predetermined locations laterally along the illumination intensity profile improves the detection of unstable lamps.

Abstract: The color sorting apparatus includes a grain guide device, a grain feeder, an illumination device for illuminating the grain, an optical detector consisting of an optical detection section for receiving the light from the illuminated grain and a background, and ejector for rejecting the grain. The illumination device employs at least one light source having spectral energy distribution in both the visible light region and the near infrared region. At least one set of the optical detection device for monitoring a predetermined detection field is provided. The optical detection section of the optical detection device includes a first light receiving sensor having high sensitivity to the visible light region and a second light receiving sensor having high sensitivity to the near infrared region.

Abstract: A method and apparatus are provided for detecting the presence of pit fragments as small as 2 mm.sup.2 in pitted peach halves. Pitted peach halves are agitated into a cup-up position, are conveyed to a position adjacent an inspection zone and are launched airborne into the inspection zone. Each peach half in the inspection zone is illuminated by a pair of quartz halogen lights and the diffusely reflected light is separated into first and second beams. The first and second beams are filtered to extract a first relatively wide wavelength band centered at 600 nm and a second relatively wide wavelength band centered at 750 nm. Preferably, each wavelength band is approximately 70 nm. Each of the wavelength bands enters a separate line scan camera for acquiring image signals from each wavelength band. The signals from both cameras are combined and enhanced to determine the presence or absence of fragments.

Abstract: The present invention discloses a method and system for determining the total colorant loading and relative colorant proportions for a color formula that is used for reproducing a color standard. In the present invention, a spectrophotometer measures the spectral reflectance of the color standard. A plurality of color matching attributes are then specified and used for attaining a match with the color standard. A merit function scale for quantifying how well a previously used color match corresponds to the color standard is developed. The merit function scale includes qualitative descriptions for the color matching attributes and a corresponding range of quantitative values. Next, a database of previously used color matches are searched and the merit function scale is used for determining a set of color matches that best approximates the color standard. A color match is determined from the set of previous color matches that optimally reproduces the color standard.

Abstract: The colorimetric value at a specified temperature is determined by measuring the colorimetric value of a colored material sample at an arbitrary temperature using a color meter such as a spectrophotometer, colorimeter, or densitometer, and by correcting the measured colorimetric value on the basis of the change in colorimetric value with temperature, which change in colorimetric value is computed from the difference in colorimetric values observed for a single colored material sample at a minimum of two different temperatures. When a spectrophotometer is applied, the spectral reflectance or the spectral transmittance of the colored material sample is measured. On the other hand, spectral reflectance or spectral transmittance is measured in advance for a dye or pigment at a minimum of two different temperatures. The difference (.DELTA.K) of absorption coefficient (K), the difference (.DELTA.S) in the scattering coefficient (S), and the difference (.DELTA.

Abstract: An apparatus for analyzing a body-fluid sample, such as a urine sample, disposed on a reagent pad is provided with means for illuminating the reagent pad on which the body-fluid sample is disposed, means for detecting light received from the reagent pad and generating a first reflectance signal at a first time and a second reflectance signal at a second time, and means for assigning a color to the body-fluid sample based upon the magnitudes of the first and second reflectance signals. The means for assigning the color to the body-fluid sample may include means for determining a pair of color coefficients each of which has a magnitude based upon the magnitudes of the reflectance signals and means for assigning the color to the body-fluid sample based upon the magnitudes of the color coefficients.

Abstract: A fiber optic diffuse light reflectance sensor is disclosed. The sensor employs illumination optical fibers to carry light emitted from a high-intensity, narrow bandwidth LED to a baffle in a readhead where the optical fibers reflect the light off of a reagent test strip. The illumination optical fibers are randomly oriented to create a more uniform light source. The light is reflected off of a pad on a reagent test strip to detect the presence of non-hemolyzed trace and hemolyzed occult blood. The reflected light must pass through another baffle to a bi-convex lens where it is focused onto a detection bundle of optical fibers. The detection bundle is optically coupled with a CCD, where the optical signal is converted to an electrical one for processing and analysis.

Abstract: A lithographic plate scanner provides more accurate representations of the color intensity of the various image areas of a plate having a fixed image by using only a single photocell to read the solid color bar, the white color bar and the successive image areas in a column of the plate. The readings are stored and a computer compares the image area readings with respect to the color bar readings and determines the amount of ink that must be flowed when the plate is mounted in a printing press to replicate the color in the printing, and stores the same on a floppy disk which is mounted in the printing press computer when the printing occurs.

Abstract: A first embodiment of the invention includes a light source (1) lighting two parallel optical branches (b1, b2) controlled respectively by two optical shutters (4, 6), one comprising a transparent cell (3) containing a substance to be studied, and the other being used to divert the light from the source. The light coming successively from one and from the other branch is applied selectively to three color filters (F1-F3) filtering three wavelengths selected according to the substance to be studied. The successive luminous intensities which have crossed each of the filters are measured through three detectors (D1 to D3) and the measurings are combined by means of a control (0). Analogous measuring sequences may be achieved with an embodiment comprising three light sources and a single detector. The device can be used for determination of the pH value of a substance.

Abstract: The present invention discloses a method and system for formulating a color match. In the present invention, there is provided a method and system for formulating a color match from a set of previously used color formulations. The present invention includes reading the color spectrum of a standard. After obtaining the color spectrum, the set of previously used color formulations are searched for a set of color formulas that approximates the color of the standard. Next, a color formula is selected from the set of color formulas that best matches the color of the standard. Then a test batch is made with the color formula having the best match and examined for its acceptability. The color formula with the best match is adapted if the formula is unacceptable. The adaptation includes at least one of manual adjusting color loadings of the color formula, synthesizing a match with the color standard, or searching through the set of previously used color formulations until there is an acceptable match.

Abstract: A photo-optical detector for use in a multi-chromatic sorting machine, each detector including at least two separate photodiode materials responsive to a different spectral range and a multi-peak optical filter having transmission response characteristics that are respectively defined in a frequency spectrum of the respective spectral ranges of the materials. The sorting machine using such detectors can be selectively programmed using the various resulting signals from the detectors after appropriate amplification and threshold detection to cause resulting ejection mechanism activation.

Abstract: A device and method for grading gemstones. The device utilizes an band pass filter and detector array to obtain the spectral response of a complete image. The gemstone is illuminated in a way that provides for analysis of both reflected and transmitted light. The device utilizes multiple lighting angles to construct an composite image that is used to perform the grading of the gemstone. The device provides spectral photometric data for each individual pixel of the image, or any portion of the gemstone image.

Abstract: A method and ink composition are disclosed that utilize two mechanisms for the purpose of indicating the approximate age of an ink that has been deposited on a writing surface. The first mechanism relates to detecting color shifts of pH sensitive compounds in the ink as the result of the evaporation of certain acidic or basic chemicals thereof. The second mechanism relates to the oxidation of compounds in the ink. Spectroscopically generated curves are plotted as the ratio of reactants to products, versus time. The spectral characteristics of the ink are determined in units of percent reflectance of the active compounds in the ink so that the age of the ink can be computed by reference to known reaction rates. A plurality of dyes having differing reaction rates may be added to the ink to enable precise measurements to be made over different time intervals.

Abstract: A colorimetric measurement head, for determining the internal color of a non-opaque material, in particular the internal color of the human skin, includes an emitter which emits light, towards the material to be studied, and is separated by an opaque wall from a emitter which receives light which has penetrated into the material and which is reflected thereby. An external surface of the head, which is positioned at the material to be studied, and contacts this surface either by direct application against the surface, or with optical wetting. The light received by the detector comes from the interior of the material, whereas the light possibly reflected by the surface of the material or coming directly from the emitter cannot reach the detector because of the opaque separating wall.

Abstract: The invention relates to a process for the optical sorting of bulk material in a colour-sorting machine while it is conveyed over a transport belt and moves past an observation head with a light source and a product signal receiver arranged in the vicinity of the light source, whereby the reflected light of the image points of the examination material is broken down into several spectral ranges by various colour filters of detection elements lying next to one another of a line of the receiver and the examination material is sorted on the basis of the colour values (measured value of the intensity in the colour in question).

Abstract: A photoelectric measuring head for the contactless scanning of measurement regions, particularly of measurement fields on a printing sheet resting flat. The measuring head having outlet orifices for compressed air on its underside to generated an air cushion between the measuring head and the printing sheet. A measuring head of this kind, suspended on an air cushion provides for high stability, and the least possible distance from the base. This is achieved in that the outlet orifice for the compressed air are formed from a plate which, by virtue of a microporous structure, is air-permeable.

Abstract: Light reflected from a sample coating is measured in three directions that are angularly spaced by angles of about 15.degree., about 45.degree., and about 75.degree. or about 110.degree. from the direction of regular reflection of illuminating light toward the direction in which the illuminating light is applied. Color differences are then determined from the measured lights and known values of reference color tones, and one of the reference color tones whose color difference is minimum is determined. Flop values of the sample coating with respect to lightness, saturation, and hue are determined from the measured lights, and the color tone of the sample coating is determined based on color differences between the determined flop values and flop values that are characteristics of the reference color tones.

Abstract: The optical properties measuring device of this invention performs preliminary emission of light from a light source prior to main light emission for sample measurement, and approximates the optical properties of the sample based on the output from a photosensor at the time of preliminary emission. Then, based on the approximated optical properties, the luminous energy for the main light emission for sample measurement is determined. Main light emission from the light source in accordance with the luminous energy determined this way is then performed, and the sample's optical properties are calculated based on the output at this time. In other words, this invention is characterized in that the sample's optical properties are approximated beforehand by means of this preliminary light emission, and the luminous energy at the time of the main light emission to perform sample measurement is changed in accordance with the result of this calculation.

Abstract: A system for controlling the color of compounded polymer(s) comprises: a compounder for mixing the constituents of the compounded polymer(s) to produce a substantially homogeneous mixture; a sensor for measuring the color of the substantially homogeneous mixture at predetermined intervals; a colorant additive feeder, responsive to a controller, for providing the colorant additive(s) to the mixture at substantially predetermined colorant additive addition rates; and a controller, responsive to the sensor, for controlling the colorant additive addition rate(s) of the feeder.