Abstract: An imaging apparatus includes a light source unit that selectively outputs white light and light in a different wavelength band to an observation target, an imaging unit including an imaging device, and a spectral image formation circuit that generates a spectral image signal for a specified wavelength by an operation using an image signal based on an output from the imaging unit and predetermined matrix data. The imaging unit selectively obtains an image of the observation target for each of first, second and third light components in a visible light region and an image for each of at least fourth and fifth light components in a near-infrared region. Further, the imaging unit includes first spectral devices that make only the first and fourth light components enter first pixels of the imaging device and second spectral devices that make only the second and fifth light components enter second pixels thereof.

Abstract: The invention relates to a device for measuring dental shade comprising: —illumination means (24, 40, 42, 44, 48, 50), for successively illuminating at least one part of a tooth (D) with light of various spectral ranges, —at least one sensor (26) sensitive to light coming from said tooth part, in response to the illumination, to generate for each different color of illumination, at least one measurement signal, —means (30, 32) for converting the measurement signals corresponding to said tooth part, into the coordinates of a measurement point (202), in a shade space in which “reference” points (320, 410, 540) are also defined, corresponding to the preset shades of a dental shade guide, and—search means (114), for the tooth part, for a shade corresponding to the reference point closest to the measurement point, in the shade space.

Abstract: A system and method for full width scanning color analysis of a printed media sheet are disclosed. The full width array spectrophotometer system includes one or more substantially linear elongated illumination arrays of closely spaced multiple illumination sources. The sources include sets of illumination sources, including a first set of different color illumination sources and a second set including one or more UV-emitting illumination sources. The sets are arranged to span a printer paper path or other object path to illuminate a band extending transversely across a printed print media sheet or other object moving in the path. A full width array light imaging sensor includes an elongated array of multiple closely spaced photodetectors for detecting plural colors and is positioned adjacent to and extending substantially parallel to the linear array(s) to receive radiation reflected from the transverse illuminated band.

Abstract: A miniature readhead is provided for photometric color detection using ambient light. The readhead is hand-held, including a superposed plate and tray. The tray receives sample media configured to react and to change color according to an amount of analyte in a sample. The plate is optically transmissive, so that ambient light is transmissible therethrough to the sample media indexed within the tray. An array of light detectors is disposed along the plate, including sets of detectors configured to detect light of at least three mutually distinct wavelengths reflected from the test areas. Light shields superposed with each of the light detectors selectively permit ambient light to pass to the tray, while substantially preventing ambient light from reaching the light detectors prior to reflecting from the test areas. The readhead may be incorporated into a photometric diagnostic instrument configured to analyze the reflections and derive a diagnosis value.

Abstract: A method of improving an initial color filter comprises a numerical generation of sinusoidal spectra. Two steps of selecting said spectra are then executed. The first selection is carried out according to a criterion of colorimetric similitude with respect to the initial filter. The second selection is carried out according to the capacity of dummy filters corresponding to each spectrum to restore hues in a natural manner. To do this, observations of samples of hues through each dummy filter are simulated numerically, using a color appearance model to take account of a visual perception of a human observer. In this way, an improved filter is determined, which has a color close to that of the initial filter and which affords a natural rendition of hues.

Abstract: A color identifying device includes a mount block, a color detector, a lens and a color identifier. A reactive board having a plurality of surfaces to be measured in respective predetermined positions is mounted in the mount block. The color detector has a plurality of color measuring areas corresponding respectively to the reaction surfaces of the reactive board mounted in the mount block. The lens forms images of the surfaces of the reactive board mounted in the mount block on the respective color measuring areas. The color identifier identifies the colors of the surfaces based on output signals from the corresponding color measuring areas.

Abstract: The color difference and/or chromaticness difference between target objects and background objects can be enhanced. Different colors with different color attributes mean different objects. In some cases, different chromaticness, such as saturation and hue, mean different two- or three-band ratio. The light from the surface of objects is filtered by optical system integrated with two- and three-band mixing method so that only the light in the wavelength range of the pass bands can reach optical sensors for opto-electronic sensing devices. With this kind of opto-electronic sensing devices, two- and/or three-band ratio criteria widely used in remote sensing and machine vision applications can be calculated in terms of color attributes. Multi-spectral imaging system can be replaced by this kind of sensing devices. This kind of two- or three-band mixing illumination can be used to identify, classify, and detect objects for human visual application, remote sensing, and machine vision application.

Abstract: Light from a tissue sample undergoes self-interference on a detector. A low coherence light source may illuminate the sample, and an interferometer receives light from the sample, divides and directs the received light along two paths, phase-delaying one and recombining the beams on a detector to form a signal. A processor coordinated with the phase delay and optionally with spatial scanning or detector array addresses, converts the signal to a tomographic image. Using self-interfering radiation from the sample, rather than interference of a reference source and a return signal, permits imaging with light naturally emitted by the sample, or with wavelength-shifted, delayed or induced light signals, allowing new diagnostic imaging modalities. The processor may create images in registry from different (for example, close but separable) wavelengths. Systems may also operate without an illumination source or may apply other stimuli to evoke emission from the sample.

Abstract: The measuring device comprises a lighting system, a photoelectric receiver unit and optical means. The lighting system applies light to image elements disposed in strip-shaped lighting regions (15) at a standardized angle of incidence range. The photoelectric receiver unit comprises several photoelectric line sensors (21) disposed parallel at a distance apart which are sensitized to different wavelength ranges by color filters (22) connected upstream. The optical means comprise linear optical arrays (31) which pick up the measurement light reflected by the image elements at a standardized range of angle of reflection and direct it to one of the respective line sensors (21). By means of optical screening and other structural features, cross-talk effects between adjacent image elements are largely reduced.

Abstract: A color density measuring device (10) for determining the color density of an ink layer applied to a printing material (22), having a light source (24) for illuminating the printing material (22) and a sensor for receiving the light remitted from the printing material (22), is characterized according to the invention in that the sensor is fashioned as a multicolor image sensor (12), and a device (14, 24, 26; 30) is provided with the aid of which the light incident at the multicolor image sensor (12) is restricted to at least one predetermined wavelength band.

Abstract: A method and system for spectroscopically determining surface and product characteristics is employed for rapid detection of product characteristics and/or the presence or absence of suspected analytes, and the concentration of the analyte. The method and system uses a signal wide band detector that does not require focusing optics in many environments. It can be used for cleaning validation of pharmaceutical products and process equipment.

Abstract: An optical assembly is disclosed that includes an illumination source, a detection sensor, a monitor sensor, and an optical piece having a first side adapted to face a sample. The optical piece defines an illumination channel extending from the illumination source toward the first side, a detection channel extending from the first side toward the detection sensor, and a monitor channel extending from the illumination channel toward the monitor sensor. A spectrophotometer is also disclosed that includes a circuit board, illumination source and one or more sensors. The circuit board includes an optically transparent region, wherein the illumination source is mounted and situated relative to a first surface of the circuit board, so as to direct light through the optically transparent region. Each sensor is mounted and situated relative to a second surface of the circuit board opposite the first surface.

Abstract: Systems and methods are provided to address the potential impact of lighting conditions/light sources on color measurement and/or color matching, particularly as such light variation relates to UV levels. The systems and methods generally include a UV visualizer that is adapted to establish and/or compare UV profiles for individual substrates/samples, e.g., print materials, under various illuminating conditions. According to the disclosure, it is possible to determine both (i) how a sample (e.g., a printing material) responds to UV light, and (ii) the amount of UV light under which the sample is viewed without the need to measure the excitation pattern of the sample/paper or the spectra of the illuminating light. In this way, a true color reading and/or color match may be achieved. Color corrections may be implemented that necessarily address the level of color brightener, if any, in the substrate or paper to be printed upon.

Abstract: A system of measuring light transmission and/or reflection has a light transmitter(s) and at least one light sensor which are used to generate a defined light environment over a specified light frequency range.

Abstract: An imaging apparatus includes a light source unit that selectively outputs white light and light in a different wavelength band to an observation target, an imaging unit including an imaging device, and a spectral image formation circuit that generates a spectral image signal for a specified wavelength by an operation using an image signal based on an output from the imaging unit and predetermined matrix data. The imaging unit selectively obtains an image of the observation target for each of first, second and third light components in a visible light region and an image for each of at least fourth and fifth light components in a near-infrared region. Further, the imaging unit includes first spectral devices that make only the first and fourth light components enter first pixels of the imaging device and second spectral devices that make only the second and fifth light components enter second pixels thereof.

Abstract: A color measurement system includes a hand held color measurement instrument, which may be provided with a wireless interface to a computer. The color measurement system includes a scanning guide for holding the hand held color measurement instrument in proper alignment with a color target. The scanning guide includes a calibration reference to allow convenient calibration of the hand-held color measurement instrument. The hand-held color instrument includes an illumination ring to provide visual feedback to the user. The color of the illumination ring changes in order to display a color similar to that being read by the hand-held color measurement instrument. Color management profiling of the hand held color measurement instrument illumination ring improves the color rendition capability of the illumination ring.

Abstract: A formulation for preparing water samples for determining arsenic concentration by colorimetry is provided. The chemical reagents in the formulation may be provided as premeasured and premixed tablets or pills. The chemical reagents include sulfamic acid, an oxidizer, and color reagents for selectively forming molybdenum-based color complexes with arsenates and phosphates. To test for arsenic, the water samples are acidified by addition of sulfamic acid. Sulfamic acid also advantageously reduces arsenic to an arsenite state. Arsenic in the water sample is oxidized or re-oxidized to an arsenate state by addition of the oxidizer. Then, color reagents are used to selectively bind and convert arsenates and phosphates in the water samples into molybdenum-blue color complexes.

Abstract: Systems and methods for providing spectral measurements are described. In one embodiment, a spectral measuring device comprises at least one radiation source configured to provide N (N?2) linearly independent illuxninant sources characterized by M (M?N) wavelength channels in a predetermined wavelength range; a sensor unit including at least one sensor, configured to be in optical communication with the radiation sources and an object; a memory storing an illuminant characterization matrix including spectral characteristics of the N illuminant sources in the M wavelength channels; and a processor configured to provide spectral responses of the object in the M wavelength channels, based at least in part on the illuminant characterization matrix. The embodiments of the invention can be used to construct a new class of compact spectral measuring devices, such as handheld color measuring devices.

Abstract: The present invention provides an apparatus for reading a color symbol, which comprises a matrix of color filters arranged in front of a detector. Light received from the filters of some colors is used to locate the color symbol, while light received from all the filters is used to read and decode the located symbol. Preferably, the filters used for locating the symbol are of the colors to which the detector is most sensitive. Preferably, the filters for locating the symbol are dominant in number.

Abstract: Color measuring systems and methods are disclosed. Perimeter receiver fiber optics are spaced apart from a central source fiber optic and receive light reflected from the surface of the object being measured. Light from the perimeter fiber optics pass to a variety of filters. The system utilizes the perimeter receiver fiber optics to determine information regarding the height and angle of the probe with respect to the object being measured. Under processor control, the color measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence and/or surface texture data also may be obtained. Audio feedback may be provided to guide operator use of the system. The probe may have a removable or shielded tip for contamination prevention.

Abstract: A color luminance meter 1 is provided with a polychrometer 4 as a spectral optical system including a light receiving sensor array 43, a signal processing circuit 5 and an operation control unit 6. The operation control unit 6 carries out calculations to obtain characteristics of a measurement light based on a specified spectral responsitivity, using light reception signals and specified weighting coefficients. The spectral responsitivities of light receiving sensors constructing the light receiving sensor array 43 are selected such that B?5 nm and A/B lies within a range of 1.5 to 4.0 when A, B denote the half power band width of the spectral responsitivities and a center wavelength interval of the spectral responsitivities. Accordingly, there can be provided a light measuring apparatus capable of maximally suppressing errors to highly precisely measure color luminance values and the like even in a measurement of a light lying in a narrow band such as a monochromatic light.

Abstract: Device and method for inspecting a polychromatic region, such as a polychromatic pattern, on a moving workpiece. The method includes device includes a solid-state light source, preferably a light emitting diode, adapted to emit light in a range of wavelengths for illuminating the polychromatic region. Photodetectors are positioned relative to the workpiece to intercept light from the light source reflected by the polychromatic region. Each of the photodetectors is adapted to detect reflected light within a corresponding one of a plurality of bands defined within the range of wavelengths. The method includes detecting intensities of the light reflected from the polychromatic region within different wavelength bands in the range of wavelengths and evaluating a ratio of the intensities for comparison with a standard ratio to ascertain a variation in the evaluated ratio.

Abstract: A field test-kit for analyzing arsenic concentration in water samples is provided. The kit includes a portable infrared beam photometer for measuring light absorbance in aqueous specimens. An infrared light emitting diode is configured to direct a beam of light through a specimen. A photodetector diode measures the intensity of light passing through the specimen. The photodetector output voltages relate to the light absorbed in the specimen and are displayed on a liquid crystal display screen. The kit is assembled using off-the-shelf electronic and opto-electronic components that have low power requirements. Dry cell batteries or solar cells power the kit. To test for arsenic, molybdenum based chemistries are used to selectively bind and convert arsenates and phosphates in the specimen into molybdenum-blue color complexes.

Abstract: A formulation for preparing water samples for determining arsenic concentration by colorimetry is provided. The chemical reagents in the formulation may be provided as premeasured and premixed tablets or pills. The chemical reagents include sulfamic acid, an oxidizer, and color reagents for selectively forming molybdenum-based color complexes with arsenates and phosphates. To test for arsenic, the water samples are acidified by addition of sulfamic acid. Sulfamic acid also advantageously reduces arsenic to an arsenite state. Arsenic in the water sample is oxidized or re-oxidized to an arsenate state by addition of the oxidizer. Then, color reagents are used to selectively bind and convert arsenates and phosphates in the water samples into molybdenum-blue color complexes.

Abstract: An inspection system may be configured to inspect objects, such as semiconductor wafers, using narrow-pulse broadband illumination. The illumination may be obtained in some embodiments using a laser configured to emit light into a material having a spectral broadening effect. The inspection system can include various filters which may be selectively placed in the illumination and/or imaging path in order to tune the spectrum of light impinging on the wafer and the light that is detected. The filters may include selectable filters, fixed filters, and filters whose characteristics can be adjusted in-place. In some embodiments, filters may be used to match the illumination/detection spectra of different tools. Additionally, the broadband illumination may be tuned between inspections and/or during inspections for best results. The system may support Fourier filtering whereby light, related to repetitive features of the object and in one or more wavelength sub-bands of the illumination, may be filtered.

Abstract: The invention provides a video camera fitted with telemetry means which provide, in parallel with the image, information relating to the distance of each of the filmed points of an image. A clip key calculated on the information relating to the distance may be calculated in the same way as a chroma-key without using a colored background.

Abstract: A device comprising an illumination means and a light sensing means, that can examine and memorize a discrete color of an object based on the magnitude of the reflected light bouncing off of the colored surface in at least three areas of the electromagnetic spectrum. The device also provides output as a visually and/or audibly perceptible signal for deciphering the color. The color range identified by the device is not limited to the visible spectrum and may include infra-red and ultra-violet light. A storage means for memorizing colors may also be included in the device. Applications of ColorStick technology may include children's toys, aids for the visually handicapped (e.g. blind or color blind individuals), designers, internet shoppers, gardeners, etc.

Abstract: A process is disclosed to measure or monitor ink concentration or ink thickness of an ink film as printed on a printing press, which consists of measuring light reflected from the ink film and the ink substrate.

Abstract: An instrument and related process for measuring color, shade, gloss, shape and/or translucence of a tooth. First, the instrument uses searchlight illumination to illuminate a tooth with constant irradiance. Second, the instrument uses calorimetric imaging to collect time-separated frames of different wavelengths of light reflected from a tooth and to combine those frames into a color image. Third, the instrument includes a sanitary shield to establish a reference color and a predetermined distance to a target tooth. Fourth, the instrument provides line-of-sight viewing so an operator may simultaneously view a display of the image on the instrument and the object being measured. Fifth, the instrument is impervious to pollutants because it incorporates a sealed measurement window. Sixth, optical measurements of a tooth taken by a dentist are compared to optical measurements of a prosthetic restoration for that tooth to confirm satisfactory matching of optical characteristics of the tooth and restoration.

Abstract: The present invention comprises reflectometer for detecting and measuring subtle changes in color and shade of color. In general, a pulsating light source illuminates a target surface which possesses a certain color and shade of color. An optical detection circuit synchronously detects light that is reflected from the target surface and generates an output signal whose voltage is indicative of the color and shade of the target surface. This voltage is then processed to make an evaluation and identification of any measurable quantity or quality that is represented by the detected color or shade of color.

Abstract: A method for making a dye mixture to produce a target colour on a given substrate, comprising the steps of: ?a) measuring reflectance values RT(?i) of the target colour at a plurality of wavelengths ?i=1, 2 . . . n; b) measuring reflectance values Rs (?i) of the substrate at the same wavelengths ?i; forming a set of concentrations cj of M dyes in the calculated concentrations; the database having been compiled by aa) making dyeings of combinations of the dyes Dn at different concentrations; bb) measuring the reflectance values R of the dyeings at different wavelengths; cc) defining a function f(R); dd) defining a relationship between f(R) and c involving constants g and k; and ee) for each dye Dn determining constants gn, kn, such that the calculated values for f(R), c, gn kn approximate closely the measured values.

Abstract: An instrument and method for measuring light or color using modulated illumination. The system includes an LED illuminator modulated at a specific frequency for illuminating the sample, and a sensor capable of differentiating between the modulated light from the sample and unmodulated ambient light. The instrument is therefore capable of “seeing” only light from the sample, while ignoring ambient light. In a second embodiment, the system includes multiple illuminators of different colors each modulated at a unique frequency so that the sample can be measured at multiple at each of the different frequencies.

Abstract: A method of obtaining a range of colors includes the following steps: selecting a test color from a predetermined set of colors, selecting a test palette comprising a plurality of color samples, measuring the real color of each sample when illuminated by a white light source, measuring the apparent color of each sample when illuminated by a test source formed by the white light source filtered by the test color, measuring the chromatic error between the real color and the apparent color of each sample, taking account of chromatic adaptation, measuring the mean chromatic error for all the chromatic errors, comparing the mean chromatic error to a test value, and adding the test color to the range if the mean chromatic error is less than or equal to the test value.

Abstract: The invention relates to a method for plain dyeing a textile web of fabric by means of a padding mangle. The squeezing force distribution between the rollers of the padding mangles is controlled according to the dye distribution in the web of fabric which is still provided with the initial humidity on the output of the padding mangle, whereby the dye distribution is measured on certain points by means of a dye measuring appliance. Measuring the dye of the humid web of fabric is simplified and the measured result is improved when a dye receiver is used as the dye measuring device, whereby the receiver separately detects the radiation of a white light source according to pure dyes, the radiation being reflected on the web of fabric in a diffuse manner.

Abstract: A handheld, portable color measuring device for measuring the primary colors of red, green and blue in a color target to be analyzed and connected to a built-in LCD display or connected to a separate personal computer. The color measuring device includes an elongated color measuring probe housing. A hollow cone shaped probe tip is attached to one end of the probe housing. A target contact end of the probe tip is placed against a color target to be measured. Inside the probe housing is a battery powered white LED light source connected to a color measurement switch. When the measurement switch is actuated, the white light source illuminates the color target surrounded by the target contact end of the probe tip. A light pipe is centered inside the probe housing and inside a portion of the probe tip. The light pipe captures the reflected light off the color target and projects the captured light onto a 3 color (RGB) sensor.

Abstract: A handheld, pen-like colorimeter for measuring the color of an object is provided. The invention includes three light sensors, each of which detects a separate primary color. A microprocessor in the colorimeter calculates a single composite color value from the three separate color measurements from the light sensors and then compares the composite color value with a list of color values, wherein each value corresponds to a unique color name. The colorimeter selects the color name that matches the composite color value of the object presents the color name to a user, using a liquid crystal display (LCD) or an audio speaker. Another embodiment of the present invention uses lasers emitting primary colors, rather than passive light sensors. The lasers shine on an object one at a time, and the reflected laser light from the three lasers is detected by a special light sensor. The three color measurements are then combined to produce a composite value, similar to the first embodiment.

Abstract: A colorimeter or color measuring device measures color of a sample or an object, and displays measurement value or values according to user defined index or indices, calculated by a user-defined formula. Data of the user-defined formula is read in from outside of the colorimeter and converted into a coded form which can be executed by a controller of the calorimeter. The data of the user-defined formula or the coded data is stored in the colorimeter. Accordingly, the colorimeter has good portability and convenience despite its capability of expressing the colors of various samples or objects by user-defined original index or indices.

Abstract: A remote platform obtaining a spectrum of one or more locations by moving the platform to sequentially illuminating the locations with different wavelengths of radiation. The different wavelengths of radiation reflected from the locations may be sequentially detected and converted into data. Spectra of the locations may be assembled from the data that was sequentially collected as the platform moved.

Abstract: A color detecting sensor includes a light emitting element for emitting red light, a light emitting element for emitting green light, a light emitting element for emitting blue light, a light receiving element for receiving light emitted from each of the light emitting elements through an ink ribbon, and detecting device for detecting a color of the ink ribbon forming at least a colorless and transparent portion and the colorless and transparent portion based on an output signal of the light receiving element, the detecting device including a storage section for storing, as color reference data, the output signal of the light receiving element when the light emitting elements emit light through the colorless and transparent portion of the ink ribbon respectively, and a color deciding section for comparing, with the color reference data, the output signal of the light receiving element when the light emitting elements emit light through the color formed on the ink ribbon respectively, thereby deciding the colo

Abstract: The invention is a cable identifier apparatus and a method for fast identification of multi-wire or multi fiber cable. The method is based on illumination of colored buffer of the wire or fiber, registration the reflected light and comparison the measuring data with reference data stored in the memory. The reference data is loaded by measuring the color parameters of the buffer of known identification. The cable identifier apparatus comprises a portable hand-held device with a probe for fixing the buffer in a holder, illuminating the buffer, controlling the incident light and detecting the reflected light with photodetectors. The data is proceed by a microcontroller and an identification symbol of the buffer is displayed in LCD. The variation of the ambient light is compensated by separate measurement of dark and light signals from photodetectors.

Abstract: A handheld, pen-like colorimeter for measuring the color of an object is provided. The colorimeter includes several light emitters, each with distinct color spectra, wherein the emission of each color is modulated at a specific frequency. These light emitters may be Light Emitting Diodes (LEDs) and/or lasers. The colorimeter also contains at least one light sensor which samples light reflected from an object illuminated by the light emitters. The rate of sampling is at least twice the modulation frequency of the emitted light. A microprocessor computes the fourier transform of the intensity of the reflected light over time, wherein the fourier transform provides the light intensity at each possible modulation frequency and determines the relative contribution of the reflected light from each light emitter, as well as the contribution of ambient light. A color value is calculated and a color name is selected and presented to the user.

Abstract: An optical method to measure certain optical characteristics of starch-containing materials during and/or after processing. Certain properties of the processed starch-containing materials such as flake weight and starch availability can be accurately estimated from the measured optical characteristics.

Abstract: A method of obtaining a range of colors includes the following steps:

Abstract: A low cost yet higher speed color spectrophotometer, especially suitable for on-line color printer color control systems, wherein multiple test patches of different colors may be simultaneously illuminated and substantially simultaneously discretely color analyzed. Reduced numbers of test print sheets, with multiple sets of multiple small adjacent different color test patches, may be used. Reflected images of the multiple different color test patches may be simultaneously focused on different areas of a photodetector chip to expose differently color responsive sets of multiple photo-sites to provide plural discrete color signals for each different color test patch image.

Abstract: In a light measuring apparatus, pulse-like measuring light is received by n photoelectric converting means and electric signals responsive to received light intensities are outputted therefrom. Time constant converting circuits elongate each of the electric signals in the direction of a time axis and outputs elongated electric signals. The respective levels of the elongated electric signals are detected at times different in width in the direction of the time axis. At this time, the timings with which the levels of n elongated electric signals are detected are shifted from each other. By using the result of detection, the respective integral values of the n elongated electric signals can be calculated without using integrating circuits. This reduces the number of components and the size and cost of a device.

Abstract: A cassette reader for detecting the status of stained samples is provided. The colorimeter includes one or more high power emitting diodes as the source of illuminating the sample. An elliptical mirror, with a central aperture to permit the light to penetrate on to the sample, directs the scattered light on to its focal point at a detector. The colorimeter includes a microprocessor which compares an output signal for the percent ratio value of the detected values of a sample and a standard sample. The colorimeter housing provides position sensors which allow the identification of the well being examined. Finally, the system is modified to measure cell motility by determining the ratio of motile sperms to total cell concentration.

Abstract: An image-splitting color meter. The image-splitting color meter is added at an entrance pupil of a light coming from an observing object to obtain a high uniformity and a high efficiency. The image-splitting device can split the entrance pupil into several partitions for light splitting and color filtering. The split light beams are then converged and focused onto a photodetective plane.

Abstract: Solid-patches 11, 12, and 13 each printed with color-inks of cyan, magenta, yellow, and a gray patch 14 included in a color bar 15 are printed on a printed-matter 10. A measuring and calculation device 4 measures actual ink densities at each of the solid-patches and gray patches in the color bars 15 and obtains differential values between the actual ink densities and target ink densities at the gray patch 14. Then, both the amount of the primary-color-component and that of the color-impurity-component at the solid patches 11, 12, and 13 are respectively substituted into equations at every detection of the differential values and that of the gray patches. In this way, ink supply volume is adjusted as a result of converting the differential values into primary-color-component differential amount in each of the color-inks.

Abstract: A method and apparatus for reliably and accurately matching tooth color, in which a light source is provided with an illumination lens and a relay lens to direct light to illuminate a measurement point in a chosen zone of a tooth selected in a patient's mouth. Light reflected from the tooth is passed through a third lens which focuses the reflected light simultaneously on three detectors. Each detector is provided with a color filter positioned in front of it to allow for only one of the basic red, green and blue (R,G,B) colors to reach the detector. The three detectors produce an output signal representing the R,G,B color coordinate related to the measurement point. These signals are converted to digital data suitable to be further processed by a data processing and control unit, which maps the R,G, B values into values of Hue, Saturation and Intensity (H, S, I) which are normalized to represent a tooth color vector.

Abstract: A handheld, portable color measuring device for measuring the primary colors of red, green and blue in a color target to be analyzed and connected to a built-in LCD display or connected to a separate personal computer. The color measuring device includes an elongated color measuring probe housing. A hollow cone shaped probe tip is attached to one end of the probe housing. A target contact end of the probe tip is placed against a color target to be measured. Inside the probe housing is a battery powered white LED light source connected to a color measurement switch. When the measurement switch is actuated, the white light source illuminates the color target surrounded by the target contact end of the probe tip. A light pipe is centered inside the probe housing and inside a portion of the probe tip. The light pipe captures the reflected light off the color target and projects the captured light onto a 3 color (RGB) sensor.