Colorimeter includes an illumination light reception unit, an attached part, a detection unit, a recognition unit, a color measurement control unit, and an output unit. To the attached part, a mask member is attached to cover the illumination light reception unit. The detection unit detects parts disposed on the mask member. The recognition unit recognizes information on the kind of the mask member in accordance with a detection result by the detection unit. The color measurement control unit causes the recognition unit to recognize information on the kind of mask member in accordance with the detection result at a first timing, and on the kind of mask member in accordance with the detection result at a second timing. The output unit performs a predetermined output in response to a discordance between the information on the kind of mask member at the first timing and at the second timing.

The invention relates to a measuring arrangement for detecting an absolute reflection spectrum of a sample in a process for producing the sample. It comprises a light source for generating measurement light, a homogenizer for generating a uniform spatial illuminance distribution of the measurement light; a movable reflector and a receiver for collecting the measurement light reflected from the sample and/or the reflector. According to the invention, the reflector both for a reference measurement and for a sample measurement is positioned in an observation beam path and arranged on the same side of the sample as the light source in order to feed the reflected measurement light to the receiver.

The present disclosure relates to an apparatus for measuring a colour parameter of a gemstone. The apparatus comprises a support structure for supporting the gemstone at a measurement location, an illumination system for illuminating the gemstone at the measurement location, an imaging device directed towards the measurement location for obtaining an image of the gemstone, and an image processor for analysing the image of the gemstone. The image processor is configured to identify a set of stone pixels corresponding to the gemstone in the image and identify luminance and chrominance values for each stone pixel. A colour vector is calculated from an expression of the chrominance values of the stone pixels in chrominance space, the colour vector extending in chrominance space from stone pixels having a relatively high luminance value to stone pixels having a relatively low luminance value. This colour vector is used in the determination of the colour parameter.

Disclosed are a colorimeter and a reflectivity measuring method based on a multichannel spectrum. The colorimeter includes a main unit and a calibration box, wherein the main unit includes an integrating sphere, a light source and a main sensor, a detection hole is formed in one side of a top of the integrating sphere, a light-through hole is formed in a side of the integrating sphere, and a measuring port is formed in a bottom of the integrating sphere, the light source is arranged outside the light-through hole, and the main sensor is arranged outside the detection hole; the calibration box includes a housing and a white board arranged at a top of the housing, the white board is correspondingly matched with the measuring port, and the calibration box is connected with the main unit; the sensor is a multichannel spectral sensor.

The invention relates to a method for colour recipe calculation for matt colour standards with the steps: A) experimentally determining reflection spectra R(exp) of the color standard, comprising a first reflection spectrum (SPIN) and a second reflection spectrum (SPEX), with an integrating sphere color measurement instrument, wherein said first reflection spectrum (SPIN) is obtained at (A1) d/8geometry with the specular component included, and said second reflection spectrum (SPEX) is obtained at (A2) d/8geometry with the specular component excluded; B1) calculating a recipe for the matt color standard based on the experimentally determined reflection spectrum R(exp) with the specular component included, which has been corrected for the specular component, or B2) comparing the experimentally determined reflection spectrum R(exp) with the specular component included, which has been corrected for the specular component, with reflection spectra associated to color recipes of a color recipe database for glossy color shades and identifying from said color recipe database a stored reflection spectrum which comes closest to the experimentally determined reflection spectrum R(exp) of the matt color standard, as well as the associated colour recipe; C) converting reflection spectra data of the experimentally determined reflection spectra (SPIN, SPEX) of the matt colour standard to gloss values, and D) converting the gloss values obtained to the amount of matting agent (MAA) with the assistance of previously prepared calibration curves for the available colorant system.

Disclosed are optical detection device, system, and method which increase photodetection area and enables omnidirectional and self-aligning photodetection through the use of a fluorescent lens. An optical detection device comprises a fluorescent lens having a light collecting area being a spherical, hemispherical, or cylindrical surface of the fluorescent lens, and a light outcoupling area; and a fluorophore dispersed throughout the light collection area and the fluorescent lens, wherein the fluorophore is excitable by a light beam, which is incident at any position or angle in relation to the spherical surface, to produce a light emission, wherein the light outcoupling area is arranged to allow an extraction of the light emission from the fluorescent lens, wherein the light collecting area is larger than the light outcoupling area.

In one embodiment, an apparatus for measuring a color of a non-solid colored sample includes an integrating sphere having a sensor port, a sample port, and a plurality of registration marks affixed to an interior surface of the integrating sphere, outside a periphery of the sample port, a camera positioned near the sensor port, and a plurality of filters positioned between the integrating sphere and camera. An optical axis of the camera extends from the camera, through at least one of the plurality of filters, through the sensor port, to the sample port.

The invention relates to a measuring arrangement for detecting an absolute reflection spectrum of a sample in a process for producing the sample. It comprises a light source for generating measurement light, a homogenizer for generating a uniform spatial illuminance distribution of the measurement light; a movable reflector and a receiver for collecting the measurement light reflected from the sample and/or the reflector. According to the invention, the reflector both for a reference measurement and for a sample measurement is positioned in an observation beam path and arranged on the same side of the sample as the light source in order to feed the reflected measurement light to the receiver.

An electronic device may be provided with a color sensing ambient light sensor. The color sensing ambient light sensor may measure the color of ambient light. Control circuitry in the electronic device may use information from the color sensing ambient light sensor in adjusting a display in the electronic device or taking other action. The color sensing ambient light sensor may have light detectors with different spectral responses. A test system may be used to calibrate the color sensing light sensor. The test system may have a tunable light source with light-emitting diodes that are turned on in sequence while gathering measured responses from the detectors. Numerical optimization techniques may be used to produce final versions of the spectral responses for the light detectors from the measured responses and corresponding calibration data that is stored in the electronic device.

Multiple colors of light emitted by an assembled light emitting diode (LED) based illumination device is automatically tuned to within a predefined tolerance of multiple target color points by modifying portions of wavelength converting materials associated with each color. A first color of light emitted from the assembled LED based illumination device in response to a first current is measured and a second color of light emitted from the assembled LED based illumination device in response to a second current is measured. A material modification plan to modify wavelength converting materials is determined based at least in part on the measured colors of light and desired colors of light to be emitted. The wavelength converting materials may be selectively modified in accordance with the material modification plan so that the assembled LED based illumination device emits colors of light that are within a predetermined tolerance of target color points.