Abstract:
Color is synthesized by dispersing a beam of light to form a spectrum, effectively blocking a portion of the spectrum with a mask, and recombining the light energies of the unblocked portion(s) of the spectrum to synthesize the color.
Abstract:
In a colorimeter including a light source, a first quantity of light is directed toward a color sample and from the color sample toward a single photoelectric receiving and measuring device which is capable of measuring amounts of primaries or tristimulus values in quantities of light. A first carriage has mounted thereon an X primary filter, a Y primary filter and a Z primary filter, and such first carriage is reciprocable so that a selected primary filter may be positioned in front of the single photoelectric device. Adjacent the light source is mounted a second carriage which supports thereon an X primary filter mirror, a Y primary filter mirror and a Z primary filter mirror. The second carriage is reciprocable to position adjacent the light source a selected primary filter mirror corresponding to that primary filter positioned adjacent the photoelectric device. A second quantity of light from the light source is directed toward the selected primary filter mirror which reflects and changes the spectral characteristics of the second quantity of light. This second quantity of light is then directed toward the color sample and through the selected primary filter to the photoelectric device. Thus, the photoelectric device simultaneously receives two quantities of light and measures a resultant amount of the selected primary or tristimulus value therefrom.
Abstract:
Reflectance measurements of a color sample are made by employing a diffusing sphere having target ports for a color sample, a white standard and a black body. A mirror is mounted within the sphere for pivotal motion about the axis of an exit port to sequentially reflect light from the several targets along a common optical path into a polychrometer which disperses the received light into its spectrum and projects the spectra upon a sensor surface. The sensor may be in the form of an array of light-sensitive elements or the face of an image tube that is scanned or sampled at selected wave lengths of points of the spectrum to be employed in the reflectance measurement. For each sample point, the intensity of light reflected from the black body is subtracted from the intensity of light reflected from the sample and is also subtracted from the intensity of light reflected from the white standard to thereby correct both the sample and white standard measurement for both electrical and other noise of the system, and for stray light within the optical path that impinges upon the sensor surface. The ratios of intensities of the sample to the standard provide reflectance values that may be employed in various color measurements, including calculations of tristimulus values and chromaticity coordinates.
Abstract:
A recording spectrophotometer for measuring the color density of a colored surface necessary for calculating a recipe of color matching based on a colorimetric method, characterized by an integrator capable of calculating density stimulus values of the three primary colors, and an output converter capable of converting the reflectance measured by a photometer to a physical value which is in proportion to the optical density.
Abstract:
Disclosed are a dual-optical-path spectrophotometer and a color measurement method thereof. The spectrophotometer includes an integrating sphere, a light source, and a sensor. A second shutter, a semi-reflecting and semi-transmitting device and lenses are arranged between the detection hole and the sensor, and a light guide device and a first shutter are arranged between a light guide hole formed in the integrating sphere and the semi-reflecting and semi-transmitting device. The color measurement method includes the following steps. A first shutter is closed, a second shutter is opened, light, reflected by the measuring opening, enters a sensor and the sensor measures a spectral reflected signal of the object surface. The first shutter is opened, the second shutter is closed, reflected light enters the sensor, and the sensor measures a spectral reflected signal of a light source. A final sampled signal is calculated.
Abstract:
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/8°—geometry with the specular component included, and said second reflection spectrum (SPEX) is obtained at (A2) d/8°—geometry 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.