Automatic computing colour meter

Abstract From the Canadian patent

This invention discloses a novel apparatus for the measurement of colour of a sample which comprises an illumination means to illuminate the sample, an electro-optical sensing head to receive the light from the illuminated sample and to output electronic signals and an electronic processing unit to process the signals. The light source may in the preferred embodiment be the sun or the sample itself and a reference optical path is used for reference which is the same optical path as the optical path from the light from the sample. The tristimulus values X, Y, Z and the chromaticity coordinates x y of the, sample with respect to the CIE standards for luminance and chromaticity values are …