Colorimeter and chromaticity measurement method

A colorimeter configured to measure a chromaticity of a measured object, the colorimeter comprising:

• a first light source unit configured to emit first irradiation light having a first spectrum;
• a second light source unit configured to emit second irradiation light having a second spectrum different from the first spectrum;
• a third light source unit configured to emit third irradiation light having a third spectrum different from the first spectrum and the second spectrum;
• an integrating sphere configured to have irradiation light including the first irradiation light, the second irradiation light, and the third irradiation light incident thereon;
• a light receiver configured to detect measured light resulting from irradiation of the measured object with the irradiation light emitted from the integrating sphere;
• and
• a controller configured to calculate an optical spectrum of the measured light based on a detection signal of the measured light,
• wherein a superimposed spectrum of the first spectrum, the second spectrum, and the third spectrum corresponds to a reference spectrum of a D65 standard light source as a reference for calculating the chromaticity,
• wherein the second light source unit and the third light source unit emit light in wavelength regions in which the first spectrum is depressed as compared with the D65 standard light source,
• wherein a center wavelength of the second spectrum is located, in a visible light wavelength region, at a tail of the first spectrum,
• wherein a center wavelength of the third spectrum is located, in the visible light wavelength region, at a dip of the first spectrum, and
• wherein a profile of the superimposed spectrum is approximated to a profile of the reference spectrum in an entire visible light wavelength region of the reference spectrum.