Spectrophotometer

A spectrophotometer that measures a spectral reflectance of an object to be measured and determines a color value of the object to be measured based on a color-matching function of XYZ color system and the measured spectral reflectance, the spectrophotometer comprising:

• an irradiation unit configured to irradiate the object to be measured with light;
• a spectroscope configured to disperse reflected light from the object to be measured;
• and
• a signal processing unit,
• wherein the irradiation unit comprises:
• a first light source that emits white light;
• and
• a second light source that emits light having a spectral intensity distribution in which a relative intensity at a wavelength at which a value of z reaches its peak in the color-matching function is equal to or greater than 0.5, and
• wherein the signal processing unit determines:
• the spectral reflectance of the object to be measured based on a signal of light dispersed by the spectroscope,
• a tristimulus value by comparing the spectral reflectance to the color-matching function of the XYZ color system, and
• the color value of the object to be measured based on the tristimulus value of the XYZ color system.