Accurately identify three primary color circuits

It is a circuit that accurately identifies the three primary colors . The principle is based on the wavelength characteristics of the three primary colors (different wavelengths, peaks, and positions),
with the help of peak wavelength color filters and photodiodes, the spectral sensitivity covers the entire visible light area, and outputs x, Y, Z in Figure 7-23 , Zhijingqiuduo
is enlarged and A/D converted by U4A, U4B, and U4C to obtain the final results of (red-yellow), (green-blue) and (purple) colors. The most important issues in the actual use of
  color sensors are the lighting power supply and light condensing system, and the area of ​​the distinguishing element should be as small as possible in order to effectively form an illumination
point on the object . It is most convenient to use incandescent lamps as the light source. As for the condenser system, attention must be paid to the focus of the condenser and the diameter of the illumination point.     The color sensors currently on the market are relatively expensive and are used to identify lines and strips in robot production and competitions. ,k In practice, infrared photoelectric reflective sensors can also meet the usage requirements.