The relationship between color temperature and luminous flux
There are two concepts to understand the relationship between color temperature and luminous flux
1. Visual function. That is, radiation of different wavelengths and the same power gives the human eye a different perception of "brightness"; among them, the wavelength of 555nm has the highest efficiency (1), and the efficiency of other wavelengths is low; the farther away from 555nm, the lower the efficiency. The relationship between this wavelength and visual efficiency is the "visual function".
2. The main emission peak of each phosphor. Different phosphors emit spectra (the highest point is called the main emission peak) when they are excited, and the wavelength of the main peak is also different.
In this way, the main peak wavelength is different, the visual efficiency to the human eye is also different.
The phosphor of the energy-saving lamp is made of a mixture of red, green and blue phosphors. The main peak of red powder is at 610nm, and the visual efficiency is 0.503; the main peak of green powder is at 545nm, and the visual efficiency is 0.980; the main peak of blue powder is at 450nm, and the visual efficiency is 0.038. It has a high color temperature. If more blue powder is added, the visual efficiency of the entire spectrum will decrease. Therefore, the higher the color temperature, the lower the luminous flux. Serve inversely.
LED phosphor, the main peak with high color temperature is 560-570nm, and the visual efficiency is 0.995-0.952. In order to improve the color rendering index and reduce the color temperature, gadolinium is usually added to the phosphor raw materials, and the emission spectrum is red-shifted. The main peak is greater than 570nm and the visual efficiency is less than 0.952. The visual efficiency is reduced. high. Serve proportionally.
Warm color 2700-3000k low luminous flux
Natural white 4000k-5500k luminous flux is second
The luminous flux above 6000k is relatively high
