The relationship between the spectrum of visible light and LED white light. It is well known that the wavelength range of the visible light spectrum is 380nm~760nm, which is the seven colors of light that can be felt by the human eye-red, orange, yellow, green, blue, blue, and purple, but these seven colors of light are all individually A monochromatic light. For example, the peak wavelength of the red light emitted by the LED is 565 nm. There is no white light in the visible light spectrum, because white light is not monochromatic light, but a composite light composed of a variety of monochromatic lights, just as sunlight is white light synthesized by seven monochromatic lights, while in color TVs White light is also synthesized from the three primary colors red, green, and blue.
It can be seen that, in order to make the LED emit white light, its spectral characteristics should include the entire visible spectral range. But it has not been possible to manufacture LEDs with this performance. According to people’s research on visible light, the white light that human eyes can see requires a mixture of at least two kinds of light, that is, two-wavelength light emission (blue light + yellow light) or three-wavelength light emission (blue light + green light + red light) mode . Both of the above two modes of white light require blue light, so the ingestion of blue light has become a key technology for white light manufacturing, that is, the “blue light technology” pursued by major LED manufacturing companies. There are only a few manufacturers that master the “blue light technology” in the world, so the promotion and application of white light LEDs, especially the promotion of high-brightness white light LEDs in my country, is still a process.
