The "white" LED in our eyes is not as simple as you think!

The principle of light emission of white light emitting diodes is slightly different from that of other light emitting diodes. There are currently two light emitting modes that enable the light emitting diodes to emit white light. One is a white light emitting diode using a two-wavelength blue light+yellow light emitting mode. The basic part is a blue light emitting diode. A blue light emitting diode chip is covered with a phosphor layer, and a blue light emitting diode chip. Some of the emitted blue light is absorbed by the phosphor when it is transmitted through the phosphor, and becomes yellow light. White light is emitted when the yellow light is mixed with the blue light transmitted through the phosphor. For example, some white LEDs emit light that is pure white, while others emit white-blue light.

The other is a three-wavelength blue light + green light + red light emitting mode of full-color light emitting diodes, which are red, green and blue light emitting diodes encapsulated in the same package, the three primary colors of light mixing White light can be generated, but due to the relatively high cost of producing full-color light-emitting diodes, full-color light-emitting diodes are generally not used to make lights. Full-color light-emitting diodes are mainly used to manufacture full-color displays, using full-color The manufacture of light-emitting diodes will greatly increase the cost of the product.