Understanding and Learning about LEDs: 4. What is a High Color Rendering White LED?

Developing light that is closer to natural light.

White LEDs are used as the lighting source, but there are several methods to create that white light. One method is to combine red, green, and blue LEDs. This method has good color rendering properties but faces challenges in terms of cost and luminous efficiency. Therefore, a method that combines blue LEDs with yellow phosphors has been used so far, as it allows for relatively easy attainment of high luminous efficiency. However, this method has the drawback that the emitted color is a pseudo-white, making it unsuitable for applications that require high color rendering properties. Additionally, there is a method that creates white light by combining near-ultraviolet LEDs with blue, red, and green phosphors, but this is said to have issues with brightness. In response, Citizen Electronics has adopted a method that uses blue LEDs to excite red and green phosphors. This method serves as a light source for LEDs with high color rendering properties while overcoming challenges related to cost and efficiency.

LED lighting