Where Does Blue Light Actually Come From in Displays? #display

Added: 2026-05-22

[00:00:00]Most display manufacturers today talk about low blue light screens, but as someone working in the display industry, I want to explain where blue light actually comes from. First, let's take a display apart. This part here is the LCD layer. The LCD itself does not produce light. It only controls light passing through it. You can think of it like a curtain controlling how much light goes through. So, the LCD itself is not the source of blue light. The real light source is the backlight system. Inside the backlight, we have LED light bars.

[00:00:30]The LED chips underneath actually emit blue light first. Then, the phosphor coating on top converts part of that blue light into other colors. When those colors mix together, our eyes see it as white light. So, in reality, most white LED light sources around us are based on this principle, not only display screens, but also household lighting, monitors, TVs, and many electronic devices. That's why when we talk about protecting our eyes, the most important thing is not only the display specification itself. Good usage habits matter even more. For example, don't use your phone too late at night, keep a proper viewing distance, reduce long periods of close-up screen time, especially for children. Low blue light technology can help reduce part of the high-energy blue light spectrum, but healthy viewing habits are still the key. At Fenal, we focus on customized touch display solutions, but we also enjoy sharing the real engineering principles behind displays and touch screens. If you're interested in the display industry, feel free to follow us.