The guy in the video is using inaccurate vocabulary, there are no fresnel lenses in a flat panel LCD/TV. This page shows the typical layers you’ll find in a modern display:
In the video when he shows a film, you can tell it is bending light not focusing it—so it is likely a fresnel prism sheet that he is holding (not a fresnel lens as he states).
You can use a fresnel lens to make a light source appear to be further away as he suggest, but that requires more depth as the light source needs to be at the focal point of the lens. The other problem is that you can only have 1 LED at the focal point for the whole sheet, so you won’t get that much light coming out even if you use a high powered LED.
You are likely to get better results buying a $50 LED light panel on Amazon compared to trying to recycle parts from an old LCD (though perhaps not as much fun). LED sources for LCDs often have poor CRI so the light quality you’ll get from this approach is likely to be bad in person. I suggest searching for 90+ CRI with CCT >6000K LED Light panels.
Based on this video, the Fresnel lens and diffusion layers in modern TVs do a great job of pushing light outwards and softening the gradient
That is SO COOL, thanks for the link.
The guy in the video is using inaccurate vocabulary, there are no fresnel lenses in a flat panel LCD/TV. This page shows the typical layers you’ll find in a modern display:
https://pid.samsungdisplay.com/en/learning-center/blog/lcd-structure
In the video when he shows a film, you can tell it is bending light not focusing it—so it is likely a fresnel prism sheet that he is holding (not a fresnel lens as he states).
You can use a fresnel lens to make a light source appear to be further away as he suggest, but that requires more depth as the light source needs to be at the focal point of the lens. The other problem is that you can only have 1 LED at the focal point for the whole sheet, so you won’t get that much light coming out even if you use a high powered LED.
You are likely to get better results buying a $50 LED light panel on Amazon compared to trying to recycle parts from an old LCD (though perhaps not as much fun). LED sources for LCDs often have poor CRI so the light quality you’ll get from this approach is likely to be bad in person. I suggest searching for 90+ CRI with CCT >6000K LED Light panels.