Why only OLED use direct light emission, and on the other hand we only have LCD-based manipulation of backlight? Why can’t we have small LED blubs for each pixel of screen?

Question

\* or have LED for each sub-pixel of screen.

In: 3

Answer 1

OLED and LCDs have something in common – you can make them by sticking a film of something (either the liquid crystal in LCDs or the organic light emitting layer in OLEDs) on top of a grid of transparent transistors.

Nice and easy to manufacture a screen because you’re making giant sheets of the stuff.

Not so with LEDs, microLED screens exist but each individual tiny LED needs to be manufactured separately. No-one has figured out how to make a whole sheet of the stuff in one go. So it’s very expensive.

As for why they don’t have LCDs with each pixel as a microLED? Well once you’re making LEDs that small they’re still expensive so you may as well just make 3 in R,G and B instead of 1 white one behind an LCD panel that kills some of the benefits of microLED anyway.