Millions of pixels, individually illuminated
The pixels on an OLED display each contain three sub-pixels. For example, 4K (3840 x 2400) display has 8,294,400
pixels, which means it has 24,883,200 sub-pixels. Each sub-pixel self-illuminates independently, unlike LCD displays with
pixels that need to be backlit, usually by just 50 or 60 LEDs. This means that it’s easier to
achieve true black on an OLED display, by simply turning off a pixel. This can’t be done on an
ordinary LED display, because the backlight can’t be turned off with such granularity. This fact
also gives OLED displays exceptionally high contrast.