MicroLED, also known as micro-LED, mLED or µLED, is an emerging flat-panel display technology. microLED displays consist of arrays of microscopic LEDs forming the individual pixel elements. When compared with widespread LCD technology, microLED displays offer better contrast, response times, and energy efficiency.
Along with OLEDs, microLEDs are primarily aimed at small, low-energy devices such as smartwatches and smartphones. OLED and microLED both offer greatly reduced energy requirements when compared to conventional LCD systems while also offering an infinite contrast ratio. Unlike OLED, microLED is based on conventional gallium nitride (GaN) LED technology, which offers far higher total brightness than OLED produces, as much as 30 times, as well as higher efficiency in terms of lux/W and thus lower power consumption than OLED. OLED also suffers from screen burn-in, while microLED does not, but microLED displays cannot be made flexible or transparent like OLED displays can.
So what makes MicroLED special?
In short, it’s the first brand-new display technology to be commercialized in more than a decade. The last was OLED, which debuted in TVs on thein 2008 and now dominates the TV picture quality race as well as powering most high-end phones. But even today the vast majority of screens, from TVs to laptops to tablets to phones, use older LCD technology instead of OLED. It has taken years for OLED to become more mainstream, and you should expect a similar (long) path for MicroLED.
Samsung was the first to take MicroLED to market, but it’s not the only one in the game. LG is working on MicroLED, too, and showed a demo panel at the IFA show in Berlin, while Chinese TV giant TCL in its booth at CES 2019. Sony has been working on some variation of direct LED TVs since , and both it and Samsung for movie theaters and other uses.
The tech could also light up tiny screens. Apple currently uses OLED displays for theand the , but it’s developing its own in-house MicroLED displays for use in mobile devices, starting with the watch. Details are scarce and it’ll likely be years (if ever) before Apple brings it to market, but Cupertino’s interest provides further evidence that MicroLED could be big.
It’s easy to see why. MicroLED has the potential for the same perfect black levels as OLED with no danger of. It can deliver higher brightness than any current display technology, wide-gamut excellent color and doesn’t suffer the of .
Right now the issue with MicroLED isn’t image quality, it’s manufacturing. The sources cited in the Apple report say the screens are more difficult to produce than OLED displays, to the extent that Apple almost pulled out of development a year ago.
Tiny, tiny LEDs
Turns out that process is a lot harder than it sounds. One problem is that when you shrink LEDs, the total amount of light they produce goes down. So you either need to drive them harder or increase their efficiency, or both. Just driving them harder introduces new issues. The TV will need a lot more electricity and have to dissipate a lot more heat.
Shrinking the gap between the pixels, or the “pitch size,” is another huge challenge. The circuitry and other necessary elements can only get so small. If you can’t reduce the pitch size, there’s a limit to how small a MicroLED TV can be. Hence how impressive Samsung’s smaller MicroLED is.
Sure, wall-size TVs are cool, but no one will buy them. If a manufacturer wants to make a profit on its new tech, it needs something easy to make in the 50-inch range, or smaller. Once it can do that, the big sizes will be easy. Well, easier.
And then there’s the cost. Instead of a handful, or maybe a few dozen, yellow-blue “white” LEDs like you get on a normal TV, you have 8.3 million LEDs, one for each pixel on a 4K 3,840×2,160 display. Actually, it’s way worse than that. Since you needLEDs for each pixel, that means there are nearly 25 million total LEDs. Thousands of these are then grouped in modules, and multiple modules make up a TV, wall or movie screen.