What is micro-OLED? Apple Vision Pro display explained
At WWDC 2023, Apple announced the Vision Pro, an AR/VR headset that offers an impressive amount of technology and an equally imposing price tag of $3,499. One of the things that helps the Vision Pro stand out from cheaper products from Valve and Meta is the use of a new type of display called micro-OLED. More than just a rebranding by Apple’s marketing pundits, micro-OLED is a twist on screen technology that’s become a staple on top TV lists over the past few years.
The main difference between micro-OLED and “traditional” OLED is in its name. Featuring much smaller pixels, micro-OLED has the potential for much, much higher resolutions than traditional OLED: think 4K TV resolutions on postage stamp-sized chips. Until recently, the technology was used in things like electronic viewfinders in cameras, but the latest versions are larger and have even higher resolution, making them perfect for AR and VR headsets.
Here’s an in-depth look at this technology and where it could be used in the future.
What is OLED?
OLED stands for Organic Light Emitting Diode. The term “organic” means that the chemicals that help the OLED create light incorporate the element carbon. The specific chemicals beyond that don’t matter much, at least to us end users, but suffice it to say that when given some energy, they create light.
Learn more: What is OLED and what can it do for your TV?
The fundamental differences between micro-OLED and “traditional” OLED.
The advantage of OLED in general is that it creates its own light. So unlike LED LCD TVs, which currently make up the rest of the TV market, each pixel can be turned on and off. When turned off, they emit no light. You cannot make an LED LCD pixel completely dark unless you turn off backlight quite, and that means OLED’s contrast ratio, or the difference between the lightest and darkest part of an image, is basically infinite in comparison.
OLED TVs, almost all made by LG, have been on the market for several years. Meanwhile, Samsung Display has recently introduced OLED TVs which also feature quantum dots (QD-OLED), which deliver even higher brightness and potentially greater color. These QD-OLEDs are sold by Samsung, Sony and, in computer monitor form, Alienware.
Micro-OLED, aka OLED on silicon
The layers of a micro-OLED display.
Micro-OLED, also known as OLEDoS and OLED micro-displays, is one of the few cases where the technology is exactly what it sounds like: tiny “micro” OLED displays. In this case, not only the pixels themselves are smaller, but the entire “panels” are smaller. This is possible thanks to manufacturing advancements, including mounting the display manufacturing segments in each pixel directly onto a silicon chip. This allows the pixels to be much, much smaller.
Two Sony micro-OLED screens. They look like computer chips because that’s what they’re based on.
If we look at Apple’s claims, we can estimate the actual size of these pixels. First, Apple claims the Vision Pro’s twin screens include “More pixels than a 4K TV. For each eye” or “23 million pixels.” A 4K TV measures 3,840 x 2,160 or 8,294,400 pixels, which should equate to around 11,500,000 pixels per eye for Apple displays.
Then Apple partnered with Sony (or maybe TSMC) to make these micro-OLED displays and they’re about 1 inch. To calculate the size of each pixel, I’m going to use 32-inch 4K TVs for comparison, and these display around 138 pixels per inch. We don’t know the aspect ratio of the Vision Pro’s chips, but if it’s a square resolution of 3400 x 3400 pixels that would be a total of 11,560,000 pixels, so that’s a safe bet. So if that’s the case, these displays have a ppi of around 4,808 (!) and that’s more than almost anything else on the market, and that’s by a plot. Even the Galaxy S23 Ultra’s high-resolution OLED display has a ppi of “only” 500. Regardless of the panel’s production aspect ratio, the ppi will be impressive. Apple did not immediately respond to CNET’s request for clarification.
AR and VR microscreens are so close to your eyes that they have to perform extremely well to be realistic. They need extreme resolution so you can’t see the pixels, they need high contrast ratios so they look realistic, and they need high frame rates to minimize the chance of motion blur and motion sickness. Moreover, being in portable devices means that they must be able to do all this with low power consumption. Micro-OLED seems capable of doing all of this, but at a cost. Literally a cost. The Vision Pro is the most hyped use of the tech’s top end and costs $3,499.
A monochrome micro-OLED display from Microoled, one of the largest manufacturers of micro-OLED displays. On the right is the tip of a mechanical pencil.
Micro-OLED technology isn’t particularly new, having been available in one form or another for over a decade. Sony has used them in camera viewfinders for several years, as have Canon and Nikon. Like all display technologies, however, micro-OLED has come a long way over the years. The screens of the Vision Pro, for example, are huge and very high resolution for a micro-OLED screen.
A high-resolution color micro-OLED display from Microoled.
How is micro-OLED different from MicroLED? Despite being written slightly differently, they are superficially similar in how they self-emit or can produce their own light. But on a deeper level, the differences between carbon-based OLED and carbon-free LED are unfortunately beyond the scope of this article. Suffice it to say for now that MicroLED is best suited for large wall displays using individual pixels made up of LEDs. Micro-OLED is best suited for small, high-resolution displays. That’s not to say MicroLED can’t be used in smaller screens, and we’ll probably see some eventually. But for now, they are different tools for different uses.
The future is micro?
The Engo 2 glasses use a tiny micro-OLED made by the Microoled company. The screen is mirrored inside the goggles to show you your speed, time, direction and other data. Basically everything an athlete would need for a better workout, but instead of being on a watch or phone, it’s projected in real time in front of you. Essentially, a head-up display built into the sunglasses.
Where will we see other micro-OLEDs? At MWC 2023, Xiaomi announced that its AR Glass Discovery Edition showcased the technology, and future high-end VR headsets from Meta, HTC and others will likely use it. Currently, a company called Engo uses a tiny micro-OLED projector to display speed and other data inside its AR sunglasses. I know that I don’t know need these, but I want them. Then there are the many mirrorless and other cameras that have used micro-OLED viewfinders for years.
Could we see ultra-ultra-ultra-high resolution televisions with this new technology? Technically it is possible but highly unlikely. The micro-OLED macro is only OLED. The resolutions possible with more traditional OLED manufacturing are more than enough for a screen 10 feet from your eyeballs. However, it is possible that micro-OLED will find its way into wearables and other portable devices where its size, resolution and efficiency will be an asset. That’s probably why LG, Samsung Display, Sony and others are all working on micro-OLED.
Will ultra-thin, ultra-high resolution micro-OLED displays compete in a market with ultra-thin, ultra-high resolution nanoLED? Could be. We will see.
As well as covering television and other display technology, Geoff takes photographic tours of museums and cool locations around the world, including nuclear submarines, massive aircraft carriers, medieval castles, epic 10,000 mile road trips and more. Check out Tech Treks for all of its tours and adventures.
He wrote a bestselling science fiction novel on city-sized submarines and a following. You can follow his adventures on Instagram and his YouTube channel.
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