Ask the Experts: What are transmissive and emissive displays and how should we think about them?

The display landscape is always changing. A market once consisting only of transmissive displays continues to evolve as emissive display technologies continue to emerge and improve. Each display type offers compelling benefits for a variety of use cases, and each one can benefit from advanced glass substrates.

So, what are transmissive and emissive displays and what can we expect from them in the market? We asked the Corning experts to make it crystal clear.

Q: What are the differences between transmissive and emissive displays?

We can think about these using LCD and OLED displays as prime examples.

In LCD, there’s a backlight that projects light through a liquid crystal layer that’s sandwiched between two pieces of glass. When voltage is applied to this liquid crystal layer, it lets the light of an individual pixel pass through like a shutter. Liquid crystal displays are considered transmissive, as the light is transmitted through the display panel.

On the other hand, an OLED display picture is generated at a pixel level by an electrical current that stimulates a layer of organic material to emit light. OLED displays are considered emissive displays as the display panel generates and emits the light.

Q: How do transmissive and emissive displays compare from a market perspective?

LCD is by far the dominant technology today. OLED accounted for only three percent of TV sell-through units in 2021. And while we expect both LCD and OLED technologies to improve in cost and performance in the coming years, we still expect LCD to maintain its dominant position in large-area displays, which are critically important for Corning.

Corning’s solution for LCD displays is a glass called Corning Eagle XG Glass. It’s by far our most widely adopted display glass.

On the emissive side, OLED makes up roughly 30% of viewing area in small screens – mobile phones and tablets, for example. We placed our bets on OLED years ago when we launched Corning Lotus NXT Glass. Today, we have a very high market share. So, we’re well positioned as phones move from LCD to OLED displays, but it’s worth noting that the impact is minimal because smaller screens are such a small part of the overall display market.

As the OLED TV market develops, Corning is ready. Corning Astra Glass is an excellent solution for oxide and OLED backplane technology. That means it’s particularly well-suited for high-resolution applications like tablets and monitors, but also 8K TVs.

Other emissive displays, like MicroLED, are also being developed. And while much remains to be seen about which application space they’ll serve best, high-quality display glass will be a great support.

With our balanced glass portfolio, we are well positioned for both larger and smaller, thinner, higher-resolution displays of the future.

Q: How can transmissive displays – like LCD TVs – progress from here?

LCD will continue to dominate the display landscape. That’s largely because panel makers have continued to evolve the technology over the years, achieving performance that beat expectations.

One such innovation that we’re seeing now is the use of a MiniLED backlight unit. Using MiniLED for a backlight in an LCD set improves its brightness and contrast, and helps set designs stay slim. It’s an innovative way to extend the benefits of traditional LCD.

Q: And what’s next for emissive displays?

Let’s start with Quantum Dot (QD) displays. There have been many versions of QD displays, and today, we’re supplying glass for emissive QD displays, which are compelling because they produce brighter whites and blacker blacks.

Corning’s glass portfolio is well-suited to supply two pieces of precision display glass for QD OLED displays – one is a TFT backplane and another that functions as a color filter or color convertor. The result is a stunning display technology that delivers the benefits of OLED in thin form factor, deep blacks and wide viewing angle, but also with enhanced color reproducibility and efficiency from quantum dot materials.

While QD technology is still relatively new and expected to remain in the premium niche for now, we’re confident that Corning has the right display glasses for the job.

MicroLED is similar to QD display technology in the sense that it is an emissive technology. Through individual red, green, and blue LEDs, it can enable an expanded color gamut and true-black tones.  One aspect that sets it apart is the ability to form a sort of mosaic, where panels can be connected to create enormous displays.

Now when it comes to these mosaic displays, glass becomes very important because panels need to be connected with nearly imperceptible seams. When pixels must be placed essentially edge to edge, we lose the space around the border to make the circuit connections that drive electricity through the panel. Glass, and unique glass processing, allows these connections to be made by wrapping around the edge of the panel.

In addition, glass can provide benefits of a dimensionally stable and smooth surface on which to reliably transfer these MicroLEDs, improving efficiency in manufacturing.  We are seeing large MicroLED TVs coming to market and, like QD TVs, they’re premium products and likely to remain niche for a while longer. Some other applications we might see would be public information displays or even wearables. We’re interested to see how this market develops, and we’re ready with great glass solutions.

Learn More

Visit us at SID Display Week to learn more about how Corning display glass is enabling the future of both transmissive and emissive displays.


The Future of Corning Display

The Future of Corning Display