Science of Glass
The Evolution of Resolution
TV images have been getting brighter and sharper for years. Here’s a look at high-definition imagery and where it’s headed next.
The shining prospect of 8K television is the biggest buzz to hit the electronics world over recent years.
Mainstream adoption of the platform is still a few years away. But enthusiasts are already touting the remarkably sharp, bright, fast-moving images on 8K screens – displays so stunningly realistic, viewers feel like they’re part of the action.
The technology represents a giant step toward the immersive experience consumers are growing to expect from their electronics devices, both large and small.
It’s also one of the toughest technical challenges yet for manufacturers and glassmakers.
How has TV resolution evolved?
Picture resolution has become steadily sharper since digital imagery went mainstream in the 1990s.
At the heart of the high-definition trend is the pixel, the microscopic “picture element” acting as a tiny valve for the light generated from behind it.
A pixel has three sub-pixels – red, blue, and green – each one controlled with a thin-film transistor (TFT) and deposited on a thin sheet of glass called a backplane.
Together, the pixels create vivid, fast-moving images in every color of the rainbow. And as panel makers have learned how to pack more and more pixels into a given space, images have become smooth and clear, rather than blocky or “pixelated.”
Smartphones and computer screens were early leaders in lifelike resolution. Most televisions lagged, at least in affordable models, since the large size of TV panels made the manufacturing process more challenging.
TVs made a giant leap forward in the late 2000s, though, when “full high-definition” (FHD) televisions hit the shelves. These sets featured 1,920 pixels across the face of the screen, and 1,080 pixels down the screen vertically – so they quickly became known as “1080p” screens.
Bringing new levels of high-resolution viewing to homes and offices everywhere, the platform also ushered in standard use of the a wide-screen aspect ratio of 16:9, further replicating the experience of the human eye.
Corning EAGLE XG® Glass, the market-leading LCD glass since its release in 2006, provided the perfect surface for high-definition electronics manufacturers. For both the backplane supporting the TFT array and the color filter that enables the full-color display, EAGLE XG Glass gave panel makers the stable, flat, thin, and lightweight substrates they required.
The fact that Corning could produce such a remarkable glass at an affordable price was a big factor in driving down retail prices for FHD TVs. That trend, in turn, helped spur the industry to adopt high-definition broadcast standards in the United States in 2015.
But even with the advancement of 1080p, TV resolution still paled in comparison to smartphones and handheld tablets.
By the mid-2010s, electronics engineers had devised ways to dramatically increase the number of pixels in the same small space, bringing even more brilliance and clarity to large TV screens. Thus were born “ultra-high definition” (UHD) TVs, with resolutions of 3840 by 2160 pixels. In casual reference, the industry rounded up the horizontal pixel count instead of vertical, and the platform became popularly known as 4K.
The additional pixels brought significant improvements in color, sharpness, and lifelike experience. As more consumers jumped on the 4K bandwagon – and retail prices dropped into a more-affordable range – many video streaming services and cable providers like Netflix and Hulu have launched 4K content, too. EAGLE XG Glass has continued to serve the 4K platform admirably.
Electronics lovers, though, have always yearned for more – more brightness, more clarity, more immersion – all made possible by more pixels. So, it was inevitable that industry innovators would rise to the challenge, and Sharp introduced the world’s first 8K television in 2015.
The resolution of 8K equates to 7,680 by 4,320 pixels. It also creates the most brilliant images ever showcased on in-home televisions, virtually immersing the viewer in the picture on the screen.
Since then, 8K technology has turned from a jaw-dropping fantasy to an intriguing and attainable aspiration. In early 2019, 10 manufacturers launched 8K models at the Consumer Electronics Show – twice the number from the previous year.
How will Corning glass play a role in these new 8K televisions?
It already does. Many early 8K displays are built on EAGLE XG backplanes. However, the technology is evolving and customers are starting to require glass substrates with even-higher levels of thermal and dimensional stability.
Corning has been preparing for this evolution in the market for years, and has developed a deep understanding of manufacturers’ priorities for their emerging 8K display products.
Look for Corning to continue to bring new innovations to this demanding space, putting its immeasurable materials science knowledge to work with solutions that make displays more lifelike than ever before.