Large-screen, ultra-high-definition (UHD) televisions the thickness of a smartphone might have been unthinkable until fairly recently. But innovations in glass technology are making them possible today.

One of the key components in this super-slim UHD revolution is a thin sheet of glass that acts as a light-guide plate for edge-lit LCD TVs.

Simply put, it channels the brilliance from the light-emitting diodes along the edge of the light-guide plate, then — through a pattern imprinted on its pristine surface — turns the light 90 degrees to illuminate the TV.

The result? A brilliant, lifelike display that hangs easily on the wall.

Until recently, thin plastic was the most efficient material for creating this critical component in UHD (also known as 2K4K) televisions.

But while they’re able to transmit the light effectively, the plastic light-guide plates are also inherently flimsy. They need a variety of structural components — like spacers and frames — to hold them firmly in place.

Glass scientists have created new formulas that can precisely transmit the light while not absorbing it — minimizing “color shift,” a weakening of the color quality in the image shown on the screen.

And because this thin glass is many times more rigid than plastic, it eliminates the need for extra supportive components. This, in turn, can make the televisions thinner than ever.

Early prototypes of TVs using glass light-guide plates have brilliant, 70-inch screens, yet measure fewer than 10 millimeters — about the same as a smartphone. That’s a 71-percent thickness reduction from the previous industry standard of 35 millimeters.

Even more astonishing — this TV can actually contain four thin sheets of glass in its ultra-slim package.

A light-guide plate, backplane, substrate for the color filter system, and tough protective cover are all pristine, super-lightweight examples of today’s glass technology — all working together to bring the most brilliant images to life before your eyes.