3 TVs that could change how you watch movies

Televisions often aren't very exciting. They're flat black rectangles you tend to forget about when a show or movie starts playing.

But at CES 2018, the annual tech show happening this week in Las Vegas, manufacturers are still trying to generate buzz for their lineup of TVs coming later this year. The show also features futuristic concepts, such as a display you can roll up like wrapping paper and hide away.

Those types of displays are more of a PR stunt for companies rather than a real product launch, according to Jim Nail, an analyst at research firm Forrester.

"They are clearly PR fodder for the companies," he told CNN Tech. "TV manufacturers are still casting about for what will trigger the next replacement cycle of TVs, since flat screens have now pretty fully penetrated the market."

But even though some of these TVs may not be available for purchase, they can point to what might come in the future, according to Patrick Moorhead, president of tech analysis firm Moor Insights & Strategy.

"Every year, TV manufacturers will show off aspirational products," he said.

LG Display -- an affiliate of LG Electronics -- unveiled a sleek prototype of its latest rolling screen technology. By pressing a button, you can lower the screen into a box, where it wraps around a metal cylinder, kind of like a window blind.

The 4K OLED display looks like a normal TV screen, but the back has small vertical slats which allow it to roll.

LG Display (LPL) showed off a smaller 18-inch version of the rolling screen at CES last year.

However, don't expect to see this TV in retail stores anytime soon. LG Displays sells the technology directly to display manufacturers -- they will decide if they want to use it for their own products.