Industry affiliates make photos of the new LG 55-inch OLED television during the 2012 International CES Tradeshow, Tuesday, Jan. 10, 2012, in Las Vegas. (AP Photo/Julie Jacobson)

(AP) -- Samsung Electronics Co. and LG Electronics Inc. are showing off 55-inch TV sets that use organic light-emitting diodes, or OLEDs, instead of plasma or liquid crystals.

The TVs were unveiled this week at the International Consumer Electronics Show, an annual showcase in Las Vegas for the latest smartphones, tablet computers and other consumer-electronic devices.

WHY IT'S HOT: It's the first time in years we're seeing a new screen technology for TVs. OLED screens can be extremely thin. LG's set is just 4 millimeters thick. That's one-sixth of an inch. The picture quality is stunning too, because OLED TVs can present highly saturated colors and a nearly perfect black.

THE UPSHOT: The screen technology is in use in high-end smartphones, but it has been very difficult to make larger screens with consistent results. In 2007, . started selling an 11-inch for about $2,500, but it never followed it up with a bigger model. Since then, LG and Samsung have shown prototype OLED TVs at the annual CES show, but hadn't revealed any marketing plans until this week.

THE DOWNSIDE: Samsung and LG haven't announced a price, but expect the sets to cost more than $5,000 each. It'll take at least a few years for prices to come down enough for most people.

AVAILABILITY: LG said fourth quarter of this year, tentatively. Samsung only said "this year."