After several years of sluggish sales, television manufacturers are pegging growth hopes on new technologies that deliver a more immersive and interactive experience and stunningly realistic image displays.

As new TVs were unveiled at this week's Consumer Electronics Show in Las Vegas, it was clear that so-called 4K "ultra high definition" televisions are gaining traction with consumers amid lower prices.

"We have seen 4K televisions in the past few years, but this certainly marks the year of them becoming affordable and much of the premium over high-definition vanishing," Reticle Research principal analyst Ross Rubin told AFP.

He saw 4K as a major trend at CES, and expected prices for some well-known brands to drop below $1,000, essentially eliminating the edge high-definition televisions have with budget-minded consumers.

"It comes down to price," the analyst said, dismissing concerns that a lack of 4K films or shows will discourage buyers.

"Once the price premium over HD disappears, there will be a certain level of television where the only option will be 4K."

The global market for big-screen televisions is rebounding as consumers replace their flat-screen devices that hit the market a decade ago, according to the Consumer Electronics Association, which organizes the annual event in Las Vegas.

The "ultra HD" market included fewer than one million units sold in 2013, growing to 9.3 million in 2014 with sales projected at 23.3 million in 2015, CEA said.

- Skinny and rich -

South Korean consumer electronics titan LG on Monday expanded a line of 4K OLED televisions launched at CES here last year.

Seven new 4K models shown off by LG included flexible, curved and flat screens ranging in size from 55 inches diagonally to 77 inches. LG promised to have a proto-type of a television with nearly 8K resolution on display at its booth on the CES show floor opening on Tuesday.

"OLED is simply the best TV ever and is the future of television," LG head of new product development Tim Alessi said while unveiling the expanded 4K TV line-up.

Japanese consumer electronics giant Sony is adding a dozen new 4K Ultra HD Bravia LCD television models, including a skinny, rich X9000C touted as so thin it appears as though it is "floating" against a wall. Sony boasted it is a mere 4.9 mm (0.19 inches) at its thinnest point.

- TV brains and beauty -

Japanese electronics giant Sharp on Monday unveiled what it called its "beyond 4K" television set for release later this year which offers an even more realistic image than its traditional "ultra high definition" models.

"We will bring the viewing experience closer to reality in 2015 by introducing the highest quality resolution TV available. We call it Beyond 4K," Sharp America chief Jim Sanduski said.

By enhancing the technology behind the TV "pixels" and adding "subpixels," Sharp said this new device would have resolution 167 percent higher than existing 4K models.

Sharp also announced it would offer Google-powered Android TV on some of its models to give viewers apps from that system, and would offer a variety of new televisions in the 4K format with prices as low as $750.

An array of TV makers was building Google's Android software popular in mobile phones into screens to add Internet brains to image beauty.

Samsung is ramping its SUHD television line with smarts powered by its Tizen operating software, claiming a superior solution to problems with reliability, lifespan and color richness.

"We have heard loud and clear that customers want the (ultra high-definition) experience, and that they love the large, curved UHD TVs," said Samsung America executive vice president Joe Stinziano.

- Crystals shine in screens -

Chinese maker TCL meanwhile unveiled its top-of-the-line "quantum dot" television -- which uses a film of tiny light-emitting crystals to improve picture quality at a lower cost than that of existing models.

TCL Multimedia chief executive E. Hao said the company has upgraded its line of 4K televisions to be "smarter" and more immersive.

That means viewers are recognized when they sit down in front of the television and get instant recommendations. And the TV can also be a hub for online gaming, even without game consoles, Hao told the press event at CES.

"TV is going to know who you are, what you like," he said. "TV is getting smarter."

The market for 4K had been held back in recent years by high prices, but also a lack of content available in the format. But in recent weeks Netflix and Amazon have announced they would deliver more 4K programs. And TCL said it would offer 4K content in partnership with the streaming video group Roku.

In another sign that the new standard is gaining ground, a group of Hollywood studios, consumer electronics brands and others on Monday launched the UHD (Ultra High Definition) Alliance to set new standards "to support innovation in video technologies including 4K and higher resolutions," according to a statement released by the group.

The alliance includes DirecTV, Dolby, LG Electronics, Netflix, Panasonic Corporation, Samsung, Sharp, K, Technicolor, Walt Disney Studios, Twentieth Century Fox and Warner Bros. Entertainment.

But some were not convinced that consumers will be flocking to ultra high-definition televisions.

"It was hype in 2014 and it will mostly be hype in 2015," said Forrester analyst James McQuivey. "In a world where people are content to watch movies on mobile phones, trying to push TVs into higher and higher levels of quality is solving a problem viewers don't have."