Japan's high-tech giants are gearing up for a new battle over 3D televisions offering images that jump out of the screen, but some experts doubt they will be the next big thing.

Electronics makers such as Sony, Panasonic and Toshiba hope three dimensional movies will make the leap from the big screen into the home with cutting edge flat televisions on show this week at a trade fair east of Tokyo.

Panasonic unveiled a 50-inch plasma 3D television that it aims to start selling in the United States early next year, followed later by other markets.

The company sees the US as the perfect place to roll out the new technology due to growing interest generated by the widely anticipated release in December of "Avatar," a 3D film by "Titanic" producer James Cameron.

"The North American market is essential," said Nobuo Taketani, a manager in Panasonic's plasma TV business.

"We want to offer more Hollywood movies and want demand to explode there before trying it in Europe and Japan," he told AFP.

Sony plans to launch its first 3D Bravia LCD TV next year. Users will also be able to plug in their PlayStation consoles, Blu-ray DVD players and computers.

Viewers wear a pair of active shutter glasses that open and close rapidly in time with images designed for the right and left eye, creating a three-dimensional effect.

But given the high price -- 3D TVs are expected to cost about 20 to 30 percent more than a high-definition plasma set -- and the fact that users need to wear glasses, some experts believe they may only be a niche market for now.

"With the economy in a bad shape, consumers are unlikely to splurge on entertainment," said Credit Suisse analyst Koya Tabata. "But during huge sporting events like the World Cup and Olympics, we may see demand."

Even the companies acknowledge that 3D technology is likely to get off to a slow start.

"I think they will get a break in the US due to 3D films played in theatres there," said Toshiba engineer Tsutomu Sakamoto.

"But wearing glasses can be quite bothersome, so it's hard to say how much individual households will latch on to them," he said.

Toshiba aims to sell a 3D version of its new Regza LCD television -- powered by the Cell processor developed with Sony and IBM that is the brains in the PlayStation 3 -- sometime in the next fiscal year starting in April.

Billed as a world first, viewers can watch either two-dimensional or 3D images on the TV.

The price has not been announced but the standard non-3D Regza, which allows viewers to record up to eight channels, will be rolled out in December with a price tag of a little under one million yen (11,250 dollars).

The success of the new TVs is likely depend on how many 3D movies and video games are available.

Sony has an advantage in this respect because it also owns a Hollywood studio and aims to produce networked products that enable users to download content through the Internet.

"When the content market grows, Sony is likely to be ahead of the curve in terms of the quality of its images and its vast holdings of games. That's when competition among different makers may start to take off," said Tabata.

Sony emerged victorious last year in a battle over high-definition DVDs, after its Blu-ray format trumped HD DVD, pushed by the rival Toshiba-led camp, to become the industry standard.

Panasonic is also cautious about the outlook for 3D TVs, which it expects to make up just three percent of its flat-panel display sales for the next decade.

Other companies also see new horizons for 3D technology at CEATEC, Asia's largest electronics fair which runs until October 10.

Fujitsu showed off a cellphone with a 3D motion sensor that teaches users how to perfect their golf swing.