super-sharp pictures but researchers from Japanese state broadcaster NHK have already developed its successor.

Ultra High Definition TV was on display for the first time in Europe at the International Broadcasting Convention (IBC) in Amsterdam.

U-HDTV has a screen resolution of 7680 x 4320 pixels - approximately sixteen times that of normal HDTV.

Dr. Masaru Kanazawa, one of NHK's senior research engineers, helped develop the technology.

He told the BBC News website: "When we designed HDTV 40 years ago our target was to make people feel like they were watching the real object. Our target now is to make people feel that they are in the scene."

As well as the higher picture resolution, the Ultra HD standard incorporates an advanced version of surround sound that uses 24 loudspeakers.

Londoner Mark Pascoe was among those who attended the demonstration in Amsterdam.

"I thought it was fantastic," he said. "Pin sharp, extremely lifelike, vibrant colours and fantastic sounding too. It makes regular High Definition look fairly untidy"

Big screen

Although the system is ultimately designed for television, current technology means it can only be shown on a cinema screen using a state of the art projector.

There is no LCD or plasma screen in the world with a high enough resolution to display its pictures.

Additionally, no existing TV broadcast system could cope with the massive amount of data which needs to be sent to create an Ultra HD picture.

NHK has successfully sent video using its own high bandwidth optical link.

The designers of Ultra HD TV said it might be 25 years before the technology was available to consumers.

But Dr Kanazawa is hopeful the system can be put to use before then.

"We want to look for other applications," he said. "Cinema is one target. The other might be archives. Museums need very high resolution video for archiving and our system can be used in that area."

The lack of current uses for Ultra HD has led some broadcast experts to brand it a novelty.

Technology consultant John Ive watched the demonstration and said critics were being short sighted.

"When NHK first introduced High Definition many years ago, people said they were crazy, we don't need it.

"Today everybody is talking about it. You may think Ultra HD is a technological curiosity but maybe we'll see it differently in 10 years time."