If you have just blown the budget on a new high-definition TV, look away now. Japanese broadcasters and the BBC are working on a system 33 times more detailed than the best sets on the market.

The BBC plans to use the technology, named Super Hi-Vision by its Japanese makers, to screen coverage of the 2012 Olympics on big screens in city centres across Britain.

Today's high-definition television is still in its embryonic stages in the UK. But most of the larger, flat screens sets on sale today are HD-ready and the BBC has launched a permanent high-definition channel available on cable and satellite.

Satellite TV giant Sky and cable operator Virgin offer high-definition services to subscribers with the requisite set-top boxes and compatible televisions. But researchers in Tokyo and Surrey are already working on better, sharper pictures.

Within seven years, the Japanese public broadcaster NHK hopes to begin test broadcasts of its Super Hi-Vision system, with full-time public broadcasts scheduled for 2025.

Some doubt whether the enhancements of ultra-high definition are discernible, but Nobuyuki Hiruma, associate director at NHK's laboratories in Tokyo, is sure they are. "Super Hi-Vision TV is necessary to cover the ability of human vision. It is based on research into human vision."

At present, Super Hi-Vision exists only at NHK's Broadcasting Centre in Tokyo, where it is projected on to a 10 metre by 5.5 metre screen, accompanied by 22 multi-layered speakers capable of replicating the sound of a concert hall.

Only 20 minutes of footage can be recorded at any one time and it has to be edited frame by frame. Even then, making a back-up takes the engineers an entire night, and after a week they have only enough material for one hour of Super Hi-Vision TV.

Sitting just three metres from a 450-inch screen, viewers often have an instant reaction to the picture. "Sometimes we suffer motion sickness," says Masaru Kanazawa, research engineer on the SHV project. These large screens would not fit in most living rooms, but Kanazawa thinks they soon might.

Hiroyuki Ohira, general manager of Pioneer's plasma development centre in Yamanashi, is in charge of the same team that, in the 1990s, invented the first high-definition plasma screens. "We are trying to develop a Super Hi-Vision panel to help NHK realise its broadcast plans," he said.

The two broadcasters often collaborate on programme production, most recently on the David Attenborough-narrated documentary Planet Earth which was filmed in high definition and introduced a number of new techniques.

Last November NHK had its high definition television cameras strapped to a Japan Aerospace Exploration Agency lunar probe to film an "Earth rise" over the moon in stunning detail.

The problem of how to transmit huge amounts of data remains. But NHK is using Dirac video compression technology for its Super Hi-Vision testing - a technology invented by the BBC.

Through Participate, an EU-funded project promoting public interaction with new technology, BBC engineers are getting involved in events using large outdoor screens. "Super Hi-Vision feeds nicely into that and it's definitely a long-term ambition," said Andy Bower, interim controller of the BBC Research and Innovation Centre.

Big in Japan

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Music players

The Vonia sports headband, a music player for gym bunnies, uses the bones of your skull to conduct sound straight to your inner ear.

Robotics

A new generation of inexpensive "amenity robots" does simple household chores.

Gadgets

Cyber-goggles could be the next generation in eyeware. They recognise objects in your field of vision and pop information about them up on the glass.