Wednesday, February 3, 1999 Published at 19:09 GMT
Look: 3D TV with no goggles
The future of the small screen?
An advanced display screen, which could allow you to move around a three-dimensional virtual world without goggles, has been developed by RealityVision, a London-based research company.
The screen has been demonstrated on today's computers and could allow several users to watch different images at the same time. Three dimensional videos for the system can be stored on ordinary VHS tapes.
David Trayner, who invented the system with Edwina Orr, told BBC News Online he imagined the future development of the technology would follow the pattern of stereo sound.
"That started as a specialist, high-end technology in cinemas but people then heard the difference and made it into a consumer item which you now find everywhere.
"Development is starting already. We are examining a pilot manufacturing plan in great detail and are in discussion with a range of companies over licensing the technology."
He has demonstrated the prototypes widely and believes the immediate applications would be in computer-aided design, keyhole surgery, medical imaging, cartography and, of course, computer games.
Chris Williams, chair of the European Society for Information Displays, told New Scientist magazine that the relative simplicity of the display should make mass manufacture easy: "It's been developed on a shoestring budget, yet it works incredibly effectively."
To create a 3D image, the left and right eyes must see slightly different images. Current suggestions for goggle-free 3D screens use a series of fine vertical bars to separate the images.
But this reduces the allowable viewing angles and the horizontal resolution, reducing how convincing the depth of the image looks. In extreme cases the left and right images can swap eyes, creating a "very disturbing" experience.
New backlighting system
RealityVision's new technology solves these problems by using a new backlighting system, in which the light is directed towards each eye by a holographic pattern fixed on the back of the liquid crystal display.
Another advantage of the new system is that by repositioning the light sources it is possible to instantly switch to 2D vision, say for word processing.
Viewers can move one metre back and forward and still see 3D images. Sideways movement is limited to the distance between the eyes, but the image simply fades to 2D if this is exceeded.
Mr Trayner says: "If more sideways movement is required, you can use head-tracking technology and the 3D vision will move with you. You then get full parallax in all three dimensions - you could hide an image around the inside edge of the screen."
Currently the screen is 800 by 600 pixels, but work is underway to expand that to 1280 by 1024. The new screen was reported in New Scientist.