A 3D audio, video and touch display
A new display that uses high-frequency sound waves to move an illuminated ball 'pixel' and build a convincing 3D image has been announced by UK and Japanese researchers...
This technology may sound like something straight out of science fiction, but the new display technology, announced in the latest edition of the journal Nature, brings us closer to three-dimensional imaging systems that, crucially, don't require the use of special glasses or additional bulky equipment.
The new display uses ultrasound waves, which are at frequency far beyond what a human can hear, to trap a small, illuminated ball in place and then move it at high speeds to trace out an image.
Because the ball moves faster than the human eye can discern, the result is a persistent 3D image, in colour.
The display is about the same size and shape as a microwave with the door removed; inside is where the magic happens. The device uses two grids of speakers to produce the ultrasound "sound scape" that uses the energy in the sound waves to trap and move the ball. Alongside the images, the same speakers can also create an accompanying soundtrack for viewers to hear.
This is achieved with a technique called pulse width modulation, which allows the amplitude of a signal to be controlled by switching it on (40 kHz) and off (0 Hz) very quickly. The longer the signal is kept on, the higher the average frequency of the signal.
Cleverly, the system also has a haptic dimension, and can produce a tactile experience. This works in a similar way to image production, except instead of a ball being trapped and moved, it could be a finger, enabling viewers to "feel" what they are looking at.
With this new technology, a whole new range of applications become possible, including the next generation of computer video games through to training in the medical or nuclear fields.