August 28, 2006
Arrays of thousands of tiny “super prisms” controlled by robotic muscles could bring real colour to TV screens for the first time, scientists say.
Source: BBC News
By Jonathan Fildes
The devices, known as electrically tunable diffraction gratings, have been built by researchers in Switzerland.
They manipulate light to reproduce the full spectrum of colours on screen, impossible using existing technology.
The team says the devices could also be used to make computer displays with the same resolution as high-end LCDs.
“Today’s displays can only reproduce a limited range of colours,” said Manuel Aschwanden, of the Swiss Federal Institute of Technology in Zurich and one of the team behind the work.
“The main advantage of this technology is that it can display all colours.”
Blue sky thinking
Existing screen technology, such as TV cathode ray tubes, LCDs and plasma screens, reproduce colours using three lighting elements coloured red, green and blue.
Other colours are created by combining the primary colours. For example, yellow is created by mixing red and green.
To show complex pictures, a display must combine the colours at thousands of individual points across the screen.
Different types of screen do this in different ways. For example, an LCD is divided into thousands of individual pixels, further divided into three subpixels coloured red, green, and blue by filters.
Altering the brightness of each coloured subpixel creates a palette of millions of different shades that can be used to represent most pictures.
Methods like this are unable to reproduce every colour we see in the real world. This is particularly evident when reproducing images of the sky.
“When you take a picture and download it to your laptop the blues are never the same as the real sky,” said Mr Aschwanden.