Dynamic colour-changing surface could triple resolution of displays
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Researchers at the University of Central Florida have developed a new colour-changing surface that can be controlled with an electrical voltage. This could “drastically” improve the resolution and brightness of electronic displays, they believe.
Traditional display screens are comprised of pixels – elements of a picture. Within each pixel are three subpixels with static films of red, green and blue (RGB). By combining the amount of red, green and blue transmitted and absorbed across the screen – a process called colour mixing – images and videos can be displayed.
As a result of research at the University of Central Florida's NanoScience Technology Centre, however, this model for electronic displays could soon prove cumbersome and outdated, and be replaced with a simpler alternative: a dynamic colour-changing surface.
The researchers found that it was possible to “tune” the colour of pixels by applying different electrical voltages, they report in Nature Communications. Within a single pixel, they were able to flip between different colours, and even gradations between the standard red, green and blue.
“We can make a red subpixel go to blue, for instance,” said Professor Debashis Chanda. “In other displays that is not possible because they need three static colour filters to show the full RGB colour. We don’t need that now; a single subpixel-less pixel can be tuned across a given colour gamut.”
By eliminating the need to fit three subpixels within a pixel, the size of each pixel could be reduced to a third of their current size. A screen which uses the tuneable pixels could provide triple the resolution of the same sized screen today.
“A subpixel-less display can increase resolution drastically,” said Daniel Franklin, a PhD student who worked on the study. “You can have a much smaller area that can do all three.”
The technology could have implications not just for smartphone and other general displays, but also for augmented reality, and for virtual reality headsets which require high resolution due to standing so close to the eyes.
It could also allow screens to become brighter than before; at the moment, some subpixels need to be switched off in order to display solid colour, which would be unnecessary if the pixels were capable of switching between colours.
The team applied their principle to create an embossed nanostructure surface – the basis for a display screen – and covered it with a film of reflective aluminium. By modifying the texture of the surface, they found that a range of colours could be achieved with a single nanostructure. This would make it possible to upgrade screens without having to replace the underlying hardware.
“It allows you to leverage all the pre-existing decades of LCD technology,” said Franklin. “We don’t have to change all of the engineering that went into making that.”
The team are working their efforts on scaling up their displays in preparation to move to commercialisation.