But by thinking laterally, Dr Lenssen has come up with a colourful product that, though simpler, is still useful.

That may be the eventual outcome of work being done by Kars-Michiel Lenssen and his colleagues at Philips Research, in the Netherlands.

The technology that Dr Lenssen and his team have come up with is a variation of the trick used in electronic readers like Amazon's Kindle and Sony's reader.