The always-on LCD screen is viewable without a backlight - although there is a light if needed - and in direct light, and its battery lasts for up to three days between charges connected to an Android smartphone via Bluetooth.
However, Geoffrey Ozin, from the University of Toronto, Uli Lemmer, from the Karlsruhe Institute of Technology, in Germany, and their colleagues believe they have found a way to deal with these problems.An LCD screen works with a backlight shining through red, blue or green filters to produce the pixels which make up an image.
Instead of reflecting ambient light, its PerfectLight technology uses tiny shutters that open and close quickly to allow through light from a backlight composed of red, blue and green light-emitting diodes.
Colour LCDs are grids of tiny shutters, each of which decides how much light to let through from a "backlight" behind the screen.
Sony's new televisions uses quantum dots with conventional LEDs to produce a hybrid backlight of greater intensity.
Many televisions use light-emitting diodes (LEDs) as the backlight because they are brighter and use less power than fluorescent bulbs.
Not needing a backlight, such solid-state displays generate blacks as dense as anything seen on plasma televisions.
The standard transparent layer between the backlight and the liquid-crystal shutters above it was replaced by a special aluminium layer that reflects ambient light from above, while also allowing light from below to pass through tiny pinholes.
Since they emit light directly, OLED displays do not need a backlight.
LCD displays, by contrast, filter light from a backlight through an array of tiny coloured filters and liquid-crystal shutters.
Cholesteric LCDs do not require a backlight and lack many of the layers of a traditional LCD, which should make them easier to build.
