Japan Display cranks up ultra low power colour LCD panels
No backlight means power draw of just 3mW
Japanese electronics giants Sony, Toshiba and Hitachi have been showing off new low-power LCD display technology which seems to combine the best of LCD and e-ink by dispensing with the backlight and instead relying on reflected light.
The firms formed their joint venture, Japan Display, earlier this year and appear to have been pretty busy since, showing off several designs at last week’s Flat Panel Display International conference in Yokohama.
Dispensing with the backlight means the display draws just 3mW of power when displaying static images.
It is able to do this by reflecting external light off the panel to render a monochrome image which is then filtered through a Light Control Layer featuring colour filters.
In a similar way to e-ink, each pixel is able to retain its colour without requiring any more power.
"This display is a reflective type, but as it uses liquid crystal, it has electric circuits built in,” a Japan Display spokesman told DigInfo.tv. 
“The circuits can retain signals. This feature is called Memory in Pixels. With a still picture, once the data has been written, it can be retained, so power consumption is extremely low."
There are two versions of the technology. The first has a reflection rate of 40 per cent but only five per cent of the NTSC colour gamut, while the second has a better colour gamut – 36 per cent – but a reflection rate of only 28 per cent, making the picture dimmer.
The first technology is said to be ready for mass production today and is likely to be seen in e-readers in the short term, until the Japan Display boffins can turn up the colour and improve the 30:1 contrast ratio that will make it suitable for other applications. ®