Update. This article is incorrect.
As CPU and chipset power consumption becomes less and less in phone and MID designs, the power drains of the displays, radio, peripherals and storage technology become more and more significant. One of the biggest issues, display backlighting, has been something that many people have been working on for a long time. In current high-brightness UMPCs and MIDs the screens can take up to 50% of the total power of the devices, which is exactly the scenario you’re in when you’re mobile.
LG will be tackling this issue on their Moorestown phone in 2010 by using a reflective, bi-stable technology from Mirasol Displays, a subsiduary of Qualcomm. It’s complex and vastly different from current backlit screen technologies but I can summarise by saying that it takes a lot less power, provides much more effective outdoor brightness and, due to it’s transflective nature, is easier on the eye. The method used is known as Interferometric MODulation (IMOD.)
There are some white papers and overviews on the Mirasol website which I have been through to try and get a feel for the power savings and although there aren’t any real figures given (obviously it depends on the size of the display) my gut feeling here is that in 3-5″ devices in bright room conditions, it could save 0.5 – 1W which will be extremely significant in the LG device which may only have a 2-3W profile. If you want to get a feel for the technology, take a look at this PDF which alludes to newspaper reading quality in terms of contrast and reflectivity. There’s also a very good video presentation here which the problems of traditional backlit displays and the ‘on-time’ that I’ve been highlighting recently.
It appears that current Mirasol products are currently quite small in size and obviously the technology is going to be more expensive so we might see this used as a secondary or external display (as in the two screen Nokia E90 design) but with 12-18 months to go before the product needs to be ready, Mirasol may be able to get a full 800×480 screen out.