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.)
Mirasol IMOD Structure
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.
LG / Intel Phone to use Mirasol reflective display tech. http://tinyurl.com/cx5rjd
RT @chippy: LG / Intel Phone to use Mirasol reflective display tech. http://tinyurl.com/cx5rjd
Now if one could incorporate solar panel technology into/behind this screen also, maybe there would be some nice battery time “savings”?
I doubt it. The screen area is to small for a solar panel to deliver enough power to really make a difference. Espacially as you want be facing the screen directly to the sun and a solarpaneltechnology wich wont disturb the screens quality is much less efficient than needed.
I am waiting fr someone to include a solarpanel to the back of a laptopscreen though. That way yould could use normal cells which are more efficient than those that would be needed if placed over the screen and perhaps you could really charge the laptop with some ours in the sunlight.
As this tech would be most useful for outdoor notebooks these would have to be water resistant too.
I cannot understand why manufacturers wont make smartphones/mids/micro netbooks (liek the umid) waterresistant. I doubt it would be that expensive but could come in quite handy for sure (think of spilled coffee, outdoor use in bad weather…)
I’m no expert on not Solar panels nor LCDs but it’s my understanding that such technology is possible today with more or less self sufficient LCDs
http://www.electronicstalk.com/news/did/did170.html
Solar panels have for the longest time not needed direct sunlight, that’s been the case for over two decades at least now, most of my calculators of the past two decades have been solar panel only, in fact its been the same two ones :)
Not everywhere does outdoor mean the need for water resistance, I personally don’t have a need for typing on my devices when it’s pouring rain, and just slight drops of water isn’t really an issue on my devices, they’ve been through that regularly.
The smartphones are quite resistant to moisture as it is (not watertight) as for the MIDs they really haven’t caught on yet. For anything like a laptop/netbook there’s various types of covers you can use, or “skins” if you want.
I’m no expert on not Solar panels nor LCDs but it’s my understanding that such technology is possible today with more or less self sufficient LCDs
http://www.electronicstalk.com/news/did/did170.html
Solar panels have for the longest time not needed direct sunlight, that’s been the case for over two decades at least now, most of my calculators of the past two decades have been solar panel only, in fact its been the same two ones :)
Not everywhere does outdoor mean the need for water resistance, I personally don’t have a need for typing on my devices when it’s pouring rain, and just slight drops of water isn’t really an issue on my devices, they’ve been through that regularly.
The smartphones are quite resistant to moisture as it is (not watertight) as for the MIDs they really haven’t caught on yet. For anything like a laptop/netbook there’s various types of covers you can use, or “skins†if you want.
At 10% (likely) efficiency and 20cm2, this would generate about 200mw. Not bad but considering that you wouldnt be in the sun most of the time and that you’d probably not be in direct sunlight even when you were, the 20-50mw of power wouldn’t really be worth the trouble in my opinion, especially when you lose 10-20% when charging and discharging the engery through a battery.
Solar cells need to reach 30% efficieny or devices need to average sub 500mw power before solar charging methods like this become useful.
You are right, solar cells do not NEED dirct sunlight but their Output is usally given under optimal circumstances which are direct orthogonal sunlight. Without direct sunlight or at other angles these cells often only reach 10% of their stated output which could be enough for loading the battery though it would be painfully slow.
As most batteries require more than more than 5v volatage to start charging this qould require some extra chips to get that voltage from the cells which still would be unlikly form such a small cell at anything but direct sunlight.
@c_davies I did some analysis on Mirasol earlier this year. It could save 0.5-1W in a MID. Very significant. http://bit.ly/2WuoT5