Schoolbag of the Future: Anytime Anywhere

[DonaldL.]

Schoolbag of the Future: Anytime Anywhere

At the keynote of the Future Education X Smart School Summit in Taipei Cheryl Goodman of Qualcomm’s Mirasol division discusses what the Backpack of the Future will look like.
The high points of the presentation are that devices shouldn’t create a power crisis.

[Steven Lyle Jordan]

Not surprising that Goodman would promote an e-ink device, being a Qualcomm employee. However, the "power crisis" has an easy solution that most people overlook: Multiple batteries. A student can charge multiple sets of batteries overnight and take them along with their device of choice, swapping them out as they run down, to get through the day. And hopefully battery life will extend over time so that students need carry a minimum of batteries, or even one set, to get through a day.

And there may be easy-to-use spot rechargers available down the line, such as more efficient solar cells, hand-crank generators, etc.

I caught the pro-e-ink line about "reflecting light, not emitting light" being best, and I'll simply point out that many people have no problem with backlit LCD screens.

[teh603]

Originally Posted by Steven Lyle Jordan

I caught the pro-e-ink line about "reflecting light, not emitting light" being best, and I'll simply point out that many people have no problem with backlit LCD screens.

I think what he's getting at is the fact that backlighting is one of the biggest power drains in any portable device, with the screen itself coming in somewhere around number two. Eliminate backlighting or have a way to turn it all the way off when you don't need it, and you save a ton of power.

Then again, my first laptops were passive- matrix devices whose backlight could be turned on and off, and you didn't need a backlight all the time the way the new TFT and later screens do. In bright light you could turn the backlight off and the screen was very readable, almost as good as an e-ink device. Some nameless PC one that ran on two floppies, and a PowerBook 180. They also got about two hours' battery life on a NiMH battery, which is still as good as some modern laptops get with LIon ones.

Well, passive matrix displays had their own issues. I'm not sure what the technical term is, but they had a tendency to bleed. Back in the days of the PowerBook 180, that wasn't much of an issue because laptops were bleeding edge devices that people were willing to pay for (either in inconveniences or extra cost). The situation is quite different today. People expect crisp displays.

Of course, the big issue with LCD displays is that they depend upon polarized light. That means that at least 50% of the energy put into the backlight is lost because light sources tend to be unpolarized and that a polarized filter needs to be used to polarize that light.

(Also, was the PowerBook 180 even backlit? A lot of early laptop displays placed the light in front of the display simply to avoid absorption. That is similar to some of the technologies used to provide uniform lighting to eink displays.)