Self charging phones aren't that far away(engt.co)
engt.co
Self charging phones aren't that far away
http://engt.co/oeQ1eO
6 comments
"By using polarizing organic photovoltaic cells, however, the LCD-packing gizmo can recycle its own lost backlight energy, keeping itself charged for longer." - wouldn't it be better to make the LCD not lose 75% of its energy?
That would be neat. But it's essentially impossible with a traditional LCD screen - the physics don't work that way.
The way a backlit LCD works is that the backlight produces light, which goes straight into a polarizer. That polarizer absorbs 50% of the light energy - if it absorbed any less, then the light wouldn't be polarized. Then the light passes through the liquid crystal element to another polarizer, which either passes the light through or blocks it completely.
If you assume that half the screen is lit at any given time, it's physically impossible to not absorb 75% of the light in the polarizer. There are really only two ways to improve this, one is to produce polarized light directly, and the other is to return the lost energy to the device some other way (as this does).
The way a backlit LCD works is that the backlight produces light, which goes straight into a polarizer. That polarizer absorbs 50% of the light energy - if it absorbed any less, then the light wouldn't be polarized. Then the light passes through the liquid crystal element to another polarizer, which either passes the light through or blocks it completely.
If you assume that half the screen is lit at any given time, it's physically impossible to not absorb 75% of the light in the polarizer. There are really only two ways to improve this, one is to produce polarized light directly, and the other is to return the lost energy to the device some other way (as this does).
Beam splitting polarizers split the incoming unpolarized beam into two polarized beams, or more commonly into one polarized beam and another somewhat polarized beam. By stacking many of them you can obtain a polarizer that loses less than 50% of the light.
http://en.wikipedia.org/wiki/Polarizer#Beam-splitting_polari...
http://en.wikipedia.org/wiki/Polarizer#Beam-splitting_polari...
A better solution is to have the backlight directly produce polarized light. If you do that, you do not need the first polarizer that blocks half the light. There is hope that that is possible. See http://www.semiconductor-today.com/news_items/2010/OCT/RPI_2...
[deleted]
Yes, but doubtful for an LCD. An LCD should lose at least 66% of its energy in the best case by virtue of how it works. It essentially works by sending out white light and blocking selective spectra of light for each pixel. So even if a pixel is lit up, it should still be blocking or filtering most of the light that hits it and only letting through its particular color.
The better solution is to use LEDs or OLEDs. These do not require a backlight or any blocking but just generate the necessary color of light (and only the necessary color of light) from scratch.
The better solution is to use LEDs or OLEDs. These do not require a backlight or any blocking but just generate the necessary color of light (and only the necessary color of light) from scratch.
How? It is entirely possible to be technically easier to self-charge than change the fundamental efficiency of LCD.
Just as the headline gave me hope for the future, a giant Verizon pop-up with no close button ruined my day.
Adblock!
I have it! It didn't stop it!
How bizarre. I don't get any ads on that page. (Firefox 5, Adblock Plus)
Eh, if I understand correctly, it's not self-charging. It just discharges slower.
"What's really cool is these cells can recycle indoor or outdoor light as well..."
It's self-charging at a rate perhaps slower than the rate at which is discharges, for now, but it is effectively charging itself. The question is does it break even?
It's self-charging at a rate perhaps slower than the rate at which is discharges, for now, but it is effectively charging itself. The question is does it break even?
Even if it does not break even, I would be more than happy with double the use time of my mobile. Of course, it would be even better if I just never had to charge it, but baby steps.
Exactly.
It's always great to read, shame it takes years and years to get to market. And I guess this would apply to all LCDs; would laptops benefit much; their screens are also pulling a lot of battery right?
Powered by cold fusion? This is similar to eneloop batteries I suppose where the energy circulates back in. Self-charging anything would change history.
Self charging as in not needing an external power supply? I guess history changed in 1986 then.
http://www.seiko.co.uk/technology/kinetic
http://www.seiko.co.uk/technology/kinetic