Nanotech Based Display

yodha writes "Ntera showed their NanoChromics Display (NCD) recently. The display uses a nanotechnology process to create a more paper-like image than traditional LCD screen. It delivers significant power savings (they've shoehorned one into an iPod to give people a sense of what it looks like). The image can even remain on the screen for weeks without any power and doesn't need a backlight."

Comments

Very Nice

[Omkar]

I like the increased contrast. But can anyone elaborate on "nanotachnology processes"? That's like saying any common appliance uses "electromagnetic processes".

Power Consumption?

[rincebrain]

TFA claims that initially, it will draw more power than an LCD to paint the display, but the image will remain without additional repaints, saving energy.

Now, I'd like to think I'm not an idiot...but how will that save energy on displays which, for instance, require frequent repaints? Let's say that I'm running my iPod with one of those screens, as they show in the article. The thing has to draw segments of the bar frequently, update the time remaining once per second, draw the entire "Now playing:" row to create the "scroll" effect for long titles, redraw the top if you have a clock running up there, et cetera, et cetera.

Another example would be a touch-sensitive screen. In a drawing tablet, I'd imagine the repaint levels are not going to be particularly low, especially for full-tablet images...

I suppose my question becomes...is it actually less power-hungry than traditional LCDs for its practical uses?

Re:Power Consumption?

[rusty0101]

On the assumption that most displays actually have a very small number of pixels that change with any frequency. As an example, look at an 8 element digital clock, every second the unit's second changes, every 10 seconds the tens seconds changes, every minute the minute changes, and so on. from any 30th of a second to another, the vast majority of the time, nothing has changed, so nothing needs to be refreshed, or changed.

Likewise with a spectrum analyzer view on an mp3 player. It's rather rare for the area between the bars in the analyzer to change. It's also rare that the frame, labels under the bars, scale lines, etc. change.

In an LCD system, all of those pixels need to be refreshed every refresh cycle. In this system once the pixel is set, no energy is used to keep that pixel set at that level.

Looking at my screen right now, easily 95% or more of the screen is not changing from one second to the next. Yet the entire screen is using energy to refresh itself many times a second (50-70 Hz I believe for this screen)

The place where such an interface would be expected to use significantly more energy would be in a Television type interface. Including video games on a PC which you may or may not consider related.

I don't really get your example of a touch-sensitive screen. The areas that would draw energy to be repainted are those where the stylus or mouse pointer are located. Unless you are using some interface that draws lines all over the screen when you move the stylus from one pixel to another close to it, the only pixels that should be affected are those relevant to the brush or tool in question. For a Select this usually means a couple of lines of pixels vertically, and horizontally change. Applying effects, afrects a large portion of the screen, possibly even the entire screen, but it is usually a one shot event.

Even the notorious blink tag in html documents should only cause energy to be expended with the frequency of the blink.

Let's say that it takes 60 times as much energy for a pixel change on one of these screens than on an LCD (equivalent area example, if you get 9 'nano'-pixels in the same space as an lcd pixel, each nano-pixel using ~7 times as much energy as the lcd pixel, you get what 63 times as much energy used for that same area, close enoug to 60 for this example.) If over 90% of the screen is not changing from one refresh cycle to the next, then in 60 refresh cycles after the initial screen was set, you have approximate parity. That's one to two seconds. Obviously savings go up from there.

But that's just some off the cuff calculating and thoughts. I am sure someone out there, perhaps someone who thinks that 1/20th of a dollar is not the same as 5% of a dollar will elucidate my errors.

-Rusty

there are a bunch of those...

[idlake]

This isn't the only one. There are a bunch of those kinds of display technologies in the pipeline: basically, LCD displays, but with small scall structures that increase contrast, viewing angle, and persistence.

It's a good short term solution because switching manufacturing over to those kinds of technologies should be fairly easy.

The disadvantage is that those are still heavy glass sandwidches, with all the problems that brings with it. eInk, OLED, and other new display technologies give far more flexible and lightweight displays, and promise significant weight savings.

Odd review

[JavaRob]

What a strange review -- first they give us a nice photo comparing the new screen in an iPod to the standard LCD... but the standard iPod example is turned off. There's nothing on the screen we can compare with.

Okay, maybe they're really keen on the new tech and are trying to skew things its way.

But no, further down they discuss the eBook reader example. "This ebook looked great, and really shows off the power of the digital paper. Alas, I had to keep pressing the contrast button to refresh the image. Perhaps the technology is not as far along as the company suggested."

Huh? Anything you can achieve by pressing a button is easily achievable through software, isn't it? This is just a minor flaw in the implementation of this particular prototype... and says nothing useful about the actual screen.

Anyway, I'm sure more thoughtful reviews will be coming along soon -- this looks like pretty solid and exciting tech to me. It may not be suitable for many screens (i.e., it takes *more* power than a standard LCD if the pixels are all changing frequently... so you wouldn't watch a movie on it), but it'd be perfect for putting little status monitor screens on all kinds of things, plus for the applications they prototyped.