The Future Is Coloured Paper

No backlighting - it just looks like that

What with all the stuff this week, I almost missed a new technology for electronic paper – in colour – hitting the streets in Asia.

The current leader, E Ink, uses tiny black and white spheres suspended just below the display surface and carrying opposite charges. Applying a positive charge brings the white ones up, a negative the black. Thus the display is a pattern of dots just like printing on paper, reflecting ambient light rather than emitting it like normal screens.

This is thought to be more relaxing on the eyes, and so is the technology you’ll find on Kindles, Nooks, and most other e-readers. But it doesn’t work very well for colour. (The Nook Color or Kindle Fire use ordinary backlit displays.) You have to use filters, a subtractive process that leads to a dimmer display with very muted tones.

The Qualcomm technology – branded Mirasol, but also referred to by the fun term “microelectromechanical” – takes a whole new approach, using tiny mirror-cells that reflect light back at a different frequency (colour) when an electric charge is applied. The extra-clever bit – that frequency can be in the invisible ultraviolet, meaning the screen can “shine black”.

Does it work? Well the colours look a little washed out to me, like photographs in magazines from the 1950s. Actually, like photographs in magazines from the 1950s look now. It’s not exactly vibrant, but it’s quite a pleasant effect in a low-key, old-fashioned kind of way. I’d call it usable, we can live in hope of improvements.

And excitingly, Qualcomm say that the display refreshes (changes) fast enough for Web browsing or even video. The obvious question then is what this would be like on laptops, tablets and phones. Requiring no backlight could extend battery life drastically. Are we looking forward to portable computers with weeks-long battery life like today’s e-readers? According to their white paper (PDF) on the technology, once displaying a given colour a pixel in the Mirasol screen requires “almost no power” to maintain it. So yes, this technology may really be as parsimonious as E Ink.

But the display is not the only factor of course; such devices need more powerful processors than e-readers, which are basically just glorified page-turning machines after all. They have radios that need to be on a lot – in the case of phones, constantly. We’ll want them to run greedy applications like browsers. So I doubt we’ll soon be seeing a battery life of weeks. But a few days begins to sound like a real possibility. Wouldn’t that be nice? Soon we may have phones like the ones we had years ago!

Or more seriously, I can spend a day using the mobile Internet – perhaps even a trip of several days – without worrying about where I’ll find a friendly power outlet. I think I could put up with some muted colours for that.