Color e-paper is coming

In some ways, this is news like it’s news that Apple is working on an iPad 3 or Google is working on a new version of Android. Of course they’re working on new products; of course companies are working on color e-paper displays. The conversation really gets interesting when there are devices to look at.

Electronic Paper Display

I’m using e-paper as a generic term for display technologies that try to mimic the experience of reading a printed page. Generally this means they rely on natural ambient light instead of using a backlight. But beyond that similarity there are big differences between manufacturers.

E Ink’s Triton display

E Ink is the company that builds the displays in the black & white Kindle, Sony and Nook e-readers, among others. Look at all the devices using E Ink’s screen technologies in this table of e-readers (6″ devices especially). E Ink is practically running the table. This is usually what people mean when they talk about e-ink devices, since it’s what they’ve had direct experience with.

E Ink displays use microcapsules….just watch this video from E Ink that explains how they work (start at the 45-second mark if you just want to see the explanation).The screen flash that happens when you turn a page on a Kindle makes a lot more sense, seeing this. Those microcapsules have to rotate into place to display an image or page of text.

This is true of the display in the Kindle, and it’s true of E Ink’s new Triton color display. Here’s a demonstration on YouTube (skip the first 30 seconds) that shows that familiar flash. Video isn’t coming to displays that use microcapsule technology, but devices that use this tech are on the horizon. The ECTACO jetBook Color is set to ship in January 2012. $500 gets you this color 9.7″ touchscreen E Ink display.

Qualcomm’s Mirasol display

For a different approach, Qualcomm’s Mirasol display uses pixel tech more familiar from the LCD world. Watch their explanatory video here. Qualcomm creates tiny squares (tech folks call them sub-pixels) that reflect light of different colors: red, green, and blue, just like a laptop’s display. They’re so tiny that the combinations of red-blue-green (and black, when not electrified) appear to be a single color to the eye. A set of red, blue, and green sub-pixels is called a pixel.

This technology can refresh what’s on the display more quickly. There’s no flash. Their demo video makes it look more like a tablet, and it is in fact running Android. They boast that it can show 40 frames per second (DVDs show 30 frames per second), but watching a demo of the display being used (start at 1:15). The touchscreen does not look very responsive. It can play video, however (start at about 3:05), so I don’t know if the slow response is related to the display or the processor. Its price is about $300.

Either way, neither the Triton nor the Mirasol displays are iPad-fast by quite a stretch. The quality of their color displays also depend greatly on the ambient lighting conditions. The last Mirasol demo, for example, has a bright window behind the device. That’s just about the worst lighting you could choose, which is why the colors look so washed out.

So color e-paper is coming soon. If these are the technologies available for it, will people want it when it comes? I think it will take more than an illustration or two in a book to overcome the cost and limitations of these displays.


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