20 October 2006
Michael H. Suo wrote in iMechanica recently (you may also find the discussions there on this topic interesting):

Lately, e-book readers have been a new trend in the tech industry. The potential for it is incredible: hundreds of books in the palm of your hand, digitized content distribution, and infinite number of bookmarks, searchable text, hyperlinks between books; the list goes on. However, all these benefits come at a price; namely battery life and readability.

But what kind of display should they use? The average LCD screen has about 72 dpi (dots per inch), meaning that there are 72 pixels in every inch of screen. While that's passable for regular computer usage, anyone who's tried heavy reading will tell you that it's just not clear enough. By comparison, the average newspaper has over 300 dpi, and the average book has about 400 dpi.

What can be done about this? Obviously, traditional screens won't work, as the cost of producing display with high dpi increases exponentially. But our good friends at E-Ink Corporation have since developed an entirely new kind of display especially for the purpose of reading e-books. Named (appropriately) e-ink, the company's site explains the technology like this: "millions of tiny microcapsules, about the diameter of a human hair . . . each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear fluid. When a negative electric field is applied, the white particles move to the top of the microcapsule where they become visible to the user. This makes the surface appear white at that spot. At the same time, an opposite electric field pulls the black particles to the bottom of the microcapsules where they are hidden. By reversing this process, the black particles appear at the top of the capsule, which now makes the surface appear dark at that spot." The dpi on the typical e-ink display is 150-200, which is plenty for comfortable reading.

The advantage of this approach isn't just in the dpi, but also battery life: electricity is only used when turning the page. One prototype based on e-ink technology has been displaying the same page for 3 years, and doesn't show any signs of stopping yet.

However, there are problems too. Obviously, the major one is that since each microcapsule is filled with only two kinds of particle, only black and white displays can be made. Another issue concerns usability; the screen must refresh itself each time the page is turned, forcing the reader to wait a second or two and showing an annoying black flash before displaying the next page.

Despite these complications, already many companies are jumping on the e-ink bandwagon. Sony, iRex (a spin-off of Philips Electronics), Amazon, and Staretek are all planning e-book readers, although only Sony and iRex actually have models out in the wild. Fujitsu and Hitachi are working on readers with e-ink that allows color, while HP, Epson, Siemens, Philips, Toppan, Bridgestone Tires, and some Scottish guys are working on flexible e-ink displays. Finally, others like Panasonic are still fiddling with LCD screens, but to the same e-book-centric ends.

But display technology isn't all that matters to the success of the e-book. How will users receive books? How much will they pay? What format will the books be in? All these are questions that each company has different answers to. Both Sony and iRex have proprietary distribution software (Sony Connect and iRex IDS, respectively), and although it hasn't been confirmed, it's pretty much a given that others will have their on services.

Sony has gone one step farther, offering books in a proprietary format, which can't be viewed by most other e-book readers. On top of that, they have included DRM (Digital Rights Management) that only allows the file to be viewed on 6 different devices. Many have argued that Sony is digging a hole for itself; they failed in the music store race because their format was useless on most MP3 players. However, others have noted that the piracy of e-books (already a flourishing venture) will be a significant threat to all purveyours of e-books and readers.

Reaction to the two consumer models--the Sony Reader and the iRex iLiad--have been mixed, with some touting the portability and clarity of the display, and others boo-booing the long pageturn times and non-intuitive interfaces. Some have observed that the iLiad seems to have been rushed out the door in attempt to be first on the market, and should still be in testing stages. Initial response of the Sony Reader has been postive, albeit with some misgivings.

A lot of question are still unanswered, and many details remain unrevealed. The e-reader industry is still in its infant stages, but be sure to watch it carefully for more developments in the future.

Useful links:

(via iMechanica)