From the linked article:
"E-books have not made much of an impact as the experience of reading on-screen has failed to live up to expectations. As a result although sales of e-books are growing they still account for only a tiny fraction of the overall book market.
The electronics giant aims to address this with the electronic paper used for the display in the Sony Reader. It says the six-inch black and white screen will be as easy to read as the printed page.
The technology used means the screen is not backlit, avoiding screen flicker, which can put a strain on the eyes.
The device’s display uses technology developed byUS-based firm E-Ink which works by electronically arranging thousands of tiny black and white capsules to form characters."