Sony is launching its Reader Digital Book in the UK today, with official pricing be announced shortly.

We've already had our hands on the US version of the device, which has been available across the Atlantic for the past two years. Although the software on the UK version will be different, Sony assures us the hardware specification is exactly the same.

With that in mind, here are our first impressions of Sony's Reader Digital Book.

First look

The Sony Reader Digital Book's praiseworthy attributes begin with its understated good looks and modest size. It's slightly taller and wider than a standard paperback - and significantly skinnier at half an inch thick; plus, it weighs just 255g. You could quite easily put this e-book in a small handbag and forget it was there.

Svelte design

The front of the Sony Reader Digital Book's soft, cloth-covered case (attached via a snap on the back) flips open sideways to reveal a grayish 6in screen, set in a silvery frame. A concave button on the left front turns pages, a black rocker button on the right front handles screen menu navigation, and another black button on the left lets you toggle through three font sizes, scaling the type up to 150 percent of standard (important for vision-impaired readers). The bottom edge has ports for the included USB cable (which connects the Reader to a PC to load content), the device's AC adapter, and a docking cradle and headphones (both optional); you can store and play music and other audio files on the Sony Reader Digital Book.

The device's response isn't very snappy; but a second or two after you power it on, the page that the Sony Reader Digital Book was displaying when you turned it off will reappear. This happens because - unlike with LCD-based e-books, which go blank when shut down - the Sony device's E Ink technology doesn't change until you tell it to.

E Ink uses millions of tiny positively charged white and negatively charged black microcapsules that are 'printed' on plastic film atop the circuitry; depending on what type of charge is applied to a specific capsule, the white or black particles move to the surface of the capsule to form type and images. Since the Sony Reader Digital Book consumes power only when you turn a page, its battery life depends on how much reading you do: Sony estimates that the unit's lithium ion battery will support 7,500 page turns between charges.

No eyestrain

Sony says that the Reader Digital Book's E Ink display can produce four scales of grey at a resolution of about 170 dots per inch (dpi) - more than twice the density of most conventional LCDs, and on a par with the resolution of newsprint. In our tests, both type and half-tone images looked extremely clear; and because there's no backlighting, you don't suffer eyestrain as you might when reading text on an LCD. Also, whereas LCDs generally wash out in bright light, the opposite is true for the Sony Reader Digital Book: The brighter the ambient light, the better the display's contrast.

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