Among the avalanche of Android tablets being unveiled at this week's International Consumer Electronics Show, NEC is adding something extra: an additional screen.

The LifeTouch LT-W is the first Android-based, dual-screen device, but whether it's a tablet or not is open to debate. Designed to be held like a paperback book, the device unfolds to reveal dual 7in LCD touchscreens.

The tablet moniker is typically reserved for single-screen, single-piece devices and NEC's LT-W appears closer to a dual-screen laptop, such as  Acer's Iconia or Toshiba's Libretto W-series Windows 7-based computers. NEC's LT-W, however, comes closer to tablets in its technical specifications and reliance on Google's Android operating system.

NEC sees several potential uses for the dual-screen device. Perhaps most obvious is the mimicking of a book or newspaper, but the second screen could also be used to provide more information or context on subjects in a catalogue or magazine without pushing the original page out of view.

NEC also sees the second screen as a device for user input. Notes, either typed or handwritten, could be taken on one screen while viewing content on the other.

The LT-W runs on an ARM Cortex A8 processor and is based on a version of Android 2.1 that has been modified to accommodate two screens and allow different software programs to run in each window. NEC says it's working on a version based on Android 2.2.

Despite its appearance at CES, NEC isn't planning to sell the tablet directly to consumers. Like a single-screen Android tablet it recently launched in Japan, NEC is hoping that service providers will buy it, package it with their own content, and offer it to end users.

In Japan, NEC's Biglobe ISP unit is already offering it to consumers, packaged with a custom user interface that provides news headlines, a horoscope and quick links to Biglobe services in addition to conventional Android applications.

The LT-W is relatively light. It weighs 530g, which compares favorably with the 680g of Apple's lightest iPad. The LT-W has an SD card slot, GPS sensor, Wi-Fi, Bluetooth and optional 3G. No other technical details were immediately available.

See also: NEC to show dual-screen Android tablet at CES