How do you boost screen real estate on a smartphone without increasing the device's footprint significantly? You could add a pair of slide-out panels mounted behind the main display. But you wouldn't. We'd hope. Such a concept made its way out of LG HQ and into the hands of the United States Patent and Trademark Office, however, and three years after its submission date, the proposed device has returned to haunt the South Korean manufacturer, in the form of an issued patent. The concept in question is quite simple: a primary LCD would be visible at all times, and when the occasion called for another panel or two, they'd simply slide into view, ready to serve as a number pad, or settings control, predictive text display, or even a full-fledged split keyboard.
Now, considering that there's been plenty of time since this filing to bring such a smartphone to market, we're going to guess that LG's abandoned plans for its tri-screen device, opting instead to boost the primary display size in smartphones like its Optimus G Pro, or the poorly received 5-inch Optimus Vu. That's not to say that multi-screen handsets won't continue to make an appearance, however -- NEC's Medias W has already hit NTT DoCoMo in Japan, and it's possible that BlackBerry may be considering a split device of its own. This LG concept, however, is probably destined for a dusty filing cabinet at the patent office, where it's unlikely to surface again.