Microsoft patent shows how a modular smartphone could be realized. Image: RegHardware

We know Microsoft for its software chops, but the company is tinkering with some innovative hardware design concepts on the side.

A recent Microsoft patent describes a smartphone with a slide-out section that can house one of several modules, including a QWERTY keyboard, a gaming pad, a second display or a battery pack. Even better: The modules work wirelessly when they aren’t docked in the smartphone’s slider. Another useful way the modular smartphone concept could be used: The keyboard can be used as a controller while the smartphone acts as a TV-connected media hub.

Such a modular design combines capabilities normally found in different phones or accessories. For a gaming pad, your phone of choice right now would be something like the Xperia Arc. Want a slide-out QWERTY keyboard? You’re probably looking at one of several Android smartphones. If you’re looking for extra juice, you’ll need a special case or a phone with a removable battery.

How would something like this work if it came out within the next year or so?

With continued Xbox Live integration with Windows Phone 7.5 (Mango), gaming would definitely be fun with the d-pad module.

If you’re writing long emails or sending text after text, a QWERTY keyboard can be more comfortable to use but not something you necessarily need all the time. Windows Phone has tight social media integration, which would make it easy to stay connected with friends and family and keep chatting via email, Facebook or other methods.

Windows’ Live Tile-based UI looks fantastic on a single display. I can only imagine that spreading to dual screens — the ability to check status updates, weather notifications and more on one, and watch video, check email or browse the web on the other. However, dual-screened devices have largely disappointed in practice. Perhaps the slide-out, rather than the folding-style double screen, could be an improvement though.

A battery-pack module would be ideal for a long day (or weekend) traveling when you may not have access to an outlet for charging, like on a camping trip. Your phone would be alive — but would you have access to 3G or 4G? At least you’d be able to take photos and perhaps access some sort of offline map app. Along the same lines, a battery pack could keep the phone juiced up while you use the gaming pad wirelessly.

Would such a design be practical? Smartphones wear many hats these days, especially if it is being shared among members of a household (web-surfing mom or dad, text-happy kids who also suck batteries dry playing games … you get the picture). The biggest problem might be misplacing modules and the risk of dirt or debris damaging the slider.

Microsoft’s patent isn’t the first of its kind. Other modular cellphones include the Modu Phone, which featured interchangeable cases and a prototype from NTT Docomo. More recently, we’ve seen the smartphone itself work with larger accessories, like with the Motorola Atrix and its laptop dock.

RegHardware via Geek