Microsoft has shown off a new prototype device called LucidTouch that allows users to control a device from behind, but while still being able to see their fingers.

The concept was shown off alongside a number of new technologies as apart of its TechFest fair, an internal event highlighting key tech from the company's 800 research and development staff.

Blaming the problems of your fingers getting in the way of small screens the concept is a mobile device that addresses this limitation by allowing the user to control the application by touching the back of the device.

According to the company, the key to making this usable is what it calls pseudo-transparency: by overlaying an image of the user’s hands onto the screen, the illusion of the mobile device itself being semitransparent is created.

This pseudo-transparency allows users to accurately acquire targets while not occluding the screen with their fingers and hand.

LucidTouch also supports multi-touch input, allowing users to operate the device simultaneously with all 10 fingers.

According to Microsoft in initial studies, results suggest that many users found touching on the back to be preferable to touching on the front, due to reduced occlusion, higher precision, and the ability to make multi-finger input.