Telephone patent made from two parts

The curiosity of the prototype Sony Ericsson mobilephone under is that it's made of two separated parts, and these are able to work without each other. The larger part of the clamshell, slide or rotatable phones contains the keyboard, the battery and the GPS module, and the display is a fully separated, removable mini-mobilephone which works even if it's removed from the larger part. According to the description of the Japan-Sweedish manufacturer, the two parts are communicating with each other on Bluetooth, so GPS function remains available till the two parts are close enough to each other.