Nokia keeps on filing patent applications with the clear intention to make future improvements in the way users interact with mobile phones. After a patent filed in December 2007 for a 2 in 1 keypad idea, now the Finnish company has another keyboard-related idea, but this time we are talking about a virtual one (the keyboard, not the idea).

The new concept requires, first of all, a phone with a built-in camera and optical sensors and comes to enhance the way we write text messages or e-mails on our phones - we all know it's not really the fastest way to do it, due to handsets' reduced sizes. Samsung has found a way to overcome this drawback, by adding projectors to phones, in order to project a virtual (and large) display that will enable easy text input. However, this is also just a concept and it will be a while until it can be functional.

Nokia, in return, comes with a virtual keyboard that doesn't require additional equipment, since photo cameras are now becoming common for most mobile phones. The patent application, entitled "Mobile device with virtual keyboard", reveals an entirely new concept: the main idea is to use the built-in camera for capturing user's fingers movement. As seen in the picture from the patent, the phone would sit in a special cradle, in a vertical position, while the user types behind it, allowing the camera to record its moves and send the data in real time to the phone's screen, where both a virtual keypad and the entered text are displayed. Furthermore, the handset would also come with sensors capable of capturing vibrations and sound generated by users and translate them into input commands, but we don't have more details about how exactly this works.

While some might say that text input could be simply done with a hardware QWERTY keyboard (like the ones packed in Nokia E90 Communicator or HTC TyTN), the new virtual keypad from Nokia might be a much better option. Or at least that's how it seems now, when the keypad is only a concept. Nevertheless, this idea is surely interesting and may really improve the text input on mobile phones but, as any new concept, it has to overcome many implementation difficulties until it becomes usable.