How floating touch technology works

Remember our announcement on the Sony Xperia sola yesterday? Well, surely one of the biggest featuers of the Xperia sola would be the new touch sensor technology known as “floating touch”, where it lets you interact with the phone’s touchscreen display without having to touch it at all. This special user experience is capable of register the presence of your finger up to 20mm above the display, allowing it to detect the screen coordinates that you are pointing at in addition to your finger’s distance from the screen. You can read Erik Hellman’s explanation after the jump. Erik is the research engineer at Sony Mobile as well as one of the inventors of floating touch technology.

As part of the team that invented this technology, it’s a great pleasure to see the magic of floating touch on a smartphone for the first time now. In the article, I’ll try to explain how this technology works. Like many other smartphones, Xperia sola uses capacitive touch sensing to register the user’s input on the screen. The event that occurs when you touch the screen of your smartphone is called touch event. Capacitive touch works by having an X-Y grid of electrodes covering the screen, on which a voltage is then applied. When a finger is near the electrodes, the capacitance changes and can be measured. By comparing the measures from all electrodes you can accurately pinpoint the location of the fingers position. There are two types of capacitive sensors used for touch screens, mutual capacitance and self-capacitance. Mutual capacitance makes multi-touch detection possible. Self-capacitance generates a stronger signal than mutual capacitance, which allows accurate detection of the finger further away from the sensors. However, with self-capacitance it is not possible to perform multi-touch detection due to an effect called “ghosting”.

Do you think floating touch is a must-have feature for future smartphones?

Edwin Kee
Categories: Cellphones
Tags: Sony, xperia sola