How the iPhone’s touchscreen really works

For most of us, the iPhone is a mystical slab of goodness that delivers the content we need, among other things, on a daily basis. The iPhone’s interface was touted as “revolutionary” and “intuitive” when it was first introduced, but very few people actually know how the touchscreen- the driving force behind the interface- really works. A traditional touchscreen can only sense a single pressure point on its surface. That technology works fine for stylus-based devices, since interacting with the operating system only requires one click. On the other hand, the iPhone’s interface is completely touch-based, and there are only a few physical buttons dedicated to operating the device.

In order to make the iPhone easy to use, Apple had to attribute functions to a series of finger movements, many of of which had to be performed with two digits. Enter the iPhone screen. Unlike traditional touchscreens, the iPhone’s LCD screen is overlayed with a coordinate system of capacitors which can detect touch. When you touch the iPhone’s screen, a circuit is created and the devices is able to calculate exactly where that circuit was completed.
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