First touchscreen phone

First touchscreen phone was made by IBM Simon in august 1994. To February 1995 IBM sold 50,000 units.
IBM Simon Phone - CHI 2011

How it works?

How it works

The basic idea is pretty simple -- when you place your finger or a stylus on the screen, it changes the state that the device is monitoring. In screens that rely on sound or light waves, your finger physically blocks or reflects some of the waves.
Big image

Types of touchscreens