Rabu, 23 Desember 2009

Why the iPhone is Faster: Resistive versus Capacitive Touch Screens

Thanks to an informative article in the 전자신문 (etnews.co.kr) I now understand one major reason why I like my iPhone 3GS.   It is faster than my old Motorola Razr and even faster than other touch screen phones, like Samsung's T-Omnia.   There are two main types of touch screens used in today's mobile phones.  Resistive touch screens, used in most of Samsung's and LG's phones, depend upon the pressure of a finger, or a small stylus.   The capacitive touch screen used by the iPhone, on the other hand, uses the electro static field created by the human finger, allowing faster recognition than a resistive touch screen.  Capacitive touch screens also allow multi-touch functionality, such as using two fingers to enlarge the screen for better viewing of a map, picture or other document.

In a small computer or internet device like the iPhone, customers value speed. Speed matters, as I've touched on in earlier posts.  Now I know a bit about the technology underpinning this speed.   I'd only add that the capacitive touch screen also has a natural feel to it, in contrast to the more mechanical approach of the resistive touch screen, even with haptic effects added.