Thursday, December 24, 2009

Why the iPhone is Faster: Resistive versus Capacitive Touch Screens

Thanks to an informative article in the 전자신문 ( 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.

1 comment:

  1. One extra advantage you didn't mention is that capacitive screen never need to be calibrated. There are some calls in the USA to change voting machines to capacitive types so you don't get the "miscalibrated screen that mis-voted" kind of bunk.

    The only downside to capacitive touch screens? You can't use them while wearing gloves! That's a real pain for 4-5 months out of the year in Korea ...

    Still, I'll take the glove problem if it means getting all the advantages that capacitive screens provide. Also, some vendors are filling the void by making gloves that conduct electricity from the finger:

    You can also add conductive thread to your current gloves to be able to control it:

    - Mike in Daegu