Question on Mobile Phones:

Hi, what are the differences between resistive and capacitive touchscreens? Are they both capable of multitouch?

Submitted by Reader

Answer:

That's a good question and I think it will also help other users who may be confused about the types of touchscreens on mobile devices. A resistive touchscreen typically comprises two sheets of resistive materials separated by a narrow gap. When you press one of them, with a finger or a pointing device like a stylus, the sheets come into contact and the location of the touch will be registered.

A capacitive touchscreen, like the one used on the iPhone, acts like a capacitor and reacts only when there are changes to the electrical field. This happens when you tap on it with your finger (human bodies conduct electricity) as it changes the field of the current. It won't work if you are wearing a glove or using a stylus, unless the latter is made from a conductive material. One of the features of capacitive displays is they support multitouch.

There's also a third type of touch display though this is less commonly used. Some examples are the HP TouchSmart desktops. These systems use an array of infrared LEDs and photosensors lined on the bezels of the display. This creates an invisible cross grid and when the beams are interrupted, it registers the location and thus the touched coordinate.

mambo22

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mambo22 says...
Good answer Damian . . !!

Jul 06, 2009 19:24

tzevoon

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tzevoon says...
Does this mean that capacitive touch screen consumes more power since electricity is always flowing? Compare to resistive screen, where current only flows where there is a contact?

Jul 15, 2009 16:49