Stand azi in fata pcului, am luat stylusul de la pda, si hai sa ma joc pe iphone. Am observat atunci ca nu merge…trageam bara de deblocare degeaba…dau cu degetul, mergea. Dupa un search pe nea’ gogu, am aflat ca iphoneul foloseste “touchscreen capacitiv”..cica! Restul telefoanelor cu touch screen normal folosesc tehnologie rezistiva. In cateva cuvinte inseamna ca iphoneul are “senzori” separati pentru fiecare zona a ecranului, de aici ne dam seama si cum functioneaza multi-touchul. Nu e singurul telefon care foloseste tehnologia aceasta, LG Prada de exemplu e la fel.

Dar, de la multi-touch pana la faza cu degetul, e ceva diferenta. Se pare ca atunci cand atingi ecranu, acesta simte in punctul acela energia electrica a corpului tau.

Aici e si postul original, in engleza, cititi si intelegeti mai bine ce si cum:

Why You Can Only Touch With Your Finger

There is a drawback to all this. Most other touch screen devices allow the use of a stylus, or at least the touch screen can function when you touch it with something besides your finger. But with the iPhone, you have to touch the screen with your finger. This is because the iPhone can have a capacitor at every point on the screen only because each capacitor relies on feedback from the electricity in your finger to operate. When you touch the screen, the screen at that point senses the natural capacitance of your body (your body’s ability to hold an electrical charge) and then registers a change in current at that point on the screen. If you use a stylus to touch the iPhone’s screen or touch it with a gloved hand, the iPhone will not be able to pick up any natural capacitance and so it won’t know you’re touching it there.
In reality, the iPhone has one half of a capacitor at every point on the screen. The other half of the capacitor is your finger. Together, the circuit beneath the glass cover and the capacitance in your finger change the electrical charge at that point on the screen.

Multi-Touch

Each position on the iPhone’s screen can independently pick up a touch. This means that you can touch the screen in more than one place at a time, and the iPhone will register all touches. Apple used this multi-touch feature in many of the applications and software on the phone. For example, when you are using a maps application or browsing your pictures on the phone, you can make a pinching motion on the surface of the screen and that gesture will zoom the image out. If you want to zoom in, you start with your fingers together on the screen’s surface and then pull your fingers apart and watch as the application zooms in on where you first touched the screen.