The Working Principle of Projected Capacitive Touch Technology
With the recent explosion in popularity of the smart phones, projected capacitive touch has grown extremely rapidly from obscurity to the top-notch touch technology.
Projected capacitive, the touch technology used in the iPhone touch screen, has become the first choice for many small-to-medium, generally smaller than 10 inches, touch-equipped products now in development.Projected capacitive technologies detect touch by measuring the capacitance at each addressable electrode. When a finger or a conductive stylus is near the electrode, it disturbs the electromagnetic field and changes the capacitance of the electrode. This change in capacitance can be measured by the electronics and then converted into X, Y locations that the system can use to detect touch. There are two main types of sensing methods, self-capacitance and mutual capacitance.
Excellent optical performance (high transmissivity)
Unlimited multi-touch (controller-dependent)
Ease of integration
Small-and-medium size applications (3.5” to 10.4”), mainly smart phones
Embedded systems and applications