Touchscreen solutions based on conventional projective capacitance (p-cap) methods would be incapable of coping with such a demanding set of criteria, as they lack the sensitivity to determine touch events through more than one or two mm of front glass. However, Zytronic’s PCT touch sensor products are particularly suited to, and are proven in, applications of this kind due to their unique construction and sensing method. The near invisible XY matrix of highly conductive capacitors that make up PCT sensors, are a mere 10 microns in diameter. Zytronic’s proprietary self-capacitive touch sensing technique induces a known frequency (around 1 MHz) within these capacitors, which in turn, is altered by a user’s body capacitance when their finger comes in proximity with that part of the touchscreen’s surface. Through sophisticated algorithms embedded within the connected touch controller’s firmware, the position of peak frequency change is interpolated. This method of touch detection is so sensitive, that the PCT sensor matrix may be embedded within a laminated, thick protective overlay. The firmware may also be easily tuned by the user via a driver to adjust touch sensitivity and threshold detection levels so that the screen will respond to the lightest of touches or full finger pressure, depending on application requirements. It can also support heavily gloved hand operation, making it highly optimised for outdoor and industrial applications.
