Understanding Modern Projected Capacitive Touchscreen Technology

Projected capacitive touchscreen (PCT) technology is becoming very popular in different industrial settings. This technology allows the use of touch-enabled devices even with a protective layer. PCT works by detecting a change in the electromagnetic field when a finger or stylus comes into contact with the screen. The change in capacitance caused by this converts into locations on the grid.

PCT is used in applications such as ATMs, bar top or through-counter applications, ticketing machines, and pay-at-the-pump fuel machines. Hospitals use PCT especially in labs when practitioners have to use touch screen device with their gloves on. Industrial businesses also utilise the technology in their operations.

Advantages of PCT

Different features of PCT makes it suitable for use in these industries. One is the durability that the touch screen technology offers. Devices can have a protective layer such as chemically strengthened glass or tempered glass and still responds to touch. This protective layer provides a longer life for devices preventing them from scratches, cracks, and surface wear.

PCT also has anti-stiction traits. It means that users don’t have to deal with fingers sticking to the surface, thereby, improving the performance of devices. Projected capacitive touchscreen is suitable for harsh environments because it can withstand the base. The nature of PCT is that it remains undisturbed by most contaminant on the surface. The ability to use gloved fingers when operating PCT devices is advantageous to many industries. PCT devices are also easy to clean.

Sensing Methods for PCT

Projected capacitive technology work with two sensing methods, which are self-capacitance, and mutual capacitance. In self-capacitance, sensing occurs by measuring the current of a single electrode to the ground. This sensing method can be through rows and columns or multi-pad construction.

Mutual capacitance, on the other hand, capitalises on the ability of most objects to hold more than one charge in proximity. When a finger comes close to these two charged objects, it causes a shift in the capacitance. Mutual capacitance makes better use of space and produces higher resolution.


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