Ruggedising Projected Capacitive Touch Technology for Industrial Uses

Richard B. Projected Capacitive Touchscreen

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Touch screen technology has had an impact outside of the consumer sector with industrial applications realising the potential of using the technology in devices.

However, the harsh conditions that computers have to endure in industrial surroundings mean that the use of projected capacitive touch technology is impractical, which forces most sectors to rely on resistive touch.
A resistive touch panel can operate in factory settings because it uses a plastic surface as opposed to glass; and so, it can persist through moisture and dust exposure. Even though resistive touch is more durable than capacitive, it still doesn’t last long in industrial settings, so workers have to deal with downtime during repairs.

Also, customers are nowadays used to the instantaneous responsiveness of capacitive touch and the numerous gestures that are available, which resistive doesn’t offer.

 

Projected capacitive technology

Projected capacitive technology is the alternative that the industrial sector sought so as to meet its touchscreen needs.

A PCT panel has electrodes that detect electromagnetic changes when a finger approaches its surface. This change is measured as capacitance and used to locate where a finger is touching the surface.

The difference with PCT is that a finger does not have to touch the surface directly to register a touch. Projected capacitive touch is useful in industrial applications because it can register multiple touch locations (multi-touch).

 

Interference of PCT

One problem that projected capacitive technology experiences is registering false touches when other conductive substances are in the surroundings.

Water droplets, for instance, have conductive capabilities and can interfere with the functioning of the touch panel. The palm of the hand also causes this interference.
When ruggedising a PCT sensor, manufacturers take this into consideration and use firmware to filter out false signals.

Creating the smart projected capacitive technology means that users don’t have to deal with problems of interference. Manufacturers also use unique designs when integrating PCT into devices to ensure that the metal chassis does not cause the same interference.

Ruggedised projected capacitive technology provides surfaces that are durable, water resistant and reliable to use in industrial settings.

 

Sources:

Ruggedizing Capacitive Touch for Industrial Computing, ruggedpcreview.com

Okay, but how do touch screens actually work?, scienceline.org