Touch Screen Technologies – which to choose?

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Touch Screen - NECTouch screens are now second nature to many of us. With the rise of smart phones and tablets many people now expect to interact with visual content by direct touch. So why limit this technology to small devices? Bring large format touch screens to your presentations, signage and information systems. Pixelution supply a range of touch screen technologies each with their own strengths for particular tasks. We thought we’d use this post to explain a few key differences and highlight what touch technology can bring to your visual media.

There are four basic touch technologies used in large format public display monitors.

Projective Capacitive Touch (PCT) is the most durable of all the touch technologies. This makes it ideally suited for use in Public spaces where it can expect a high volume of traffic from the general public. PCT uses a fine mesh of wires beneath the screen to sense the users input. This means the touch sensor is protected from interference by the user and is resistant to scratching and gouging on the screen. The sensor is capable of dual touch input and works best with custom interfaces designed around large, simple buttons. This is the limitation of PCT. The larger the display the less accurate the input and as such it is not suitable for fine detail or precise input.

Dispersive Sensor Technology (DST) is a similarly tough touch technology using a sensor below the surface of the glass. Our DST screens use the 3M touch sensor that provides fast and accurate input. It is a single input device that can respond to any input – finger, gloves, stylus etc. and is not affected by surface grime or scratches.  It also has the advantage of being able to ignore static input signals making it ideal for table-top applications where a resting glass or leaning hand do not register while other inputs are happening.

For fast and accurate input we move to optical and infra-red sensors. Both these technologies provide multi-touch capabilities and are ideally suited to precise and fluid input making them the perfect choice for whiteboard replacements and creative applications. Unlike the other touch technologies both these screens are designed to work in only one orientation and must be ordered as either Landscape or Portrait format.

Optical Touch Screens (OST) use two cameras built into the bezel of the monitor to track user input. They can track up to 6 input points and provide very fast feedback. What makes OST so fast and accurate is also its weakness. As the camera sensors are located in front of the screen they can be tampered with making them un-suitable for use in public or unattended areas which could be prone to vandalism.

Infra-Red Touch Screens (IRT) take the basic principles of the OST screens and improve on the technology with the addition of more touch points and a larger sensor array which avoids any touch-point confusion that can happen with the optical system when input points intersect. IRT is capable of tracking up to 30 input points at once but you need to consider if this number required for your application. IRT screens come with the number of touch inputs pre-determined by the sensor. Screens are available with 2, 6, 10, 15 and 30 points. Many customers automatically look at getting a screen with the highest number of touch input points – at additional cost – but then go on to use only one, two or maybe four inputs at most. It is important to consider your software application and how you will use the touch input to enhance its operation before making a purchase.

With the rise of interactive signage, touch based gestures built into operating systems and the general public’s awareness of touch interaction there has never been a better time to bring touch technology to your screens. As well as the large format displays we also have a range of desktop touch screens suitable for office and digital signage / POS applications. If you feel touch is something you want to experience then get in touch with us to discuss the options.