Common Types of Touch Screens

Touch-screen technology is the new wave of computer engineering, and it’s improving the human to computer interaction every day. The convenience of shedding that old mouse and keyboard is allowing more and more industries to adopt touch screen applications. System automation, point-of-sale (POS), promotional kiosks, and consumer electronics are just a few examples of the impact of touch screen technology.  There are many types of touch screens all with their own advantages and disadvantages.

Three common types of touch screens used in everyday applications are resistive, capacitive, and surface acoustic wave (SAW). Each type has different properties which are designed to comply with national electronic standards for different applications.

1. Resistive touch panels are made up of two panes of glass coated with a resistive material and separated by a very thin gap or microdots.  There are two different metallic layers that can be used: a matrix or an analogue. A matrix is a series of striped electrodes that face each other on the two layers of glass. An analogue is made up of transparent electrodes that do not have a pattern or face each other. Both metallic layers operate the same way, but the analogue set up is a more cost-effective method to build a touch panel. When there is contact, the two layers touch together sending a signal to the touch controller and a touch event is registered on the screen. Resistive touch panels are cost effective and allow for more flexibility, such as multiple points of contact, but can easily be damaged.

2. Capacitive touch panels work by sensing conductive objects, usually the skin of your fingertip. Capacitive panels allow for a better user experience when operating smartphones and tablets. Instead of pressing down on the screen with a resistive touch panel, users can gently swipe or touch the screen for a touch response. The sensitivity of capacitive touch panels make for a pleasant electronic experience but limits the means of how the panel will respond. Using a stylus or wearing a glove will limit what you can do but as the technology advances, capacitive panels are becoming more and more sensitive to detect objects such as these.

3. Surface acoustic wave touch panels use ultrasonic waves that pass through the panel. A signal on the touch-screen sends parts of the ultrasonic waves to the touch controller and registers the event. Because of their reliability issues, SAW panels are not frequently used in today’s applications. User abuse or even contaminants on the screen can greatly affect how the touch panel responds.

All of these models have unique traits that qualify them for a variety of functions. Use this information to select the appropriate touch screen for your application.

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