Common Types of Touch Screens

5-Wire Resistive Touch Panels (RTP)

The touch screen technology with the most longevity is the 5-wire resistive touch panel. This type of touch membrane technology can sense when a finger, stylus, or other object presses the top layer of the panel into the bottom layer, producing a switch closing of the circuit. The bottom layer contains both X and Y axis conductors, while the top layer uses a looped conduction layer. The controller pings the location of the touch by calculating the resistance of the closed loop.

Capacitive Touch Screens

Capacitance touch panel technology has seen significant growth in the last several years, as it has been adopted by many of the most popular smart phone manufacturers. While resistive technology relies on mechanical closure, cap touch products actually rely on the minor electrical charges that run through the human body. When we touch the top surface of the panel, the capacitance values of this surface are changed. Cap touch, while more costly than resistive touch, is extremely accurate and is becoming one of the most widely implemented touch screen technologies.

Infrared Touch Panels

Infrared touch panels utilize a series of light beams that are arranged in a matrix slightly above the face of the touch panel. When an object comes in close proximity to the touch panel, it breaks an “X” and a “Y” beam, sending the coordinates of this light breakage to the touch switch. Though infrared has not yet been broadly adopted, the benefits of this technology make it a good choice for certain niche applications.

SAW (Surface Acoustic Wave) Touch Screens

Surface acoustic wave touch panels utilize ultrasonic sound wave technology to sense touch. These panels have been utilized in different industries for many years. High frequency sound waves are emitted over the surface of the touch panel, and when a finger or object breaks the plane of these waves, a change in frequency occurs. Information is simultaneously sent to the controller, which calculates the location of the activation.

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