Touch Screen Technologies for Interactive Whiteboards and Other Electronic Devices

Posted: Aug. 28th, 2015

Touch screen technologies have quickly become a popular means of controlling most electronic devices. From refrigerators and washing machines to smartphones and laptops, touch screens have almost completely replaced buttons in virtually all electronic devices. Despite the recent increase in their popularity, touch screen technologies are among the oldest forms of technology in the digital age, first seen in older ATMs and POS systems.

Apart from home appliances and computers, different types of touch screens have been implemented in ATMs, industrial machinery, vending machines, navigational equipment, and POS terminals. Types of touch screen technologies are broadly classified under two categories: overlay and perimeter based technologies.

1. Overlay-based Touch Screen Technology
Overlay-based touch screens use the screen’s physical properties to receive and register input. An object such as a finger or a stylus pen is used to create a touch event every time the object comes into contact with the screen.


Overlay-based touch screens come in two distinct types. The first, capacitive touch screens, utilize the object’s conductive properties to register a touch event on the screen’s surface. Displays with this type of touch technology are durable although water or other liquids negatively affect their functionality. They are also non-responsive to non-conductive materials like gloves. They are common with tablets, smartphones, and some types of interactive whiteboards.
Capacitive Touch Screen Technology Used in Interactive Whiteboards


The second type of overlay-based touch technology is resistive touch technology. Screens with such technology have different moving parts, with two layers separated by an empty gap. When pressure is applied to the outermost layer, this layer touches the inner layer and completes a circuit that sends location-specific data to the central processor. Despite the fact that they are cheaper than capacitive touch screens, they are less sensitive and more liable to wear and tear.
How Does Resistive Touch Screen Technology Work?
2. Perimeter-based Touch Screen Technology
These types of touch screens incorporate sensors and cameras embedded in the structure of the display that monitor characteristics of light beams. These sensors and cameras detect acoustic waves and light that has been emitted from transducers and LEDs that are also embedded in display’s bezel.

A touch event is registered when an object breaks the beam of light rays that are passing across the screen. Sensors detect this change when the object touches the surface and, using complex algorithms and data processing, detect the position of the touch event and register it as input.

There are three common types of perimeter-based touch technologies. These include Infrared, Surface Acoustic Wave, and Optical touch technologies. Infrared Touch Technology incorporates infrared light beams to detect and register touch events on the surface of the display screen. Surface Acoustic Wave Touch Screen Technology use ultrasonic waves for detection and recognition of input while Optical Touch Technology utilizes optical sensors to detect input and touch events.

Touch screen technologies are undoubtedly driving the technological evolution in many industries. The ability to integrate non-touch screens with touch screen technologies is further contributing to the touch screen evolution. For instance, traditional non-touch screen LCDs can be converted into Open Frame touch screen monitors for enhanced touch screen capabilities.

In the education sector, interactive whiteboards implemented in schools and business establishments are among the devices driving touch screen technology to the next level. An interactive whiteboard with modern, multi-touch screen capabilities, when implemented correctly, can offer students and instructors improved learning conditions in classrooms.





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