Tech: 3 Types Of Sensor Technologies Explained

sensor technologies

Ever wondered what technology lays behind your every day gadgetry such as smartphones and tablets? In this article, we explain what sensor technology is, its advantages, and disadvantages.

We won’t go deep into the technical aspects of equipment, but rather give a general understanding and principles of operation of various sensor technologies.

The first touchscreen display was developed in the USA in 1972. Samuel Hirst – the future founder of Elographics and now Elo Touch Solutions – created the world’s first touch screen using infrared technology (IR grid). The logic behind the operation of this screen was quite simple and extraordinary, but it was a discovery – a discovery thanks to which today almost everyone has a phone or tablet with a touchscreen screen.

Since then, a lot has changed: new developments, new possibilities, and with them the requirements for sensor equipment have appeared. The position of Elo Touch Solutions in the global market has remained unchanged, they remain the leaders and innovators in the field of touch technologies.

Infrared sensor technology

Infrared technology is based on sensors located in a special frame around the screen. With their outgoing rays, they create a so-called infrared grid. When an object hits the screen, these rays are interrupted and, thus, the touch coordinate is calculated.

The advantage of infrared technology is that almost any object can be applied to the touch screen, and the screens themselves are not very expensive and therefore are often used in production.

But the technology also has serious drawbacks, the most important of which is the impossibility of installing full-fledged anti-vandal protection on screens with infrared technology.

Projected Capacitive Technology

The touch screen, made according to the projection-capacitive technology, consists of a thin plate on which a grid of micro-sensor-conductors and two plates of protective glass is applied, between which the working layer is located. When touched between the finger and the sensor grid, a capacitance is created, the change which is calculated by the controller. Such a screen reacts to exposure to any non-metallic object.

Being behind protective glass, the screen works stably in conditions of atmospheric precipitation (snow, rain), and is also resistant to dust and dirt. The installed top glass can be of any degree of vandal resistance, including armored.

The disadvantage of screens with projected capacitive technology is their price. They are almost perfect, but they are still quite expensive to manufacture. What is sensor technology for if nobody is able to buy it?

Surface acoustic wave technology

The operation of SAW technology is based on acoustic waves that pass through the glass of the screen. Thus, when you touch the screen, the wave is partially absorbed, and special sensors determine the coordinates of the touch. Such a screen can only be influenced by objects that absorb the acoustic wave, for example, a finger, a gloved finger, a special stylus, etc.

The disadvantage of surfactant technology is the impossibility of using it on screens in outdoor touch terminals since they do not tolerate water well.

Water, like a finger, absorbs acoustic waves and therefore, a wet screen simply will not respond to other touches. But one of the main advantages of surfactant sensor technology is the ability to install full-fledged anti-vandal protection (SecureTouch screen).