SAW Touch Screen: The Power Of Sound

SAW Touch Screen: The Power Of Sound


saw touch screen

The SAW touch screen uses one of the least known technologies on touch screens. A SAW touch screen uses sound waves to detect touches on its surface. In a way SAW screens are similar to infrared touch screens; they both use pairs of emitters and sensors around the edges of the screen. The only difference is that SAW screens replace infrared light with sound waves.

What Is A SAW Touch Screen And How Does It Work?

SAW stands for Surface Acoustic Wave, a touch screen technology which relies on sound waves to detect touches on the screen’s surfaces, which are then converted into data or instruction inputs.

These touch screens have transducers, receivers and reflector patterns in the screen’s glass. The transducers emit acoustic energy coupled to the touch screen glass and reflected in an X and Y grid pattern. The receivers are only able to receive the acoustic waves after they have travelled across the screen. When a finger touches the screen, it causes the acoustic signal under the finger to decrease. This change allows a built in program to determine the X and Y location of the touch allowing data input.

The Pros and Cons of SAW Technology Touch Screens

Let us first line up the advantages of SAW technology touch screens:

  • These screens exhibit high transmission and optical clarity; onscreen images are crisp and clear.

  • It also has a high sensitivity to touch so that even the lightest touches are recognized. It does not require the touch to come from a conductor such as a naked finger – touches from conductive and non-conductive materials are equally recognized.

  • A SAW technology screen offers a completely flat and sleek appearance.

  • SAW screens provide fast and accurate touch response.

  • SAW technology touch screens are not sensitive to most interferences such as ambient light, humidity, vibration, EMI, RFI, and cleaning chemicals.

  • Excellent scratch resistance

  • Cost of manufacture is lower than projected capacity screens.

Despite the long list of advantages, SAW touch screens have a few disadvantages too, among them:

  • Durability issues: The sensors on SAW screens are not expected to outlast the display.

  • They are sensitive to surface contaminants, snow and rain. Snow and rain are sometimes recognized as touches, and surface contaminants impair reception of sound waves resulting in response errors.

  • They require periodic calibration.

How SAW Touch Screens Are Used

The reliability of touch screens has promoted their use in various devices such as desktop touch monitors and laptop computers. A number of institutions and business establishments make use of touch screen point of information kiosks. You are likely to see this in buildings, trade shows, providing direction to tourists in high traffic areas of town, in hospitals and malls.

SAW screens are also used for gaming consoles, vending and ticket sales, interactive digital signage, industrial control consoles and in pre-qualifying transactions in banks. A recent news article even tells how touch screens were used by an animal welfare group to get a stray dog adopted!

With its many advantages, we will see increased uses for SAW touch screens. Maybe it’s time you discovered what a SAW touch screen can do to help your business.

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Meg has been writing for close to ten years now, her insights in the field of technology has earned her editor status for more than 10 blogs that all focus on the ongoings of the IT world.