There are four transducers mounted on the glass panel, each axis having a transmitting and receiving transducer and a set of reflector stripes. The controller sends a 5.5 MHz electric signals to the transmitting transducers which convert the electric signals into surface acoustic waves.Surface acoustic waves are mechanical waves that spread across the surface of glass ,after reflected twice by the reflector stripes, the waves reach the receiving transducers which convert the waves into electric signals which is analyzed by the controller. When a finger, gloved hand or soft stylus touches the touchscreen, a portion of the wave is absorbed. The resulting change in the received signal is analyzed by the controller and a digitized X and Y coordinate is determined. A Z-axis coordinate is also determined by measuring how much signal was absorbed.

Each axis needs only a pair of transducers, this greatly reduces its production cost ?its design is very wise.

Comparison for performance of different types of touchscreen

Listed as follows:

Advantages of surface acoustic wave touchscreen

You can find out the following advantages from the table above :

• The optical performance is the best, because its body of panel is made up of pure glass while there are films of other materials on the glass for both capacitive panels and resistor panels.
• High scratch resistance. The surface acoustic wave touchscreens can work normally even with scratches.Solvents and razor blades can be used to remove paint, Mohs' hardness rating of 7. For capacitive touchscreens , scratches can cause non-linearity and disable touchcreens, Mohs' hardness rating of 5. It cannot be scratched using stylus with Mohs' rating of less than 6. When cleaning the panel you must be careful not to damage its coatings.For resistor touchscreen, it can't work correctly when the ITO film is cut open. But the ITO film is easy to be cut open using sharp tools.
• High resolution up to 4096×4096 while responding quickly and correctly.
• Free of electromagnetic interference, No drifting. Being a kind of mechanical vibration, the acoustic wave can not be affected by electromagnetic signal.
• The longest life-span. Unlike capacitive panel or resistor panel whose surface is mounted with coatings and films, the acoustic wave touchscreen has no coating or film on its glass, it's free from the problem that parts of the panel is dull due to the aged coatings or films while other area of the panel is sensitive . It can bear more than 50 millions touches in one location with no failure while resistor panel can bear up to 35 millions touches in one location and capacitive panel can bear up to 20 millions touches in one location.
• Shortage of acoustic wave panel is that it may be influenced by dust,water and oil.It's necessary to be cleaned at regular intervals. This kind of shortage can be avoided if using our waterproof or dustproof panels.
• Another advantage of acoustic wave panel is its low production cost, especially for panels whose size are more than ten inches. Every axis needs only a pair of transducers, this greatly reduces its cost.