Surface Acoustic Wave Touch Screens (SAW)

Surface acoustic wave technology is based on transmitting acoustic wave across the surface of a glass overlay.

How it Works

A transducer mounted on the edge of the glass emits the acoustic wave, which travels along the surface of the glass and is reflected back across the overlay. Since the speed of the wave is known and the size of the glass overlay is fixed the first reflector will send the first signal back first, then the second and so on. When an absorbent stylus (finger, gloved or un-gloved) touches the screen it attenuates the wave by basically absorbing some of it, this change is detected by the touch controller and an X & Y coordinate at the point of contact is sent to the host computer. SAW touch also has a Z axis, which is generated by the amount of pressure you apply to the screen and the amount of the wave you absorb.

Specification

Size Range	8.4” ~ 47.0”
Resolution	4096 x 4096 (256 Z Axis points)
Material	Pure Glass
Light Transmission	90% ~ 92%
Accuracy	<2mm (0.080”)
Durability/Life	50 Million Touches on a single point
Surface Hardness	Mohs rating 7H
Operating Temp.	-20°C ~ +60°C
Storage Temp.	-40°C ~ +70°C
Operating Altitude	3800m
Humidity	10% ~ 90% @ 40°C
Chemical Tolerance	All chemicals not harmful to glass.

Highlights & Benefits

• Large range of sizes 8.4” ~ 47.0”.
• Excellent optical clarity up to 92% transmissivity.
• Any absorbent stylus, gloved or un-gloved hand without changing settings.
• Z-Axis capability.
• Excellent anti-vandal properties.
• NEMA3 or IP65 rated.
• UL, CE, FCC, RoHS, CB approval standards.
• Individual RS-232C or USB interface options or a dual interface version both RS-232C and USB interfaces supported on the one controller all supplied with full cabling and windows or Linux software.

Image on right shows the controller for a SAW touch component.