Surface Acoustic Wave

Key Advantages	Advantages over Capacitive
Advantages Over Infrared	Mechanical Specifications

What Is The Surface Acoustic Wave (SAW) Touchscreen?

The SAW touchscreen is a glass overlay with transmitting and receiving piezoelectric transducers for both the X and Y axes. The touchscreen controller sends a five-megahertz electrical signal to the transmitting transducer, which converts the signal into surface waves. These mechanical waves are directed across the opposite side gather and direct the waves to the receiving transducer, which reconverts them into an electrical signal. When the front surface of the touchscreen is touched, a portion of the mechanical wave is absorbed, thus changing the received signal. The signal is then compared to a stored reference signal, the change recognized, and a coordinate calculated. This process happens independently for both the X and Y axes. By measuring the amount of the signal that is absorbed, a Z-axis is determined.

SAW technology is based on measuring time. A touch location is determined by relating time to path length, providing reliability and accurate "no-drift" operation.

Advantages of SAW

Advanced Surface Wave Technology.	Excellent Image Clarity.
Very High Light Transmission.	Excellent Durability.
Stable "No-Drift" Operation.	High Resolution.
Finger or Gloved-Hand Operation.	Very Light Touch.
Fast Touch Response.	X-, Y-, and Z-axis Response.
Overlay That Can Be Antiglare-Treated.	UL Recognized Components, File E133802.

Advantages Over Capacitive

The user's body is not part of the circuit, so touch reports are accurate and do not vary due to body size, ground path, or touch contact resistance.	Does not require front coatings, which can be easily damaged or wear excessively at one location due to repetitive touches.
Inherently stable and does not need to be recalibrated when environmental conditions change.	Can be activated by any glove.
High Light Transmission and Clarity.

Advantages Over Infrared

Fits curvature of the display tightly to maximize accuracy and minimize parallax.	Provides very high resolution and accuracy.
Does not require expensive customized bezels or unsightly add-on frames.	Touch performance is not affected by sunlight or dust.
Intuitive operation--operates only when the user actually touches the screen.

Pixel's Total Touch Solution

Pixel Touch offers a variety of touchscreen sizes, several controller options, and advanced software that all work together to make it easy to integrate into your touch system.

SPECIFICATIONS

Mechanical Specifications

Construction:	Glass panel with transducers attached to the front surface of the glass.
Resolution:	4096 x 4096 touchpoints pre square inch.
Z-Zxis:	256 Levels of pressure.
Accuracy:	Extremely Consistent, Very Stable, No-Drift.
Conversion Time:	Approximately 10.4 ms per coordinate report
Baud Rate:	9600 only.
Reliability:	MTBF: greater than 450,000 hours per MIL-HDBK-217-F2 using the parts stress calculation method for ground benign environment with an ambient temperature of 35º C.
Touch Activation Force:	Typically 2 to 3 ounces (55 to 85 grams).
Surface Durability:	Surface durability is that of glass, Mhos' hardness rating of 7.
Expected Life Performance:	No known wear-out mechanism, as there are no layers or coatings. The SAW technology has been operationally tested to more than 50 million touches in one location with-out any failure, using a stylus similar to a finger.
Controllers Available:	PC-Bus, RS232 Serial, or Mac ADB.

Optical Specifications

Light Transmission:	Over 90% per ASTM D1003-61.
Visual Resolution:	Clear Surface: Excellent with no noticeable degradation. Antiglare surface: 5:3 minimum.
Gloss:	Clear Surface: N/A Antiglare Surface: 60 +/- 20 gloss units per ASTM D2457-70, using a 60-Degree gloss meter.