Atlanta, Georgia-based Carroll Touch Inc is now shipping touch-screen products it displayed at Comdex in April. The company’s Guided Wave products include add-on touch screen kits for flat panel displays ranging from 6.4 to 14 diagonally. Carroll Touch describes guided acoustic wave as the most advanced touch technology available since it offers z-axis capability to give a third dimension of touch measurement to the traditional x-y-axis systems so that a single touch target can launch a command as well as to measure variable levels, such as colour intensity and sound volumes. The capability does away with the need for glass sensors, which is usually the way z-axis is achieved and which are three times thicker than those on guided acoustic wave systems and cannot be sealed against potentially harsh environments. Carroll touch says that because Guided Wave touch sensors feature are so thin, they offer excellent optical clarity and transmissivity. Guided wave uses a thin screen overlay as an acoustic wave guide in which sound waves in the VHF band are transmitted between the surfaces at 7,000mph; when a finger touches the screen it absorbs some of their energy and the attenuation in an otherwise constant amplitude wave pattern is used to detect the touch; z-axis is detected by the strength of the pressure and hence the energy absorbed. The company claims they are not subject to drift so calibration is not an issue, the touch screen being calibrated once, at the factory. The company is aiming the products at medical instrumentation, industrial process control, and other industries where flat panels and cathode ray tubes are commonly used, such as kiosks, point-of-sale systems, interactive video. The new products include five touch screen kits for flat panel displays and were developed to enable the addition of a touchscreen interface to an OEM flat panel system. The kits include the touch sensor, cables, serial controller, and software drivers to customise the flat panels.
