We use touch screens everywhere: tourist kiosks, automatic teller machines, point-of-sale terminals, industrial controls. Half a dozen vendors, plus
wow goldin-house departments at major manufacturers, produced $800 million worth in 2000. The market is growing because the interfaces are easy-to-use, durable and
wow gold inexpensive. Touch screens employ one of three physics principles for detecting the point of touch. Pressing a resistive design with a finger
wow gold or other stylus raises a voltage. In capacitive models, a finger draws a minute current (this method is often used for cursor pads on notebook computers). In other designs, a finger or stylus
wow gold interrupts a standing pattern of acoustic waves or infrared lights that blanket the
wow goldsurface. Resistive screens are the oldest, most widely used and least expensive, and they work with any stylus (finger, pen). Capacitive screens must be touched by a finger or an electrically grounded stylus to
wow gold conduct current. Wave screens are
wow goldthe newest and most expensive. Surface acoustic
wow gold wave screens must be touched by a finger or a soft stylus such as a pencil eraser to absorb energy; infrared screens work with
wow gold eurany stylus. The different technologies may be used in the same applications, although pros and cons lead to prevalent combinations: resistive screens
wow goldfor industrial controls and Palm Pilots; capacitive screens for slot machines; wave screens for ATMs and indoor kiosks. Most people are unaware
wotlk gold of the type of screen they are using. But tricks can help you tell, according to Frank Shen of Elo TouchSystems in
wow wotlkFremont, Calif., the largest U.S. maker. Push the screen lightly with your fingernail (not your skin). If it responds, it could be resistive or
wow gold infrared. In this case, place two separated fingers against the screen at
wow gold eurthe same time. If the cursor moves beneath one finger, the unit is infrared (software registers the first touch); if the cursor moves
wow gold between the fingers, it is resistive (the points are averaged). If the unit
wow gold does not respond to your fingernail, again place two separated fingers against it. If the cursor
wow accountsmoves beneath one finger, the unit is acoustic wave; if the cursor moves between the fingers, it is capacitive