Not too long ago, the only it seemed that the touch screen technology could only be found in styus-driven PDAs and tablet PCs. At one point, they were too expensive still and thus too costly too actually replace the functions of the keyboard and the mouse. But the latter mass demand for touchscreen technology called for using the interface in more than the PDAs and tablet PCs. But touchscreen technologies are not really the same for all type of devices. Here are a few insiders regarding touchscreen tech.
Touchscreen types. The simplest touchscreen tech is the resistive screen, a two layered electrically conducive material separated by a transparent insulators often observed as dots when a person presses the screen. It’s durable and works best for outdoors and industrial environments. However, it may not exactly be suitable for touch-based devices like tablet PCs because they only let 75% of the light from the screen.
Capacitive screens on the other hand work using glass that’s horizontally and vertically coated electrodes. This makes the screens more sensitive, thus there would be no need to physically push down screen to make it work. It lets through over 90% of the screen’s light.
Surface acoustic wave )SAW) touchscreens use ultrasonic transducers that send waves though the surface of a glass screen. Once the screen is touched, the touch interrupts the waves and they are converted into coordinates for software use. This type works with ATMS.
Another touchscreen types surrounds the screen with infrared LEDs, each having photodetectors installed grid-like across the screen’s area. Touching the screen actually breaks the infrared beam. This works optically through interfering with a light beam.
The multi-touch technology. The four mentioned touchscreen tech types are traditional and the touchscreen tech considered to be most wanted when it comes to devices involve more than the four types. This is the multi-touch technology, the one that is responsible for Apple’s success with its iPhone devices. Multi-touch technology allows sensors to detect several finger presses at one time. The alternative name for multi-touch is ‘mutual capacitance’. In a mutual capacitance screen, a small capacitor is found at every row and column intersection. iPhone 4 for instance having a 960×640 screen has 614,400 capacitors.Each capacitor is run by a voltage that changes at a finger’s touch. This interruption is usually fed back to the software as an X-Y coordinate pair.