Touch screen

By Holly

Resistive System

Touch screens works by the person that is touching the screen and there are three ways that the devise can tell that the screen is being touched...........

  • Resistive
  • Capacitive
  • Surface acoustic wave

The resistive system includes a normal glass layer that is covered with another resistive metallic layer. They held apart by spacers, and a scratch-resistant layer is placed on top of the layers. Then an electrical current runs through the two layers while someone is using/touching the devise. When someone touches the screen, the two layers make contact in the exact spot where someone has touched the screen. Once the coordinates have been noticed, a special driver translates the touch into something that the operating system can understand, for example how the computer can detect the mouse's when someone click's or a drag's.

Remeber its not just ipods,phones and ipads that have touch screens

The Capacitive System

In the capacitive system, a layer that stores electrical charge is placed onto of the glass panel on the monitor. When someone touches the monitor with their finger, some of the charge is transferred to the person(user), then the charge on the device gradually decreases (that's how your device can tell when to make the battery lower) . This decrease is measured in circuits by each corner of the monitor. One advantage that the capacitive system has over the resistive system is that it transmits almost 90% of the light from the monitor, but the resistive system is only able to transmit about 75%.
Microsoft Surface - Commercial HD

Surface Acoustic Wave System

On the monitor of a surface acoustic wave system, two messengers (one receiving and one sending) are placed along the x and y axes of the monitor's glass plate. They are also placed on the glass. There are reflectors that can send messages to the corners. The receiving transducer is able to tell if the wave has been disturbed by a touch.