Saturday, October 16, 2010
How Does a touch screen function ?
A basic touch screen hes three main components :a touch sensor,a controller,and a software driver
1).Touch Sensor: A touch sensor is a ear glass pannel with a touch responsive surface.The touch sensor pannel is placed over a display screen so that the responsive area of the pannel covers the viewable area of the video screen
There are different touch sensor technologies on market today,each using a different method to detect touch input.
The sensor generally has an electrical current or signal going through it and touching the screen causes a voltage or signal change.this voltage change is used to determine the location of touch to the screen
2).Controller: The controller is a small PC card that connects between the touch sensor and the pc. It takes information from the touch sensor and translates it into information that PC can understand. The controller is usually installed inside monitor /plastic case for external add-ons .
The controller determines what type of interface /connection you will need on PC. Integrated touch monitors will have an extra cable connection on the back for touch screen .Controllers are available thatcan connect to a serial /COM port (pc) or to a USB port .Specialized controllers are available that works with DVD players .
3). Software driver . The driver is a software update for the PC system that allows the touch sreen and computer to work together .Most touch screen drivers are mouse- emulation tye driver.
This makes the touching the screen the same as clicking your mouse at the same location on the screen . This allows the touch screen to work with the existing software and allows new applications to be developed without the need for touch screen specific programming .
When you touch the screen ,the mouse cursor will move to that point and make a mouse click .You can trap the screen twice to perform a double click ,and you can also drag your finger across the touch screen to perfprm drag and drops.