Touch Screen Technology Noor Al-Nassar

Overview : Introduction History Components Technologies Pros & Cons Applications Conclusion

Introduction : - A touch screen is a display that can detect the presence and location of a touch within the display area. - Touch screen can also sense other passive objects such as stylus.

History : - Touch screen emerged from academic and corporate research labs. - In 1971 , the first touch sensor was developed by Doctor Sam Hurts ( founder of Elographics ) while he was an instructor at the University of Kentucky.

- This sensor, called the “Elograph”. - Touch screen first gained some visibility with the invention of the computer-assisted learning terminal, which came out in 1975 as part of the PLATO project.

components : A basic touch screen has three main components : - Touch sensor. - Controller - Software drive.

Touch sensor : - A touch screen sensor is a clear glass panel with a touch responsive area. - The touch sensor is placed over a display screen so that the responsive area of the panel covers the viewable area of the screen.

Controller : - The controller connects between the touch sensor and PC. - Take information from the touch sensor and translate it into information that PC can understand.

Software drive : - The drive allow the touch screen and computer to work together. - This makes touching the screen as same as clicking the mouse at the same location on screen.

Technologies: - Resistive - Surface acoustic wave - Capacitive - Infrared - Optical imaging

Resistive : - Composed of several layers. - Two Electrically conductive layers.

Surface acoustic wave : - Uses ultrasonic waves. - Surface wave touch screen panels can be damaged by outside elements. - When the panel is touched, a portion of the wave is absorbed.

Open frame SAW Touch Monitor

Capacitive : - Consist of an insulator such as glass. - Coated with transparent conductor such as ITO (Indium Tin Oxide) . - Touching the surface of the screen results in a distortion of screen’s electrostatic field, measurable as a change in capacitance.

Infrared : An infrared touch screen uses an array of X-Y infrared LED and photo detector pairs around the edges of the screen to detect a disruption in pattern of LED beams.

Optical imaging : In this two or more image sensor are placed around the edges of the screen. A touch shows up as a shadow and each pair of camera can then be pinpointed to locate the touch.

Comparison :

PROS & CONS

PROS : - User friendly. - Fast response. - Error free input. - Use finger, fingernail, gloved hands, stylus or any soft tip pointer. - Easy to clean. - Does not interfere mouse and keyboard. - Make computing easy, powerful and fun. -It benefit children.

CONS : - Finger stress. - Fingerprints. - Screen has to be really big not to miss things when pressing them with your finger. - Big screen leads to low battery life. - Touch screen means screen can’t be read too well in direct sunlight as it applies an additional not 100% transparent. - Fatigue.

Applications : - Museums. - Cell phones . - Library recourse guides. - Corporate information. - Airport terminal passenger internet and emails. - ATM’s. - Restaurants'.

Conclusion : - Designers are trying to use touch screen to simplify input commands. - Today, touch screen has becomes adopted by computers users of all abilities because it is simple, fast and innovative. - In future there is no usage of mouse and keyboard as they will be replaced by touch screen.

References : http://en.wikipedia.org/wiki/Touchscreen http://www.google.com.sa/search?q=touch+screen&um=1&h l=ar&safe=active&gbv=2&tbm=isch&ei=psDeUJevLq2T0 QWS44C4Dw&start=240&sa=N http://www.touchwindow.com/c/TouchScreens.html