Monika Puppy

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 screens emerged from academic and corporate

research labs In 1971, the first "Touch Sensor" was developed by

Doctor Sam Hurst (founder of Elographics) while he was an instructor at the University of Kentucky.

Contd… This sensor, called the “Elograph”. Touch screens 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 driver

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

the PC. Take information from the touch sensor and translate it

into information that PC can understand.

Software Driver

The driver allow the touch screen and computer to work together

This makes touching the screen as same as clicking the your mouse at the same location on the screen.

Resistive Surface acoustic wave Capacitive Infrared Optical Imaging

Technologies

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 the 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 the pattern of LED beams.

Optical imaging

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

Comparison

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 benefits 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•Library resource guides•Corporate information •Airport terminal passenger internet and emails•ATM’s•Restaurants'•Grocery stores

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 keyboards as they will be replaced by touch screen.