By: Ravi Ranjan RajC.S.E. 7th

Sem.

TOUCH SCREEN TECHNOLOGYIndus Institute of

Technology & Management,

Kanpur

TALK FLOWINTRODUCTIONHISTORYWORKINGDIFFRENT TOUCH SCREEN TECHNOLOGIESPROS & CONSAPPLICATIONCONCLUSIONFEATURES OF TOUCH SCREEN

INTRODUCTIONA touch screen is a computer display screen that is sensitive to human touch, allowing a user to interact with the computer by touching pictures or words on the screen.

A touch screen is an input device that allows users to operate a PC by simply touching the display screen which has a sensitive glass overlay placed on it .

A touch screen accepts direct onscreen inputs.

Example of Touchscreen

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.

HOW DOES A TOUCHSCREEN WORKS?A basic touch screen has three main components: Touch sensor Controller Software driver

TOUCH SENSORThe touch sensor is a clear glass panel with a touch responsive area and it is placed over the display screen.

It allows the electric current and signal to pass through it and change in these signal is used to detect the location of touch on the screen.

CONTROLLERThe 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.

SOFTWARE DRIVERThe driver is a software that allows the touch screen and computer to work together.

It tells the operating system how to interpret the touch event information that is sent from the controller.

Most touch screen drivers today are mouse-emulation type drivers. This makes touching the screen the same as clicking your mouse at the same location on the screen.

Diagram showing How it Works

•Resistive•Capacitive• Infrared•Surface acoustic wave•Optical Imaging

TECHNOLOGIES

●The resistive touch screen uses a glass panel with a uniform conductive ITO(Indium Tin Oxide) coating on the side surface.

●A PET film is a tightly suspended over the ITO coating surface of a glass panel.

RESISTIVE TOUCH SCREEN TECHNOLOGY

CAPACITIVE TOUCH SCREEN TECHNOLOGYIn the capacitive system, a layer that stores electrical charge is placed on the glass panel.

When a user touches, some of the charge is transferred to the user, so the charge on the capacitive layer decreases.

This decrease is measured in electrodes located at each corner of the monitor.

The computer then calculates the coordinates, from the relative differences in charge at each corner.

•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.

INFRARED TOUCH SCREEN TECHNOLOGY

SURFACE WAVE TECHNOLOGY•It has a transmitting and receiving transducers for both the X and Y axes.•The touchscreen controller sends a five-megahertz electrical signal to the transmitting transducer, which converts the signal into ultrasonic waves within the glass.

•These waves are directed across the front surface of the touchscreen by an array of reflectors.

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&

CONS

Pros ConsFast responseError free inputUse finger , fingernail , gloved hands , stylus or any soft tip pointerEasy to cleanDoes not interfere mouse and keyboardMake computing easy , powerful and funIt benefits children

FingerprintsFinger stressScreen 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

ATM’s and

Banks

Mobile phones

and Tablets

Gaming

Industrial and Medical instrumentat

ion

Market Reserch

Applications

Though the touch screen technology contains some limitations it’s very user friendly, fast, accurate, easy for the novices & fun to operate. It has been widely accepted. And now by just modifying a little it can replace the mouse and key board completely in near future

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.