Touch Screens Seminar Final

8/3/2019 Touch Screens Seminar Final

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SEMINAR

ON:³ToUcH

ScrEeNS´

BANERJEE NIVEDITA



INTRODUCTIONy A touchscreen is an electronic visual display that can detect the presence andlocation of a touch within the display area. The term generally refers to touching thedisplay of the device with a finger or hand. Touch screens can also sense otherpassive objects, such as a stylus.

y Fields of application:

y GUI

y room automation

y game consolesy information appliances

y hospitality, and in heavy industry

y for kiosk systems in retail and tourist settings

y smart phones



THE ACER ASPIRE

8920

USES TOUCH TECHNOLOGY TOINCREASE OR REDUCE

VOLUME OF A SPEAKER.



Evolution of touch screensy In 1971, the first "Touch Sensor" was developed by Doctor Sam Hurst

(founder of Elographics) in The University of Kentucky Research

Foundation.y This sensor, called the "Elograph ¶·. The "Elograph" was not transparent

like modern touch screens; however, it was of great significance in touchscreen technology.

y In 1974, the first true touch screen incorporating a transparent

surface was developed by Sam Hurst .y In 1977, he developed and patented five-wire resistive technology, the

most popular touch screen technology in use today. [5] Touchscreensfirst gained some visibility with the invention of the computer-assisted

learning terminal,



ELOGRAPH(left) and 1STTRANSPERENT TOUCHSCREEN(right)



attributesThere are 2 main attributes of touch screens:

y First, it enables one to interact directly with what is displayed, rather thanindirectly with a cursor controlled by a mouse or stylus.

y Secondly, Such displays can be attached to computers, or to networks

as terminals. They also play a prominent role in the design of digitalappliances such as the personal digital assistant (PDA), satellite

navigation devices, mobile phones, and video games.



TOUCH MONITORS

CAN BE OPERATED WITHFINGER TIPS OR STYLUS



Basic components of touch

screens

Touch screen has 3 main components: a touch sensor, a controller and a

software driver. To make a complete touch input system, a touch screen

is combined with a display and a PC or other device.

y 1) Touch screen censor

A touch screen sensor is a glass plate having touch responsive surface. .

The sensor has an electrical current or signal passing through it and

touching the screen causes change in voltage or signal. This voltage orsignal change is used to find out the location of the touch to the screen.



y 2) Controller

The controller used in touch screen is a small PC card that interconnects

between the touch sensor and the PC. Controller takes data from thetouch sensor and converts it into information that PC can understand.

y 3) Software Driver

The driver is software for the PC system that permits the touch screen

and computer to work together. It tells operating system of computer howto interpret the touch event information that is sent from the controller.



COMPONENTS OF A TOUCH SCREEN

TOUCH SCREEN SENSOR

CONTROLLER

SOFTWARE DRIVER



How to construct a touch

screen?

There are several principal ways to build a touchscreen. The key goals are to recognize one or

more fingers touching a display, to interpret the command that this represents, and to

communicate the command to the appropriate application.

In the most popular techniques, there are typically

four layers:

y Top polyester layer coated with a transparent metallic conductive coating on the bottom

y

Adhesive spacery Glass layer coated with a transparent metallic conductive coating on the top

y Adhesive layer on the backside of the glass for mounting.



TOP ADHESIVE

LAYER OF A TOUCH

SCREEN



ITO(INDIUM TIN

OXIDE LAYER)

TRANSPERNT CONDUCTIVELAYER USED IN CAPACITIVE

TOUCH SCREENS



TechnologiesRESISTIVE TECH:

y The least expensive type of touch screen. These screens are coated with

electrically conductive and resistive layers. Insulating spacers separate the twoconductive or resistive layers. When pressure is applied to the screen, by a

finger or other objects, the layers are brought into electrical contact which

causes a switch closure and a command is registered.

y to use in areas of large use and demanding environments. widely used due to

their durability. Outside elements rarely affect the performance



The figure below shows pressure being applied to a resistivetouch screen, causing a electrIcal contact when the twolayers come in contact with each other.



Surface acoustic wave

y (SAW) technology uses ultrasonic waves that pass over the touchscreen

panel. When the panel is touched, a portion of the wave is absorbed. Thischange in the ultrasonic waves registers the position of the touch event

and sends this information to the controller for processing. Surface wave

touch screen panels can be damaged by outside elements. Contaminants

on the surface can also interfere with the functionality of thetouchscreen.[6]



CAPACITIVE

y A capacitive touchscreen panel is one which consists of an insulator such

as glass, coated with a transparent conductor such as indium tin oxide(ITO).As the human body is also a conductor, touching the surface of the

screen results in a distortion of the screen's electrostatic field,

measurable as a change in capacitance. Different technologies may be

used to determine the location of the touch. The location is then sent tothe controller for processing.



Capacitivetouchscreen of a

mobile phone



conclusionScience and technology is booming at a fast rate ,new inventions and

their practical usage has affected us significantly. These applications have

made our lives better , faster and scientific . each one of us benefits fromthese applications.

Touch screens have hits the world with a big bang and its presence is

strongly felt in every sphere be it in your cell phones ,computers , ATMs or

video games . the evolution of touch screens has made our efforts inmanual labour effectively less and simpler.



THANK YOU!

Touch Screens Seminar Final

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