TOUCH SCREEN TECHNOLOGY

PRESENTED BYGIRISH HARMUKHM.Sc. ELECTRONICS

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TALK FLOW

INTRODUCTION HISTORY FUNCTIONS OF TOUCH SCREEN TECHNOLOGY COMPONENTS OF TOUCH SCREEN TECHNOLOGY WORKING OF TOUCH SCREEN TECHNOLOGY DIFFERENT TOUCH SCREEN TECHNOLOGY ADVANTAGES DISADVANTAGES APPLICATION CONCLUSION REFERENCES

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INTRODUCTION

A touch screen is a computer display screen that is sensitive tohuman touch ,allowing a user to interact with the computer bytouching picture or word on the screen.

The display screen has a sensitive glass placed on it and we couldthe desired input by touching it.

A touch screen is based on CRT (cathode ray tube ) technology,that accepts direct on screen input.

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HISTORY The first touch screen was a capacitive

touch screen ,invented by E.A.Johnson in the UK around 1965 the inventor Initially developed this technology for Air traffic control. then more fully along withphotographs and diagrams in an articlepublished in 1967.

In 1971 the first touch sensor was developed by doctor Sam Hurst while he was an instructor at the university of Kentucky.

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The university of Kentucky research foundation named it as ‘ Elograph’.

The Elograph was not transparent like modern touch screens.In 1974 the first true touch screen incorporating a transparent Surface came.

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THE FIRST TOUCH PHONE

Apple was the first with a touch

screen phone in 1983. Jason Ford

of Elo Touch Systems, the company

whose founder invented touch

screen technology, for providing the

touch technology. In 1971, the first

"touch sensor" was developed by

Doctor Sam Hurst.

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FIRST TOUCH MOBILE

The Nokia 7710 is a first touch screen

mobile phone model produced

by Nokia. The 7710 is based on

the Nokia 7700 which was never

released. It is Nokia's first, and so

far only smart phone to run

the Series 90 GUI a top the Symbian

OS.

FUNCTIONS OF TOUCH SCREEN

Pressure sensitive activation by finger or stylus.

Emulates mouse functions click, double click , and drag.

Touch screen and mouse can be used currently.

Durable and scratch resistant coated surface.

Compatible with windows 95,98,NT,2000,XP,linex

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COMPONENTS OF TOUCH SCREEN TECHNOGIES

A basic touch screen has three main components

Touch sensor

controller

Software driver

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TOUCH SENSOR A touch screen sensor is a clear glass panel with a

touch Responsive surface.

The touch sensor/panel is placed over a display screenso that the responsive area of the panel covers the viewable area of the video screen.

The sensor generally has an electrical current or signalthrough it and touching the screen causes a voltageor signal change.

This voltage is used to determine the location of thetouch to the screen.

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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.

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SOFTWARE DRIVER

The driver is a software update for the PC system thatallows the touch screen and computer to work together.

It tells the computer’s operating system how to interpretthe touch event information that is sent from thecontroller.

Most touch screen drivers today are a mouse emulationtype driver . this makes touching the screen the same asclicking your mouse at the same location on the screen.

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DIFFERENT TOUCH

SCREEN TECHNOLOGIES RESISTIVECAPACITIVESURFACE ACOUSTIC WAVEINFRARED

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RESISTIVE TOUCHSCREEN TECHNOLOGY

POLYESTER FILM

TOP RESISTIVE LAYER

CONDUCTIVE TRANSPARENT METAL COATING

BOTTOM RESISTIVE LAYER

INSULATING DOTS

GLASS SUBSTRACT

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RESISTIVE TOUCHSCREEN TECHNOLOGY

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RESISTIVE TOUCHSCREEN TECHNOLOGY

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The resistive touch screen uses a glass panel with a uniformconductive ITO (Indium Tin oxide) coating on the side surface.

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

When the screen is touched ,it pushes the conductive ITO coating on the PET Film. that results the electrical contact, producing thevoltages. it presents the position touched.

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RESISTIVE TOUCHSCREEN TECHNOLOGY

ADVANTAGES OF RESISTIVE TOUCHSCREEN TECHNOLOGY

Can be activated with any device Low cost solution Low power consumption

DISADVANTAGES OF RESISTIVE TOUCHSCREEN TECHNOLOGY

Poorer durability compared to other technologies.

Very short life, especially considering cosmetic wear.

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CAPACITIVE TOUCH SCREEN TECHNOLOGY

Capacitive touch screen technology is a four multi layer glass. Small amount of voltage is applied to the electrodes on the four

corners. A human body is an electric conductor, so when touched the screen

with a fringer,a slight amount of current is drawn.

The Capacitive, a layer that stores electrical charge is placed on the glass panel of the monitor. When a user touches the monitor with hisor her finger, some of the charge is transferred to the user, so the charge on the capacitive layer decreases.

This decrease is measured in circuit located at each corner of the monitor. The computer calculates, from the relative differences in charge at each corner, exactly where the touch event took place and then relays that information to the touch-screen driver software.

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ADVANTAGES OF CAPACITIVE TOUCH SCREEN TECHNOLOGY

More durable than resistive. Higher transmittance than resistive.

DISADVANTAGES OF CAPACITIVE TOUCH SCREENTECHNOLOGY

Accepts input from finger only.Accuracy is dependent on capacitance of person.

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SURFACE WAVETOUCH SCREEN TECHNOLOGY

On the pure glass substrate, there are four piezoelectric transmitting and receiving transducers on the three corners for Both the x and y axes.

The SAW controller sends a 5 MHz electrical signal to the x axis and y axis transmitting transducers.

When the touch screen is touched, the finger absorb a portion of the wave passing across the surface of the panel.

SAW can be used in any and all application for the best possible Image clarity an unlimited life. 25

SURFACE WAVETOUCH SCREEN TECHNOLOGY

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ADVANTAGES

Very high transmittance. Very high durability.

Disadvantages Requires soft input device. Surface obstructions can cause a false touch.

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INFRARED TOUCH SCREEN TECHNOLOGY

IR makes use of a ‘frame’ around the perimeter of the display. On two sides there are closely spaced IR LEDs and on the opposing two sides there are matching photo transistor.

The LEDs are turned on in sequence and the signal is readfrom the matching transistor. if no signal is read, then that indicates a blocked IR beam, meaning a touch.

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ADVANTAGES

Highest quality of underlying image. Very high transmittance. Very high durability and reliability.

DISADVANTAGES

Lower resolution than other technologies. Surface obstructions can cause a false touch.

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APPLICATION

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APPLICATION

Public access

Mobile phones Library resources guidesComputersPublic transportation schedules / statusAirport terminal passenger internet and email systemAutomated travel and entertainment ticket dispensers

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BUSINESS

Gas station Points of sales Restaurants Grocery stores Hospital and hostel directories Banks and financial reporting Bank cash advance and teller machines

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CONCLUSION

Designers are trying to use touch screen to simply inputcommands for largely unsophisticated computer users.

Today, a larger share of population is pc literate, yet the touch screen has become adopted by computer 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.

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REFERENCES

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www.slideshare.net/MrQaz996/touch-screen-technology-presentation.

www.slideshare.net/ritanshugoel/touchscreen-technology-14037188.

https://wiki.mozilla.org/images/9/93/TANU1.ppt.

https://www.wiziq.com/tutorial/31468-Touch-Screen-Presentation.

www.slideshare.net/Ammybhardwaj/touchscreen-ppt

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ANY QUERIES ?

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