Touch Screen - Ppt Final

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a presentation on Touch screen technology by Ahmed

Text of Touch Screen - Ppt Final

Touch Screen TechnologyClick to edit Master subtitle styleAHMED A. S.(1GC06EC092) UNDER THE GUIDANCE OF :A PRESENTATION BY :-

MR. C.K. VENKATESH7/18/12 11

CONTENTS

Introduction (What are Touch Screens?) History Components Of Touch Screen Types Of Touch Screens Comparision Of Technologies Advantages And Disadvantages7/18/12

Applications

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What are Touch Screens?

It is the most user friendly input device used to interface with a PC. The user touches the screen to select options presented on it, where associated

hardware and software locates that touch.7/18/12 33

History-1971the first "touch sensor" was developed by Doctor Sam Hurst (founder of Elographics) called Elograph.

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History-1974the first true touch screen incorporating a transparent curved glass sensor surface came on the scene developed by Sam Hurst and Elographics.

-1977Elographics developed & patented five-wire resistive technology, called AccuTouch.

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History

-1987 new technology were purchased. The surface acoustic wave product, named IntelliTouch.

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Components Of Touch ScreenThere Are Three Major Components Of The Touch Screen

Touch Sensors Controller Software Driver

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Components Of Touch ScreenTOUCH SENSORSTouch sensor

Covering screen

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Components Of Touch Screen

Panels

Cont TOUCH d.. Touch Sensors are located In Between Clear Glass SENSORS

Responsive Area -> Entire Area Of The Display Screen

Sensors -> Detects Electrical Current Or Signal

Touching -> Causes A Voltage Or Signal Change, Thereby The Location Can Be Determined

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Components Of Touch ScreenCONTROLLER

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Components Of Touch ScreenCONTROLLERCont d..

PC card -> Touch sensor and the PC. Change in voltage -> Translated into the information that CPU understands. Translated bits -> Position where the touch occurs. Processor -> change the screen accordingly.

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Components Of Touch Screen

SOFTWARE DRIVER

Acts as a bridge Between the Screen and the processor. Makes the operating system to interpret the touch event information. Touch screen drivers today are like Mouseemulation type driver ( like touching the screen the same as clicking mouse) Recent research -> To make it as PNP1212

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Types Of Touch Screen

Resistive Touch screen Capacitive Touch screen

Surface capacitive Projected capacitive

Surface wave Touch screen Touch screen

Infrared 7/18/12

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Types Of Touch Screen

RESISTIVE TOUCH SCREENS

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Types Of Touch Screen>Resistive Touch Screens

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Types Of Touch Screen>Resistive Touch Screens1. Polyester Film. 2. Top Resistive Layer. 3. Conductive Transparent Metal Coating. 4. Bottom Resistive Layer . 5. Insulating Dots . 6. Glass Substrate7/18/12 1616

Cont d..

Types Of Touch Screen>Resistive Touch Screens

Working Of Resistive Sensors When the screen is touched, it pushes

the conductive layer on the PET film. That results the electrical contact, producing The voltages. It presents the position touched The microprocessor applies +5V to pin (X left) on the glass panel, and the voltage is uniformly decreasing to pin (X right) for 0V because of the resistive ITO coating on the glass substrate, and the PET film is grounded.

Cont d..7/18/12 1717

Types Of Touch Screen>Resistive Touch Screens-> Consists of a glass or acrylic panel that is coated Advantages :with electrically conductive ->High touch resolution ->Pressure sensitive, works with any and resistive layers. Thestylus ->Not affected by dirt, dust, water, or light thin layers are low when compared with - >Costs are relatively separated active touch screen technologies. by invisible separator dots. Disadvantages :->75 % clarity ->Resistive layers can be damaged by a sharp object ->Less durable then 5-Wire Resistive technology 7/18/12

4-Wire Resistive TouchScreens

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Types Of Touch Screen>Resistive Touch Screens- better version of 4-Wire Resistive technology.Advantages :-> High touch resolution -> Pressure sensitive, works with any stylus -> Not affected by dirt, dust, water, or light Disadvantages :-> More durable than 4-Wire Resistive ->75 % clarity technology ->Resistive layers can be damaged by a sharp object ->much expensive than 4-Wire Resistive technology 7/18/12 1919

5-Wire Resistive TouchScreens

Types Of Touch Screen

CAPACITIVE TOUCH SCREENS

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Types Of Touch Screen>Capacitive Touch Screens

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Types Of Touch Screen>Capacitive Touch Screens

Uniform conductive coating on a glass panel. Operation --> Electrodes around the panel's edge evenly distribute a low voltage across the conductive layer & creates an uniform electric field. Finger touch --> Draws current from each corner. Controller --> Measures ratio of the current flow from the corners & calculates the touch location.2222

WORKING OF CAPACITIVE TOUCHSCREEN

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Types Of Touch Screen>Capacitive Touch ScreensCapacitive Touch ScreensAdvantages ->High touch resolution ->Pressure sensitive, works with any stylus ->Not affected by dirt, dust, water, or light Disadvantages ->Must be touched by finger, will not work with any nonconductive input7/18/12 2323

Pen TouchCapacitive Touch Screens

Types Of Touch Screen>Capacitive Touch Screens->

is a durable Capacitive type touch screen with an attached7/18/12

Advantages ->High touch resolution ->Pressure sensitive, works with any stylus ->Not affected by dirt, dust, water, or light Disadvantages Attached pen stylus by finger orinput -> Must be touched for precise attached pen stylus, will not work with any non-conductive input 2424

Types Of Touch Screen

SURFACE ACOUSTIC WAVE TOUCH SCREENS

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Types Of Touch Screen-> SAW Touch ScreensSAW TOUCH SCREEN

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Types Of Touch Screen-> SAW Touch Screens

Contains Transmitting and receiving transducers

WORKING OF SAW SENSORS

Touchscreen controller --> 5 MHz electrical signal to the transmitting transducer. Converts electrical signal --> ultrasonic waves within the glass. Waves --> Directed across the front surface of screen.

Reflectors - -> Reflects & directs towards receiving transducer. 7/18/12 2727

Types Of Touch Screen-> SAW Touch ScreensSAW TOUCH SCREENAdvantages High touch resolution Highest image clarity All glass panel, no coatings or layers that can wear out or damage. Disadvantages Must be touched by finger, gloved hand, or soft-tip stylus. Something hard like a pen won't work Not completely sealable, can be affected by large amounts of dirt, dust, and / or water in the environment.

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Types Of Touch Screen

INFRARED TOUCH SCREENS

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Types Of Touch Screen-> IR Touch ScreensIR TOUCH SCREENConventional optical-touch systems use an array of infrared (IR) light-emitting diodes (LEDs) on two adjacent bezel edges of a display, with photo sensors placed on the two opposite bezel edges to analyze the system and determine a touch event.

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Types Of Touch Screen-> IR Touch ScreensIR TOUCH SCREENAdvantages

IR eliminates the use of glass or plastic overlay that most other touch technologies require in front of the display.

Disadvantages

High cost of the technology. IR increases the noise floor at the optical sensor3131

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Comparision Of TechnologiesTechnology Durability Stability Resistive 5 years High SAW 5 years Higher Good Finger/ pen 10ms Infrared 3 years High Good Sharp $300 (Approximately Rs. 13.4 K) 42 LCD (SONY) -> $3600 (Approx. Rs. 161K)

USD to INR Conversion As Per http://www.xe.com/ucc 7/18/12 4040

ConclusionThough The Touch Screen Technology Contains Some Limitations Its User Friendly. Fast. Accurate. Easy To Operate.

It Has Been Widely Accepted And A Little Modification Can Replace The Mouse And Key Board Completely In Near Future.

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References

http://en.wikipedia.org/wiki/Touch_screen http://www.edufive.com/seminartopics/computer/CS35.ht ml http://www.ehow.com/about_5436883_historytouchscreens.html? ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_ca mpaign=yssp_art http://bugclub.org/beginners/history/TouchScreen.html http://electronics.howstuffworks.com/iphone1.htm http://inventors.about.com/gi/dynamic/offsite.htm? site=http://www.touchscreens.com/compare.shtml http://inventors.about.com/gi/dynamic/offsite.htm?site=http://ww www.touchscreens.com7/18/12 4242

Thank You . . . . .

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