devesh singh 2k8 ec 634

7/29/2019 Devesh Singh 2K8 EC 634

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DELHI COLLEGE of ENGINEERING

Presented by:-DEVESH SINGH

2K8/EC/634

Presentation on

TOUCH TECHNOLOGY


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Points of Discussion

Introduction to touch

technology

History & Development

Construction of Touch

Screen

Types of TouchTechnologies

Comparison

Manufacturer

Applications

Advantages

Disadvantages

Future

Closing Thought

Q&A


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Introduction

A touch screen is an electronic

visual display that can detect the

presence and location of a touch

within the display area.

Touch screens can sense Finger

and other passive objects, suchas a stylus.


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History & Development

In 1971 Dr. Sam Hurst, founder of Elographics developed thefirst touch opaque sensor Elograph at the University of

Kentucky.

In 1974 He developed the first real touch screen.

In 1977, Elographics developed the five-wire resistive

technology then with the backing of Siemens Corporation,

developed a curved glass sensor called the touch screen.

The new transparent technology, AccuTouch, was later

developed by the founders of Elographics, Dr. Hurst and Bill

Colwell


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Dr. Samuel Hurst

Dr. Samuel Hurst is considered as the

father of the touch screen technology.

In 1971, while he was working as an

instructor at the University of Kentucky

Research Foundation, he had to read a great

volume of information during the

graduation exams. In an effort to save some

time he invented the first touch sensor that

he called lo graph(electronic graphics),which allowed him to enter data faster.


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First Touch Phone

Apple was the first with a touchscreen phone in 1983.

Jason Ford of Elo TouchSystems, the company whosefounder invented touch screentechnology in 1971, providedthe touch technology to Apple.


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First Touch Mobile

The Nokia 7710 was the first

touch screen mobile phone model

produced by Nokia in 2004.

The 7710 was based on the Nokia

7700 which was never released. It

was Nokia's first, and so far only

smart phone to run the Series

90 GUI a top the Symbian OS.


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Construction of Touch screen

A basic touch screen has three

main components:

Touch sensor,

Controller,

Software driver.

The touch screen is an input

device, so it needs to becombined with a display and a

PC or other device to make a

complete touch input system.


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Touch Sensor

A touch screen sensor is a clear glass panel with atouch responsive surface which is placed over adisplay screen so that the responsive area of the panel

covers the viewable area of the display screen.

The sensor generally has an electrical current or signalgoing through it and touching the screen causes a

voltage or signal change. This voltage change is usedto determine the location of the touch to the screen


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A Touch Sensor


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Controller

The controller is a smallhardware card that connects

between the touch sensor and the

Processor.

It takes information from the

touch sensor and translates it into

information that Processor can

understand.


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Software Driver

The 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 a mouse-emulation type

driver. This makes touching the screen the same as clicking

your mouse at the same location on the screen.


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Types of Touch Technologies

There are mainly Four types of touch Technologies:-

1.Resistive

2. Surface Acoustic Wave (SAW)

3. Capacitive

4. Infrared


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1. Resistive

A resistive touch screen panel is composed

of several layers, the most important ofwhich are two thin, metallic, electrically

conductive layers separated by a narrow gap.

When an object, such as a finger, presses

down on a point on the panel's outer surfacethe two metallic layers become connected at

that point.

This causes a change in the electrical

current, which is registered as a touch event

and sent to the controller for processing. It is

used in Grocery Stores, Hotels, Restaurants

and Retail Stores.


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Advantages&Disadvantages of Resistive

Cost-effective solution

Activated by any stylus

Very accurate

Low power requirements

Liquids won't affect touch

screen performance

Polyester surface can be

damaged

Lower endurance (35million touches)


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2. Surface Acoustic Wave (SAW)

Surface acoustic wave (SAW) technologyuses ultrasonic waves that pass over the touch screen panel.

When the panel is touched, a portion of the wave is absorbed.

This change in the ultrasonic waves registers the position of

the touch event and sends this information to

the controller for processing.

SAW touch screen technology is suggested for use in ATMs,

Amusement Parks, Gaming Environments, Industrial Control

Rooms etc.


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Advantages&Disadvantages of SAW

Durable glass construction

High optical clarity

Activated by a finger, gloved

hand, or soft tip stylus

Moving liquids or

condensation can cause false

touches

Solid contaminants createnon-touch areas until removed

Doesn't support drag or draw

effectively


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3. Capacitive

A capacitive touch screen panelconsists 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 body's electrostatic field,

measurable as a change

in capacitance.


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Advantages& Disadvantages of Capacitive

Scratch resistant, durable

surface

High endurance (225million touches)

Very accurate

Good optical clarity

Liquids doesn't affecttouch screen performance

Does not work with

gloved fingers or stylus


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4. Infrared

An infrared touch screen uses an array

of X-Y infrared LEDs and photo

detector pairs around the edges of the

screen to detect a disruption in the

pattern of LED beams.

Infra-red bezels have proven to be a

very reliable technology for use in

ATMs, Medical Instrumentation andTransportation, Tracking applications.


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Advantages & Disadvantages of Infrared

Touch Screen

Highest quality of underlying

image

Excellent anti-glare, with use of

chemically etched glass Can be activated with almost any

device

Higher accuracy than other

technologies Very high durability and

reliability

Surface obstructions can

cause a false touch

It is very sensitive and can

be activated by straytouches.

Low resolution

Parallax problems


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Touch Screen Technology Comparison Chart

Resistive Infrared SAW Capacitive

Touch

Resolution

High High Average High

Clarity Average Good Good Good

Operation Finger or Stylus Finger or Stylus Finger or Soft-

tipped Stylus

Finger only

Durability Can be

Damaged by

Sharp Objects

Highly Durable Susceptible to

Dirt and

Moisture

Highly durable


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Manufacturers

Apple Inc. was the first companywhich introduce the touch phone and

after that Nokia come into existence

with their Nokia 7710.

Now a days the big companies like

Nokia, Samsung, Sony Ericsson,

Motorola, Blackberry are making

touch screen technology.


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Applications of Touch Screens

Informational kiosks

Trade show displays

Museum / tourism displays

Point-of-sale terminals

Restaurant systemsEmployee time clocks

Industrial process controls

World Wide Web access kiosks

Home automation systems

Casino and other gaming systems

Computer access for the physically disabled


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Advantages & Disadvantages

of

all Touch Technologies


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Advantages

A touch screen is easy to use (as the user simply touches what

he or she sees on the display).

Save space as no buttons are required.

Touching a visual display of choices requires little thinking

and is a form of direct manipulation that is easy to learn.

Touch screens are the fastest pointing devices with easier hand

eye coordination than buttons.

Touch screens are durable in public access and in high volume

usage.


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Disadvantages

Screen has to be really big not to miss things when pressing

them with your finger.

Big screen leads to low battery life.

Touch screens cant be read too well in direct sunlight as it

applies an additional not 100% transparent touch panel.

Touch screen devices usually has no additional keys and this

means when an app crashes, without crashing the OS, you cant

get to the main menu as the whole screen becomes unresponsive.

Screens get very dirty.


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Future

If we're among those who think that touch screen phones are only available on

high-end devices, think again! Gartner Inc estimates that the global market for

touch screen mobiles will cross 362.7 million units in 2010, a 96.8 per cent

increase from the 184.3 million units sold in 2009. And by 2013, touchscreen

mobiles will account for 58 per cent of all global mobile sales, and more than 80

per cent in high-end markets, such as North America and Western Europe.


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CLOSING THOUGHTS

Though the touch screen technology contains some limitations itsvery 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.


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devesh singh 2k8 ec 634

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