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PRESENTATION ON TOUCH TECHNOLOGY

IN MOBILES


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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, such

as a stylus.


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Dr. Samuel Hurst

The father of the touch screen technology

is Dr. Samuel Hurst. 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 duringthe 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 datafaster.


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First Touch Phone

Apple was the first with a touchscreen phone in 1983. JasonFord of Elo Touch Systems, thecompany whose founderinvented touch screentechnology, for providing thetouch technology. In 1971, thefirst "touch sensor" wasdeveloped by Doctor SamHurst.


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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.


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Construction of Touch screen

A basic touch screen has threemain components: a touch

sensor, a controller, and a

software driver. The touch

screen is an input device, so itneeds to be combined 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 a touchresponsive surface which is placed over a display screen so thatthe responsive area of the panel covers the viewable area of thedisplay screen.

The sensor generally has an electrical current or signal goingthrough it and touching the screen causes a voltage or signalchange. This voltage change is used to determine the location

of the touch to the screen


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TOUCH SENSORS

Touchsensor

Covering screen


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Controller

The controller is a small PC cardthat connects between the touch

sensor and the PC. It takes

information from the touch sensor

and translates it into informationthat PC can understand.


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Types of Touch Technologies

There are mainly 4 types of touch Technologies:-

1.Resistive

2. Surface acoustic wave

3. Capacitive

4. Infrared


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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

surface the two metallic layers becomeconnected 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 andRetail Stores.


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Surface Acoustic Wave (SAW)

Surface acoustic wave (SAW)

technology uses 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 theposition of the touch event and sends

this information to the controller for

processing. SAW touch screen

technology is suggested for use inATMs, Amusement Parks, Gaming

Environments, Industrial Control

Rooms etc.


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Advantages & Disadvantages of SAW

Advantages

High optical clarity

Activated by a finger, gloved hand, or soft tip stylus

Disadvantages Solid contaminants create non-touch areas until removed

Doesn't support drag or draw effectively


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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 changein capacitance.


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Advantages & Disadvantages of Capacitive

Advantages

Scratch resistant, durable surface

High endurance (225 million touches)

Very accurate Good optical clarity

Liquids won't affect touch screen performance

Disadvantages

Does not work with gloved fingers or stylus


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Advantages & Disadvantages of Infrared Touch

Screen

Advantages-Highest quality of underlying image

-Can be activated with almost any device

-Higher accuracy than other technologies

-Very high durability and reliability

Disadvantages

- Surface obstructions can cause a false touch

It is very sensitive and can be activated by stray touches.


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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

M lti T h


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Multi Touch

Fl ti T h


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Floating Touch

Sony Xperia sola

Self capacitance"ghosting" (the redcrosses) occurs when youplace two fingers on the

screen. The phone can'tdetermine the exactposition of the fingers andinstead detects fourinstead of two contactpoints.
http://www.phonearena.com/phones/Sony-Xperia-sola_id6814http://www.phonearena.com/phones/Sony-Xperia-sola_id6814http://www.phonearena.com/phones/Sony-Xperia-sola_id6814http://www.phonearena.com/phones/Sony-Xperia-sola_id6814http://www.phonearena.com/phones/Sony-Xperia-sola_id6814


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Prepared by:

Lokesh Chawla

p Touchtechnology 111228093448 Phpapp02

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