Seminar Report

A Seminar Report

ON

TOUCH SCREEN TECHNOLOGY

BY

MAYANK KUMAR1PI08TE053

GUIDED BY

Ms. MILINA

January – May 2011

DEPARTMENT OF TELECOMMUNICATION & ENGINEERING

Dept of TE, PESIT Jan-May 2011

PES INSTITUTE OF TECHNOLOGY100 FEET RING ROAD, BANASHANKARI III STAGE,

BANGALORE – 560085.

PES Institute of Technology, 100 Feet Ring Road, BSK 3rd Stage, Bangalore-560085

DEPARTMENT OF TELECOMMUNICATION & ENGINEERING

CERTIFICATE

Certified that the Seminar work entitled TOUCH SCREEN TECHNOLOGY is a

bonafide work carried out by MAYANK KUMAR in partial fulfillment for the award of degree of Bachelor of Engineering in Telecommunication & Engineering Autonomous Institute under Vishvesvaraya Technological University, Belgaum during the year 2011. It is certified that all corrections / suggestions indicated for Internal Assessment have been incorporated in the Report deposited in the Departmental Library. The Seminar has been approved as it satisfies the academic requirements in respect of Seminar work prescribed for the Bachelor of Engineering Degree.

Signature of the Guide Signature of the HOD

Ms. MILLINA Prof. K.K.G


ACKNOWLEDGMENTS

The seminar report on “TOUCH SCREEN TECHNOLOGY” is outcome of guidance, moral support and devotion bestowed on me throughout my work for this I acknowledge and express my profound sense of gratitude and thanks to everybody who have been a source of inspiration during seminar preparation.

First and foremost I offer our sincere phrases of thanks with innate humility to Ms.MILLINA, lecture, PES Institute of Technology, Bangalore, & guide of my seminar for providing help whenever needed.

If I can say in words I must at the outside tender our intimacy for receipt of affectionate care to PES Institute of Technology for providing such a stimulating atmosphere and wonderful work environment.

MAYANK KUMAR


ABSTRACT

A touch screen is a display that can detect the presence and location of a touch within the display

area, generally refers to touch or contact to the display of the device by a finger or hand. Touch

screen is also an input device. The screens are sensitive to pressure; a user interacts with the

computer by touching pictures or words on the screen, Touch screens can also sense other passive

objects, such as a stylus, the touch screen has two main attributes. First, it enables one to interact

with what is displayed directly on the screen, where it is displayed, rather than indirectly with a

mouse or touchpad. Secondly, it lets one do so without requiring any intermediate device, again,

such as a stylus that needs to be held in the hand. Such displays can be attached to computers or, as

terminals, to networks. They also play a prominent role in the design of digital appliances such as the

personal digital assistant (PDA), satellite navigation devices, mobile phones, and video game


INDEX

1. Introduction

2. History of touch screen

3.Why touch screen?

4. Benefits of touch screen

5.How does a touch screen works

6.Type of touch screen technology

7. Comparisons between different technologies

8.What are touch screen used for?

9. Advantages over other pointing devices

10. Conclusion

11. References


INTRODUCTION

A touch screen is a computer display screen that is sensitive to human touch, allowing a user to

interact with the computer by touching pictures or words on the screen. Touch screens are used

with information kiosks, computer-based training devices, and systems designed to help individuals

who have difficulty manipulating a mouse or keyboard. Touch screen technology can be used as an

alternative user interface with applications that normally require a mouse, such as a Web browser.

Some applications are designed specifically for touch screen technology, often having larger icons

and links than the typical PC application. Monitors are available with built-in touch screen

technology or individuals can purchase a touch screen kit.

A touch screen kit includes a touch screen panel, a controller, and a software driver. The touch

screen panel is a clear panel attached externally to the monitor that plugs into a serial or Universal

Serial Bus (USB) port or a bus card installed inside the computer. The touch screen panel registers

touch events and passes these signals to the controller.

The controller then processes the signals and sends the data to the processor. The software driver

translates touch events into mouse events.

Drivers can be provided for both Windows and Macintosh operating systems. Internal touch screen

kits are available but require professional installation because they must be installed inside the

monitor.


HISTORY

In 1971, the first "touch sensor" was developed by Doctor Sam Hurst (founder of

Elographics) while he was an instructor at the University of Kentucky. This sensor, called the

"Elograph," was patented by The University of Kentucky Research Foundation. The

"Elograph" was not transparent like modern touch screens; however, it was a significant

milestone in touch screen technology. In 1974, the first true touch screen incorporating a

transparent surface was developed by Sam Hurst and Elographics. In 1977, Elographics

developed and patented five-wire resistive technology, the most popular touch screen

technology in use today. Touchscreens first gained some visibility with the invention of the

computer-assisted learning terminal, which came out in 1975 as part of the PLATO project.

Touchscreens have subsequently become familiar in everyday life. Companies use touch

screens for kiosk systems in retail and tourist settings, point of sale systems, ATMs, and

PDAs, where a stylus is sometimes used to manipulate the GUI and to enter data. The

popularity of smart phones, PDAs, portable game consoles and many types of information

appliances is driving the demand for, and acceptance of, touchscreens.

From 1979–1985, the Fairlight CMI (and Fairlight CMI IIx) was a high-end musical

sampling and re-synthesis workstation that utilized light pen technology, with which the user

could allocate and manipulate sample and synthesis data, as well as access different menus

within its OS by touching the screen with the light pen. The later Fairlight series III models

used a graphics tablet in place of the light pen.


The HP-150 from 1983 was one of the world's earliest commercial touchscreen computers. It

did not have a touchscreen in the strict sense; instead, it had a 9" Sony Cathode Ray

Tube (CRT) surrounded by infrared transmitters and receivers, which detected the position of

any non-transparent object on the screen.

Until recently, most consumer touchscreens could only sense one point of contact at a time,

and few have had the capability to sense how hard one is touching. This is starting to change

with the commercialization of multi-touch technology.

Touch screens are popular in hospitality, and in heavy industry, as well as kiosks such as

museum displays or room automation, where keyboard and mouse systems do not allow a

suitably intuitive, rapid, or accurate interaction by the user with the display's content.

Historically, the touch screen sensor and its accompanying controller-based firmware have

been made available by a wide array of after-market system integrators, and not by display,

chip, or motherboard manufacturers. Display manufacturers and chip manufacturers

worldwide have acknowledged the trend toward acceptance of touch screens as a highly

desirable user interface component and have begun to integrate touch screen functionality

into the fundamental design of their products.


WHY TOUCH SCREEN?

User interface PCs are quickly becoming the control device of choices for the plant floor, machine

control and any application where the user interface is important. This change has not been without

its difficulties. One challenge industrial PC manufacturers have faced is simplifying the human

machine interface while maintaining accuracy of input. Industrial grade touches Screen system have

quickly become the input device of choice for several reasons. Touch systems generally have no

additional hardware to mount and protect, such as a mouse or keyboard. A flat panel display can

also be sealed by the factory to prevent damage from dust and water. The ultra thin nature of a

touch screen on a LCD saves critical space, which is a vital for most application.

Durability is tested to over 35 million finger touches with no over performance degradation. 1

million-touch life max

Design Flexibility: -

Advanced design allows flat and spherical design.

Touch screen are very intuitive; it is natural for people to respond to there environment by

touching. Touch screen are usually manipulated with ease and require minimal

instrumentation training for a user. Best of all, touch screens draw an operator “into” the

application, improving accuracy attention span and speed of response. Although the touch

screen system for the riggers of everyday life, for rugged environments and the best solution

for your application.


BENEFITS OF TOUCH SCREEN

•Reduce training expenses

Touch screen system are far easier to learn then traditional keyboard based. Everyday retail

function like Selection tender, editing and voiding line items and capturing customer

demographic information are made intuitive by virtue of the touch screen- and the right touch

screen software. Many retailers, especially those in the service sector, sell items that cannot

be easily bar coded. Touch system make it easy to ring up these items and of course, still to

allow the use of all standard bar coded technologies. Studies show reduction in training time

in excess of 50% can be expected .Enhanced POS function can be added with the knowledge

that employees will be able to utilizes them quickly and easily.

•Improve customer Service

If your customer has to wait for your employees to figure out how to use the store’s system,

you are going lose costumer. Touch screen system eliminate this embarrassing and all too

common, problem. Today’s retailers need to learn as much as possible about there customers

needs and buying habits. Capturing customer’s information is a snap with touch screen POS

systems.

Reduce Transaction Times


Studies show touch screen systems process transactions up to 60% faster than traditional

keyboard POS systems. One info touch’ customer has clocked in with a traction rate of over

60 per Hrs. per register, over20, 000per day-with volunteers.

•Decrease Cost

In a touch screen POS system, the lay out of the color coded “keys” is stored in file on your

hard drive. Change to the layout can be accomplished during the nightly poll of store data the

time and expense of changing hardware key caps is eliminated.


How Does a Touch Screen Work ?

A basic touch screen has three main components: a touch sensor, a controller, and a software

driver. The touch screen is an input device, so it needs to be combined with a display and a

PC or other device to make a complete touch input system.

A basic touch screen has three main components:

1. Touch sensor

2. Controller

3. Software driver.


1. 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 screen so that the responsive area of the panel covers the

viewable area of the video screen. There are several different touch sensor technologies on

the market today, each using a different method to detect touch input. The sensor generally

has an electrical current or signal going through it and touching the screen causes a voltage or

signal change. This voltage change is used to determine the location of the touch to the

screen.

2. 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.

The controller is usually installed inside the monitor for integrated monitors or it is housed in

a plastic case for external touch add-ons/overlays. The controller determines what type of


interface/connection you will need on the PC. Integrated touch monitors will have an extra

cable connection on the back for the touch screen. Controllers are available that can connect

to a Serial/COM port (PC) or to a USB port (PC or Macintosh). Specialized controllers are

also available that work with DVD players and other devices.

3. Software Driver

The driver is a software update for the PC system that allows the touch screen and computer

to work together. It tells the computer's 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. This allows the touch screen to work with existing software and

allows new applications to be developed without the need for touch screen specific

programming. Some equipment such as thin client terminals, DVD players, and specialized

computer systems either do not use software drivers or they have their own built-in touch

screen driver external touch add-ons/overlays. The controller determines what type of

interface/connection you will need on the PC. Integrated touch monitors will have an extra

cable connection on the back for the touch screen. Controller are available that can connect to


a Serial/COM port (PC) or to a USB port(PC or Macintosh). Specialized controllers are also

available that work with DVD players and other devices.


TYPES OF TOUCH SCREEN TECHNOLOGY

1. Resistive Technology

A resistive touch screen panel is composed of several layers, the most important of which 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 become

connected at that point: the panel then behaves as a pair of voltage dividers with connected

outputs. This causes a change in the electrical current which is registered as a touch event and sent

to the controller for processing. In another way the resistive system consists of a normal glass panel

that is covered with a conductive and a resistive metallic layer. These two layers are held apart by

spacers, and a scratch-resistant layer is placed on top of the whole setup. An electrical current runs

through the two layers while the monitor is operational. When a user touches the screen, the two

layers make contact in that exact spot. The change in the electrical field is noted and the coordinates

of the point of contact are calculated by the computer. Once the coordinates are known,

a special driver translates the touch into something that the operating system can understand, much

as a computer mouse driver translates a mouse's movements into a click or a drag.


4-Wire Resistive touch technology:

4-Wire Resistive touch technology consists of a glass or acrylic panel that is coated with electrically

conductive and resistive layers. The thin layers are separated by invisible separator dots. When

operating, an electrical current moves through the screen. When pressure is applied to the screen

the layers are pressed together, causing a change in the electrical current and a touch event to be

registered.

4-Wire Resistive type touch screens are generally the most affordable. Although clarity is less than

with other touch screen types, resistive screens are very durable and can be used in a variety of

environments. This type of screen is recommended for individual, home, school, or office use, or less

demanding point-of-sale systems, restaurant systems, etc.


Advantages

• High touch resolution

• Pressure sensitive, works with any stylus

• Not affected by dirt, dust, water, or light

• Affordable touchscreen technology

• 75 % clarity

Disadvantages

• Resistive layers can be damaged by a sharp object

• Less durable then 5-Wire Resistive technology

Touchscreen Specifications

Touch Type: 4-Wire Resistive

Screen Sizes: 12"-20" Diagonal

Cable Interface: PC Serial/COM Port or USB Port

Touch Resolution: 1024 x 1024

Response Time: 10 ms. maximum

Positional Accuracy: 3mm maximum error

Light Transmission: 80% nominal

Life Expectancy: 3 million touches at one point

Temperature: Operating: -10°C to 70°C

Storage: -30°C to 85°C

Humidity: Pass 40 degrees C, 95% RH for 96 hours.

Chemical Resistance: Alcohol, acetone, grease, and general household detergent


Software Drivers: Windows XP / 2000 / NT / ME / 98 / 95, Linux, Macintosh OS

5-Wire Resistive Touch screens:

5-Wire Resistive touch technology consists of a glass or acrylic panel that is coated with electrically

conductive and resistive layers. The thin layers are separated by invisible separator dots. When

operating, an electrical current moves through the screen. When pressure is applied to the screen

the layers are pressed together, causing a change in the electrical current and a touch event to be

registered.

5-Wire Resistive type touch screens are generally more durable than the similar 4-Wire Resistive

type. Although clarity is less than with other touch screen types, resistive screens are very durable

and can be used in a variety of environments. This type of screen is recommended for demanding

point-of-sale systems, restaurant systems, industrial controls, and other workplace applications.

Advantages

• High touch resolution

• Pressure sensitive, works with any stylus

• Not affected by dirt, dust, water, or light

• More durable then 4-Wire Resistive technology

• 75 % clarity

Touch screen Specifications

Touch Type: 5-Wire Resistive

Cable Interface: PC Serial/COM Port or USB Port


Touch Resolution: 4096 x 4096

Response Time: 21 ms.

Light Transmission: 80% +/-5% at 550 nm wavelength (visible light spectrum)

Expected Life: 35 million touches at one point

Temperature: Operating: -10°C to 50°C

Storage: -40°C to 71°C

Humidity: Operating: 90% RH at max 35°C

Storage: 90% RH at max 35°C for 240

Chemical Resistance: Acetone, Methylene chloride, Methyl ethyl ketone , Isopropyl alcohol, Hexane,

Turpentine, Mineral spirits, Unleaded Gasoline, Diesel Fuel, Motor Oil, Transmission Fluid,

Antifreeze, Ammonia based glass cleaner, Laundry Detergents, Cleaners (Formula 409, etc.), Vinegar,

Coffee, Tea, Grease, Cooking Oil, Salt

Software Drivers: Windows XP, 2000, NT, ME, 98, 95, 3.1, DOS, Macintosh OS, Linux, Unix (3rd Party)

Positives of Resistive Touch screen

1. Cheaper compared to capacitive touch

2. Touch can be made with any solid material

Negatives of Resistive Touch screen


1. Does not allow multi-touch

2. Transparency of screen is low compared to capacitive touch screen

3. Response time is more compared to capacitive touch screen

2. Projected-capacitive touch screen

Projected capacitive touch screens have front and back protective glass

providing optical and strength enhancement options.

Its middle layer consists of a laminated sensor grid of micro-fine wires, and

optical enhancement options.

During a touch, capacitance forms between the finger and the sensor grid. The embedded serial

controller in the touch screen calculates touch location coordinates and transmits them to the

computer for processing.


3. Surface-capacitive touchscreen

Surface capacitive technology consists of a uniform conductive coating on a glass panel. Electrodes

around the panel’s edge evenly distribute a low voltage across the conductive layer, creating a

uniform electric field.

Positives of Capacitive Touch screen

1. Allows multi-touch

2. Response time is very less compared to resistive touch screen

3. Visibility and transparency of the screen is high

4. Smooth scrolling

Negatives of Capacitive Touch screen

1. Costlier compared to resistive touch screen

2. Only hand can be used to touch, no stylus or other materials can be used to touch


4. Infrared touch screen

Infrared (IR) technology relies on the interruption of an IR light grid in front of the display screen.

The touch frame contains a row of IR-light emitting diode (LEDs) and photo transistors, each

mounted on two opposite sides to create a grid of invisible infrared light.

The IR controller sequentially pulses the LEDs to create a grid of IR light beams. When a stylus, such

as a finger, enters the grid, it obstructs the beams. One or more photo transistors from each axis

detect the absence of light and transmit signals that identify the x and y coordinates.

Characters:

1. Clear as glass, improves reading ability

2. Most durable surface

5. SAW touch screen

Surface waves are readily absorbed when a soft object such as a fingertip touches the substrate.


SAW Touch Screen use pure glass with transmitting and receiving piezoelectric transducers for both

the X and Y axes.

The touch screen controller sends an electrical signal to the transmitting transducer, which converts

the signal into ultrasonic waves within the glass.

When you touch the screen, you absorb a portion of the wave traveling across it. The received signal

is then compared to the stored digital map, the change recognized, and a coordinate calculate

Characters:

1. Durable glass construction

2. High optical clarity

3. Activated by a finger, gloved hand or soft tip

4. Not completely sealable, can be affected by large amounts of dirt, dust, and / or water in the

environment


COMPARISION BETWEEN THE TECHNOLOGIES


WHAT ARE TOUCH SCREEN USED FOR?

The touch screen is one of the easiest PC interfaces to use, making it the interface of choice

for a wide variety of applications. Here are a few examples of how touch input systems are

being used today:

Public Information Displays:

Information kiosks, tourism displays, trade show displays, and other electronic displays are

used by many people that have little or no computing experience. The user- friendly touch

screen interface can be less intimidating and easier to use than other input devices, especially

for novice users. A touch screen can help make your information more easily accessible by

allowing users to navigate your presentation by simply touching the display

screen.

Retail and Restaurant Systems:

Time is money, especially in a fast paced retail or restaurant environment. Touch screen

systems are easy to use so employees can get work done faster, and training time can be

reduced for new employees. And because input is done right on the screen, valuable

counter space can be saved. Touch screens can be used in cash registers, order entry stations,

seating and reservation systems, and more.


Customer self-services:

In todays fast pace world, waiting in line is one of the things that has yet to speed up. Self-

service touch screen terminals can be used to improve customer service at busy stores, fast

service restaurants, transportation hubs, and more. Customers can quickly place their own

orders or check themselves in or out, saving them time, and decreasing wait times for other

customers. Automated bank teller (ATM) and airline e-ticket terminals are examples of self-

service stations that can benefit from touch screen input.

Control and Automation Systems:

The touch screen interface is useful in systems ranging from industrial process control to

home automation by integrating the input device with the display. Valuable workspace can be

saved. And with a graphical interface, operators can monitor and control

complex operations in real-time by simply touching the screen

Computer Based Training:

Because the touch screen interface is user-friendlier than other input devices, overall training

time for computer novices, and therefore training expense, can be reduced. It

can also help to make learning more fun and interactive, which can lead to a more beneficial

training experience for both students and educators.


Assistive Technology:

The touch screen interface can be beneficial to those that have difficulty using other input

devices such as a mouse or keyboards. When used in conjunction with software such as on-

screen keyboards, or other assistive technology, they can help make computing resources

more available to people that have difficulty using computers.

And many more uses...

The touch screen interface is being used in a wide variety of applications to improve human-

computer interaction. Other applications include digital jukeboxes, computerized gaming,

Student registration systems, multimedia software, financial and scientific applications, and

more.


ADVANTAGES OVER OTHER POINTING DEVICES

Touch screens have several advantages over other pointing devices:

• 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.

• Touch screens have easier hand eye coordination than mice or keyboards.

• No extra work space is required as with other pointing devices.

• Touch screens are durable in public access and in high volume usage.

Disadvantages

• User’s hand may obscure the screen.

• Screens need to be installed at a lower position and tilted to reduce arm fatigue.

• Some reduction in image brightness may occur.

• They cost more than alternative devices.


CONCLUSION

Touch systems represent a rapidly growing subset of the display market. The majority of touch

systems include touch sensors relying on vacuum-deposited coatings, so touch coatings present

opportunity for suppliers of vacuum coatings and coating equipments.

Touch sensor manufactures currently require thin films in the areas of transparent conductors,

optical interference coating and mechanical protective coatings. Touch sensors technical

requirements dovetail well with those of the flat panel and display filter markets. The reality should

provide value added opportunities to operations participating in these areas.


REFERENCES

1.www.touchscreen.org

2.www.touchscreen.com

3. www.wikipedia.org


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