touch screen main report

INTRODUCTION :

A touch screen is 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 screen are

used with information kiosks (an interactive computer terminal available for public use, as

one with internet access or site specific information), computer based training devices, and

system designed to help individuals who have difficulty in manipulating a mouse or

keyboard. Touch screen technology can be used as an alternative user interface with

application that normally requires a mouse, such as a web browser. Some applications are

designed specifically for touch screen technology, often having larger icon and link than

typical PC application. Monitors are available with built in touch screen kit. A touch screen

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

are is a clear panel attached externally to the monitors that plug in to a serial or a universal

serial Bus (USB) port a bus Card installed in side the computer. The touch screen panel

registers touch event and passes these signal to controller. The controller then processes the

signals and sends the data to the processor. The software driver translates the touch events

into mouse events. Driver can be provided for both Window and Macintosh operating

systems. Internal touch screen kits are available but require professional installation because

the must be installed inside the monitors.

Fig 1.1

Touch screen monitors

HISTORY OF TOUCH SCREEN MONITORS:

Dr. Sam Hurst, founder of Elo-graphics, developed the first “touch screen” while he

was an instructor at the university of Kentucky in 1971.

Ten stockholders founded Elo-graphics, Inc. in March 1971, to produce Graphical data

Digitizers for use in research and industrial application, with the, principal being Dr. Sam

Hurst. He was on leave from the Oak Ridge National Laboratory to tech at the University of

Kentucky for two years, where he was faced with a need to read a huge stack of strip chart

data. It would have taken two graduate student s approximately two month to do the task. He

started to thinking of a way to read the and during the process, the “Elo-graph” (Electronic

graphics) coordinate measuring system and Elo-graphics the company were born. The

University Kentucky research foundation applied for and was granted a patent on the Elo-

graph. The foundation granted an exclusive license to Elo-graphics.

The touch screen is one of the easiest to use and most intuitive of all PC interface of

choices fro a wide variety of applications. A touch interface to allows users to navigate a

computer system by touching icon or links on the screen.

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.

Touch screen Characteristics:

Speed: high

Accuracy: low (finger), high (pen)

Speed control: yes

Continuous movement: yes

Directness: direction, distance, speed

Fatigue: high

Footprint: no

Best uses: point, select


The touch screen can be operated by two ways:

.1.Finger-Operated: 2.Stylus operated:

Fig 4.1 fig 4.2

Types of Touch Screen Technologies:

1. Resistive Touch Screen

2. Capacitive Touch Screen

3. Surface Acoustic Wave Touch Screen

4. Infrared Touch Screen

1. Resistive

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.


fig 5.1

All types of resistive touch screens:

Resistive touch screens are used in more applications than any other touch technology– for

example, PDAs, point-of-sale, industrial, medical, and office automation, as well as

consumer electronics.

All variations of resistive touch screens have some things in common:

fig 5.1.1

They are all constructed similarly in layers-a back layer such as glass with a uniform resistive

coating plus a polyester coversheet, with the layers separated by tiny insulating dots. When

the screen is touched, it pushes the conductive coating on the coversheet against the coating

on the glass, making electrical contact. The voltages produced are the analog representation

of the position touched. An electronic controller converts these voltages into digital X and Y

coordinates which are then transmitted to the host computer. Because resistive touch screens

are force activated, all kinds of touch input devices can activate the screen, including fingers,

fingernails, styluses, gloved hands, and credit cards. All have similar optical properties,

resistance to chemicals and abuse.


fig 5.1.2

Both the touch screen and its electronics are simple to integrate into imbedded systems,

thereby providing one of the most practical and cost-effective touch screen solutions.

1.1 Four-Wire Resistive:

Four-wire resistive technology is the simplest to understand and manufacture. It uses both the

upper and lower layers in the touch screen "sandwich" to determine the X and Y coordinates.

Typically constructed with uniform resistive coatings of indium tin oxide (ITO on the inner

sides of the layers and silver buss bars along the edges, the combination sets up lines of equal

potential in both X and Y. In the illustration below, the controller first applies 5V to the back

layer. Upon touch, it probes the analog voltage with the coversheet, reading 2.5V, which

represents a left-right position or X axis. It then flips the process, applying 5V to the

coversheet, and probes from the back layer to calculate an up-down position or Y axis. At any

time, only three of the four wires are in use (5V, ground, probe).

fig 5.1.3

The primary drawback of four-wire technology is that one coordinate axis (usually the Y

axis), uses the outer layer, the flexible coversheet, as a uniform voltage gradient. The constant

flexing that occurs on the outer coversheet with use will eventually cause microscopic cracks

in the ITO coating, changing its electrical characteristics (resistance), degrading the linearity


and accuracy of this axis. Unsurprisingly, four-wire touch screens are not known for their

durability. Typically, they test only to about 1 million touches with a finger-far less when

activated by a pointed stylus which speeds the degradation process. Some four-wire products

even specify 100,000 activations within a rather large, 20 mm x 20 mm area. In the real world

of point-of-sale applications, a level of 100,000 activations with hard, pointed styluses

(including fingernails, credit cards, ballpoint pens, etc.) is considered normal usage in just a

few months' time. Also, accuracy can drift with environmental changes. The polyester

coversheet expands and contracts with temperature and humidity changes, thereby causing

long-term degradation to the coatings as well as drift in the touch location. While all of these

drawbacks can be insignificant in smaller sizes, they become increasingly apparent the larger

the touch screen. Therefore, Elo normally recommends four-wire touch screens in

applications with a display size of 6.4" or smaller. However, the relative low cost, inherent

low power consumption, and common availability of chipset controllers with support from

imbedded operating systems, makes four-wire touch screens ideal for hand-held devices such

as PDAs, wearable computers, and many consumer devices.

1.2 Eight-Wire Variation:

Eight-wire resistive touch screens are a variation of four-wire construction. The primary

difference is the addition of four sensing points, which are used to stabilize the system and

reduce the drift caused by environmental changes. Eight-wire systems are usually seen in

sizes of 10.4" or larger where the drift can be significant. As in four-wire technology, the

major drawback is that one coordinate axis uses the outer, flexible coversheet as a uniform

voltage gradient, while the inner or bottom layer acts as the voltage probe. The constant

flexing that occurs on the outer coversheet will change its resistance with usage, degrading

the linearity and accuracy of this axis. Although the added four sensing points helps stabilize

the system against drift, they do not improve the durability or life expectancy of the screen.


1.3 Five-Wire Resistive:

fig 5.1.4

As we have seen, four- and eight-wire touch screens, while having a simple and elegant

design, have a major drawback in terms of durability in that the flexing coversheet is used to

determine one of the axes. Field usage proves that the other axis rarely fails. Could it be

possible to construct a touch screen where all the position sensing was on the stable glass

layer? Then the coversheet would serve only as a voltage probe for X and Y. Microscopic

cracks in the coversheet coating might still occur, but they would no longer cause non-

linearities. The simple buss bar design is not sufficient and a more complex linearization

pattern on the edges is required.In the five-wire design, one wire goes to the coversheet (E)

which serves as the voltage probe for X and Y. Four wires go to corners of the back glass

layer (A, B, C, and D). The controller first applies 5V to corners A and B and grounds C and

D, causing voltage to flow uniformly across the screen from the top to the bottom. Upon

touch, it reads the Y voltage from the coversheet at E. Then the controller applies 5V to

corners A and C and grounds B and D, and reads the X voltage from E again. So, a five-wire

touch screen uses the stable bottom layer for both X- and Y-axis measurements. The flexible

coversheet acts only as a voltage-measuring probe. This means the touch screen continues

working properly even with non-uniformity in the coversheet's conductive coating. The result

is an accurate, durable and more reliable touch screen over four- and eight-wire designs.

1.4 Six- and Seven-Wire Variations:

There are some manufacturers who claim improved performance over five-wire resistive with

additional wires. The six-wire variation adds an extra ground layer to the back of the glass. It


is not needed for improved performance, and in some cases is not even connected to the

companion controller. The seven-wire variation adds two sense lines, like with the eight-wire

design, to decrease drift due to environmental changes. The proprietary "Z border" electrode

pattern is a better solution to prevent drift.

2. Capacitive:

A capacitive touch-screen panel is a sensor typically made of glass coated with a material

such as indium tin oxide (ITO). The sensor therefore exhibits a precisely controlled field of

stored electrons in both the horizontal and vertical axes - it achieves capacitance. The human

body is also an electrical device which has stored electrons and therefore also exhibits

capacitance. Capacitive sensors work based on proximity, and do not have to be directly

touched to be triggered. It is a durable technology that is used in a wide range of applications

including point-of-sale systems, industrial controls, and public information kiosks. It has a

higher clarity than Resistive technology, but it only responds to finger contact and will not

work with a gloved hand or pen stylus. Capacitive touch screens can also support Multi-

touch. Examples include Apple Inc.’s iPhone and iPod touch, and HTC’s G1 & HTC Magic.

Two types are available: Capacitive technology & Pen-touch Capacitive

Fig 5.2 fig 5.3

3. Surface Acoustic Wave

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 the position of the touch event and sends this information to the

controller for processing the location. Surface wave touch screen panels can be damaged by

outside elements. Contaminants on the surface can also interfere with the functionality of the

touch screen.

Fig 5.4

4.Infrared touch screen:

Conventional 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.

The LED and photo sensor pairs create a grid of light beams across the display. An object

(such as a finger or pen) that touches the screen interrupts the light beams, causing a

measured decrease in light at the corresponding photo sensors.

The measured photo sensor outputs can be used to locate a touch-point coordinate.

Widespread adoption of infrared touch screens has been hampered by two factors: the

relatively high cost of the technology compared to competing touch technologies and the

issue of performance in bright ambient light.

Another feature of infrared touch which has been long desired is the digital nature of the

sensor output when compared to many other touch systems that rely on analog-signal

processing to determine a touch position. Infrared touch is capable of implementing multi-

touch, something most other touch technologies cannot easily achieve.


Fig 5.5


WORKING OF TOUCH SCREEN MONITORS:

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.

fig 6.1

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.

About Touch Screen Displays:

Touch screen displays are the most user-friendly PC interface. They are input devices, a way

to communicate with the PC. The user touches the screen to select options presented on the

screen. Associated hardware and software are used to determine the location of the

press. Touch screen displays can be either internally mounted, or externally mounted on an

existing screen. An internally mounted screen is a touch screen input device that is designed

to be installed on the inside of a PC monitor. It is commonly a touch sensitive glass panel that

uses a touch screen controller and a software driver to interface with a PC system. The

internal touch screen requires a sometimes-technical installation, as the monitor needs to be

opened and in some cases the touch screen controller needs to be wired to a power source

inside the monitor. An external touch screen panel is a touch screen input device that is

designed to mount on the outside of a PC monitor. The external touch screen does not require

any difficult installation or opening of the monitor. It is commonly a touch sensitive glass

panel that uses an external touch screen controller and a software driver to interface with a

PC system. There are five basic types of touch screen displays: resistive, capacitive, infrared,

surface acoustic wave (SAW) and strain gauge. Resistive and capacitive touch screen

displays are the most common. Resistive touch screens consist of a glass or acrylic panel that

is coated with electrically conductive and resistive layers. The thin layers are separated by

invisible separator dots. During operation, an electrical current moves through the screen.

When pressure is applied to the touch screen, the layers are pressed together, causing a


change in the electrical current and a touch event to be registered. A capacitive touch screen

consists of a glass panel with a capacitive (charge storing) material coating its surface.

Circuits located at corners of the screen measure the capacitance of a person touching the

overlay. Frequency changes are measured to determine the X and Y coordinates of the touch

event.

Infrared touch screens are similar to resistive products. Infrared touch screens project

horizontal and vertical beams of infrared light over the surface of the screen. When a finger

or other object breaks those beams, the X/Y coordinates are calculated. Surface acoustic

wave (SAW) technology sends acoustic waves across a clear glass panel with a series of

transducers and reflectors. When a finger touches the screen, the waves are absorbed, causing

a touch event to be detected at that point. In a strain gauge touch screen, the screen is spring

mounted on the four corners and strain gauges are used to determine deflection when the

screen is touched. This touch screen display technology can also measure the Z-axis


Comparing Touch Technologies

Each type of screen has unique characteristics that can make it a better choice for certain

applications. The most widely used touchscreen technologies are the following:

4-Wire Resistive Touchscreens

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 Disadvantages

•Hightouch resolution

•Pressuresensitive, works with any stylus

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

• Affordable touchscreen technology • 75 % clarity

• Resistive layers can be damaged by a sharp object

• Less durable then 5-Wire Resistive technology

Touchscreen Specification

TouchType:4-WireResistiveScreen 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 Touchscreens

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 similiar 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 Disadvantages

• 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

• Resistive layers can be damaged by a sharp object


Touchscreen Specifications

Touch Type: 5-Wire Resistive

Cable Interface: PC Serial/COM Port or USB Port


Response Time: 21 ms.

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

Expected Life: 35 million touches at one point



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)

Touchscreen Specifications

Touch Type: Capacitive

Cable Interface: PC Serial/COM Port (9-pin) or USB Port


Light Transmission: 88% at 550 nm wavelength (visible light spectrum)


Durability Test: 100,000,000 plus touches at one point



Humidity: Operating: 90% RH at max 40°C, non-condensing

Chemical Resistance: The active area of the touchscreen is resistant to all chemicals that do

not affect glass, such as: Acetone, Toluene, Methyl ethyl ketone, Isopropyl alcohol, Methyl

alcohol, Ethyl acetate, Ammonia-based glass cleaners, Gasoline, Kerosene, Vinegar

Software Drivers: Windows XP, 2000, NT, ME, 98, 95, 3.1, DOS, Macintosh OS, Linux,

Unix (3rd Party)Software, Cables, and Accessories

Software:

Touchscreen related software, including presentation development software and other utilities

1. Mytsoft:my-t-soft on-screen keyboard software

2. RIGHTTOUCH

RightTouch Right-Click Utility Software

MYTSOFT

My-T-Soft On-Screen Keyboard Software

My-T-Soft is an On-Screen keyboard utility that works with any Windows 95 / 98 / Me / NT /

2000 / XP software. It provides on-screen keyboards and user programmable buttons that

allow users to enter data using a touchscreen display.

my-t-soft can be used by itself in home or workplace applications, and it includes a

developer's kit that allows the keyboard to be called up from web pages and other programs.

By allowing systems to operate without the need for a physical keyboard, external templates,


membranes, or buttons, My-T-Soft can provide the finishing touch on sealed systems that

only require a touchscreen for user input.

My-T-Soft uses a concept called "Heads Up Display" technology and its principal objective

is to keep the users focus and concentration centered in one place. My-T-Soft uses that

concept to reduce the visual re-focusing and re-positioning caused by the

head's up and down motion of going from screen to keyboard to screen.

Features:

Over 40 "Heads-Up Display" Keyboards with 12 base sizes and infinitely larger size

ABCD Alphabetical, QWERTY, 3 DVORAK's, and over 40 International (German, Spanish,

French, etc.) with Edit and Numeric panels.

Store up to 2000 keystrokes/menu selections (or the applications macro scripts) on each

button. Up to 15 buttons can be grouped on individual Panels, which auto-open when their

assigned application becomes active.

Developer friendly

Show & Hide keys, program keys in Key Options, Custom logo display, Operator mode, on-

demand functionality. The Developer's Kit comes with all kinds of utilities, source code,

sample code, and a wealth of information for integrating My-T-Soft with your own

application. Assignable Functions for Pointing Device Buttons

RIGHTTOUCH

RightTouch Right-Click Utility Software

An easy interface to bring Right Click capability to any touchscreen.

Most touchscreens work by emulating left mouse button clicks, so that touching the screen is

the same as clicking your left mouse button at that same point on the screen. But what if you

need to right click on an item? Some touchscreens do include right click support, but many

do not. The Right Touch utility provides an easy way to perform right clicks with any

touchscreen.

The Right Touch utility places a button on your desktop that allows you to switch the


touchscreen between left and right clicks. When the screen is emulating left clicks, simply

touch the Right Touch button to change to right click mode. Touch again, and you're back to

the standard left click.

Software Requirements

Windows95/98/ME/NT/2000/XP

Please Note: Many of the touchscreen systems include a similar right-click tool with their

software driver. The Right-Touch software is useful for touchscreens that do not have an

included right click utility.

Cables:

Cables for use with the touch monitors, includes video and serial port extension cables.

Serial Cables

SERIAL25: 25-Foot Serial Extension Cable

SERIAL50: 50-Foot Serial Extension Cable

SERIAL100: 100-Foot Serial Extension

VGA Video Cables

VGA25: 25-Foot VGA Extension Cable



VGA-Y: VGA Video Y-Splitter Cable

Accessories:

Stylus Pens

A stylus pen can be used along with our touchscreen systems for precise input.

STYLUS1

Stylus Pen for Resistive Touchscreens


STYLUS2

Stylus Pen for Surface Acoustic Wave Touchscreens

Touch Screen Drivers

UPD Driver 3.5.18

These drivers are for 3M Dynapro SC3 and SC4 Controllers

The new UPD Driver will work for the following controllers: SC3 Serial, SC4 Serial, SC4

USB. Supported platforms are Win2000/WinNT/Win9x/Me/XP. DOS and other drivers

Linux Drivers for SC3 and SC4 Controller

Linux drivers for SC3 and SC4 were developed by a third party, not 3M Touch Systems, and

are provided for our customers convenience. 3M Touch Systems cannot offer any warranty or

technical support for them.

Linux Drivers

TouchWare Driver, Release 5.63 SR3

These drivers are for MicroTouch Touch Controllers (EXII, SMT3, MT3000, MT410,

MT510)

This release improves performance for Windows XP drivers. It provides multiple monitor

support, including dual head video adapters, from TouchWare 5.63. Supported platforms are

WinXP/Win2000/WinNT/Win9x/Me.

This service release also corrects known problems with silent installation.

Microcal 7.1

Use this utility to modify controller settings and to calibrate the sensor at different resolutions

under DOS. Microcal is compatible with fully-integrated ClearTek capacitive and TouchTek

resistive touchscreens. This release supports any serial and PS/2 SMT controller, PC BUS

controllers and the MT400 controller.

Near Field Imaging OEM Drivers

Use the OEM drivers below with Near Field Imaging touch screen products.

For Windows NT/9X:

8.4-inch Near Field Imaging touch screens (approx. 2.5MB)

For Windows NT/9X/3.1 and MS-DOS:


10.4-inch and larger Near Field Imaging touch screens (approx> 3.6MB)

For Windows XP/2000 for 10.4-inch and larger Near Field Imaging touch screens

Linux Drivers for NFI

Linux drivers for NFI were developed by a third party, not 3M Touch Systems, and are

provided for our customers' convenience. 3M Touch Systems cannot offer any warranty or

technical support for them.


Pros and Cons of Touch screens:

The following overview lists advantages and disadvantages of touch screens and summarizes

their characteristics.

Touch screen Pros:

Direct : Direct pointing to objects, direct relationship between hand and cursor movement

(distance, speed and direction), because the hand is moving on the same surface that the

cursor is moving, manipulating objects on the screen is similar to manipulating them in the

manual world

Fast (but less precise without pen)

Finger is usable, any pen is usable (usually no cable needed).

No keyboard necessary for applications that need menu selections only -> saves desk space

Touch screen Cons:

.Dirt: The screen gets Low precision (finger): Imprecise positioning, possible problems with

eye parallaxis (with pen, too), the finger may be too large for accurate pointing with small

objects -> a pen is more accurate.

Hand movements (if used with keyboard): Requires that users move the hand away from

the keyboard; a stylus requires also hand movements to take up the pen.

Fatigue: Straining the arm muscles under heavy use (especially if the screen is placed

vertically).

Sitting/Standing position: The user has to sit/stand close to the screen

Screen coverage: The user's hand, the finger or the pen may obscure parts of the screen.

Activation: Usually direct activation of the selected function, when the screen is touched;

there is no special "activation" button as with a light pen or a mouse


Uses for Touch screens:

Best Suited to Applications Where...

Opportunity for training is low

Frequency of use is low

Accurate positioning is not required

Little or no text or numerical input is required Desk space is at a premium

The environment may be chemically or otherwise "aggressive"

Not Suited to Applications...

Requiring training/trained users

With high-frequency use

Requiring accuracy

Requiring a lot of typing

Uses of touch screen in regular life: 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 today's 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.


PROBLEM WITH TOUCH SCREEN MONITORS AND

TROUBLESHOOTING:

ATM system is one of the application of touch screen monitors.

Hardware failure can occur in touch screen monitors.

We have mentioned some of the most common hardware problems of touch screen and have

given some of the troubleshootings.

Hardware problems:

Touch screen does not respond

Portions of the touch screen do not respond

Touch screen is very slow to respond

Troubleshooting:

The first step in troubleshooting a touch screen system is to determine whether the problem is

related to the display, software, or hardware:

Do not confuse display problems with touch screen problems—the two are unrelated.

Software problems are determined by a basic hardware functionality test. If the

hardware transmits touch coordinates correctly, then the problem is with the driver or

application software.

Hardware problems may be caused by the touch screen, controller, cabling, power

supply, or by the integration of the touch screen components in the display.

The easiest way to verify a hardware failure is by substitution, if you have more than

one unit to try.


Limitations of Touchscreens:

Size:

Fingers have a certain size, So, screen elements have to have a minimum size, to ensure that

a touch screen can be operated with few errors.Even with a stylus, which makes possible to

use smaller screen elements, there are limiting factors.

Sequential Input:

Input on a touch screen is inherently sequential:

One finger is used for clicking. This slows input down compared to keyboard input where

several fingers can be used virtually in parallel.

Strain:

Keying in many numbers or letters by pointing with the finger is also very straining and

tiring. Therefore, touch screens make no sense in workplaces, where much text or number

input is required.

Feedback:

On touch screens, there is no analogue to mouse-move events. Mouse users can move the

mouse pointer over screen elements, get feedback about the selected element (e.g. by

highlighting), and may confirm the selection by clicking the mouse button. Touch screen

users directly point on a screen element. If they are lucky, they can withdraw their finger if

they touched the wrong screen element. On other touch screens, the touch immediately

initiates an action - there is no opportunity to cancel the action.

Drag Operations:

Dragging is generally not well suited to finger-operated touch screens,Here ,pointing is the

preferred interaction. However, this is different for stylus-operated touch screens. Here

gestures and handwriting offer promising possibilities for making interaction with

computers easier and more intuitive. But here, too is the limitation of strictly sequential input.

There are also no means to constrain drag operations to, e.g. straight lines, like with mouse-

based interfaces.


touch screen main report

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