i want the seminar topic about"touch screen technology report and ppt",,,,,,,,,,,,,,

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the above post containing full details on 'touch screen technology'. you please

Prepared by:TRAILOKYA NATH SASAMAL


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INTRODUCATION TO THE TECHNOLOGY
A touch screen is an input device to operate a PC by a touch.

Display screen has a sensitive glass overlay placed on it .

Direct onscreen input by an external (pen) 
HOW DOES A TOUCHSCREEN WORK?
Main touch screen components:
Touch sensor
Controller
Software driver

TOUCH SENSOR
A clear glass panel with a touch responsive surface which is placed over a display screen. The responsive area of panel covers the viewable area of the display screen.

An electrical current or signal going through it. Touching the screen causes a voltage or signal change. Change determine the location of the touch.
CONTROLLER
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.
SOFTWARE DRIVER
A software that allows the touch screen and computer to work together.
operating system interpret the touch event information that is sent from the controller.

Touch screen drivers today are a mouse-emulation type driver.
Touchscreen Technology
Resistive Touch screen
Surface wave Touch screen
Capacitive Touch screen
*Surface capacitive
*Projected capacitive

RESISTIVE TOUCH SCREEN
Continued…
Resistive touch screen monitor is composed of a flexible top layer and a rigid bottom layer separated by insulating dots.

The inside surface layers coated with a transparent metal oxide coating
Pressing the flexible top sheet creates electrical contact between the resistive layers.

The controller gets the alternating voltages between the two layers and X, Y coordinates of the activated area.


VS20UA CONTROLLER
Supply Voltage
5.0V  DC
Maximum Current 
20mA (Pick)

SURFACE WAVE TECHNOLOGY
Transmitting and receiving transducers for both axes.

The touchscreen controller sends a 5 MHz electrical signal
Waves are directed across the front surface by an array of reflectors.

Reflectors on the opposite side gather and direct the waves to the receiving transducer.
Continued…
When we touch , we 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 calculated.
2701RSU CONTROLLER
Voltage
+5 VDC
Baud Rate
9600 (default) and 19200

Conversion Time
10 ms per coordinate set

CAPACITIVE TOUCH SCREENS  Surface Capacitive
An uniform conductive coating on a glass panel.
Electrodes around the panel's edge distribute a low voltage across the conductive layer & creates an uniform electric field.
A finger touch draws current from each corner.
Controller measures the ratio of the current flow from the corners.

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BY
S.ABDUL KAREEM

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How Does a Touchscreen Work?  
A basic touchscreen has three main components:
1 Touch sensor;
2 Controller;
3 Software driver.
The touchscreen 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.
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 can cause a voltage or signal change. This change is used to determine the location of the touch to the screen. 
Controller
The controller 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 determines what type of interface/connection you will need on the PC. Controllers are available that can connect to a Serial/COM port (PC) or to a USB port. Specialized controllers are also available that work with DVD players and other devices.
Software Driver
The driver allows the touchscreen 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 as same as clicking your mouse at the same location on the screen. This allows the touchscreen to work with existing software and allows new applications to be developed without the need for touchscreen specific programming.
Touchscreen Technology
Resistive touchscreen
Capacitive touchscreen
Infrared touchscreen
Surface acoustic wave (SAW) touchscreen
Strain gauge touchscreen
Optical imaging touchscreen
Dispersive signal technology touchscreen
Resistive touchscreen
Structure
Resistive touch screens consist of a glass or acrylic panel that is coated with electrically conductive and resistive layers made with indium tin oxide (ITO) .The thin layers are separated by invisible spacers.

4-wire resistive touchscreen
5-wire resistive touchscreen
The construction of the panels are similar with 4-wire technology, but for a 5-wire touch screen all four bus bars are connected to the lower, non-flexible layer of the screen. The flexible layer is always used as a sense layer to read the voltage connection point to the bottom layer.

8-wire resistive touchscreen

Resistive touchscreen
Characters:
Cost effective solutions
Activated by a stylus, a finger or gloved hand
Not affected by dirt, dust, water, or light
75%~85% clarify
resistive layers can be damaged by a very sharp object

Projected-capacitive touchscreen
Structure
Projected capacitive touchscreens have front and back protective glassproviding optical and strength enhancement options.
Its middle layer consists of a laminated sensor grid of micro-fine wires, andoptical enhancement options.
Projected-capacitive touchscreen
During a touch, capacitance forms between the finger and the sensor grid.The embedded serial controller in the touchscreen calculates touch location coordinates and transmits them to the computer for processing.
Surface-capacitive touchscreen
Structure
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.

Surface-capacitive touchscreen
Working principle
A human body is an electric conductor, so when you touch the screen with a finger, a slight amount of current is drawn, creating a voltage drop. The current respectively drifts to the electrodes on the four corners. Theoretically, the amount of current that drifts through the four electrodes should be proportional to the distance from the touch point to the four corners. The controller precisely calculates the proportion of the current passed through the four electrodes and figures out the X/Y coordinate of a touch point.

Capacitive touchscreen
Characters:
Durable and resistant to scratches for demanding applications
Faster and more responsive
Immune to surface contaminants
Superior optical clarity, brighter display and less surface reflection
Must be touched by finger, will not work with any non-conductive input
Infrared touchscreen
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 identifies the x and y coordinates.
Infrared touchscreen
Infrared touchscreen
Characters:
Clear as glass, improves reading ability
Most durable surface

SAW touchscreen
Principle
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.

SAW touchscreen
SAW touchscreen
Characters:
Durable glass construction
High optical clarity
Activated by a finger, gloved hand or soft tip
Not completely sealable, can be affected by large amounts of dirt, dust, and / or water in the environment

Multi-touch technology
Multi-touch denotes a set of interaction techniques which allow computer users to control graphical applications with several fingers.
Products:
Apple iPhone, iPod touch, MacBook Air, and MacBook Pro
Microsoft Surface
……

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Submitted by
SANJEEEV KUMAR

Under Guidance of
Mr.B.R.Ambedkar

INSTITUTE OF ENGINERRING & TECHNOLOGYROHILKHAND UNIVERSITY, BAREILLY

Abstract
First computers became more visual, then they took a step further to understand vocal commands and now they have gone a step further and became ‘TOUCHY’, that is skin to screen.

A touch screen is an easy to use input device that allows users to control PC software and DVD video by touching the display screen. A touch system consists of a touch Sensor that receives the touch input, a Controller, and a Driver. The most commonly used touch technologies are the Capacitive & Resistive systems. The other technologies used in this field are Infrared technology, Near Field Imaging & SAW (surface acoustic wave technology). These technologies are latest in this field but are very much expensive.

The use of touch systems as Graphical User Interface (GUI) devices for computers continues to grow popularity. Touch systems are used for many applications such as ATM’s, point-of–sale systems, industrial controls, casinos & public kiosks etc. Touch system is basically an alternative for a mouse or keyboard.

The market for touch system is going to be around $2.5 billion by 2004. Various companies involved in development of touch systems mainly are Philips, Samsung etc. Even touch screen mobile phones have been developed by Philips.

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 page 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 inside 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.

HISTORY OF TOUCH SCREEN TECHNOLOGY

Dr. Sam Hurst, founder of Elographics, developed the first “touch screen” while he was an instructor at the university of Kentucky in 1971.

Ten stockholders founded Elographics, 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 “Elograph” (Electronic graphics) coordinate measuring system and Elographics the company were born. The University Kentucky research foundation applied for and was granted a patent on the Elograph. The foundation granted an exclusive license to Elographics.

The touch screen is one of the easiest to use and most intuitive of all PC interface of choices from a wide variety of applications. A touch interface to allow users to navigate a computer system by touching icon or links on the screen.

The 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 have 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 customers 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, over 20,000per 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.

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.

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.

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.

we offer two main types of touch screen products, touch screen add-ons and integrated touch screen monitor. Touch screen add-ons are touch screen panels that hang over an existing computer monitor. Integrated touch screen monitors are computer displays that have the touch screen built-in. Both product types work in the same way, basically as an input device like a mouse or track pad.


Diversity of touch Screen

Resistive this technology uses to layers of conductive material to create an X/Y grid (vertical lines on one surface, horizontal). When pressure is applied to the flexible top layer, the grid surfaces come in contact and allow current to flow. The presence of current in a vertical and horizontal line gives the X/Y coordinate of the touch.
Because the screen itself supplies all current, workers with heavy gloves can work this type of screen.
The draw back to resistive screen is that they are subject to scratches, burns and others type of damage to protect against damage, companies such as DynaPro apply and additional Mylar over laminate, which can be replaced if damaged.

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thanks it is so useful for me

PLEASE SEND FULL REPORT AND PPT ON TOUCH SCREEN

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Touch Screen technology
A touchscreen is a display which can detect the presence and location of a touch within the display area.
• The term generally refers to touch or contact to the display of the device by a finger or hand.
History
• In 1971, the first "touch sensor" was developed by Doctor Sam Hurst (founder of Elographics).
• This sensor called the "Elograph“ .
• The "Elograph" was not transparent like modern touch screens; however, it was a significant milestone in touch screen technology.
• On February 24, 1994, the company officially changed its name from Elographics to Elo Touch Systems.
Touch Screen Technology
• A basic touchscreen has three main components:
▫ Touch sensor
▫ Controller
▫ Software driver.
1.Touch Sensor
• A touch screen sensor is a clear glass panel with a touch responsive surface.
• 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.
3.Software Driver
• The driver is a software update for the PC system that allows the touchscreen 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.
Types of Technologies
• There are three basic systems that are used to recognize a
person's touch:
Resistive
Capacitive
Surface acoustic wave
Resistive Touch Screen technology
• 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.
• An electrical current runs through the two layers while the monitor is operational.
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.

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Touch Screen and Future Interfacing Devices
Abstract
In the 21st century , when technology is at par with what sometime back was called as
Science fiction , there is extensive acceptance of innovative , newer , smaller and user
friendly interfacing Devices. The most common of the recent 20th century are the Touch Screens.
Touch screen is the Interfacing Device of the New Age. It is an Input as Well as Output device. It is a display screen that has a touch-sensitive transparent panel covering the
screen. Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen.
As Touch screen’s are very intuitive , they are now commonly used in Smart Phones ,
LCD attachments , ATM machines , Camera , Industrial Machine Use , Hospital
Machines, Single-touch buttons are found in everything around the home, office, or
anywhere in between: cell phones, landline phones,remote controls, televisions,
computers and all of its peripherals, gaming systems, refrigerators, ovens, toasters, car
interior controls like radio and air conditioning, and so on and the best part is any LCD
screen can be converted into a Touch screen for convenience.
Touch screen and future interfacing devices would be discussed further.
What is Touch screen?
A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area. The term generally refers to touching the display of the device with a finger or hand.
Why Touch Screens?
The touch screen has two main characteristics; it facilitates one to interact with what is
displayed straightforwardly on the screen, rather than indirectly with a mouse or touchpad and it lets one perform the touch operations without necessitating any middle device.
Such touch screen displays can be connected to computers, laptops, PDAs, cell phones
etc. They also project an important function in the blueprint of digital.
Touch screen monitors are a way to both input information and receive information from
a single peripheral device (usually a monitor screen). Instead of using a keyboard or mouse, you can easily input data directly into the touch screen where you are also able to receive information
2.1 Types of Touch Technology[6,9]
Touch-screen technology falls into categories: resistive, capacitive and surface wave.
Each technology has strengths suited for specific applications.
Resistive
A resistive touch screen display is composed of a standard glass sheet that is coated with a thin conductive and a resistive metallic sheet. These two levels are kept separated by
spacers (objects positioned between two or more sheets of glass in order to retain a
uniform width between the glasses and avoid sealant deformation). A scratch-resistant
coating is positioned above the entire arrangement. An electrical current travels between the two layers while the monitor is being used. When a user makes contact with the display, the two layers touch each other contact in same location. The modification in the electrical current is identified and the coordinates of the touch are computed by the computer. An exceptional driver program then transforms the touch into a language which the computer can comprehend.
Being quite reasonably priced they only offer about 75 percent clarity. They can also be
easily damaged by objects that are sharp. Resistive touch screen monitors are the most
popular types of touch screen monitors used today. They are usually not effected by dust or liquids which make them very reliable.
Surface wave. [ 8 ]
Surface wave touch screen monitors use ultrasonic waves to process inputs from the
screen. A surface wave touch screen display is composed of two transducers (acting as
receivers and senders) positioned along the X and Y axis of the display’s glass layer.
Reflectors are placed on the glass layer which reflects an electrical signal propelled from one transducer to the other. The receiving transducer is capable to identify if the signal has been altered by a touch at any moment, and can trace it consequently. Ultrasonic waves flow over the touch screen, when a person touches the pad at a specific location, the wave is absorbed and immediately processed by the computer. The wave arrangement has no metallic coatings on the display, permitting for 100 percent light throughput and ideal picture clearness. This formulates the surface wave touch screen display as finest for exhibiting detailed pictures.
While not as common as resistive touch panels, they are used in certain applications. Dust and water can contaminate a surface wave touch screen so it is important to keep the screens properly maintained.

[attachment=9112]
ABSTRACT
TOUCH SCREEN
First computers became more visual, then they took a step further to understand vocal commands and now they have gone a step further and became ‘TOUCHY’, that is skin to screen.
A touchscreen is an easy to use input device that allows users to control PC software and DVD video by touching the display screen. A touch system consists of a touch Sensor that receives the touch input, a Controller, and a Driver. The most commonly used touch technologies are the Capacitive & Resistive systems. The other technologies used in this field are Infrared technology, Near Field Imaging & SAW (surface acoustic wave technology). These technologies are latest in this field but are very much expensive.
The uses of touch systems as Graphical User Interface (GUI) devices for computers continues to grow popularity. Touch systems are used for many applications such as ATM’s, point-of–sale systems, industrial controls, casinos & public kiosks etc. Touch system is basically an alternative for a mouse or keyboard.
The market for touch system is going to be around $2.5 billion by 2004. Various companies involved in development of touch systems mainly are Philips, Samsung etc. Even touch screen mobile phones have been developed by Philips.
INTRODUCTION
A touchscreen is an easy to use input device that allows users to control PC software and DVD video by touching the display screen. We manufacture and distribute a variety of touch screen related products.
A touch system consists of a touch
Sensor that receives the touch input, a Controller, and a Driver. The touch screen sensor is a clear panel that is designed to fit over a PC. When a screen is touched, the sensor detects the voltage change and passes the signal to the touch screen controller. The controller that reads & translates the sensor input into a conventional bus protocol (Serial, USB) and a software driver which converts the bus information to cursor action as well as providing systems utilities.
As the touch sensor resides between the user and the display while receiving frequent physical input from the user vacuum deposited transparent conductors serve as primary sensing element. Vacuum coated layers can account for a significant fraction of touch system cost. Cost & application parameters are chief criteria for determining the appropriate type determining the system selection. Primarily, the touch system integrator must determine with what implement the user will touch the sensor with & what price the application will support.
Applications requiring activation by a
gloved finger or arbitrary stylus such as a plastic pen will specify either a low cost resistive based sensor or a higher cost infra-red (IR) or surface acoustic wave (SAW) system. Applications anticipating bare finger input or amenable to a tethered pen comprises of the durable & fast capacitive touch systems. A higher price tag generally leads to increased durability better optical performance & larger price.
The most commonly used systems are
generally the capacitive & resistive systems. The other technologies used in this field are Infrared technology & SAW (surface acoustic wave technology) these technologies are latest in this field but are very much expensive.

pls send me touch screen technology report and ppt.........

i am in need of touch screen technology report and ppt..............pls send me

Touch Screens
Introduction
A type of display screen that has a touch-sensitive transparent panel covering the screen. Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen.
Although touch screens provide a natural interface for computer novices, they are unsatisfactory for most applications because the finger is such a relatively large object. It is impossible to point accurately to small areas of the screen. In addition, most users find touch screens tiring to the arms after long use.
Touch-screens are typically found on larger displays, in phones with integrated PDA features. Most are designed to work with either your finger or a special stylus. Tapping a specific point on the display will activate the virtual button or feature displayed at that location on the display.Some phones with this feature can also recognize handwriting written on the screen using a stylus, as a way to quickly input lengthy or complex information
A touchscreen is an input device that allows users to operate a PC by simply touching the display screen. Touch input is suitable for a wide variety of computing applications. A touchscreen can be used with most PC systems as easily as other input devices such as track balls or touch pads. Browse the links below to learn more about touch input technology and how it can work for you.
History Of Touch Screen Technology
A touch screen is a special type of visual display unit with a screen which is sensitive to pressure or touching. The screen can detect the position of the point of touch. The design of touch screens is best for inputting simple choices and the choices are programmable. The device is very user-friendly since it 'talks' with the user when the user is picking up choices on the screen.
Touch technology turns a CRT, flat panel display or flat surface into a dynamic data entry device that replaces both the keyboard and mouse. In addition to eliminating these separate data entry devices, touch offers an "intuitive" interface. In public kiosks, for example, users receive no more instruction than 'touch your selection.
Specific areas of the screen are defined as "buttons" that the operator selects simply by touching them. One significant advantage to touch screen applications is that each screen can be customized to reflect only the valid options for each phase of an operation, greatly reducing the frustration of hunting for the right key or function.
Pen-based systems, such as the Palm Pilot® and signature capture systems, also use touch technology but are not included in this article. The essential difference is that the pressure levels are set higher for pen-based systems than for touch.Touch screens come in a wide range of options, from full color VGA and SVGA monitors designed for highly graphic Windows® or Macintosh® applications to small monochrome displays designed for keypad replacement and enhancement.
Specific figures on the growth of touch screen technology are hard to come by, but a 1995 study last year by Venture Development Corporation predicted overall growth of 17%, with at least 10% in the industrial sector.Other vendors agree that touch screen technology is becoming more popular because of its ease-of-use, proven reliability, expanded functionality, and decreasing cost.
This deals with the new technology named ‘Touch Screen’. By this, technology the purpose means just in the name touch the screen and activate instructions. Instead of the keyboard or mouse we can operate or stimulate an instruction or command by touching on the screen by our finger.And through this seminar trying to explain about the touch screen, the advantages and major marketing areas where the touch screens used and some applications.This technology is nothing but software with CPU like hardware and touch screen technology digital camera. This technology will obviously bring much developments in the e-commerce sector.
The benefit of using such kiosks is to bring down human efforts and to increase the customer services. The future development of wide area networks based on ISDN will permit retailers to update their kiosks on a regular basis over night if necessary. Customers will be able to carry out an increasing range of transactions using smart Cables and Satalite as well as telephone lines, can be used to deliver information and retail services to the home..

i need computer science touch screen technology report and ppt

Submitted by
Juned shaikh
Salahuddin shaikh

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[attachment=9806]
TOUCH SCREEN TECHNOLOGY
Introduction
Definition:-
“ A computer display screen ,sensitive to human touch, allowing user to interact with computer by touching on screen” .
* works instantly with all programs like mouse .
* touch event is registered when finger touches screen .
* components making a complete touch system :-
1. A touch sensor .
2. A controller .
3. A s/w driver .
How does a touch screen works ?
1. A touch sensor -
* a glass panel with touch responsive surface .
* covers whole viewable area .
* touching the screen causes voltage change ,
input for controller .
2. A controller -
* interface between sensor & PC .
* converts voltage change into digital signal .
* type of interface required
3. A s/w driver -
* touch screen & PC works together .
* converts touch events into mouse events .
Types of touch screens
3 major types-

1. Resistive touch screens
2. Capacitive touch screens
3. Surface acoustic wave
Comparison of different touch screens
System requirements
O . S . : Ms Dos version 5.0+windows 3.0,
windows ME/2000/XP/7/Linux
Processor: 386 PC compatible or higher
Disk : 2MB of free space hard disk , 3.5”(1.44MB)
floppy drive
Memory : 14kb resident memory
K/B : Not required after installation
Video : ½ MB SVGA or higher
Ports : RS 232, mouse port or USB(depends on type)
Touch screen strengths
• Convenience of push button control
• Easy enough for a child to use
• All output and inputs are done through one device
• 3-5 times faster than a speeding mouse
• No dragging mouse to each starting point
• More intuitive than other input devices Lasts (2-5 times)
longer than a mouse.
• Low maintenance.
• No training needed (push button control)

thanx,bt i need 50pages docment on this plz send whole doc to my e-mail ------raj.mydhams[at]gmail.com

[attachment=10239]

Abstract
A touchscreen is an electronic visual display that can detect the presence and location of a touch within
the display area. The term generally refers to touching the display of the device with a finger or hand.
Touchscreens can also sense other passive objects, such as a stylus. Although the touchscreen technology
dates back to about forty years ,it has made a revolution in the past five years with its application into
devices that we deal in our day to day life .There are basically three underlying technologies used in
touchscreens ,namely Resitive,,Capacitive and Acoustic. The latest developments in touchscreen
technology are Multitouch and Haptic Touch.

Introduction
A touchscreen is an electronic visual display that can
detect the presence and location of a touch within the
display area. The touchscreen has two main
attributes. First, it enables one to interact directly
with what is displayed, rather than indirectly with a
cursor controlled by a mouse or touchpad. Secondly,
it lets one do so without requiring any intermediate
device that would need to be held in the hand. Such
displays can be attached to computers, or to networks
as terminals. 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 games.

History
The prototype x-y mutual capacitance touchscreen
(left) developed at CERN in 1977 by Bent Stumpe, a
Danish electronics engineer, for the control room of
CERN’s accelerator SPS (Super Proton Synchrotron).
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.
The Main Components of Touch Screen
Every touch screen has three main components:

digital signal that computer can understand
Touch Sensitive Surface
The touch sensitive surface is an extremely
durable and flexible glass or polymer touch
response surface, and this panel is placed
over the viewable area of the screen. In most
sensors there is an electric signal going
across the screen, and a touch on the surface
causes change in the signal depending on the
touch sensor technology used.This change
allows the controller to identify the location
of the touch.
• The Controller
The controller is a device that acts as the
intermediate between the screen and the
computer. It interprets the electrical signal
of the touch event to. The controller can be
placed with the screen or housed externally.
• The Software Driver
The software driver is an interpreter that
converts what signal comes from the
controller to information that the operating
system can understand.

Technologies
1.Resistive
A resistive touchscreen panel is composed of several
layers, the most important of which are two thin,
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.
2.Capacitive
A capacitive touchscreen panel is one which consists
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
screen's electrostatic field, measurable as a change in
capacitance. Different technologies may be used to
determine the location of the touch. The location is
then sent to the controller for processing.The
different technologies under capacitive sensing are
Surface capacitance, Projected capacitance, Mutual
Capacitance, Self Capacitance.
3. Surface acoustic wave
Surface acoustic wave (SAW) technology uses
ultrasonic waves that pass over the touchscreen
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. Surface wave touch screen panels can be
damaged by outside elements. Contaminants on the
surface can also interfere with the functionality of the
touchscreen


Other Technologies
An infrared touchscreen uses an array of X-Y
infrared LED and photodetector pairs around the
edges of the screen to detect a disruption in the
pattern of LED beams. These LED beams cross each
other in vertical and horizontal patterns. This helps
the sensors pick up the exact location of the touch. A
major benefit of such a system is that it can detect
essentially any input including a finger, gloved
finger, stylus or pen.Unlike capacitive
touchscreenspatterning on the glass which increases
durability and optical clarity of the overall system.

Optical imaging
This is a relatively modern development in
touchscreen technology, in which two or more image
sensors are placed around the edges (mostly the
corners) of the screen. Infrared back lights are placed
in the camera's field of view on the other side of the
screen. A touch shows up as a shadow and each pair
of cameras can then be triangulated to locate the
touch or even measure the size of the touching
object . This technology is growing in popularity, due
to its scalability, versatility, and affordability,
especially for larger units.
Dispersive signal technology
This system uses sensors to detect the mechanical
energy in the glass that occurs due to a touch.
Complex algorithms then interpret this information
and provide the actual location of the touch. The
technology claims to be unaffected by dust and other
outside elements, including scratches. Since there is
no need for additional elements on screen, it also
claims to provide excellent optical clarity. Also, since
mechanical vibrations are used to detect a touch
event, any object can be used to generate these
events, including fingers and stylus. A downside is
that after the initial touch the system cannot detect a
motionless finger.
Acoustic pulse recognition
This system uses piezoelectric transducers located at
various positions around the screen to turn the
mechanical energy of a touch (vibration) into an
electronic signal. The screen hardware then uses an
algorithm to determine the location of the touch
based on the transducer signals. The touchscreen
itself is made of ordinary glass, giving it good
durability and optical clarity. It is usually able to
function with scratches and dust on the screen with
good accuracy. The technology is also well suited to
displays that are physically larger. As with the
Dispersive Signal Technology system, after the initial
touch, a motionless finger cannot be detected.
However, for the same reason, the touch recognition
is not disrupted by any resting objects.

Refernces
• Shneiderman, B. (1991). "Touch screens
now offer compelling uses". IEEE Software
8 (2): 93–94, 107.
• Potter, R.; Weldon, L. & Shneiderman, B.
(1988). Improving the accuracy of touch
screen: An experimental evaluation of three
strategies. Proc. CHI'88. Washington, DC:
ACM Press. pp. 27–32.
• Sears, A.; Plaisant, C. & Shneiderman, B.
(1992). "A new era for high precision
touchscreens". In Hartson, R. & Hix, D..
Advances in Human-Computer Interaction.
3. Ablex, NJ. pp. 1–33 .
• http://en.wikipediawiki/Touchscreen"C
ategories: Touchscreens | Computer
hardware
• Howstuffworks - How do touchscreen
monitors know where you're touching?
.
• MERL - Mitsubishi Electric Research Lab
(MERL)'s research on interaction with touch
tables. .
• Jefferson Y. Han et al. Multi-Touch
Interaction Research. Multi-Input
Touchscreen using Frustrated Total Internal
Reflection

Presented by:
Quanling zheng

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[attachment=11034]
Touch Screen Sensor
How Does a Touchscreen Work?
A basic touchscreen has three main components:
• 1 Touch sensor;
• 2 Controller;
• 3 Software driver.
The touchscreen 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.
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 can cause a voltage or signal change. This change is used to determine the location of the touch to the screen.
Controller
The controller 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 determines what type of interface/connection you will need on the PC. Controllers are available that can connect to a Serial/COM port (PC) or to a USB port. Specialized controllers are also available that work with DVD players and other devices.
Software Driver
The driver allows the touchscreen 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 as same as clicking your mouse at the same location on the screen. This allows the touchscreen to work with existing software and allows new applications to be developed without the need for touchscreen specific programming.
Touchscreen Technology
• Resistive touchscreen
• Capacitive touchscreen
• Infrared touchscreen
• Surface acoustic wave (SAW) touchscreen
• Strain gauge touchscreen
• Optical imaging touchscreen
• Dispersive signal technology touchscreen
Resistive touchscreen
• Structure
Resistive touch screens consist of a glass or acrylic panel that is coated with electrically conductive and resistive layers made with indium tin oxide (ITO) .The thin layers are separated by invisible spacers.
4-wire resistive touchscreen
5-wire resistive touchscreen
• The construction of the panels are similar with 4-wire technology, but for a 5-wire touch screen all four bus bars are connected to the lower, non-flexible layer of the screen. The flexible layer is always used as a sense layer to read the voltage connection point to the bottom layer.
8-wire resistive touchscreen
Resistive touchscreen
• Characters:
1. Cost effective solutions
2. Activated by a stylus, a finger or gloved hand
3. Not affected by dirt, dust, water, or light
4. 75%~85% clarify
5. resistive layers can be damaged by a very sharp object
Projected-capacitive touchscreen
• Structure
Projected capacitive touchscreens 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 touchscreen calculates touch location coordinates and transmits them to the computer for processing.
Surface-capacitive touchscreen
Structure
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.
Working principle
A human body is an electric conductor, so when you touch the screen with a finger, a slight amount of current is drawn, creating a voltage drop. The current respectively drifts to the electrodes on the four corners. Theoretically, the amount of current that drifts through the four electrodes should be proportional to the distance from the touch point to the four corners. The controller precisely calculates the proportion of the current passed through the four electrodes and figures out the X/Y coordinate of a touch point.
Capacitive touchscreen
• Characters:
1. Durable and resistant to scratches for demanding applications
2. Faster and more responsive
3. Immune to surface contaminants
4. Superior optical clarity, brighter display and less surface reflection
5. Must be touched by finger, will not work with any non-conductive input
Infrared touchscreen
• 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 identifies the x and y coordinates.
• Characters:
1. Clear as glass, improves reading ability
2. Most durable surface
SAW touchscreen
• Principle
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
Multi-touch technology
• Multi-touch denotes a set of interaction techniques which allow computer users to control graphical applications with several fingers.
• Products:
• Apple iPhone, iPod touch, MacBook Air, and MacBook Pro
• Microsoft Surface

PRESENTED BY
B.LAKSHMAN

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[attachment=11179]
TOUCH SCREEN TECHNOLOGY
COMPONENTS
 Three major components
 Touch sensor
 Controller
 Software driver
TOUCH SENSORS
 A touch screen sensor is a clear glass panel with a touch responsive surface.
 The touch sensor/panel is placed over a display screen.
 Sensors detects electrical current or signal.
 Touching causes a voltage or signal change, there by the location can be determined.
CONTROLLER
 The controller is a small PC card that connects between the touch sensor and the PC
 It takes information from the touch sensor
 It translates information into the PC that can understand
SOFTWARE DRIVER
 It act as a bridge between the screen and the processor
 The driver is a software that allows the touch screen and processor to work together.
 Most of the touch screen drivers today are mouse emulation type driver .
 Technologies
 Resistive Touch screen
 Surface wave Touch screen
 Capacitive Touch screen
Resistive touch screen
 Structure
Resistive touch screens consist of a glass panel that is coated with electrically conductive and resistive layers made with indium tin oxide (ITO) .The thin layers are separated by invisible spacers.
CONTROLLER
 Supply Voltage
◦ 5.0V DC
 Maximum Current
◦ 20mA
 Resolution
◦ 12-bit
SURFACE WAVE TOUCH SCREEN
SURFACE WAVE SENSORS
 Contains Transmitting and receiving transducers.
 It uses ultrasonic waves that pass over the touch screen panel.
 When the panel is touched the wave is absorbed and sends this information to the controller for processing.
CONTROLLER
 Voltage
◦ +5 VDC
 Baud Rate
◦ 9600
 Touch Resolution
◦ 12bit, size independent
◦ Conversion Time
◦ 10 ms per coordinate set
Capacitive Touch screen:
 It is a four multi-layer glass.
 A human body is an electric conductor, so when touched the screen with a finger, a slight amount of current is drawn, creating a voltage drop. The current respectively drifts to the electrodes on the four corners.
 The capacitive system has very long life (about 225 million clicks).
CONTROLLER
o Supply Voltage:
◦ +5 V DC or +12V
 Baud Rate
◦ 9600 (default) and 19200
 Touch Resolution
◦ 12bit, size independent.
 Conversion Time
◦ Approximately 15 ms per coordinate set
Advantages & Disadvantages:
Advantages:
 Fast response.
 Error free input.
 Easy to install.
 Easy to clean and maintain.
 Compatible with Windows ,and Linux.
Disadvantages:
 Finger stress: Stress on human fingers when used for more than a few minutes at a time. (for example, ATMs).
 Fingerprints: Touch screens can suffer from the problem of fingerprints on the display.
 User has to sit closer to the screen as compared to external keyboard.
 The screen may be covered more by using hand.
Applications
 General Stores
 Restaurants
 ATM’S
 Digital Computer
 Mobile Phones

PRESENTED BY:
Vijay s. waghmode

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[attachment=11237]
Touch Screen Technology
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Flat Screen TV Comparison: Plasma vs LCD
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DDR1 Double Data Rate-SDRAM, or simply DDR1, was designed to replace SDRAM. DDR1was originally referred to as DDR-SDRAM or simple DDR. When DDR2 was introduced, DDR became referred to as DDR1. Names of components constantly change as newer technologies are introduced, especially when the newer technology is based on a previous e one

plz send the ppt of given topic ....

Presented by:-
Tarantej Singh

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[attachment=11478]
Touchscreen Technology
Touchscreen
• A touchscreen is an electronic visual display that can detect the presence and location of a touch within the display area.
• The term generally refers to touching the display of the device with a finger or hand.Touchscreens can also sense other passive objects, such as a stylus. However, if the object sensed is active, as with a light pen, the term touchscreen is generally not applicable.
Attributes of Touchscreen
The touchscreen has two main attributes.
1. it lets one to interact directly with what is displayed rather than indirectly with cursor controlled by mouse or touchpad without requiring any intermediate device that would need to be held or used in the hand.
2. Such displays can be attached to computers, or to networks as terminals.
3. 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 games.
History of Touchscreen
• The first self capacitance touchscreen technology was developed at CERN 1972
• This led to the development of the prototype x-y mutual capacitance touchscreen developed at CERN in 1977 by Bent Stumpe, a Danish electronics engineer, for the control room of CERN’s accelerator SPS (Super Proton Synchrotron).
• Touchscreens emerged from corporate research labs in the second half of the 1940s. Touchscreens first gained some visibility with the invention of the computer-assisted learning terminal, which came out in 1975 as part of the PLATO (Programmed Logic for Automated Teaching Operations)project.
Applications of Touchscreen
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.
Touchscreens are popular in heavy industry, as well as museum displays or room automation, where keyboard and mouse systems do not allow a satisfactory, intuitive, rapid, or accurate interaction by the user with the display's content.
the touchscreen 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 touchscreens as a highly desirable user interface component and have begun to integrate touchscreen functionality into the fundamental design of their products
Other applications of Toucscreen
The following devices also use the same properties of touchscreen for various purposes:-
• Touchpad
• Dual Touchscreen
• Graphics Tablet
• Electronic Signature
Touchscreen Technologies
1. Resistive
2. Surface acoustic wave
3. Capacitive
4. Surface capacitance
5. Projected capacitance
6. Mutual Capacitance
7. Self Capacitance
8. Infrared
9. Strain gauge
10. Optical imaging
11. Dispersive signal technology
12. Acoustic pulse recognition
13. Coded LCD: Bidirectional Screen
Construction of Touchscreen
There are several principal ways to build a touchscreen. The key goals are to recognize one or more fingers touching a display, to interpret the command that this represents, and to communicate the command to the appropriate application.In the most popular techniques, the capacitive or resistive approach, there are typically four layers:
1. Top polyester layer coated with a transparent metallic conductive coating on the bottom
2. Adhesive spacer
3. Glass layer coated with a transparent metallic conductive coating on the top
4. Adhesive layer on the backside of the glass for mounting.
When a user touches the surface, the system records the change in the electrical current that flows through the display.
• Dispersive-signal technology which 3M created in 2002, measures the piezoelectric effect — the voltage generated when mechanical force is applied to a material — that occurs chemically when a strengthened glass substrate is touched.
• There are two infrared-based approaches. In one, an array of sensors detects a finger touching or almost touching the display, thereby interrupting light beams projected over the screen. In the other, bottom-mounted infrared cameras record screen touches.
• In each case, the system determines the intended command based on the controls showing on the screen at the time and the location of the touch.
Development of Touchscreen
• The development of multipoint touchscreens facilitated the tracking of more than one finger on the screen, thus operations that require more than one finger are possible. These devices also allow multiple users to interact with the touchscreen simultaneously.
• With the growing acceptance of many kinds of products with an integral touchscreen interface, the marginal cost of touchscreen technology is routinely absorbed into the products that incorporate it and is effectively eliminated.
• As typically occurs with any technology, touchscreen hardware and software has sufficiently matured and been perfected over more than three decades to the point where its reliability is proven.
• As such, touchscreen displays are found today in airplanes, automobiles, gaming consoles, machine control systems, appliances, and handheld display devices of every kind.
• The ability to accurately point on the screen itself is also advancing with the emerging graphics tablet/screen hybrids.
Usage
1. Finger stress
• An problem of touchscreens is their stress on human fingers when used for more than a few minutes at a time, since significant pressure can be required for certain types of touchscreen.
• This can be alleviated for some users with the use of a pen or other device to add leverage and more accurate pointing.
• The introduction of such items can sometimes be problematic, depending on the desired use (e.g., public kiosks such as ATMs).
• Also, fine motor control is better achieved with a stylus, because a finger is a rather broad and ambiguous point of contact with the screen itself.
2. Screen Protector
Some touchscreens, primarily those employed in smart phones, use transparent plastic protectors to prevent any scratches that might be caused by day to day use from becoming permanent.
3. Fingernail as stylus
• The issues of direct touch can be bypassed by using a different technique, provided that the user's fingernails are either short or sufficiently long.
• Rather than pressing with the soft skin of an outstretched fingertip, the finger is curled over, so that the tip of a fingernail can be used instead.
• The thumb is optionally used to provide support for the finger or for a long fingernail, from underneath.
• This method does not work on capacitive touch screens.
• The fingernail's hard, curved surface contacts the touchscreen at one very small point. Therefore, much less finger pressure is needed, much greater precision is possible (approaching that of a stylus, with a little experience), much less skin oil is smeared onto the screen, and the fingernail can be silently moved across the screen with very little resistance, allowing for selecting text, moving windows, or drawing lines.
• The human fingernail consists of keratin which has a hardness and smoothness similar to the tip of a stylus (and so will not typically scratch a touchscreen). Alternately, very short stylus tips are available, which slip right onto the end of a finger; this increases visibility of the contact point with the screen.
4. Fingerprints
• Touchscreens can suffer from the problem of fingerprints on the display.
• This can be mitigated by the use of materials with optical coatings designed to reduce the visible effects of fingerprint oils, such as the oleophobic coating used in the iPhone 3G S, or by reducing skin contact by using a fingernail or stylus.
5. Combined with haptics
• The user experience with touchscreens without tactile feedback or haptics can be difficult due to latency or other factors.
6. Gorilla arm
• Gorilla Arm is defined as the failure to understand the ergonomics of vertically mounted touch screens for prolonged use.
• The proposition is that human arm held in an unsupported horizontal position rapidly becomes fatigued and painful, the so-called "gorilla arm".
• Vertical touchscreens still dominate in applications such as ATMs and data kiosks in which the usage is too brief to be an ergonomic problem.

Presented By
Sumi Scaria

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[attachment=11854]
INTRODUCTION
 Most sophisticated computer access technology.
 Detect the presence and location of a touch.
 Eliminates the need for the mouse and keyboard.
The touchscreen has two main attributes:
 Enables to interact with what is displayed on screen.
 No intermediate devices required.
HISTORY
 Emerged in the second half of the 1960s.
 In 1971, Sam Hurst, invented first touch sensor
 In 1977 , "touchscreen."
TECHNOLOGIES
1) RESISTIVE:
 Composed of two thin, metallic, conductive layers.
 Change in current is registered as touch event.
 Advantages:
 fingertip input.
 Costs low.
 Supports multi-touch input.
 Not affected by outside elements.
 DISAdvantages:
 Offer only 75% clarity.
 The layer can be damaged.
 Cannot press hand down on the screen while writing.
2) SURFACE ACOUSTIC WAVE:
 Uses ultrasonic waves.
 It is based on sending waves across a clear glass panel with a series of transducers and reflectors.
 Advantages:
 High touch resolution.
 Highest image clarity.
 Glass panel.
 Disadvantages:
 Touched by finger, gloved
hand, or soft-tip stylus.
 Not completely sealable.
3) CAPACITIVE:
 Consists of insulator coated with a transparent conductor.
 Touching results in a distortion of the electrostatic field.
 Advantages:
 Not affected by outside elements.
 high clarity.
 Multi touch support available.
 High touch resolution.
 Disadvantages:
 Must be touched by finger.
 More expensive.
Surface capacitance:
 Only one side of the insulator is coated with a conductive layer.
 A small voltage is applied to the layer.
Projected capacitance:
 Permits more accurate and flexible operation, by etching the conductive layer.
4) INFRARED:
 It employs one of two very different methodologies.
 Use an array of infrared light-emitting diodes.
Advantages:
 Military applications.
 Have the most durable surfaces.
Disadvantages:
 Relatively high cost.
 Issue of performance in bright ambient light.
5) Strain gauge :
 The screen is spring-mounted on the four corners.
 Used to determine deflection when the screen is touched.
6) Optical imaging:
 Two or more image sensors are placed around the edges of the screen.
 Revolutionizes the way we interface with computer technology.
7) Dispersive signal technology:
 Chemically-strenghtened glass substrate with piezos mounted on each corner.
 Determines position by pinpointing the source of “bending waves”.
 Disadvantages:
 After the initial touch the system cannot detect a motionless finger.

8) Acoustic pulse recognition:
 Uses four piezoelectric transducers located at each side of the screen.
 Turn the mechanical energy of a touch into an electronic signal.
 Advantages:
 Optics and durability of pure glass.
 Works with finger, glove, pen.
 Resistant to water, dust, grease.
DISADVANTAGES:
 After the initial touch the system cannot detect a motionless finger.
 Comparison of touchscreen technologies
CONSTRUCTION
 Three main components:
1) Touch Sensor
 Touch response surface.
 It is a clear glass panel.
2) Controller
 Interface between a touch screen sensor and the device the sensor is used to control.
 determines what type of interface/connection.
3) Software Driver
 Software update for the PC system.
 Allows the touchscreen and computer to work together.
WORKING
 control board.
 Electrically conducting layer.
 print circuit board.
APPLICATIONS
 Public Information Displays.
 Retail and Restaurant Systems .
 Customer Self-Service.
 Control and Automation Systems.
 Computer Based Training.
 Assistive Technology.

hi this is report for touch screen. thank u

[attachment=12424]
Introduction
A touchscreen is an easy to use input device that allows users to control PC software and DVD video by touching the display screen.
A touch system consists of a touch Sensor that receives the touch input, a Controller, and a Driver. The touch screen sensor is a clear panel that is designed to fit over a PC. When a screen is touched, the sensor detects the voltage change and passes the signal to the touch screen controller. The controller that reads & translates the sensor input into a conventional bus protocol (Serial, USB) and a software driver which converts the bus information to cursor action as well as providing systems utilities
As the touch sensor resides between the user and the display while receiving frequent physical input from the user vacuum deposited transparent conductors serve as primary sensing element. Vacuum coated layers can account for a significant fraction of touch system cost. Cost & application parameters are chief criteria for determining the appropriate type determining the system selection. Primarily, the touch system integrator must determine with what implement the user will touch the sensor with & what price the application will support.
Applications requiring activation by a gloved finger or arbitrary stylus such as a plastic pen will specify either a low cost resistive based sensor or a higher cost infra-red (IR) or surface acoustic wave (SAW) system. Applications anticipating bare finger input or amenable to a tethered pen comprises of the durable & fast capacitive touch systems. A higher price tag generally leads to increased durability better optical performance & larger price.
The most commonly used systems are generally the capacitive & resistive systems. The other technologies used in this field are Infrared technology & SAW (surface acoustic wave technology) these technologies are latest in this field but are very much expensive.
How Does a Touchscreen Work?
A basic touchscreen has three main components: a touch sensor, a controller, and a software driver. The touchscreen 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.
TouchSensor
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.
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 Tor 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 touchscreen. 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.
Software Driver
The driver is a software update for the PC system that allows the touchscreen 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 touchscreen to work with existing software and allows new applications to be developed without the need for touchscreen 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.
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:
Resistive Wire Technology:
Resistive touch screens consist of a glass or acrylic panel that is coated with electrically conductive and resistive layers made with indium tin oxide (ITO) .The thin layers are separated by invisible spacers.
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
High touch resolution
Pressure sensitive, works with any object
Not affected by dirt, dust, water, or Affordable touchscreen technology
Disadvantages
75 % clarity
Resistive layers can be damaged by stylus
Less durble then 5-Wire Resistive technology