SUBMITTED BY:Nitin Gupta

Nitesh Tyagi

SUBMITTED BY:Nitin Gupta

Nitesh Tyagi

MAHARANA PRATAP COLLEGE OF

TECHNOLOGYGWALIOR

SEMINAR

2012-13

SUBMITTED TO:Mrs. Nidhi Sharma

SUBMITTED TO:Mrs. Nidhi Sharma

INTRODUCTION Touch screen technology is a part of our everyday lives

now. From just simply playing music to controlling the temperature in your house touch screen technology has invaded and become a major part of our lives. Touch screen technology has been around for awhile but it only started becoming hugely popular not to long ago. There are many different types of touch screen technologies out there too. They each work in their own different ways but are relatively similar in how they work. The question i have is, can we benefit from touch screen technology and apply it to more pre-exsiting technology or will this touch screen technology lead to new inventions?

HISTORY Touch screen technology started appearing in the

late 1960's. In 1968 an article was published on how touch screen technology could be applied for air traffic control canters. 1975 PLATO releases a computer-assisiting terminal that was touch screen. since then touch screen technology started to grow slowly. Fairlight CMI was a high-end musical sampling and re-sythesis workstation, from 1979-1985, that utilized a kind of stylus on screen to work. In 1983 the HP-150 was one of the first touch screen computers. Video games and touch screen did not become popular until 2004, when the Nintendo DS was released, because of the high cost of touch screen technology in the 1990's

How to work Touch Screen The touch screen is an input device, so it

needs to be combined with a display and a PC or other device to make a complete touch input system.

A basic touch screen has three main components:1 Touch sensor2 Controller 3 Software Driver

1. Touch Sensor A touch screen sensor is a clear glass

panel with a touch responsive surface. The touch sensor/panel is placed over a display screen so that the responsive area of the panel covers the viewable area of the video screen. There are several different touch sensor technologies on the market today, each using a different method to detect touch input. The sensor generally has an electrical current or signal going through it and touching the screen can cause a voltage or signal change. This change is used to determine the location of the touch to the screen.

2. 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.

3. Software Driver The driver 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 as 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.

WORKING When a person presses his finger on the top

of the screen, there will be a change in the electrical current in the display module. Because The touch pad contains several layers of material. The top layer is the pad that you touch. Beneath it are layers containing horizontal and vertical rows of electrodes that form a grid. Beneath these layers is a circuit board to which the electrode layers are connected. The layers with electrodes are charged with a constant alternating current (AC). As the finger approaches the electrode grid, the current is interrupted and the interruption is detected by the circuit board. This change is measured in either ways explained below and the exact location of touch and the amount of force applied is calculated. Later, the command to be carried out is passed on to the operating system and the command is carried out.

PROS & CONS Touch-screen monitors are useful for many

reasons, but they also have a few disadvantages. Before deciding on whether to invest in a touch-screen monitor of any kind for your business or personal use, look at the advantages and disadvantages

ProsBig screen is ideal for web browsing,

picture and moviesDirect pointing to objects, direct

relationship between hand and cursor movement

Easy to movableNo keyboard necessary for applications

that need menu selections onlyTouch screens virtually eliminate operator

errors because users select from clearly defined menus

Touch screens ensure that no space is wasted, as the input device is completely integrated in to the monitors

ConsBig screen leads to low battery lifeScreens get very dirtyTouch screen devices usually has no

additional keys and this means when an app crashes, without crashing the OS, you can’t get to the main menu as the whole screen becomes unresponsive

Most user interfaces are not optimized for thumb operation, so a stylus in necessary, and this means using two hands

It has low accuracy

USES OF TOUCH SCREEN1. Public Information Displays:-

Tourism displays, trade show displays, Information kiosks and other electronic displays are used by large number of people who have little or no computing experience.

2. Retail and Restaurant Systems:- In retail or restaurant environment, touch screen systems are easy to use so employees can get work done faster and also training time can be reduced for new employees.

USES OF TOUCH SCREEN3. Control and Automation Systems:- The

touch screen device is useful in systems ranging from industrial process control to home automation.

4. Computer Based Training:- The touch screen interface is more user-friendly than other input devices so overall training time for computer novices and therefore training expense can be reduced.

5. Customer Self-Service:- Self-services 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.

TOUCH SCREEN TECHNOLOGIES

ResistiveCapacitiveSurface AcousticInfraredOptical ImagingDispersive Signal TechnologyAcoustic Pulse Recognition

RESISTIVE Resistive touch technology two

opposing layers each coated with a transparent material called indium tin oxide. The cover sheet consists of a hard outer surface with a coated inner side. When the outer layer is touched it causes the conductive layers to touch creating a signal that the analog controller can interpret and determine what the user wants to be done.Resistive touch tech is used in restraunts, factories and hospitals due to its high resistance to liquids and contaminants. A major benefit to resistive touch technology is it is extremely cost-effective. One disadvantage to resistive technology is its vulnerability to being damaged be sharp objects.

CAPACITIVE Capacitive works by having a two-layer

grid that are connected to the integrated circuit. The integrated circuit measures the Mutual Capacitance between the horizontal electrodes and the vertical electrodes. So when a human finger touches the screen some of the charge is transferred to the user. The X and Y information of where the touch happened and the charge was transferred is then sent to the main control in the device and the device now knows exactly where the touch occurred.Capacitive tech can be used in kiosk and there is a big use in gaming and amusement devices with capacitive technology. Capacitive is more efficient than resistive due to the quick response and excellent dragging abilities.

SURFACE ACOUSTIC WAVE

(SAW) SAW's main component that makes it

work is called a reflector which is placed on the glass. Basically these reflectors refract waves to receiving transducers and when a finger touches the glass these waves patterns are interrupted and the touch can be detected at that point.SAW technology is used in high traffic indoor environments, Amusement parks, ATM's, and Information kiosks. Some advantages of SAW include superior image clarity and resolution compared to Capacitive and Resistive. SAW is highly durable how ever can only be activated with a finger, gloved hand, or soft tip stylus (something hard like a pen wouldn't work).

INFRARED An infrared touch screen uses an array

of X-Y infrared LED and photo detector 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. It is generally used in outdoor applications and point of sale systems which can't rely on a conductor (such as a bare finger) to activate the touch screen.

Credit Card Scanner

Phones

Digital Camera

GPS

Tablet PC

Monitor

ATMInteractive Kiosks and learning stations

etc….

CONCLUSION Touch screen technology will increase in

significance as an I/O technique for user oriented embedded systems. Vendors have been steadily reducing or eliminating the weaknesses in touch sensors as well as adding new capabilities. This combination of steady improvement punctuated by innovation will continue to broaden the range of applications that touch screens can serve.

With these improvements, touch screen technology has become a viable user interface for many embedded systems. The inclusion of electronic ink services in Windows 9x indicates that touch screens will become a dominant interface. You need only to carefully match the technology to the application environment.

Thank You

“Things that think…

don’t make sense unless they

link.”