TOUCH SCREEN TECHNOLOGYA Seminar ReportSubmitted to the Department of Electronics & Communication EngineeringCollege Of TechnologyG.B. Pant University of Agriculture & TechnologyPantnagar

Submitted by MANISH NAIN42112Electronics & Communication Engineering Date of Seminar-26/03/2015DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING

CONTENTS

1. Introduction:.......32. History:.......43. Why Touch Screen??:........................................................................................................54. Types Of Touch Screen Technology:..6 4.1 Resistive:..7 4.2 Capacitive:.8 4.3 Infrared Touch Screen:.95. Working Of Touch Screen Monitors:.....106. Pros & Cons :..127. Uses Of Touch Screen:.13 6. Limitations:....157.Conclusion:......168.Refrences:....179.Bio Data:..18

CHAPTER-1IntroductionA 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 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.

Fig 1.1 Touch Screen

CHAPTER-2HISTORY 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. The touch screen can be operated by two ways:.1.Finger-Operated: 2.Stylus operated: Fig 4.1 Finger Operated Fig 4.2 Stylus Operated

CHAPTER-3WHY TOUCH SCREENUser 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 applicationDesign Flexibility: -Advanced design allows flat and spherical design.Touch screen are very intuitive; it is natural for people to respond to their 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 rigors of everyday life, for rugged environments and the best solution for your application. Touch screen Characteristics:1. Speed: high2. Accuracy: low (finger), high (pen)3. Speed control: yes 4. Continuous movement: yes5. Directness: direction, distance, speed6. Fatigue: high7. Footprint: no8. Best uses: point, selectCHAPTER-4Types of Touch Screen Technologies1. Resistive Touch Screen2. Capacitive Touch Screen3. Surface Acoustic Wave Touch Screen4. Infrared Touch Screen

1.ResistiveA 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 Resistive Touch ScreenResistive 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 Layers In Resistive Touch ScreenThey 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. 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. 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 HTCs G1 & HTC Magic.Two types are available: Capacitive technology & Pen-touch Capacitive

Fig 5.2 Capacitive Touch Screen

3.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 Infrared Touch ScreenInfrared touch screen monitors are based on light-beam interruption technology. A frame surrounds the displays surface. The frame has light sources, or light-emitting diodes (LEDs),on one side, and light detectors on the opposite side. This design creates an optical grid across the screen. When any object touches the screen, the invisible light beam is interrupted, causing a drop in the signal received by the photo sensors. One concern with this technology is that it might respond to a very light touch, even that of an insect crossing the monitor, making unwanted system adjustments. This is the only type of touch technology that are available for large displays such as 42-inch Plasma screens. It is a durable technology that offers high image clarity.

CHAPTER-5WORKING 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 Components Of Touch Screen1. 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.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. 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.

CHAPTER-6Pros 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 screenScreen coverage: The user's hand, the finger or the pen may obscure parts of the screen. CHAPTER-7Uses for Touch screens:Best Suited to Applications Where...1. Opportunity for training is low2. Frequency of use is low 3. Accurate positioning is not required4. Little or no text or numerical input is required Desk space is at a premium 5. The environment may be chemically or otherwise "aggressive"

Not Suited to Applications...1. Requiring training/trained users 2. With high-frequency use 3. Requiring accuracy 4. 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 use

1.Public Informattion DisplayInformation 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. 2.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. 3.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. 4.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 withValuable workspace can be saved. And with a graphical interface, operators can monitor and control complex operations in real-time by simply touching the screen

5.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.

CHAPTER-8Limitations 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.

CHAPTER-9 CONCLUSION

Touch systems represent a rapidly growing subset of the display market. The majority of touch systems include touch sensors relying on vacuum-deposited coatings, so touch coatings present opportunity for suppliers of vacuum coatings and coating equipments.

Touch sensor manufactures currently require thin films in the areas of transparent conductors, optical interference coating and mechanical protective coatings. Touch sensors technical requirements dovetail well with those of the flat panel and display filter markets. The reality should provide value added opportunities to operations participating in these areas

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.

CHAPTER-10References1. http://en.wikipedia.org/wiki/Touchscreen2. http://en.wikipedia.org/wiki/Resistive_touchscreen3. http://www.authorstream.com/Presentation/balamadhu2007-366056-touch-screen-technology-bala-science-ppt-powerpoint/4. http://www.authorstream.com/Presentation/aSGuest21619-209927-touchscreen-technologies-enter-tags-education-ppt-powerpoint/5. http://www.seminarprojects.com/Thread-touch-screen-technology-report-and-ppt6. http://docs.google.com/viewer?a=v&q=cache:1mcxvteOcCYJ:courses.ee.nd.edu/87022/documents/Touch%2520screen%2520sensor.ppt+ppts+on+touch+screen+technology&hl=en&gl=in&pid=bl&srcid=ADGEEShmbSa_iRtYmz9sMm2GJCDDtAR4-64H6AQ-4vIfAUHE9jAvEUn9AIwt0Rgbc5O6Ag9kTxA4651BXemkDSM9Tha49WW4VV-x5TUvCTdaqqOOOH929xCkzMrk0wNYfrnPmiFkdy98&sig=AHIEtbQqB3LBjH_wCaG9eMrqaP1X-YUjFQ

BIODATA

1. Name : Manish Nain

2. ID No. : 42112

3. Fathers Name : Mr. Satender Nain

4. Mothers Name : Mrs. Bimlesh Devi

5. Educational Qualifications:ExaminationSchool/Board Year of passing Marks (%) Division (Position)

X C.B.S.E. 2008 84.00 First

XII C.B.S.E. 2010 78.60 First

B.Tech G.B.P.U.A&T 2015 69.46 (up to VII Semester) First

6. Address for correspondence : H.N.-186, S-5, Greater Green Park, Bareilly Uttar Pradesh. 7. Email: nain4aryan@gmail.com

8. Mobile No. : +91-8791663681

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