March 2020 | IJIRT | Volume 6 Issue 10 | ISSN: 2349-6002 IJIRT 149090 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 347 Screen Touch Technology Chilakalapalli Yaswanthsai1 , Chaduvula sushma rani2 1,2 Department of Electronics and Communication Engineering, Aditya Institute of Technology and Management, Tekkali, Srikakulam District Abstract- The main purpose of this paper is to illustrate different types of touch technologies. With the emerging of new electronic gadgets, the existing button system is becoming ineffective to operate them. So, there is a need to replace this obsolete system with the touch screen technology. This replacement will make the use of gadgets very comfortable. Index terms- ITO, Acoustic, Infrared 1.INTRODUCTION Touch screen is a display which is sensitive to a human touch. It enables a human to select an option on the screen just by giving a touch. This technology is replacing the existing button system. This technology will surely become an inevitable part of most of the electronic gadgets. Basic touch screen is having a touch sensor, a controller, and a software driver as three main components. The touch screen is combined with a display and a PC to make a touch screen system. 1.1 Touch sensor: The touch sensor generally has an electrical current passing through it and touching the screen causes a change in the electrical current(signal). This change is used to determine the location of the touch of the screen. 1.2 Controller: Controller is connected between touch sensor and PC. It gets information from sensor and translates it for understanding of PC. The controller decides what type of connection is needed. 1.3 Software driver: Software driver allows computer and touch screen to work together. It tells operating system how to interact the touch event information that is sent from the controller. 2. HISTORY In the year 1965, E.A. Johnson developed the first touch screen (capacitive type).In the year 1971, Doctor Samuel Hurst[1]invented a touch sensor at the University of Kentucky. Then, later in the year 1974, the first transparent touch screen was developed. These inventions gave a boost up to this technology. Then, different multinational companies started using this technology for the development of their gadgets. And today we are in a era where it has become difficult to imagine a phone without touch screen. 3. TYPES OF SCREEN TOUCH TECHNOLOGIES 3.1 RESISTIVE SCREEN TOUCH A resistive touch screen basically comprises of two transparent layers of glass or plastic, facing each other. There inner walls are coated with Indium Tin Oxide (ITO)[2]. This coating makes the inner layer conductive. The conducting are separated by an air gap or the spacers. When we press the screen with our finger, it causes the top and bottom layers to come in contact. Due to this, the circuit gets completed and marks in the flow of an electric current at the point of contact. This results in change of electric field at the point of contact, which is then sensed and the system software executes the option underneath it. Figure 1. Resistive touch screen view March 2020 | IJIRT | Volume 6 Issue 10 | ISSN: 2349-6002 IJIRT 149090 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 348 I. ADVANTAGES OF RESISTIVE SCREEN TOUCH Economical Responds to touch of anything, including pens, gloved fingers etc. Can work in presence of moisture. Rarely Detects any accidental touches. II. DISADVANTAGES OF RESISTIVE SCREEN TOUCH Less sensitivity. Does not support multi- touch. 3.2 SURFACE CAPACITIVE TOUCH SCREEN The capacitive screen touch consists of three layers. The top most layer is the protective layer. Under it, lies the bonding layer [2]. The next layer is very thin one, which comprises of the driving lines (these lines carry the flowing charge). And the next layer contains the sensing lines (these lines sense the amount of charge being carried). When a body which is capacitive in nature, touches the screen, then some of the charge gets transferred to that body. This results in the increased capacitance at that point, which decreases the potential drop at the point. Then the sensing lines sense the point, after which the system software implements the option under it. Figure 2. Illustration of capacitive touch screen I. ADVANTAGES OF CAPACITIVE TOUCH SCREEN Highly sensitive to touch. Supports multi-touch. Capable of fast typing. II. DISADVANTAGES OF CAPACITIVE TOUCH SCREEN It does not work when the user wears gloves. expensive prone to breakage 3.3 PROJECTED CAPACITIVE TOUCH SCREEN It is simply an upgraded version of surface capacitive touch screen. It consist of a sheet of glass, which has an IC chip and a transparent electrode film embedded in it. This creates a 3D electrostatic field, so that when a finger meets the screen, it lets the device to determine the precise co- ordinates of the touch points. Due to this, Projected Capacitive touch screens can be operated even if the user is wearing thin cotton gloves or surgical gloves. 3.4 INFRARED TOUCH SCREEN The screen consists of light emitting diode at the two adjacent edges. These emit infrared light across the screen, which builds an invisible net [3]. And the other two adjacent edges consist of photo detectors. These act as the sensors which can identify a break due to any obstacle. So, When we touch the screen, we block the transmission of two are more beams. This results in loss of light, which is used to detect the location of the touch. mostly these are used in the applications in ATM, factory automation, plant control system, ticketing machines, medical equipment, Kiosk, POS, interactive whiteboard and office automation. Figure 3. Illustration of Infrared touch screen March 2020 | IJIRT | Volume 6 Issue 10 | ISSN: 2349-6002 IJIRT 149090 INTERNATIONAL JOURNAL OF INNOVATIVE RESEARCH IN TECHNOLOGY 349

1. Mention the touch screen's three primary components and functionalities.

2. Explain how Resistive Screen Touch works.

3. Compare the differences between the Projected Capacitive Touch Screen and the Surface Capacitive Touch Screen.

4. How does the Infrared Touch Screen technique determine where the touch was made?

5. Which of the listed technologies senses touch through sound?

6. Compare and contrast Apple Phone's Fingerprint Scanner with Microsoft Free Touch Technology.

7. Name a few advantages of Projected Capacitive Touch Screen.

8. Describe the development of touch screen technology.

9. Name a few common uses for touch screens in daily life.

10. What issues do users have when utilising touch-screen devices?