1. Touch Screen Technology Review
16 February 2014
UNIVERISTY OF TURKISH AERONAUTICAL ASSOCIATION
Department of Electrical and Electronics Engineering
EEE 512 : Sensors & Signal Conditioning
Touch Screen Technology Review
Presented by :
Hamza Emhemed Hebrisha
ID:
Supervisor:
Dr. Hassan SHARABATY
Ankara - December 2016

2. Touch Screen Technology
16 February 2014
Contents
Introduction.
History and Development.
Components of Touch Screen.
Types of Touch Screen Technologies.
Advantages & Disadvantage.
Applications.
Future Scope.
Conclusion.
Eng : Hamza Hebrisha
Touch Screen Technology

3. Touch Screen Technology
16 February 2014
Introduction
A touch screen is a 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.
A touch screen is an input device that allows users to operate a PC by simply touching the display screen which has a sensitive glass overlay placed on it.
A touch screen accepts direct onscreen inputs.
Eng : Hamza Hebrisha
Touch Screen Technology

4. History and Development
16 February 2014
History and Development
In 1971 Dr. Sam Hurst, founder of Elographics developed the first touch opaque sensor “Elograph” at the University of Kentucky.
In 1974 He developed the first real touch screen.
In 1977, Elographics developed the five-wire resistive technology then with the backing of Siemens Corporation, developed a curved glass sensor called the touch screen.
Eng : Hamza Hebrisha
Touch Screen Technology

5. Components of Touch Screen
16 February 2014
Components of Touch Screen
A basic touch screen has three main components:
1. Touch Sensor
2. Controller
3. Software Driver
Eng : Hamza Hebrisha
Touch Screen Technology

6. Touch Screen Technology
16 February 2014
1. Touch Sensor
The sensor generally has an electrical current or signal going through it and touching the screen causes a voltage or signal change.
A touch screen sensor is a clear glass panel with a touch responsive surface which is placed over a display screen.
Eng : Hamza Hebrisha
Touch Screen Technology

7. Touch Screen Technology
16 February 2014
2. Controller
The controller is a small PC card that connects between the touch sensor and the computer.
It takes information from the touch sensor and translates it into information that computer can understand.
Eng : Hamza Hebrisha
Touch Screen Technology

8. Touch Screen Technology
16 February 2014
3. Software Driver
The driver is a software that allows the touch screen and computer to work together.
It tells the operating system how to interpret the touch event information that is sent from the controller.
Most touch screen drivers today are mouse-emulation type drivers. This makes touching the screen the same as clicking your mouse at the same location on the screen.
Eng : Hamza Hebrisha
Touch Screen Technology

9. Diagram showing How it Works Touch Screen Technology
16 February 2014
Diagram showing How it Works
Eng : Hamza Hebrisha
Touch Screen Technology

10. Types of Touch Screen Technologies:
A- Resistive Touch Screen.
B- Capacitive Touch Screen.
C- Surface Acoustic Wave Touch screen (SAW).
D- Infrared Touch Screen.
Eng : Hamza Hebrisha
Touch Screen Technology

11. A- Resistive Touch Screen
A resistive touch screen panel is composed of several layers, the most important of which are two thin metallic electrically conductive layers separated by a narrow gap. When an object, such as a finger, presses down on a point, causes a change in the electrical current, which is registered as a touch event and sent to the controller for processing.
Eng : Hamza Hebrisha
Touch Screen Technology

12. Advantages And Disadvantages of Resistive
Cost-effective .
Activated by any stylus.
Very accurate.
Low power requirements.
Liquids won’t affect touch screen performance.
Polyester surface can be damaged .
Poorer durability compared to other technologies .
Eng : Hamza Hebrisha
Touch Screen Technology

13. B- Capacitive Touch Screen
A capacitive touch screen panel consist 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 body’s electrostatic field , measurable as a change in capacitance
Eng : Hamza Hebrisha
Touch Screen Technology

14. Touch Screen Technology
Capacitive Touch Screen:
1. Surface Capacitive Touch Screen projected Capacitive Touch Screen.
1. Surface Capacitive Touch Screen.
Surface capacitive technology consists of a uniform conductive coating on a glass panel.
Eng : Hamza Hebrisha
Touch Screen Technology

15. 2. projected Capacitive Touch Screen
The design of projected capacitive touch screen is somewhat similar to that of resistive touch screens. An XY array is formed either by etching a single layer to form a grid pattern of electrodes, or by etching two separate, perpendicular layers of conductive material with parallel lines or tracks to form the grid.
Eng : Hamza Hebrisha
Touch Screen Technology

16. Advantages and Disadvantages Of Capacitive
Projected - capacitive panels have multiple sensors
Scratch resistance, Durable surface.
Very accurate.
Good optical clarity.
Liquid won’t affect touch screen performance .
Does not work with gloved fingers
Accepts input from finger only.
Eng : Hamza Hebrisha
Touch Screen Technology

17. C- Surface Acoustic Wave Touch screen (SAW)
Surface Acoustic Wave (SAW) technology uses ultrasonic waves that pass over the touch screen panel.
When the panel is touched, a portion of the wave is absorbed. The change in the ultrasonic waves registers the position of the touch event and sends this information to the controller for processing.
Eng : Hamza Hebrisha
Touch Screen Technology

18. Advantages and Disadvantages of SAW
Better clarity than Resistive and Capacitive
Work almost with any stylus
Very high scratch immunity
can be deployed to a curved surface
provides superior resolution
Must use soft object to enable touch
Low weather immunity (water and dust)
Cannot be completely sealed
require periodic cleaning of sensor
can be activated inadvertently by dirt
Eng : Hamza Hebrisha
Touch Screen Technology

19. D- Infrared Touch Screen
An infrared touch screen uses an array of X-Y infrared LED and photo detector pairs around the edges of the pattern of LED beams. Infra-red bezels have proven to be a very reliable technology for use in ATMs, Medical Instrumentation and Transportation Tracking applications.
Eng : Hamza Hebrisha
Touch Screen Technology

20. Advantages and Disadvantages of Infrared Touch Screen
It is very sensitive & can be activated by stray touches.
Low resolution.
Highest quality of underlying image.
Very high transmittance.
Can be activated with almost any device.
Higher accuracy than other technologies.
Very high durability and reliability.
Eng : Hamza Hebrisha
Touch Screen Technology

21. Advantages for Touch screen Touch Screen Technology
16 February 2014
Advantages for Touch screen
High touch resolution.
High image clarity.
Not affected by contaminant.
User friendly.
Fast response.
Error free input.
No keyboard necessary.
Eng : Hamza Hebrisha
Touch Screen Technology

22. Disadvantages for Touch Screen Touch Screen Technology
16 February 2014
Disadvantages for Touch Screen
Finger stress.
Fingerprints.
Accepts input from finger only.                     
big screen leads to low battery life.
Eng : Hamza Hebrisha
Touch Screen Technology

23. Touch Screen Technology
16 February 2014
Applications
ATMs.
Phones.
Computers.
Gaming machines.
Point of Sale
Industrial controls.
Hand held electronics.
Eng : Hamza Hebrisha
Touch Screen Technology

24. Touch Screen Technology
Future Scope
Wood touch
Touch screen Video Projectors.
Eng : Hamza Hebrisha
Touch Screen Technology

25. Touch Screen Technology
16 February 2014
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.
Eng : Hamza Hebrisha
Touch Screen Technology

26. Touch Screen Technology
16 February 2014
Thank You
Eng : Hamza Hebrisha
Touch Screen Technology