TOUCH SCREEN TECHNOLOGY

1. TOUCH SCREEN TECHNOLOGY PRESENTED BY PriyaMishra Saroj Singh ShikhaGhodeshwar

2. INTRODUCTION • Works with the principle of CRT (Cathode Ray Tube) technology. • Input device --> Operates a PC by simply touching the display screen. • Made of sensitive glass overlay & desired inputs can be given by touching it. • Inputs --> External (light pen) or an internal device (touch overlay and controller) .

3. COMPONENTS OF TOUCH SCREEN • Three major components viz, • Touch sensor • Controller • Software driver

4. TOUCH SENSORS • Touch sensor Covering screen

5. Contd.. • Touch sensor --> In between clear glass panels. • Responsive area --> Entire viewable area of the display screen. • Sensors --> Detects electrical current or signal. • Touching -->causes a voltage or signal change, thereby the location can be determined.

6. CONTROLLER

7. CONTD… • PC card --> Touch sensor and the PC. • Change in voltage --> Translated into the information that CPU understands. • Translated bits --> Position where the touch occurs. • Processor --> change the screen accordingly.

8. SOFTWARE DRIVER • Acts as a bridge --> Screen and processor. • Makes the operating system --> To interpret the touch event information. • Touch screen drivers today --> Mouse-emulation type driver ( like touching the screen the same as clicking mouse) • Recent research --> To make it as PNP

9. TYPES OF TOUCH SCREEN • Resistive Touch screen • Surface wave Touch screen • Capacitive Touch screen • Surface capacitive • Projected capacitive • Infrared Touch screen

10. RESISTIVE TOUCH SCREENS

11. RESISTIVE TOUCH SCREEN

12. CONTD… • 1. Polyester Film. • 2. Top Resistive Layer. • 3. Conductive Transparent Metal Coating. • 4. Bottom Resistive Layer . • 5. Insulating Dots . • 6. Glass Substrate

13. WORKING OF RESISTIVE SENSORS • Resistive touch screen monitor composed of : • Flexible top layer • Rigid bottom layer • Insulating dots • Along with touch screen controller. • Top & Bottom layers --> transparent metal oxide coating. • Pressure over the flexible top sheet --> Makes electrical contact between the resistive layers & the switch closing in the circuit. • Controller --> Alternating voltages & converts them into the digital X and Y coordinates.

14. CONTROLLER • NAME: • VS20UA CONTROLLER • Supply Voltage • 5.0V  DC • Maximum Current • 20mA • Resolution • 12-bit

15. PROPERTIES • 2 conductive layers that connects when touched. • Capable of multi touch. • Not affected by dirt or dust. • Good for outdoor use.

16. SURFACE WAVE TOUCH SCREEN

17. SURFACE WAVE TOUCH SCREEN

18. WORKING OF SURFACE WAVE SENSORS • Contains Transmitting and receiving transducers • Touchscreen controller --> 5 MHz electrical signal to the transmitting transducer. • Converts electrical signal --> ultrasonic waves within the glass. • Waves --> Directed across the front surface of screen. • Reflectors - -> Reflects & directs towards receiving transducer. • Receiving transducer --> reconverts --> An electrical signal & digitally maps the touchscreen

19. CONTROLLER • NAME: • 2701RSU CONTROLLER • Voltage • +5 VDC • Baud Rate • 9600 • Touch Resolution • 12bit, size independent • Conversion Time • 10 ms per coordinate set

20. CAPACITIVE TOUCHSCREEN

21. CAPACITIVE TOUCHSCREEN

22. WORKING OF CAPACITIVE TOUCHSCREEN • Uniform conductive coating on a glass panel. • Operation --> Electrodes around the panel's edge evenly distribute a low voltage across the conductive layer & creates an uniform electric field. • Finger touch --> Draws current from each corner. • Controller --> Measures ratio of the current flow from the corners & calculates the touch location. • Capacitance --> Finger and the sensor grid.

23. LAYERS OF CAPACITIVE TOUCHSCREEN • Contains 3layers ,viz • Front Protective glass • Back protective glass - provides optical & strength enhancement options • Middle layer - laminated sensor grid of micro-fine wires

24. CONTROLLER • Name: • 5000 RSU SERIAL CONTROLLER • 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

25. PROPERTIES • Conductive coating that emits electric field. • Very durable. • Must be touched by some conductive materials. • Capable of multi touch.

26. PROS & CONS OF TOUCH SCREENS PROS CONS • Direct pointing to the objects. • Fast. • Finger or pen is usable (No cable required) • No keyboard necessary • Suited to all interactive applications. • Low precision when we use finger. • Screen may be covered more by using hand • No direct activation to the selected function

27. applications • Public Information Displays::: • Tourism displays • Trade show display • Awareness kiosks • Customer Self-Services::: • General departmental Stores • Restaurants • ATMs • Airline ticket terminals, etc. • Other uses::: • Digital jukeboxes • Computerized gaming • Student Registration systems, etc.

28. RECENT PRODUCT S UNDER DEVELOPEMENT

29. Recent trends • Introduction of • i-PAN7: Flat Touchscreen computer - Panel PC • Introduced by Keith & Koep of Japan. • Small frame computer. • Runs with Windows Embedded CE & built with low power ARM processor. • Uses Capacitive touch panels.

30. conclusion • Though the Touch screen technology contains some limitations it’s • user friendly. • Fast. • Accurate. • easy to operate. • It has been widely accepted and a little modification can replace the mouse and key board completely in near future.

31. THANK YOU