Touch screen technology

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Touch screen technology

  1. 1. TOUCH SCREEN TECHNOLOGY
  2. 2. DEFINITION What is touch screen
  3. 3. 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) .
  4. 4. COMPONENTS OF TOUCH SCREEN Three major components viz,  Touch sensor  Controller  Software driver
  5. 5. TOUCH SENSORS Touch sensor Covering screen
  6. 6. 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.
  7. 7. CONTROLLER
  8. 8. 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.
  9. 9. 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
  10. 10. TYPES OF TOUCH SCREEN Resistive Touch screen Surface wave Touch screen Capacitive Touch screen  Surface capacitive  Projected capacitive Infrared Touch screen
  11. 11. RESISTIVE TOUCH SCREENS
  12. 12. RESISTIVE TOUCH SCREEN
  13. 13. CONTD… 1. Polyester Film. 2. Top Resistive Layer. 3. Conductive Transparent Metal Coating. 4. Bottom Resistive Layer . 5. Insulating Dots . 6. Glass Substrate
  14. 14. 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.
  15. 15. CONTROLLER NAME:  VS20UA CONTROLLER Supply Voltage  5.0V DC Maximum Current  20mA Resolution  12-bit
  16. 16. PROPERTIES2 conductive layers that connects when touched. Capable of multi touch. Not affected by dirt or dust. Good for outdoor use.
  17. 17. SURFACE WAVE TOUCH SCREEN Introduction
  18. 18. SURFACE WAVE TOUCH SCREEN
  19. 19. WORKING OF SURFACE WAVE SENSORS Contains Transmitting and receiving transducers Touch screen 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 touch screen
  20. 20. CONTROLLER NAME:  2701RSU CONTROLLER Voltage  +5 VDC Baud Rate  9600 Touch Resolution  12bit, size independent Conversion Time  10 ms per coordinate set
  21. 21. CAPACITIVE TOUCHSCREEN Introduction
  22. 22. CAPACITIVE TOUCHSCREEN Figure
  23. 23. WORKING OF CAPACITIVE TOUCHSCREEN Uniform conductive coating on a glass panel. Operation --> Electrodes around the panels 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.
  24. 24. LAYERS OF CAPACITIVE TOUCHSCREEN Contains 3layers ,viz  Front Protective glass  Back protective glass - provides optical & strength enhancement options  Middle layer  laminated sensor grid micro-fine wires
  25. 25. 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
  26. 26. PROPERTIES Conductive coating that emits electric field. Very durable. Must be touched by some conductive materials. Capable of multi touch.
  27. 27. PROS & CONS OF TOUCH SCREENSPROS CONS Direct pointing to the  Low precision when we use objects. finger. Fast.  Screen may be covered Finger or pen is usable (No more by using hand cable required)  No direct activation to the No keyboard necessary selected function Suited to all interactive applications.
  28. 28. 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.
  29. 29. EXCLUSIVE HIGH PERFORMANCEOF TOUCH SCREEN TECHNOLOGY High resolution enhanced infraredBENEFITS1:Easier to pin point2:Better drag and drop3:Extra resolution4:Better sensitivity to environment
  30. 30. RECENT PRODUCT SUNDER DEVELOPEMENT
  31. 31. 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.
  32. 32. DISADVANTAGES User hand’s may obscure the screen Screens need to be installed at lower position and tilted to reduce arm fatigue Some reduction in image brightness may occur They cost more than alternative devices
  33. 33. HOW IS TOUCH SCREEN DIFFERENTFROM OTHER DEVICES No special commands to learn No use of keyboards Entering wrong information is impossible No fear of damage or lost of loose hardware pieces
  34. 34. 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.

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