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. COMPONENTS OF TOUCH SCREEN
Three major components viz,
Touch sensor
Controller
Software driver
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.
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. 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
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. CONTROLLER
NAME:
VS20UA
CONTROLLER
Supply Voltage
5.0V DC
Maximum Current
20mA
Resolution
12-bit
16. PROPERTIES
2 conductive layers that connects when touched.
Capable of multi touch.
Not affected by dirt or dust.
Good for outdoor use.
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. CONTROLLER
NAME:
2701RSU CONTROLLER
Voltage
+5 VDC
Baud Rate
9600
Touch Resolution
12bit, size independent
Conversion Time
10 ms per coordinate set
23. 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.
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. PROPERTIES
Conductive coating that emits electric field.
Very durable.
Must be touched by some conductive materials.
Capable of multi touch.
27. PROS & CONS OF TOUCH
SCREENS
PROS 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. 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. EXCLUSIVE HIGH PERFORMANCE
OF TOUCH SCREEN TECHNOLOGY
High resolution enhanced infrared
BENEFITS
1:Easier to pin point
2:Better drag and drop
3:Extra resolution
4:Better sensitivity to environment
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. 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. HOW IS TOUCH SCREEN DIFFERENT
FROM 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. 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.