1. PRESENTED BY:
NIKHIL LOSALKA(30)
PANKAJ CHOWDHURY(31)
PRITAM BOSE(33)
TOUCH SCREEN
TECHNOLOGY

2. INTRODUCTION
 Most sophisticated computer access technology.
 Detect the presence and location of a touch.
 Eliminates the need for the mouse and keyboard.

3. HISTORY
Emerged in the second half of the 1960s.
In 1971, Sam Hurst, invented first touch sensor
In 1977 , "touchscreen."

4. 1) SURFACE ACOUSTIC WAVE:
 Uses ultrasonic waves.
 It is based on sending waves across a clear glass panel
with a series of transducers and reflectors.

5. Disadvantages
Touched by finger, gloved
hand, or soft-tip stylus.
Not completely sealable.

6. TECHNOLOGIES
2) RESISTIVE:
 Composed of two thin, metallic, conductive layers.
 Change in current is registered as touch event.

7. DISADVANTAGES
Offer only 75% clarity.
The layer can be damaged.
Cannot press hand down on the screen while writing.

8. 3) CAPACITIVE:
Consists of insulator coated with a transparent
conductor.
Touching results in a distortion of the electrostatic field.

9. 4) INFRARED:
It employs one of two very different methodologies.
Use an array of infrared light-emitting diodes.

10. 5) Strain gauge :
 The screen is spring-mounted on the four corners.
 Used to determine deflection when the screen is
touched.

11. 6) Optical imaging:
 Two or more image sensors are placed around the edges of
the screen.
 Revolutionizes the way we interface with computer
technology.

12. 7) Dispersive signal technology:
Chemically-strengthened glass substrate with piezos
mounted on each corner.
Determines position by pinpointing the source of
“bending waves”.

13. Comparison of touchscreen technologies
Technology 4-Wire SAW 5-Wire Infrared Capacitive
Durability:5 year 5 Year 3 Year 3 Year 2 Year
Stability:High Higher High High Ok
Touch:Anything Finger/Pen Anything Sharp Conductive
Response
time:
<10ms 10ms <15ms <20ms <15ms
Monitor
option:
CRT CRT CRT or LCD CRT or LCD CRT or LCD
Waterproof:Good Ok Good Ok Good

14. CONSTRUCTION
Three main components:
1) Touch Sensor
Touch response surface.
It is a clear glass panel.

15. 2) Controller
Interface between a touch screen sensor and the device
the sensor is used to control.
Determines what type of interface/connection.

16. 3) Software
Driver
Software update for the
PC system.
Allows the touchscreen
and computer to work
together.

17. APPLICATIONS
 Public Information Displays.
 Retail and Restaurant Systems .
 Customer Self-Service.
 Control and Automation Systems.
 Computer Based Training.
 Assistive Technology.

18. THANK YOU..!!