This document presents information about touch screen technology. It discusses the history and emergence of touch screens in the 1960s and 1970s. It then describes several touch screen technologies - surface acoustic wave, resistive, capacitive, infrared, strain gauge, optical imaging, and dispersive signal. It provides details on each technology and compares their durability, stability, touch capability, response time, and monitor options. The document also outlines the three main components of touch screens - the touch sensor, controller, and software driver. It concludes with examples of touch screen applications.

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..!!