1. Touchscreen Technology
Anandu Narayanan S3 EC

2. What is a Touchscreen ? It is a display which responds to human touch
It acts as both input and output device

3. Components of a touchscreen
1.Touch Sensor Controller Driver

4. History and Development
E.A Johnson invented touchscreen in
1965 at The Royal Radar Establishment.
Multi-touch was developed in 1982.
Gestures were developed during the 1990s.
First touchscreen phone IBM Simon was released in 1993.

5. Resistive Touch Screen
Advantages
Low cost of production
High resistance to dust and water
Best suited for handwriting recognition
Disadvantages
Poor sensitivity
Doesn’t support multi-touch

6. Capacitive Touchscreen
Locates touch position based on variation in capacitance
Wide application in consumer electronics
Highly sensitive
Supports multi-touch and gestures

7. Infrared grid touchscreen
Poor multi-touch accuracy
Slow response time
Hovering over screen can result in false responses

8. Surface Acoustic Wave
Works on the principle that human body absorbs ultrasonic waves
Immune to electromagnetic interferences
Easily disturbed by foreign particles

9. Optical Touchscreen
CMOS infrared cameras monitor the entire field of view
The touch location is triangulated based on information from the cameras

10. Dispersive Signal Technology
DST responds to touch by analysing the mechanical waves produced due to touch.
Piezoelectric sensors placed at the four corners of the screen accurately locates the touch location.

11. Applications
Capacitive touchscreens are extensively used in the smartphone industry
DST is used in large touch screens which are generally greater than 32 inch
Used in kiosks and for interactive navigation
Used to implement digital variant of many acoustic musical instruments

12. THANK YOU…