Touch screen Flashcards
1
Q
How many types of touch screens are there
A
4 types
- infrared
- resistive
- capacitive
- surface acoustic wave (SAV)
2
Q
What is a CAPACITIVE touch screen
A
- Made up of many layers of glass that acts like a capacitor
»> creating an electrical field between the glass plates
3
Q
How does CAPACITIVE touch screen work
A
- When the top glass layer is touched
- An on-board microprocessor determines the electric current changes and the coordinates where the screen was touched
4
Q
Pros when using CAPACITIVE touch screen
A
- Medium cost
- can see the screen when it’s in bright light
- can multi-touch
- durable
5
Q
Cons of using CAPACITIVE touch screen
A
- only allow bare fingers
6
Q
What is an infrared (heat-sensitive) touch screen
A
- use glass
- needs a warm object to carry out an input operation
7
Q
What is an infrared (optical) touch screen
A
- use glass
- detect the point of contact based on grid coordinate is touched (by an array sensor)
7
Q
What is an infrared (optical) touch screen
A
- use glass
- detect the point of contact based on grid coordinate is touched (by an array sensor)
8
Q
What is a RESISTIVE touch screen
A
- the top layer is polyester, and the bottom layer is glass
- when the screen is touched, the top and bottom layer complete a circuit
- signals are sent to the processor to calculate the coordinate of where it is touched
9
Q
Pros of using INFRARED touch screen
A
- allow multi-touch
- good visibility in strong sunlight
- good durability
10
Q
Pros of using RESISTIVE touch screen
A
- inexpensive
- possible to use fingers, stylus, gloves to carry input
11
Q
Con when using INFRARED touch screen
A
- expensive
- Heat sensitive system only allows finger
12
Q
Cons when using RESISTIVE touch screen
A
- screen visibility is poor in strong sunlight
- can’t multi touch
- vulnerable to scratches
