TOUCH PAD

 

 

TOUCH PAD

Instead of mouse we are using touch pads in laptop.
The working of touch pad is similar to that of touch screen.
We have already seen the working of touch screen in the previous post.

Types of touch-pads

There are two types of touch-pads. They are Resistive and Capacitive touch-pads

Resistive Touchpads: 

 

It has two layers. Both the layers have series of parallel lines and are placed in such a way that lines in both layers are perpendicular to each other.
When the touch-pad is pressed, two films contact each other and based on the location of contact the coordinates are calculated.
The pressure can be calculated from the resistance of the wires.
If the pressure is high then the contact between the layers will be high and resistance will be low.

Capacitive Touchpads:

 

It has electric field in between two charged plates. So that it forms capacitive layer.
When a piece of conducting material is brought in the field of capacitor, it will affect the capacitance of the capacitor.
The change in the capacitance is noted. From that the exact location can be calculated.