Mechanical Mouse

Mechanical Mouse.
Here is how the mouse translates your hand movements into actions on the screen.

1 - When moving a mechanical mouse dragging a flat surface, a ball - made of rubber or steel covered with
Rubber - protruding slightly out of the bottom of the mouse rotates the direction of motion.
2 - As the ball rotates it touches and moves the two bearings positioned at an angle of 90 degrees from each other. A bearing responds by movements back and forward mouse, corresponding to the vertical movement across the screen. The other responds by lateral movements, corresponding to horizontal movement on the screen.

3 - Each bearing is attached to a wheel, known as an encoder, as the game of a car steering
are connected by their shafts to the wheels. As the rollers rotate, they rotate encoders.
4 - In the crowns of each encoder is tiny metal contact points. Two pairs of contact bars leave the
coating mouse and touch the contact points of each coders so they pass. Each time a
contact bar touch point, generates an electrical signal. The amount of signal bars indicates how many points of contact played - the more signs, the greater the distance traveled by the mouse. The direction in which the bearings are spinning, combined with the ratio of the number of signals of vertical and horizontal bearings indicate the direction in which the mouse is moving.
5 - The signals are sent from the PC to the program via the mouse cable that converts the number, combination and frequency of the signals from the two encoders in the distance, direction and speed needed to move the cursor on the screen.
6 - Press one of the buttons at the top of the mouse causes a signal to be sent to the PC, which in
time passes the program. Based on how many times you click and the cursor position at the time of the click, the program performs the task for which it was designed.

Note - You want to know how a trackball? A trackball is actually a mouse disposed in such a way that
ball is rotated by your fingers rather than the superfide table.

Source: Evolution of Computers