Hardware - Peripherals - Input Devices
Input Devices - Mouse (2 of 2)


A mouse contains a rotating ball with two rollers held at right angles to each other which touch the ball. The rollers register the x and y axis movements of the ball.


How a mouse works


Each roller is attached to an optical encoder, a disc which has gaps in its surface. The rotation of the encoder interrupts two beams of light between the LEDs and their detectors.

These pulses of light are fed to the computer and are used to determine the speed and direction of the mouse's movement.