How does an Optical Mouse Work?

The first optical mice were introduced in the end of 1999. Since then they are very popular. These mice forced wheeled mice to extinct. This happened because of great advantages of the optical mice. An optical mouse can work on any surface, also it has immunity to dust. These features had brought optical mice to popularity.

The main idea about optical mice is that they use a very small camera like device. This camera takes 1500 pictures every second and the digital signal processor analyzes those images. The sensor that takes images is CMOS sensor. CMOS stands for complimentary metal-oxide semiconductor. Red light emitting diode is used for light bouncing from the surface. The idea is simple. Diode emits the light, light bounces off the surface and then goes to the CMOS sensor. The CMOS sensor sends 1500 surface images per second to the DSP (digital signal processor). DSP analyzes pictures and detects the movement. The movement is detected because of the pattern changes in provided pictures. The distance and the direction are evaluated by DSP and the coordinates are sent to the computer. Now it is computer's task to move the cursor to the position needed.

Optical mice have several well known advantages that forced wheeled mice to extinct. First of all, optical mice do not have moving parts. The main problem with wheeled mice was their wheel sensor mechanism, that had a tendency to break. As optical mice have no moving parts, the possibility to break such a mouse is lower. Also, optical mice are tight. This feature protects the mouse from dust and dirt. So there are very small chances to affect the sensors. Because of the capabilities of the sensor and the speed of the DSP, it is possible to create very smooth cursor movements. This advantage is also very well evaluated. And the last, but not the least, positive feature is an ability to use optical mouse on any flat surface you like. Special surfaces, such as mouse pads, are no longer needed.