Optical mouse is the commonly used mouse type used for interaction between the computer and the user. It followed the mechanical mouse that was prevalent during the nineteen nineties and came with many improvements over its predecessor. Introduced by Agilent Technologies in 1999, it has a tiny camera that detects the position and speed by taking thousands of snapshots per second.

The optical mouse has a tiny LED (light emitting diode) which usually emits red light. The light that is bounced off the surface like mouse pad or desk is sensed by a Complimentary Metal Oxide Semiconductor (CMOS) and is transmitted to the digital signal processor (DSP) to determine the position of the cursor.

Mechanical mouse

There is a ball under the body of mouse to come in contact with the mouse pad or surface of the desk. When the mouse moves, the ball also rolls.

 
There are two rollers that touch the ball. They are placed in such a way that at least one of them rolls, when you move the mouse.

Each roller is attached to a shaft which has a disk at one end. When the mouse moves, the ball, the roller and the disk rotate together.

The perforated disk has an infrared LED on one side and a sensor on another side. They send and receive the red light between the mouse and the surface on which the mouse moves.

Optical mouse

The backside of an optical mouse

LED light

First, the Light Emitting Diode emits the red light which strikes the surface (desk or mouse pad).

The light that is bounced off the surface is received by the CMOS sensor in the mouse. Then, the CMOS sensor transmits all the images that it receives to the Digital Signal Processor (DSP) for processing.

By analyzing the images and sing the co-ordinates given by the computer, the DSP studies the variation in their patterns and determines the position and the speed of the mouse. Then, DSP sends the decoded information to the information to the computer and the movement of cursor is tracked even at the slightest movement of the mouse.

All this process takes place so fast that the movement cursor on the looks very smooth to the end user.

The optical mouse has many advantages over mechanical mouse which uses the track ball. As the optical mouse has no moving components, it has longer life than its predecessor. Optical mice usually function trouble-free for years.

When you use mechanical mouse, you need to clean the dirt or debris that comes inside the mouse so that the ball and rollers are able to move freely when the mouse moves. However, there is no such problem with optical mice. So, they are very reliable and trouble-free on all occasions.

Optical mouse uses a technology that is far more advanced than that is used in a mechanical mouse. The tiny camera in the optical mouse sends thousands of images to the CMOS sensor. The DSP is much faster in processing and tracking of the movement of mouse, so the cursor movement looks much smoother to the end user.

Finally, optical mice do not need mouse pad or any special surface. Unlike the mechanical mouse, their performance and tracking ability does not depend on the surface the mouse moves. You can use them on any kind of flat surface.

When compared with wireless mice or Bluetooth mice, optical mice are quite inexpensive