Friday, November 14, 2008
The Computer Mouse
Everyone uses the mouse everyday to communicate with the computer. It has enabled even the not so computer proficient people to interact with the computer easily by just clicking on objects on the screen. The olden day mechanical mouse had two rubber wheels perpendicular to one another for motion along the two axes. The wheels were used to drive a variable resistor or a potentiometer and the change in resistance was proportional to the distance moved on the screen. Later the wheels were replaced by a rubber ball for better design. The optical mouse has an LED and a photodetector that operate in unison by sensing the number of lines crossed on the surface from the reflected light. The optomechanical mouse combines both the optical and mechanical techniques to position objects on the screen. A low level software in the computer makes it possible for the interface to be complete to transfer data for communication between the system and mouse.