Mouse
- The mouse is a small device that is shaped such that it can fit comfortably into the operators hands,such that it can be moved over a flat surface to cause the cursor to move in a corresponding way on the screen. It is one of the basic Input devices. The mouse made it possible to enter graphic information directly, by drawing the desired objects and opened the door to many new powerful ideas, windows and pull down menus.It was invented by Douglas Engelbart in the year 1963 which was then later brought forward by Xerox. A mouse basically has two buttons and some new mouse also have the option of a scrollwheel used to scroll down long pages.an electronic sensor is present which detects the movement and sends the distance travelled in X and Y directions to the computer.
Types of Mice
There are basically three types of mice:-
- Mechanical Mouse:- A mechanical mouse consists of rubber or metal on its inside which can roll in all directions and their movement can be detected with the help of mechanical sensors which thereby move the cursor accordingly on the screen. The rotation of the ball is sensed and used to advance two counters one for each of the two axes of motion. The information from the counters and buttons is collected by a microcontroller, encoded into a 3 byte packet and then it is send over to the computer over a serial link.
- Optomechanical Mouse:- An opto mechanical mouse is very much similar to the the mechanical mouse. It also has a ball underneath it but optical sensors are used in order to devise the direction in which the user wants to move the cursor.
- Optical Mouse:- An optical mouse uses a LED(Light-emitting diode) to illuminate the surface over which it is kept. A light sensitive device senses the reflected light. The reflected light changes as the mouse moves from light to dark areas on the surface underneath and the mouse measures the distance travelled by counting these changes.
- A much more advanced optical mouse was introduced by Microsoft in the year 1990, known as the "Intelli Mouse".