Pointing Input Devices

1.    Mouse

In computing, a mouse functions as a pointing device by detecting two-dimensional motion relative to its supporting surface. It is used as a pointer. It can perform functions like selecting menu commands, moving icons, resizing windows, starting programs, and choosing options.

Types of mouse

There are basically three different types of mice:

Mechanical

Type of computer mouse that contains a metal or rubber ball on its under side. When the ball is rolled in any direction, sensors inside the mouse detect this motion and move the on-screen mouse pointer in the same direction.

Opto-mechanical

The most common type of mouse found in most PCs is the opto-mechanical mouse. This mouse works by using a small rubber ball that rotates as the mouse is moved around the mouse pad.

Optical

The most common type of mouse found in most PCs is the opto-mechanical mouse. This mouse works by using a small rubber ball that rotates as the mouse is moved around the mouse pad.

2.     Track ball

A trackball is a pointing device that works like an upside-down mouse. You rest your index finger or thumb on an exposed ball, then place your other fingers on the buttons. To move the pointer around the screen, you roll the ball with your index finger or thumb. Because you do not move the whole device, a trackball requires less space than a mouse.

3.    Game Controllers

Game controllers generally fall into two broad categories: game pads and joysticks. Joysticks enable the user to “fly” or “drive” through a game, directing a vehicle or character. They are popular in racing and flying games. A variant of the joystick is the racing game controller, which includes an actual steering wheel; some racing game controllers even include foot pedals and gearshifts. A game pad is a small, flat device that usually provides two sets of controls—one for each hand. These devices are extremely flexible and are used to control many kinds of games.

4.    Touch pad

A touchpad is an input device which is usually found on a laptop computer. A touchpad can be used in place of a mouse. By dragging your finger over the surface of the touchpad, sensors underneath detect the movement direction and speed. The sensors only react to a fingertip and not a pencil or other object. There are usually two buttons next to the touchpad which are used to replace the left and right mouse button.

5.    Touch screen

A touch screen is the only device which works as both an input and an output device. You view the options available to you on the screen (output) and you then use your finger to touch the option that you have chosen (input). Touch screens accept input by allowing the user to place a fingertip directly on the computer screen, usually to make a selection from a menu of choices. Most touch screen computers use sensors on the screen’s surface to detect the touch of a finger, but other touch screen technologies are in use, as well.

6.    Light pen

An input device that utilizes a light-sensitive detector to select objects on a display screen. A light pen is similar to a mouse except that with a light pen you can move the pointer and select objects on the display screen by directly pointing to the objects with the pen.