Input Devices are used to input provide data to the computer. Depending upon data to be input, we use different input device. Some input devices are:
|• Computer mouse
• Trackball (or roller ball)
• Light pen
• Yoke (aircraft)
• Image scanner
• 3D scanner
|A mouse (plural mice or mouses) is a computer pointing device; it is designed to detect two-dimensional motion relative to its supporting surface and consists of a small case, to be held under one of the user’s hands, and one or more buttons. It sometimes features other elements, such as “wheels”, which allow the user to perform various system-dependent operations, or extra buttons or features can add more control or dimensional input. The mouse’s motion typically translates into the motion of a pointer on a display.
|A Keyboard is a basic input device for a computer. Keyboards are designed for the input of text and characters and also to control the operation of a computer. In normal usage, the keyboard is used to type text into word processor, text editor, or any other textbox. A keyboard is also used to type commands in a computer. Under Linux, MS-DOS and some older versions of Windows, Ctrl+Alt+Delperforms either a ‘cold’ or ‘warm’ reboot.
|A trackball is a pointing device consisting of a ball housed in a socket containing sensors to detect rotation of the ball about two axes—like an upside-down mouse with an exposed protruding ball. The user rolls the ball with the thumb, fingers, or the palm of the hand to move a cursor. Large tracker balls are common on CAD workstations for easy precision. Before the advent of the touchpad, small trackballs were common on portable computers, where there may be no desk space on which to run a mouse. Some small thumb balls clip onto the side of the keyboard and have integral buttons with the same function as mouse buttons.
|A touchpad is an input device commonly used in laptop computers. They are used to move the cursor, using motions of the user’s finger. They are a substitute for a computer mouse. Touchpads vary in size but are rarely made larger than 20 square centimeters (about 3 square inches). They can also be found in PDA [Personal Digital Assistant] . Touchpads commonly operate by sensing the capacitance of a finger, or the capacitance between sensors. It is a relative motion device.
|Touchpads are primarily used in portable laptop computers, because the usual mouse device requires a flat table adjacent to the keyboard not always available away from the office. But touchpads have some advantages over the mouse, particularly that the pad’s position is fixed relative to the keyboard, and very short finger movements are required to move the cursor across the display screen. Some computer users prefer them for such reasons, and desktop keyboards with built-in touchpads are available from specialist manufacturers.
|A joystick is a personal computer peripheral or general control device consisting of a handheld stick that pivots about one end and transmits its angle in two or three dimensions to a computer.
|Joysticks are often used to control games, and usually have one or more push-buttons whose state can also be read by the computer.
|It is a input device in the form of a light-sensitive wand used in conjunction with the computer’s CRT monitor. It allows the user to point to displayed objects, or draw on the screen, in a similar way to a touch screen but with greater positional accuracy. A light pen can work with any CRT-based monitor.
|In computing, a scanner is a device that analyzes an image (such as a photograph, printed text, or handwriting) or an object (such as an ornament) and converts it to a digital image.
|A 3D scanner is a device that analyzes a real-world object or environment to collect data on its shape and possibly color. The collected data can then be used to construct digital, three dimensional models that are used in a wide variety of applications. These devices are used extensively by industry in the production of such things as movies and video games. Other applications include industrial design and prototyping, computer vision and documentation of cultural artifacts.