INPUT DEVICES OF COMPUTER SYSTEM

INPUT DEVICES

Following are few of the important input devices which are employed in a computer:

 * Keyboard

* Mouse

* Joy Stick

* Pointer

* Track Ball

* Scanner

* Graphic Tablet

* Microphone

* ink Card Reader (MICR)

* Optical Character Reader (OCR)

* Code Reader

* Optical Mark Reader (OMR)

Keyboard:

Keyboard is that the most typical and really popular data input device which helps in inputting data to the pc. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions. Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys also are available for Windows and Internet. The keys on the keyboard are as follows: SL. No Keys Description 1 Typing Keys These keys include the letter keys (A-Z) and digit keys (0-9) which generally give same layout as that of typewriters. 2 Numeric Keypad it's accustomed enter numeric data or cursor movement. Generally, it consists of a group of 17 keys that are laid enter the identical configuration employed by most adding machines and calculators. 3 Function Keys The twelve function keys are present on the keyboard which are arranged in a very row at the highest of the keyboard. Each function key has unique meaning and is employed for a few specific purpose. 4 Control keys These keys provide cursor and screen control. It includes four directional arrow keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc). 5 Special Purpose Keys Keyboard also contains some special purpose keys like Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen.

Mouse :

Mouse is preferred pointing device. it's a really famous cursor-control device having atiny low palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed. Generally it's two buttons called left and right button and a wheel is present between the buttons. Mouse will be wont to control the position of cursor on screen, but it can't be accustomed enter text into the pc. 

Advantages

* Easy to use

* Not very expensive

* Moves the cursor faster than the arrow keys of keyboard.

Joystick:

Joystick is additionally a pointing device which is employed to maneuver cursor position on a monitor screen. it's a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a very socket. The joystick is moved altogether four directions. The function of joystick is analogous to it of a mouse. it's mainly utilized in Computer Aided Designing (CAD) and playing computer games. Light Pen Light pen may be a pointing device which is analogous to a pen. it's wont to select a displayed menu item or draw pictures on the monitor screen. It consists of a photocell and an optical system placed in a very small tube. When the tip of a light-weight pen is moved over the monitor screen and pen button is pressed, its photocell sensor detects the screen location and sends the corresponding signal to the CPU. Track Ball Track ball is an device that's mostly utilized in notebook or notebook computer, rather than a mouse. this is often a ball which is half inserted and by moving fingers on ball, pointer will be moved. Since the full device isn't moved, a track ball requires less space than a mouse. A track ball comes in various shapes sort of a ball, a button and a square.

Scanner:

Scanner is an data input device which works more sort of a photocopy machine. it's used when some information is obtainable on a paper and it's to be transferred to the magnetic disc of the pc for further manipulation. Scanner captures images from the source which are then converted into the digital form which will be stored on the disc. These images may be edited before they're printed.

Digitizer :

Digitizer is an device which converts analog information into digital form. Digitizer can convert a symbol from the tv or camera into a series of numbers that might be stored in an exceedingly computer. They will be utilized by the pc to make an image of regardless of the camera had been pointed at. Digitizer is additionally called Tablet or Graphics Tablet because it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is employed for doing fine works of drawing and image manipulation applications. Graphic Tablet

Microphone:

Microphone is an data input device to input sound that's then stored in digital form. The microphone is employed for various applications like adding sound to a multimedia presentation or for mixing 

Magnetic Ink Card Reader (MICR):

 MICR device is usually utilized in banks thanks to an outsized number of cheques to be processed a day. The bank's code number and cheque number are printed on the cheques with a special sort of ink that contains particles of magnetic material that are computer readable. This reading process is termed ink Character Recognition (MICR). The most advantages of MICR is that it's fast and fewer error prone. Magnetic Ink Card Reader(MICR)

Optical Character Reader(OCR): 

OCR is an data input device wont to read a printed text. OCR scans text optically character by character, converts them into a code code and stores the text on the system memory.

 Bar Code Readers:

 Bar Code Reader could be a device used for reading bar coded data (data in sort of light and dark lines). Bar coded data is usually employed in labelling goods, numbering the books etc. it's going to be a hand-held scanner or is also embedded in a very stationary scanner. Universal Product Code Reader scans a Universal Product Code image, converts it into an alphanumeric value which is then fed to the pc to which code reader is connected.

Optical Mark Reader(OMR): 

OMR may be a special kind of optical scanner wont to recognize the sort of mark made by pen or pencil. it's used where one out of some alternatives is to be selected and marked. it's specially used for checking the solution sheets of examinations having multiple choice questions.

VIDEO TUTORIAL OF INPUT DEVICES