1-Keyboard :- The most common and popular device is a Keyboard. That contain all the alphanumeric and symbol keys. It allows the user to enter the letter, numbers and symbols into the computer, basically this keyboard help the user for inputting the data into the computer system. Keyboard is basically of two size 84 keys or 102 keys, but now a days 104 keys or 108 keys is available.
There are basically a five types of keys in there in keyboard-
I
- Function keys:- There are f1 to f12 are 12 functions keys are present on the keyboard.these are the short keys. These are arranged on the top of the keyboard. Each keys has its own individual function.
II- Control key:- These includes Home, End, Insert, Page up,Page down, Delete, Ctrl, Alt, Esc. These provide cursor and screen control. There are also four arrows keys.
III- Special purpose keys:- It include Shift, Caps lock, Num Lock, Space bar, Tab, etc.
IV- Typing keys- These include the letter keys A to Z and digits keys 0-9 which generally look like a typewriter.
V- Numeric Keypad- It consist of 17 keys that are used for some calculation like arithmetic operation. These are basically to put the numeric data.
2- Mouse:- The another popular input device is a mouse. This is a pointing device. This is basically used for control the movement of cursor on the display or on the screen. There are mainly three types of mouse.
-Mechanical mouse.
-Opto-mechanical mouse.
- Optical mouse.
The first mouse used in the market is a mechanical mouse. In the mechanical mouse there is two click right and left and there is no scroll bar. After that there optomechanical mouse comes in market with a scroll bar in between the left and right click. After that at last now a days we used the optical mouse.In this optical mouse we used the laser light , there is a grid in the center part of mouse with a sensor there, that sense the laser light which move the cursor movement on the screen.The fig shows the optical mouse.
3- Light pen- This is another pointing device. It is used to select any of the picture or menu items on the display or monitor screen. It consist of photocell and optical system placed in a small tube.Light pen can work with an CRT based display but not with LCD's and other display technology.
4- Track ball- This is another input device that is mostly used to move the pointer by moving the ball direction. It is like a mouse, there are also three buttons are there along with the ball.
5- Joystick- This is another input device. It is consist of a stick which is pivot on the base and move its angle or direction to the device which is controlling. Basically there is lever that move the direction of a pointer on the monitor screen. Pointer move according the movement of the joystick. These are normally used for computer games. Its like a mouse, the difference is when mouse stop moving the cursor on the screen stop moving but in this case the pointer continuing moving in the direction in which pointer is moving.
6- Scanner- This is a input device which is mainly used for scanning the documents mean it work more then a photocopy machine. It is basically scan your hard copy and make a soft copy on your system, and transfer it to the hard disk for further manipulation. In this when any document is scanned, it is converted into digital form that is called a soft copy which can be editable. Scanner is used in many ways-
- Flatbed scanner.
- Sheet fed scanner.
- Handheld Scanner.
- Drum Scanner.
7- Graphic tab- It is another input device. This is used as a drawing tab, in which is used by the user to draw a picture, animation and graphics. It is used like user draw a image on paper using pencil. Today's some tab are also used to capture the data or signature.
8- Microphone- Microphone is a peripheral that allows computer user to input audio into the system. There is fig which show how microphone look like. It is basically used for Online chatting, voice recognition, adding sound to a multimedia presentation or for mixing music.
9- Optical mark reader- It is a special type of optical scanner that gather information by using a hardware device that detect a reflection and the type of mark made by pen or pencil from a card or from a piece of paper.Basically it scan printed form and reads predefined position and records where marks are made on the form.
10- Optical character reader- It read text from paper or take a photograph of that one and convert them into that in which computer can understand.
11-Bar code reader- It is a device for reading bar coded data which are in the dark line. there is fig that show the bar code reader. That mainly give the detail about the product like price etc.
12- Magnetic ink card reader - MICR is a font capable of recognition using magnetically charged ink. That are basically used in banks because there are large number of cheques to be processed everyday.This is enable them to process something 300 cheques per minute with 100% accuracy.. There at the bottom of every cheque there are a series of number which records the cheque number, customer's account number etc.
