Input Devices

M1-R5.1 & CCC · Chapter 1: Introduction to Computer · 6 min read

Input devices

  • Input devices are used to input data and instructions into a computer system. 
  • An input device converts input data and instructions into a suitable binary form which is stored the primary memory of a computer.

Types of Input Device- 

Typing Device

Keyboard: 

  • The most widely used input device today is the keyboard. 
  • They allowed data entry into a computer system by pressing a set of Keys. 
  • The most popular keyboard used today is 101 to 108 keys.
  • Keyboard which is also known as Qwerty keyboard. 
  • Sir Christopher Latham Sholes invented the first Qwerty keyboard.
  • Keyboards are of Two types-
    • Standard Keyboard (General purpose keyboard) 
    • Multimedia keyboard (Special Purpose keyboard)
  • Types of Keys
    • Alphanumeric Keys— [A-Z],[a-z],[0-9]
    • Numeric Keyboard —The numeric Keyboard is a set of keys that looks like an adding machine with it 10 digit and mathematical Separator [ +, -, *, / ] 
    • Arrow keys — [up (↑), down (↓), right (→), left (←)]
    • Special function Keys — The Keyboard also has a set of special function keys,  Some important keys are –→ Enter Key, Backspace, Tab, Capslock, Numlock, Home, End, delete, page up, page down, insert space bar, print screen etc.
    • Function keys — there are 12 function keys in a keyboard. F1, F2, F3, F4 F5, F6, F7 F8, F9 F10. F11, F12 
    • Symbol Keys —  [<,>,+,-,*,-,!,#,@,&,%,$,\,/,{} 

Mouse :– 

  • It performs functions by detecting mouse dimensions motion.. 
  • It is held in one hand and moved across a flat surface. 
  • Generally it consists of two or three buttons on the top.
  • The mouse can also be used to control the computer system. 
  • It is also used to draw sketches, diagrams etc. 
  • Mouse was invented by Douglass Engelbart of Standard research centre in 1963.
  • Various technique that are used by mouse:- Operations performed by mouse-

1)pointing

2)Click, double click, triple click

3)left click (primary button), Right click (secondary button)(shortcut menu)

4.Scrolling

5.Drag and drop

6.Selection

  • There are two types of mouse:

I. Mechanical mouse(It uses rubber ball and sensor)

II. Optical mouse(It was light emitter and light detector or sensing based)

Trackball: It has a ball on its top which can be rolled by finger to move a graphics cursor around the screen.

Joystick: A joystick is a pointing device that looks like a car's gear and has a handle and a button on the top of the handle for controlling it is used to play games.

Light-pen or electric pen: It is a pen based system, you hold the pen in your hand and directly point with it  on the monitor or digitizer screen to select menu,icons,creating any image and canvas.

Touch screen: 

A touch screen enables us to choose from available options by simply touching with our finger on the desired icon or menu items, displayed on the screen.

Data scanning device:

Scanner: Data scanning devices are used for direct data entry into the computer system from the source document. A Scanner is a scanning device. It is a hardware device which is used to scan text or images into the computer system.

Type of scanner:

  1. Flatbed scanner [desktop scanner]
  2. Sheet bed scanner[roller fed scanner]
  3. handheld scanner [portable scanner]

OMR[Optical mark reader]: OMR are special scanners used for recognizing a pre-specified type of marks made by pencil or pen. It is used in various entrance examinations.

OCR[Optical characteristics reader]: This device is capable of detecting alphabetic and numeric characters on a computer print out containing a complete page of typed or handwritten text.

BCR[Bar code recognition ]: BCR are special devices used to read bar coded data. Bar code is a specialised code used for fast identification of items. It consists of small, dark and light strips called a bar.

MICR[Magnetic ink Character recognition]: MICR is used by the banking industry to facilitate the processing of cheques . MICR characters are printed in a special type face with a magnetic ink or toner usually containing iron oxide .

MICR code is made up of 9 characters.

Example: 201209202 →  201     209                202

                                 City name  Bank name    Branch name

Electronic or magnetic card reader: It is normally connected to a computer. It is used to read data encoded on the magnetic card and transfer it to a computer for further processing.

Digitizer: It is used for converting pictures, maps and drawing into a digital form for storage in computer. It is a tool used to convert hand-drawn images into a format suitable for computer

processing. It is also known as a graphics tablet.

Voice recognition system: This device allows a person to input data into a computer system by speaking to it.

Ex: Microphone.

Vision based: A vision based input system allows a computer to accept an input by seeing an object. Ex: web Camera