Input Devices of Computer

by | Apr 17, 2021 | Computers

inputDevices

In this blog we are going to discuss about Input Devices in computer System and the functions of different Input Devices.

As we know computer takes data or command input to process any task because processing needs data and instruction.

What is Input Device in Computer System?

An Input Device is a piece of Hardware which is used to send data and control signals into computer system for processing.

Some of the most common input devices nowadays are keyboard, mouse, touch pad and touch screen.

  • Keyboard
  • Mouse
  • Joystick
  • Light Pen
  • Graphic Tablet
  • Track Ball
  • Touch screen
  • Scanner
  • Optical Character Recognition (OCR)
  • Optical Mark Recognition (OMR)
  • Magnetic Ink Character Recognition (MICR)
  • Bar Code Reader(BCR)
  • Web Camera
  • Microphone

Keyboard

Keyboard is the most common input device. Christopher Latham Sholes (February 14, 1819 – February 17, 1890) was an American inventor who invented the QWERTY keyboard, and, along with Samuel W.

Keyboard is very much similar to an Electric typewriter with some additional keys. It allows a user to input alphabet, numbers and symbols into the computer. Not only typing keys keyboard also have modifier and function keys.

Depends upon the number of keys the keyboard can be categorized as Normal Keyboard or Multimedia keyboard. A normal keyboard may have 101 keys while a multimedia can have keys more than 111.

Mouse

Mouse is a hand-held pointing input device which is essential for GUI environment. As we move the mouse a cursor or pointer also moves on the screen.

Mouse has Three buttons-  Primary, Secondary and Scroll wheel. Basic operation of primary button is Single click, Double click, Press and release. Secondary button has only single click operation. Wheel button is used to scroll pages or lines.

The computer mouse was invented and developed by Douglas Engelbart, with the assistance of Bill English, during the 1960s and was patented on November 17, 1970.

Joystick

Joystick is a pointing type input device used to play games on computer. Actually it is like a handle that pivot on a base and sends its direction or angle to the computer as data.

A joystick, also known as the control column, is the principal control device in the cockpit of many civilian and military aircraft, either as a centre stick or side-stick.

Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer. Most of the time joystick used to play racing games.

A popular variation of the joystick used on modern video game consoles is the analog stick.

Light Pen

A light pen is also a computer pointing input device. It’s light-sensitive wand used in conjunction with a computer’s cathode-ray tube (CRT) display. It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy.

Digitizer or Graphic tablet

Graphic Tablet is a pointing input device, also known as digitizer used for converting hand-drawn artwork into digital images. The user draws with a stylus on a special flat surface as if they were drawing on a piece of paper. The drawing appears on the computer screen and can be saved, edited, or printed.

While scanners can only create digital images from drawings, graphic tablets offer greater control and versatility for artists by allowing them to see their drawing appear live on their monitor as they create it.

Trackball

Trackball is a pointing input device that look like a upside down mechanical mouse. Instead of moving the whole device to move the cursor on the screen, trackball requires the ball to be rotated

Touch Screen

Touch screens is an input device that accepts input when the user places a fingertip on the computer screen. The computer selects the option from the menu of screen to which the finger points. Touch screen are generally used in applications like Automated Teller Machine (ATM)

Touch screens have an infrared beam that criss-cross the surface of screen. When a fingertip is touched on the screen, the beam is broken, and the location is recorded.

Scanner

Scanner is an optical input device that uses paper document as a source input data. The scanned data can be text or image on a paper. Scanner convert data into an electronic form that can be stored on the computer.

Scanners come with utility software that allow the stored scanned documents to be edited, manipulated and printed. Hand-held scanner and flat-bed scanner are the two common types of scanners.

Optical Character Recognition (OCR)

Optical Character Recognition is an optical input device. It is used to scan printed page using OCR software that can translate the image as ASCII text that is editable. The text file generated with OCR can store in different format.

Optical Mark Recognition (OMR)

OMR is an optical input device used to detect marks on a paper. The marks are recognized by their darkness.  The OMR scans the forms, detects the mark that is positioned correctly on the paper and is darker than the surrounding paper, and passes this information to the computer for processing by application software.

OMR is widely used to read answers of objective type tests, where the student marks an answer by darkening a particular circle using a pencil. OMR is also used to read forms, questionnaires, order forms, etc.

For this, it uses a beam of light that is reflected on the paper with marks, to capture presence and absence of marks. The optical mark reader detects the presence of mark by measuring the reflected light. The pattern of marks is interpreted and stored in the computer.

Magnetic Ink Character Reader (MICR)

Magnetic ink character reader is an optical input device. When a cheque is passed through Magnetic Ink Character Reader, the magnetic field causes the read head to recognize the characters or numbers of cheque.

MICR is used in banks to process large volumes of cheques. It is used for recognizing the magnetic encoding numbers printed at the bottom of a cheque.

The numbers on the cheque are human readable, and are printed using an ink which contains iron particles. These numbers are magnetized. The readers are generally used in banks to process the cheques. The numbers in the bottom of the cheque include the bank number, branch number and cheque number. The reading speed of MICR is faster than OCR.

Bar Code Reader(BCR)

Bar code Reader is an optical input device. Bar codes are adjacent vertical lines of different width that are machine readable. Goods available at supermarkets, books, etc. use bar code for identification. Bar codes are read using reflective light by bar code readers. This information is input to the computer which interprets the code using the spacing and thickness of bars. Hand-held bar code readers are generally used in departmental stores to read the labels, and in libraries to read labels on books.

Bar code readers are fast and accurate. They enable faster service to the customer and are also used to determine the items being sold, number of each item sold or to retrieve the price of item.

Webcam or Web camera

Webcams are different from digital cameras in two ways. Firstly, they cannot operate independently from a computer, and second, they have no inbuilt memory. Although webcams can capture photographs and videos, they are more often used to live-stream videos or facilitate video chats.

Microphone

Microphone is an input device used to input sound or voice into the computer.

Conclusion

Input device is the hardware equipment  used to input data into the computer. There are so many input devices we discused in this blog. You are free to email us for any doubt or to suggest new topic.