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  1. Computer Systems and Information Technology Applications Facilitator: Nischeet Ratna Tuladhar Email:
  2. Unit II: Input Devices 1. Definition of Input Devices 2. its type (Mouse, Keyboard, Microphone, Scanner, TouchPanel, MICR, OBR and OMR), 3. Uses of input devices.  Content of this unit
  3. What is Input Device?  An input device is any hardware device that sends data or instruction to a computer, allowing you to interact with and control it.  For example  Keyboard and mouse are primary input devices of Computer System.  There are many types of input devices like: Microphone, Scanner, webcam, bar-code Reader, TouchPanel, MICR, OBR(Optical Braille Recognition)and OMR (Optical Mark Recognition)
  4. Types of Input Devices: 1. Keyboard 2. Mouse 3. Microphone 4. Scanner 5. Touch Panel 6. MICR 7. OBR 8. OMR
  5. Keyboard:  Keyboard is an input device consisting of a set of typewriter like keys that enables you to enter data into a computer.  Computer keyboards are similar to electric typewriter keyboard but contains additional keys .  Different types of keys are:  Alphanumeric Keys: alphabet and numbers  Punctuation Keys: Comma, Period, Semicolon and so on.  Special Keys: Function, Command, arrow, Caps lock etc.  The standard layout of keyboard is QWERTY keyboard.  It was designed in 1800 for mechanical typewriter to write slowly to avoid jam while typing.  Another keyboard design for fast typing is Dvorak Design  IBM Keyboard contains additional page up, page down, home, end, Insert, pause, numlock, scroll, break, etc  Apple computer have several keyboards called ADB keyboards
  6. Mouse:  Mouse is a device that controls the movement of the cursor or pointer on display screen.  A mouse is a small device that can be roll along the hard flat surface.  Mouse / Mice contains at least one button and sometimes three buttons which have different functions.  Invented by Douglas Engelbart of Stanford Research Center in 1963, and pioneered by Xerox in 1970  Mouse is a breakthrough technology to use as main input device in GUI based programs.  Types of Mouse/Mice:  Mechanical: Used Metal or rubber ball as it can know the direction of device with the rolling.  Opto-mechanical: Used optical sensor but still is mechanical mouse.  Optical: Uses laser to detect the mouse’s movement. It is more quick than mechanical mouse.  Mouse or mice are connected to PC with either Serial mice Connect which is PS/2 port or Bus mice through interface card or Cordless which is not connected physically.
  7. Microphone  A Microphone is an input device that was developed by Emile Berliner in 1877.  It is used to convert sound waves into electric waves or input the audio into computers.  It captures audio by converting sound waves into an electrical signal, which may be a digital or analog signal.  This process can be implemented by a computer or other digital audio devices.  Regularly, microphones are designed on the basis of directionality, besides the type of device.  Such as, Omnidirectional microphones are capable of picking up all sounds in an area, but it is unable to dfocus on a particular subject with background noise.  What is the use of a microphone on the computer?  It is used for voice recording.  It offers users the option of voice recognition.  It allows users to record sound of musical instruments.  It enables users to online chatting.  It allows us for VoIP (Voice over internet protocol).  It is also used for Computer gaming.  Furthermore, it can record voice for singing, podcasts, and dictation.
  8. Scanner  Scanner is an input device that reads text or image that translated the information into a form that the computer uses.  Scanner works by digitizing an image dividing into a grid of boxes and representing each box whether with zero or one.  The resulting matrix of bits, called a bit map can then be stored in a file, displayed on a screen and manipulated by programs.  Optical scanners do not distinguish text from illustrations.  For reading text type scanning require OCR (Optical Character Recognition) system to translate the image into ASCII characters  Different Types of Scanner:  Flatbed Scanner: It has a glass pane and a moving optical CIS or CCD array.  Handheld Scanner: It is a small manual scanning device which is held by hand and is rolled over a flat image that is to be scanned.  Sheetfed Scanner: In this scanner, the document is inserted into the slot provided in the scanner.  Drum Scanner: Drum scanner has a photomultiplier tube (PMT) to scan images.  Photo Scanner: It is designed to scan photographs.
  9. Touch Panel  Touch panel or screen is a type of display screen that has a touch sensitive transparent panel covering the screen.  Instead of using a pointing device such as a mouse or light pen, you can use your finger to point directly to objects on the screen.  Although screens provide a natural interface for computer novices.  These types of devices like smartphone, tablet, touch monitors that uses touch of a figure as input data.  But due to the big size of the finger touch some time its is not ideal for input.  For that a touch pen can be useful as the touch point of pen will be much smaller than that of a figure which can be useful for some precise work like graphics design.
  10. MICR  MICR (magnetic ink character recognition) is a technology invented in the 1950s that's used to verify the legitimacy or originality of checks and other paper documents.  It allows the computer to recognize characters printed using magnetic int.  It is use in bank.  In the bank, cheques that are have some number which is printed on the bottom are made with special type of magnetic ink and these devices reads those characters.  Some other related technology will be debit / credit card black magnetic strip which is read in ATM machines some information about user in a bank.  Another example can be ID card that which use such technology to verify the user to enter some place or room.
  11. OBR  Optical Bar Code Reader (OBR) which is used for reading bar- coded data.  It scans a set of vertical bars of different width for specific data and is used to read tags.  Bar code reading is done by a light pen or scanner connected to a computer.
  12. OMR:  OMR is gathering information from human beings by recognizing marks on a document.  OMR is accomplished using a hardware device (scanner) that detects a reflection or limited light transmittance on or through a piece of paper.  OMR allows for the processing of hundreds or thousands of documents per hour.  For example, students may recall taking tests or surveys where they filled in bubbles on paper (shown right) with a pencil.
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