INPUT DEVICES - Uses, Advantages & Disadvantages

KEYBOARDS

Keyboard is a manual input device, used for inputting text and commands to the computer. It has QWERTY- layout.

Uses

  • Keyboards are used to input data into application software.
  • To input numbers into spreadsheets.
  • Also used to type commands to the computer (eg. Ctrl+P, Alt+F4, etc)

Advantages

  • Enables fast entry of new text into a document
  • Well tried technology and well known method of data entry
  • Ideal for applications like word processors, composing emails where you have to create original text.
  • Easy to do verification check as data is entered, as it appears on the screen simultaneously.

Disadvantages

  • Users with limited arm/wrist use can find keyboards hard to use
  • Entering data is slow when compared to direct data entry (e.g. Optical mark recognition)
  • They use up desk space as they are quite large

MOUSE

Mouse is a pointing device used for making selections and giving instructios to the computer. The left button is for making selection by double clickig o it and the right button is to bring drop-dow meus. There is a scroll button whch speeds up the process of moving through the document. 

USES

  • Make selections in a Graphical User Interface (GUI)
  • Move the pointer onto a button, icon, hyperlink etc.
  • Activate context/pup-up menu (on right click)
  • Scroll quickly through long documents

ADVANTAGES

  • Easier to select and move items than keyboard
  • Enables rapid navigation through long documents/web browsers
  • Occupies smaller area on the desktop.

DISADVATAGES

  • Difficult to use for people who have limited wrist/finger movement
  • Needs a flat surface to operate, so cannot be used on the move

CONCEPT KEYBOARD

Concept keyboard uses icons or phrases instead of standard letters. A single key represents an item on the keyboard.

USES

  • Used in fast food restaurants, offices ad shops.

ADVANTAGES

  • Eables fast data etry - there is no eed to type i the whole command.
  • Waterproof - usefull in restaurant enviroment.
  • Tamperproof - preveting people from keying in information which could corrupt the system.

NUMERIC KEYPADS

Numeric keypad is a keyboard with numbers only.

USES

  • Used in Automatic teller machines (ATMs), where customers can key in their personal identification number (PIN), or an amount of money
  • Used to key in phone numbers into telephones
  • Electronic point of sale (EPOS) terminals have numeric keypads in case the barcode reader fails
  • Used in Chip and PIN devices to key in PIN, or amount of money
  • Used to enable fast entry of numeric data into a spread sheet

ADVANTAGES

  • Numeric keypads are faster than standard keyboards for entry of numeric data
  • Since many are small devices (e.g. mobile phones), they are easy to carry around

DISADVANTAGES

  • Can be difficult to use due to the very small keys
  • Difficult to use for entering text
  • Sometimes the order of the numbers isn’t very intuitive

TOUCHPAD

Touchpad is a pointing device used in laptops to controll the pointer by moving finger on the touchpad.

USES

  • Used for opening, closing and minimising programs.
  • Used for grouping, moving and deleting files
  • Useful when editing images (e.g. controlling the size and position of the image)
  • Used for controlling the position of a pointer on the screen to select meu items.
  • Used for selecting an icon.

ADVANTAGES

  • Does not need a flat surface to operate, so can be used while travelling.
  • Built-in on laptops, so no need to carry an extra device.

DISADVANTAGES

  • Difficult to use for people who have limited wrist or finger movement
  • Hard to use for actions like – drag and drop
  • Long term use can lead to health problems like RSI

TRACKERBALL

Trackerball is a pointing device similar to a mouse except that it has a ball on the top of the device. Users can cotrol the pointer on the screen by rotating the ball.

USES

  • Used in a similar way as that of a mouse
  • Usually used by people with poor motor skills such as very young people with disabilities

ADVANTAGES

  • Easier to use than a mouse if the user has wrist or finger problems
  • Allow faster navigation than mouse
  • Requires less space than a mouse as the device remains stationary and only the ball over it moves

DISADVANTAGES

  • Not a part of default peripherals (like mouse, keyboard) and needs to be purchased separately
  • Takes time for the user to get used to the device.

JOYSTICK

Joystick is a pointing device used for selecting objects on the screen.

USES

  • Playing Computer games
  • Operating Car-driving, flight simulators, automatic wheel-chairs
  • Selecting items, menu options similar to mouse

ADVANTAGES

  • Ideal for quick movements – games, simulators
  • Easy to use for disabled people as joysticks can be operated by foot or mouth

DISADVANTAGES

  • Text selection-entry is very slow compared to keyboard, mouse
  • Expensive than mouse, keyboard
  • Generally not part of the default peripheral (keyboard, mouse) and needs to be purchased separately

TOUCHSCREEN

USES

  • Information Kiosks
  • Tablet computers
  • Laptops
  • Smart phones
  • Supermarkets EPOS
  • ATMs
  • Restaurants
  • Airport - self check in

ADVANTAGES

  • Simple to use without any training required.
  • Ideal where space is limited like Smartphone, tablet etc.
  • Tamper proof so other data cannot be entered that could corrupt the system
  • Allows faster selection than keyboard or mouse.

DISADVATAGES

  • Screen gets dirty making items on screen hard to see.
  • Danger of spreading germs with many people touching the same screen
  • Expensive than keyboard, mouse

REMOTE CONTROL

USES

  • Operate home appliances – TV, DVD players, satellite receivers, music systems, Air conditioners etc.
  • Used to operate multimedia projectors, industrial and domestic robots.

ADVANTAGES

  • Can operate a device wirelessly.
  • Ideal for people with disabilities to operate devices at a distance.
  • Can control devices safely from a distance (eg: robot used to investigate a bomb).

DISADVANTAGES

  • Uses infra-red signals which may be blocked by objects in the path thus making remote control not to operate.
  • Needs batteries to operate that need regular replacement.
  • Small buttons can be pressed by mistake that could alter the device settings

SCANNER

USES

  • To convert hard copy documents to digital format (Soft copy).
  • Used for scanning text into word-processing or other packages using built-in OCR (Optical Character Recognition)

ADVANTAGES

  • Faster data entry than keyboard if used for scanning text with OCR software.
  • Can be used to digitise old documents such as maps, pictures, photographs for archive purposes.
  • Can be used with image editors to repair, improve old photographs

DISADVANTAGES

  • Takes up a lot of space.
  • Takes long time to scan long documents like books.
  • Quality of scanned items depends on scanner resolution.
  • Text scanned using OCR may contain errors.

GRAPHIC TABLET

Graphic tablet is a flat sesitive surface on which we  can draw usig a special pen and the drawing will appear on the moitor for saving in the computer. it is mailny used for free-hand drawing.

USES:

  • Used for retouching photographs.
  • Inputting free hand drawings.
  • Used for specialist applications such as designing a kitchen using Computer Aided Design (CAD)

ADVANTAGES:

  • Accurate free hand drawing than using a mouse.
  • Used in countries like Japan, China where graphical characters are used instead of letters and words.

Disadvantages:

  • Takes up a lot of space.
  • Specialist tablets are Expensive

 

DIGITAL CAMERA

Advantages:

  • No film to develop, so quicker to produce a photo.
  • Images can be previewed and deleted immediately
  • Images are stored in the form that can be placed in documents, presentations, websites etc.
  • Many cameras are now equipped with Bluetooth, Wi-Fi enabling them to send directly via internet.

Disadvantages:

  • Quality of photos may not be as high quality as those produced using films (limited by camera resolution)
  • Photographer needs to have computer skills to use digital photographs properly.

VIDEO CAMERA

Advantages:

  • Can capture both still and moving images
  • Easy to transfer video to the computer
  • Can preview the video
  • Allows to use built in filters.

Disadvantages:

  • Can erode privacy as CCTV camera are present in many public places
  • It is difficult to produce good video without training
  • Expensive to buy.

WEBCAM

USES

  • Simple Video-conferencing.
  • Record video for inclusion in websites.
  • Taking quick photos in emigration counters in airports, identifications (ID) cards etc.

Advantages:

  • Can see reactions of people as your are talking to them.
  • Compact in size.

Disadvantages:

  • Image/video quality is poorer than Digital/Video camera
  • Usually operates in fixed positions

MICROPHONE

USES

  • Hands free operation (eg. In a car).
  • Can be used to dictate text rather than typing (Voice recognition)
  • Video conferencing
  • Add narrations in presentations, videos
  • Input speech for VoIP – Voice over Internet Protocol, an inexpensive way of conducting phone calls using internet.

Advantages:

  • Can be used by disabled people to input data/instructions.
  • Can improve safety for car phones.
  • Inexpensive

Disadvantages:

  • Background noises can cause problems for voice recognition systems
  • Voice recognition systems are inaccurate
  • Sound files, when stored, take up a lot disk space.

SENSORS

Sensors are input devices used to measure physical quantities such as temperature, pressure, humidity, amount of light, etc. The analog signals picked up by sensors can be sent to and then analysed by the computer.
Since the computer is a digital device, the analog signals from sensors have to be converted into digital using ADC – Analog to digital converter.

Advantages:

  • Accurate readings than those taken by humans.
  • Readings can be taken more frequently than humans
  • They can work even when a human is not present, so costs less
  • They can work in dangerous environments (eg: down deep mines or in nuclear reactions etc.)

Disadvantages:

  • Purchase cost
  • Dirt and grease may affect performance.

TEMPERATURE SENSOR

USES

  • Monitors temperature

  • When the temperature data is sent to the computer/microprocessor it can be used to:

    • Control heaters and coolers

    • Automatic washing machines

    • Central heating systems

    • Air conditioning systems

    • Green houses

    • Environmental monitoring systems

PRESSURE SENSOR

USES

  • Measure liquid pressure, physical and atmospheric pressure.
  • When connected to the computer/microprocessor it can be used in:
    • Burglar alarms
    • Washing machines
    • Vehicle actuated traffic signals
    • Robotics – production line control
    • Environmental monitoring (Eg. Flood warnings in rivers)

LIGHT SENSOR

USES

  • Measures light intensity.
  • When the light sensor data is sent to the computer/microprocessor it can be used to:
    • Security lights in campus
    • Street lights
    • Burglar alarm systems
    • Production line control
    • Scientific experiments
    • Environmental monitoring (Eg. Greenhouse conditions)

HUMIDITY SENSOR

USES

  • Measures amount of moisture in the air or soil.
  • When the moisture sensor data is sent to the computer/microprocessor it can be used to:
    • Ensure ideal plant growing codition in greenhouses.
    • Weather stations
    • Farming Industries to measure coating thickness, oil, resin content, protein, fat, sugar etc.

DIRECT DATA ENTRY DEVICES

MAGNETIC STRIPE READER

Used to read information on the magnetic stripe of ATM /Credit card. The stripe contain information such as start and expiry date.

Uses

  • Credit and debit cards have magnetic stripes that are used by ATMS or EFTPOS (electronic funds transfer point of sale) terminal
  • Security cards for entering building e.g. hotel rooms
  • Travel systems e.g. train and underground tickets

Advantages

  • Data entry is fast compared with keying in using a keyboard or keypad
  • System is error free, no typing involved
  • Information is secure since there is no typing and the information can’t be read directly by a person
  • Can prevent access to restricted/secure areas
  • Magnetic stripes are unaffected by oil water and moisture
  • No moving parts therefore physically robust

Disadvantages

  • If the magnetic stripe is damaged the data is lost
  • Card needs to be in close contact with the reader
  • Since the information is not human readable, they need to find a way to show the information to the customer (e.g. hotel room number not printed on cards)

CHIP AND PIN READERS

The device has a slot where the card is placed and the chip is read. A small screen is part of the reader which gives instructions to the operator

Uses

  • Chip and PIN readers are used where payments are made using cards e.g. Super markets, travel agents

Advantages

  • Provide a more secure payment system than requiring a signature or using magnetic stripe, since the PIN typed in must match up with the PIN stored on the chip
  • Provide a more robust system than magnetic stripe since the chip does not need to be in contact with the reader

Disadvantages

  • Customer needs to be careful when typing in the PIN so nobody reads it giving an opportunity for Fraud

RFID (Radio Frequency Identification)

MICR -Magnetic Ink Character Reader

Magnetic ink character recognition is a system which can read characters printed in a magnetic ink

Uses

  • Used to process cheques in banking operations – cheque is read using a batch processing method

Advantages

  • MICR offers great security than OCR since the oriented characters cannot be altered
  • There is no manual input, thus errors are reduced
  • If somebody writes over the magnetic ink characters it can still be read

Disadvantages

  • Only certain characters can be read and the number of different characters is very limited
  • It is a more expensive method than other methods used for direct data entry

OMR - Optical Mark Reader

Optical mark recognition is a system which can read marks written in pen or pencil.

Uses

  • OMR devices are used to read questionnaires, multiple choice examinations papers and other types of forms in the form of lines or shaded areas

Advantages

  • A very fast way of inputting results of a survey Since there is no typing,
  • it is more accurate than keying in data, OMR is more accurate than OCR

Disadvantages

  • Forms need to be carefully designed to make sure that the marks/shadings are correctly positioned to gather accurate information
  • There can be problems if forms aren’t filled correctly, sometimes they have to be checked manually before being read by an OMR, this is both time consuming and expensive

OCR - Optical Character Reader

Optical Character recognition is a software that takes scanned text and converts it into a computer readable form

Uses

  • Processing of passports and Identity cards
  • OCR is used when scanning documents to modify them using a suitable software

Advantages

  • Much faster data entry system than manually keying in data
  • Since there is no manual data entry, the number of errors is reduced

Disadvantages

  • The system has difficulty reading handwriting
  • It is still not a very accurate technique

BARCODE READER

Used to read information in the form of a barcode. Handheld scanners or wands are very common for reading barcodes

Uses

  • Used in supermarkets and other shops where the goods are marked with a barcode
  • Used in libraries to scan users library card and barcodes on books (in order to keep track of books on loan)
  • Used as a safety function in many companies to ensure that electrical equipment is checked on a regular basis

Advantages

  • Faster than keying in information, and fewer mistakes are made
  • Used as a way of recording data, can improve safety
  • Barcodes enable automatic stock control Barcode scanning is a tried and trusted technology
  • When an item price is changed, only the central database needs to be updated, there is no need to change the prices individually on each item.

Disadvantages

  • Barcode scanning is an expensive system to administer since every item in the shops needs a barcode and every barcode needs to be entered on the system.
  • Also there is a need to invest in the computer technology together with staff training, which can all be expensive
  • The system is not fool proof- barcode can be swapped around on items

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