Input Devices

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

• Used in fast food restaurants, offices and shops.

• Enables fast data entry - There is no need to type in the whole command.
• Waterproof - useful in a restaurant environment.
• Tamperproof - preventing people from keying in information which could corrupt the system.

A numeric keypad is a keyboard with only numbers.

• 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 the PIN, or amount of money.
• Used to enable fast entry of numeric data into a spreadsheet.

• 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.

• 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.

A mouse is a pointing device used for making selections and giving instructions to the computer. The left button is for making a selection by double-clicking on it and the right button is to bring drop-down menus. There is a scroll button which speeds up the process of moving through the document.

• 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.

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

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

The touchpad is a pointing device used in laptops to control the pointer by moving fingers on the touchpad.

• 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 menu items.
• Used for selecting an icon.

• 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.

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

• 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

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

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

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

• Used for playing Computer games.
• Operating Car-driving, flight simulators and automatic wheelchairs.
• Selecting items and menu options similar to a mouse.

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

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

Touch screens are popular on handheld and portable devices for input as well as output.

• Used in information Kiosks
• Used on Tablet computers
• Uses as Laptops screens
• Used on Smartphones
• Used in Supermarkets on EPOS machines
• Used in ATMs
• Used in Restaurants
• Used in Airport - for self-check-indevices

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

• Screen gets dirty making items on-screen hard to see.
• The danger of spreading germs with many people touching the same screen.
• Expensive than a keyboard and mouse.

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

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

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

Scanner is an input device, which is used for coverting hardcopy documents to digital formats or soft copies.

• 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).

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

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

A graphic tablet is a flat sensitive surface on which we can draw using a special pen and the drawing will appear on the monitor for saving in the computer. it is mainly used for free-hand drawing.

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

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

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

Digital cameras are input devices used for capturing digital images and videos of objects.

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

• 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.

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

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

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

Tra

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

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

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

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

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

• 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 the cost is less.
• They can work in dangerous environments (eg: down deep mines or in nuclear reactors etc.).

• Purchase cost.
• Dirt and grease may affect performance.