Topics / Hardware and Software / Input Devices

Input Devices

Input devices are peripherals used to provide data and control signals to a computer.  Input devices allow us to enter raw data for processing.

There are many examples of input devices, each with their own benefits and drawbacks.


MouseWhat is a mouse?

A mouse is an input device that allows you to control the coordinates and movement of the onscreen cursor/pointer by simply moving the mouse across a flat surface with your hand.

Items can be selected or moved using the left mouse button, whilst the right button usually displays additional menus.

Most mice are now optical which means they use a laser to detect and track movement across the surface.

Mice can be wired or wireless.

Typical Applications

  • Used in everyday computing to control the pointer in GUIs.
Benefits Drawbacks
Simple and easy to use Requires a flat surface
Efficient way to navigate Requires space to operate


Input Device - TrackballWhat is a trackball?

A trackball is an input device used to control a pointer/cursor. Unlike a mouse, the device stays stationary whilst the user moves the ball within its socket.  Trackballs can be stand-alone devices or combined into a keyboard or control panel.  Some people prefer using a trackball over a mouse as they believe it gives them a finer degree of control over the pointer.  They are also handy for people with limited hand motor skills as they are less demanding then a mouse.

Typical Applications

  • Computer Aided Design (CAD) for fine control
  • Situations when space is limited
  • Disabled people with limited motor skills
Benefits Drawbacks
Needs little desk space May take some getting used to
Fine control over the pointer
Can be integrated into a keyboard



What is a keyboard?

Keyboards are input devices that allow the entry of data and commands by simply pressing down keys on the keyboard.

Keyboards are a common place input device, often used alongside a mouse.  They can be wired or wireless.

Typical Applications

  • Used in everyday computing to maunally enter data and commands, e.g. writing a report in a word processor
Benefits Drawbacks
Simple and easy to use A slow way to enter lots of data if not a trained typist
Potentially a fast way to enter data Mistakes can be made if not careful

Concept Keyboard

What is a concept keyboard?

A concept keyboard is an input device similar to a traditional keyboard but each key/button is identified by an image.  The images are chosen to symbolise the command/option each key represents.  E.g. In a fast food restaurant, the concept keyboard belonging to the cashier’s till may use images to represent each type of meal available to purchase, or each size of drink that can be chosen.

Traditional ‘overlay’ concept keyboards are now being replaced with virtual concept keyboards using touchscreens.

Typical Applications

  • Cashier tills, e.g. fast food restaurant
Benefits Drawbacks
Reduces the training required as they are easy to use Not suitable for large amount of options/choices
Ideal when options/choices are few Not suitable for all tasks
May speed up data entry


Input Devices - MicrophoneWhat is a microphone?

Microphones are input devices that take analogue sound waves and converts them into electrical signals, suitable for a computer to understand.  Microphones play an important role in speech recognition, a technology that is gaining in popularity and usage.

Typical Applications

  • Mobile phones, e.g. for traditional phonecalls or VoIP
  • Tablets and laptops, e.g. for video conferencing or VoIP
  • Voice recognition systems, e.g. to input data and commands using spoken words
Benefits Drawbacks
Allows disabled users to give instructions to a computer Speech recognition accuracy can sometimes be hit and miss
Enables the use speech recognition software
Allows voice calls and the audio in video calls (VoIP)

Digital Camera

Digital CameraWhat is a digital camera?

Digital cameras are input devices that capture images (and sometimes video) digitally.  Digital cameras use an image sensor chip to capture the image, rather than the film used by a traditional camera.

The images recorded on a digital camera are stored on memory cards, although some may have a limited amount of external memory of its own.

Digital cameras feature an LCD screen which allow you to preview and review your images, plus change menu settings.

Typical Applications

  • Professional photography, using DSLRs
  • Amateur photography
  • Speed cameras, e.g. using OCR software to read registration plates
Benefits Drawbacks
Images can be reviewed immediately via the screen A good camera is needed to match the quality of traditional film
Images can be copied or edited easily on a computer Large capacity memory cards are needed if shooting lots of photos
Images can be automatically added to sharing sites

2D Scanners

Flatbed Scanner

What is a 2D scanner?

2D scanners perform the task of turning a 2D document or image into a digital file.  They come in two varieties, flatbed or handheld.  Some printers have inbuilt flatbed scanners.

The functionality of 2D scanners is enhanced when combined with OMR and OCR software.  For example, OCR software can convert scanned in text into a computer readable form.

Typical Applications

  • Converting a hard copy of a document into an electronic / digital form for storage, sending or editing
  • Reading passports
Benefits Drawbacks
Can produce high quality digital copies of a document Scanned documents use a lot of computer storage space
Digital copies of documents can be sent electronically, stored securely, or edited on the computer

3D Scanners

Airport Security Scanner

What is a 3D scanner?

A 3D scanner is an input device that creates a 3D model of the object scanned.

Scanning can be achieved either by using lasers, light, radio waves or x-rays.

Typical Applications

  • Security screenings to check for weapons or restricted objects
  • Creating a computer model ready for 3D printing
  • Biometric devices
  • Turning real people into gaming characters


Benefits Drawbacks
The technology can scan through clothing and other materials Repeated exposure to x-rays can be harmful
3D scanning provides accurate 3D computer models

Interactive Whiteboard

Interactive WhiteboardWhat is an interactive whiteboard?

Developed long before touchscreens became affordable, interactive whiteboards combine a large touch sensitive board with a projection screen.  Interactive whiteboards are versatile input devices, allowing navigation and drawing/writing via your finger or special dummy pens.

Typical Applications

  • Classrooms
  • Business board rooms and training centres
Benefits Drawbacks
Large display allowing multiple people to view at once Requires the interactive board, a projector and a computer
Interactivity helps learning and presentations Difficult to complete tasks that require precision accuracy
Very versatile Can be difficult to view in bright light
Text and drawings made using the special pen can be captured and stored for later use


touchscreenWhat is a touchscreen?

A touchscreen is an electronic visual display that also incorporates an input device that responds to touch.  This allows users to select options from a screen by simply touching them.

There are three main types of touchscreen technology, all of which are outlined below.

Typical Applications

  • Smartphones and tablet computers, e.g. easy input of data and selection of apps/icons
  • Ticket / Information kiosks, e.g. allows limited options that can be selected easily
Benefits Drawbacks
Save space as both input and output are combined Difficult to complete tasks that require precision accuracy
Simple and easy to use Difficult to use if damaged
Works well with icons, allowing options to be selected easily

Capacitive touchscreens

Electrical current is sent from the four corners of the screen.  When your finger (or stylus) touches the screen, the current changes.  This allows the location of the touch to be calculated.

Benefits Drawbacks
Good visibility in sunlight Glass screen can shatter/break on impact
Very durable surface Cannot use wearing standard gloves
Allows multi-touch

Resistive touchscreens

Resistive touchscreens use multiple layers of material that transmit electrical currents.  When the top layer of the screen is pushed/touched into the bottom layer the electrical current changes.  This allows the location of the touch to be found.

Benefits Drawbacks
Inexpensive to manufacture Poor visibility in sunlight
Can use stylus, finger, gloved finger or pen to operate Vulnerable to scratching
Wears through time
Does not allow multi-touch

Infra-red touchscreens

Infra-red touchscreens use a pattern of LED infra-red beams to form an ‘invisible’ grid on the screen.  Sensors detect where the screen has been touched by detecting a break in the infra-red beams.  The position of touch is then calculated.

Benefits Drawbacks
Good durability Expensive to manufacture
Allows multi-touch Glass screen can shatter/break on impact
Can use stylus, finger, gloved finger or pen to operate Sensitive to dust and dirt

Barcode Reader

barcode readerWhat is a barcode?

A barcode is a machine readable code represented by an image consisting of black and white lines.  The lines in a barcode relate to numbers 0 to 9.  Black and white surfaces reflect light differently, this is how the scanner is able to identify the corresponding digits from the lines.  Scanning a barcode is easier and faster than typing in the series of numbers by hand.

A barcode identifies an item, it does not store any further information relating to it, this is achieved by looking up the value in a database.

When used in retail, you no longer need to trust sales staff to remember or key in the prices of products. Accurate receipts can be given to customers whilst the business benefits from reliable sales and stock reports.  Prices can be changed immediately without changing any barcodes.

Typical Applications

  • Tracking/identifying items in warehouses and factories
  • Retail checkouts, e.g. to find product prices and descriptions, allowing automatic stock control
  • Airports, e.g. tracking luggage
  • Library systems, e.g. tracking books and borrowers
Benefits Drawbacks
Quick and easy to identify products Difficult to use if damaged
Additional information can be easily retrieved from a database Requires expertise to setup a database
Allows the use of automated stock control and sales reports
Related information is changed in the database, meaning the barcode always remains the same

QR Code Reader

Input Devices - QR Code SmartphoneWhat is a QR code?

A QR code is a computer generated pattern capable of holding a modest amount of data.  This data is accessed when the QR code is read by a QR scanner. We often see a smartphone used as the scanning device although this doesn’t have to be the case.

QR codes often store simple data such as a URL address, contact information, calendar entries and product details (in factories and warehouses etc).

Typical Applications

  • Packaging
  • Promotional materials
  • Warehouses
Benefits Drawbacks
Data is stored within the pattern, so no need for a connected database Changing the data alters the pattern, so not suitable for information that changes regularly, e.g. prices.
Simple and quick way to store and retrieve information People need a device that can read the QR code
Can store a variety of information

Topics / Hardware and Software / Input Devices