Topics / Hardware / Input Devices

Input Devices

What is an input device?

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.

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Information about a range of sensors can be found on our Sensors page.


What 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 for a mouse

  • Used in everyday computing to control the pointer in GUIs.

Benefits of a mouse

  • Simple and easy to use
  • Efficient way to navigate

Drawbacks of a mouse

  • Requires a flat surface
  • 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 for trackballs

  • Computer Aided Design (CAD) for fine control
  • Situations when space is limited
  • Disabled people with limited motor skills

Benefits of trackballs

  • Needs little desk space
  • Fine control over the pointer
  • Can be integrated into a keyboard

Drawbacks of trackballs

  • May take some getting used to



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 for keyboards

  • Used in everyday computing to manually enter data and commands, e.g. writing a report in a word processor

Benefits of keyboards

  • Simple and easy to use
  • Potentially a fast way to enter data

Drawbacks of keyboards

  • A slow way to enter lots of data if not a trained typist
  • 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 for concept keyboards

  • Cashier tills, e.g. fast food restaurant

Benefits of concept keyboards

  • Reduces the training required as they are easy to use
  • Ideal when options/choices are few
  • May speed up data entry

Drawbacks of concept keyboards

  • Not suitable for large amount of options/choices
  • Not suitable for all tasks


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 for microphones

  • Mobile phones, e.g. for traditional phone calls 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 of microphones

  • Allows disabled users to give instructions to a computer
  • Enables the use speech recognition software
  • Allows voice calls and the audio in video calls (VoIP)

Drawbacks of microphones

  • Speech recognition accuracy can sometimes be hit and miss

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 for digital cameras

  • Professional photography, using DSLRs
  • Amateur photography
  • Speed cameras, e.g. using OCR software to read registration plates

Benefits of digital cameras

  • Images can be reviewed immediately via the screen
  • Images can be copied or edited easily on a computer
  • Images can be automatically added to sharing sites

Drawbacks of digital cameras

  • A good camera is needed to match the quality of traditional film
  • Large capacity memory cards are needed if shooting lots of photos

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 for 2D scanners

  • Converting a hard copy of a document into an electronic / digital form for storage, sending or editing
  • Reading passports

Benefits of 2D scanners

  • Can produce high quality digital copies of a document
  • Digital copies of documents can be sent electronically, stored securely, or edited on the computer

Drawbacks of 2D scanners

  • Scanned documents use a lot of computer storage space

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 for 3D scanners

  • 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 of 3D scanners

  • The technology can scan through clothing and other materials
  • 3D scanning provides accurate 3D computer models

Drawbacks of 3D scanners

  • Repeated exposure to x-rays can be harmful

Test your knowledge of input devices with our quick quiz.

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 for interactive whiteboards

  • Classrooms
  • Business board rooms and training centres

Benefits of interactive whiteboards

  • Large display allowing multiple people to view at once
  • Interactivity helps learning and presentations
  • Very versatile
  • Text and drawings made using the special pen can be captured and stored for later use

Drawbacks of interactive whiteboards

  • Requires the interactive board, a projector and a computer
  • Difficult to complete tasks that require precision accuracy
  • Can be difficult to view in bright light


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 for touchscreens

  • 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 of touchscreens

  • Save space as both input and output are combined
  • Simple and easy to use
  • Works well with icons, allowing options to be selected easily

Drawbacks of touchscreens

  • Difficult to complete tasks that require precision accuracy
  • Difficult to use if damaged

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.

Good visibility in sunlightGlass screen can shatter/break on impact
Very durable surfaceCannot 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.

Inexpensive to manufacturePoor visibility in sunlight
Can use stylus, finger, gloved finger or pen to operateVulnerable 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.

Good durabilityExpensive to manufacture
Allows multi-touchGlass screen can shatter/break on impact
Can use stylus, finger, gloved finger or pen to operateSensitive 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, with black bars reflecting less light than white bars.

Sensors are used to capture the amount of light reflected and the different reflections are converted to binary values.

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 for barcodes

  • Tracking/identifying items in warehouses and factories
  • Retail checkouts, e.g. to find product prices and descriptions; automatic stock control management from a database
  • Airports, e.g. tracking luggage
  • Library systems, e.g. tracking books and borrowers

Benefits of barcodes

  • Quick and easy to identify products
  • Additional information can be easily retrieved from a database
  • Allows the use of automated stock control and sales reports
  • Related information (e.g. product price) is changed in the database, meaning the barcode always remains the same

Drawbacks of barcodes

  • Difficult to use if damaged
  • Requires expertise to setup a database

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 for QR codes

  • Packaging
  • Promotional materials
  • Warehouses

Benefits of QR codes

  • Data is stored within the pattern, so no need for a connected database
  • Simple and quick way to store and retrieve information
  • Can store a variety of information

Drawbacks of QR codes

  • Changing the data alters the pattern, so not suitable for information that changes regularly, e.g. prices.
  • People need a device (and software) that can read the QR code

Graphics Tablet

Graphics Tablet - GCSE

What is a graphics tablet?

A graphics tablet is an input device that uses a special pen like stylus to allow the user to “hand draw” images into a computer system.

This allows artists to draw in a similar way to how they naturally would using pen and paper; something difficult to achieve with a mouse.

Graphics tablets can also be used for day to day data input and are especially useful for capturing handwritten signatures.

Some graphic tablets also incorporate an LCD screen for a more realistic experience.

Typical applications for graphics tablets

  • Graphic design and drawing
  • Digital signatures

Benefits of graphics tablets

  • Allows artists to draw in a fashion close to how they naturally would, giving them finer control
  • Some models are pressure sensitive (which mice are not)
  • Can be used for signatures and other general computing tasks
  • Come in a range of sizes and suitable for many budgets

Drawbacks of graphics tablets

  • High end versions can be expensive

Test your knowledge of input devices with our quick quiz.

Topics / Hardware / Input Devices

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