Types of Input Devices

There are many different types of input devices, and all have various different properties that allow you to make the most of technology by providing you with easier ways of accomplishing certain tasks.

Here I will list 12 different types of input devices along with some pros and cons of each one.

Keyboard

The keyboard is the most common and widely used input device.

Pros

• Keys are grouped together in their own sections making it easier to find and reach the keys you need (e.g. all the Function keys are along the top of the keyboard and are away from the letters and numbers).

• Most computers come with a keyboard supplied.

• People are used to entering data using keyboards, and therefore need llittle training.

• A skilled typist can enter data very quckly.

• Specialist keyboards are available (e.g. ergonomic, gaming, etc.).

Cons

• Can cause Repetitive Strain Injury in hands and wrists.

• It is easy to make mistakes when typing in data.

• If you can't touch type, it can be very time consuming to enter data.

• Keyboards are not suitable for creating diagrams.

• Disabled people often find keyboards difficult to use.

Interesting Facts

There are now ergonomically designed keyboards that are designed for comfort and to reduce the chances of getting RSI due to its shape and the layout of the keyboard. However some people are used to the layout of normal keyboards, so may be reluctant to change. You can also get what’s known as a concept keyboard, which uses special software that interprets the key press for the computer. This makes it suitable for use at check out tills or restaurants as it means the operator does not have to remember the price of each item. Also very little training is required to use them so it saves the employer money training their staff. It can also be used for young children or those with disabilities to make things more accessible for them.

Mouse

Another commonly used input device, alongside the keyboard.
A mouse usually has two buttons, a left and right button, and a central wheel used for scrolling up and down a page.
The left button is usually used for selecting things on the screen, whilst cliking the right button will bring up a menu of different tasks you can perform.

Pros

• They are ideal for use with a desktop computer.

• They are usually supplied as part of a new computer system.

• Most computer users are familiar with them and therefore require little training.

• Works well in conjunction with a keyboard for data entry.

Cons

• They need a flat space close to the computer.

• Older style mice which have roller balls can become clogged with grease and grime and lose their accuracy until cleaned.

• Excessive use can lead to health problems such as Repetitive Strain Injury (R.S.I.).

• If the battery wears out in a wireless mouse, it cannot be used until it has been replaced.

Interesting Facts

A mouse is also called a 'pointing device' because it enables you to control what happens on the screen by moving the mouse on your desk and pointing, clicking and selecting items on the screen.
Many of the older styles of mice used a ball which moved against two internal rollers to record the direction that the mouse was being moved on.
Recent versions of mice use 'wireless' or 'optical' technology to track mouse movement.
If it has a red light on the bottom, it is an optical mouse.

Touchpad

A touchpad is an input device which is usually found on a laptop computer.
Because a laptop is designed to be portable, it is not always possible for a traditional mouse to be attached. This may be because it is too much of a hassle, or there simply isn't enough room to use one. There are usually two buttons next to the touchpad which are used to replace the left and right mouse button.

Pros

• Useful for laptops when using a mouse isn't practical.

• The pad's position is fixed compared to the keyboard, unlike with a traditional mouse.

• Very short finger movements are required to move the cursor.

Cons

• Takes practise and skill to control the position of the cursor using the trackpad.

• Gloves cannot be worn (e.g. in a clean room or industrial environment where gloves need to be worn

• Moist, sweaty or calloused fingers can disrupt the signals picked up by the sensors.

Interesting Facts

Touchpads work by dragging your finger over the surface of the touchpad. The sensors underneath the touchpad will then pick up the direction of the finger movement and the speed. The sensors only react to a fingertip and not a pencil or any other object.

Graphics Tablet

Graphics tablets are often used by graphics designers and illustrators.
Using a graphics tablet, a designer can produce much more accurate drawings on the screen than they could with a mouse or other pointing device. When combined with an art application such as Paint Tool Sai or Photoshop, a talented artist can produce incredible illustrations and images with it.
A graphics tablet consists of a flat pad (the tablet) on which you 'draw' with a special pen. As you draw on the pad an image is created on the computer monitor from within the application that the tablet is connected to.

Pros

• It is much more natural to draw diagrams with a pencil type implement (the stylus) rather than with a mouse.

• A great level of accuracy can be achieved.

Cons

• Not really suitable for general selection work such as pointing and clicking on menu items.

• Graphics tablets are much more expensive than a mouse.

Interesting Facts

The pen is usually radio controlled rather than touch control. This is very useful should you want to trace out an existing line drawing on paper, as you can simply place the paper over the pad and start tracing it out.
Some pens have a pressure sensitive tip to allow the artist to draw heavier or light lines.

Webcam

Webcam is short for 'web camera'.
A webcam is an input device because it captures a video image of the scene in front of it. It is either built in to the computer (e.g. laptop) or it is connected through an USB cable.

Pros

• Good for chatting and talking to people online face to face (e.g. you can use one with applications like Skype). This is sometimes known as teleconferencing.

• There are now webcams that can record in HD providing good quality videos and images. Webcams are now being used commonly by people on YouTube to vlog about themselves.

• They can be used for security. If the webcam picks up movement it will begin recording. Webcams are widely used for burglar alarms and other security equipment.

• There are hundreds of webcams placed all over the world that point at various locations of interest, including popular tourist attractions such as Niagara Falls. The webcam is attached to a computer that sends an image to a server on the internet on a regular basis. People then connect to the server to see the latest image.

Cons

• Webcams can be very expensive.

• Hackers may be able to turn them on without you knowing and they could watch you.

• There are dangers to using video chat with strangers that would record you without your knowledge.

Interesting Facts

The video signal is made up of a series of individual 'image frames' which are an instant snapshot of the scene in front of it. Each image frame is sent to the computer for futher processing by webcam software. If the 'frame rate' is fast enough (more than 25 frames per second) it appears as motion video.

Microphone

A microphone can be used to input sound.
The sound is detected by the micrphone and an electrical signal is transmitted to the computer. Special hardware is used to convert this analogue data into digital data so it can be stored and manipulated.

Pros

• Can record much better sound quality than laptop microphones.

• Combined with a good webcam you can produce very good quality videos.

• There are a range of different microphones that are suited for different things (e.g. recording music, recording voices, etc.).

Cons

• Microphones can be very expensive.

• If you get a professional microphone they can be tricky to set up and use.

Interesting Facts

In the last few years a number of voice recognition systems have been developed. These packages let the user dictate the text into a computer and then convert the speech to text.
Dictating like this can be much quicker than typing but the software isn't perfect and can interpret a word incorrectly.

Scanner

Scanners can be used to convert images or text on paper into a digital format that can be used by the computer.
A scanner works by shining a beam of light onto the surface of the object that you are scanning. This light is then reflected back onto a sensor that detects the colour of the light. This is then used to build up the digital image.
There are three types of scanner:

• Flatbed scanners

• Handheld scanners

• Specialist scanners

The most popular type is the flatbed scanner. They are used to scan large images and are more accurate than handheld scanners.

Handheld scanners are usually only a few inches wide and are held in the hand whilst they are rolled across the document to be scanned. The images produced are generally not as large or as high quality as those captured with a flatbed scanner.

If you are a photography enthusiast with a large collection of pre-digital 35mm negatives, then there are specialist scanners that can scan older 35mm film. In theory a standard scanner could do it but the film itself is relatively tiny and will result in very poor scans. The 35mm film scanner is exactly the same technology but the scan is set to go accurately over the 35mm range of the negative.

Pros

• Flatbed scanners are very accurate and can produce reasonably high quality images.

• Any image, once digitized by the scanner, can then be included on electronic documents..

• Images once digitized can be enhanced with a graphics application.

• Specialist scanners can convert old material such as 35mm negatives into digital files.

• Can accurately capture an image, but the original source may be more important than the scanned image.

Cons

• Images produced by the scanner can take up a lot of memory space.

• Images lose some quality in the scanning and digitizing process.

• The quality of the final image is dependent on the quality of the original image.

• Emotional value - is there value in the original image?

Interesting Facts

Items that are scanned are usually stored in an image format. However, special software - Optical Character Recognition - can be used to convert text on the paper into text which can be edited with a word processor.
However, the text doesn't always get converted very well and you could end up with a lot of mistakes.

Joystick

Joysticks were originally used by pilots as part of an aeroplane's controls and the technology was developed to let computer gamers experience a more realistic game environment.
You can move joysticks in many directions and the joystick tells the computer which direction it has been moved into. They also have one or more buttons whose position when pushed can be read by the computer.

Pros

• They give a better gaming experience for racing or flying styles of computer games.

Cons

• Some people find joysticks more difficult to control than a traditional mouse.

• Joysticks are not particularly robust and can break easily if too much force is used on them.

Interesting Facts

Josticks can also be used for controlling machines such as cranes, trucks and powered wheelchairs.

Magnetic Stripe Reader

Magnetic strips are usually found on the back of most credit cards, cheque guarantee cards, loyalty cards, membership cards etc.
To read the data on the card, it is 'swiped through a Magnetic Stripe Reader machine and the data is read and fed back to the computer.

Pros

• Simple for people to use - little or not training.

• Cards are inexpensive to produce.

• Data on the cards can be altered if necessary.

• Security is improved by the use of PIN numbers to confirm that the person is the rightful card owner.

Cons

• Very limited storage capacity for data.

• Data can be easily destroyed by strong magnetic fields.

• Not always secure as thieves can obtain the readers and read the data on the card.

Interesting Facts

The magnetic strip can hold personal details such as an account number and name. The strip can contain up to 60 characters, stored magnetically.

Optical Character Recognition (OCR)

An OCR system consists of a normal scanner and some special software. The scanner is used to scan text on a document or piece of paper into the computer. The OCR software then examines the page and changes the letters into a form than can be edited or processed by a normal word processing package.

Pros

• Cheaper than paying someone to manually enter large amounts of text.

• Much faster than someone manually entering large amounts of text.

• The latest software can recreate tables and the original layout.

Cons

• Not 100% accurate, there are likely to be some mistakes made during the process.

• All documents need to be checked over carefully and then manually corrected.

• If the original document is of poor quality or the handwriting is difficult to read, more mistakes will occur.

• Not worth doing for small amounts of text.

Interesting Facts

Scanners have been improved to be able to read different styles and sizes of text as well as neat handwriting.
Although they are often up to 95% accurate, any text scanned with OCR needs careful checking because some letters can be misread.
OCR is used to automatically recognise postcodes on letters at sorting offices.

Optical Mark Reader (OMR)

National Lottery ticket selection forms and multiple choice tests are scanned by a special piece of equipment called an 'Optical Mark Reader' (OMR).
They work by detecting the presence of a pencil/pen mark and reflecting light onto it. Less light is reflected where a mark has been made. The OMR then interprets the marks and send the results to the computer for storage, analysis and reporting.

Pros

• A fast method of inputting large amounts of data - up to 10,000 forms can be read per hour depending on the quality of the machine used.

• Only one computer needed to collect and process the data.

• OMR is much more accurate than data being keyed in by a person.

Cons

• If the marks don't fill the space completely, or aren't in dark enough pencil, they may not be read correctly.

• Only suitable for recording one out of a selection of answers, not suitable for text input.

• The OMR reader needs the answers to be on the prepared forms which will all be identical to one another. You can't just pick up a blank sheet of paper and mark your answers on it.

Interesting Facts

They can be used for lottery tickets, multiple choice tests, surveys, and many other documents.

Touch Screen

A touch screen is the only device that works both as an input and an output device. You view the options available to you on the screen (output) and you then use your finger to touch the option that you have chosen (input).
Touch screens work particularly well with a menu driven interface. For example, a cashpoint (ATM) at a bank would first of all ask which service you want. You touch the option 'withdraw cash' on the screen. You are then presented with another choice, 'how much cash do you want to withdraw?'. Once you have chosen how much, you then get other options such as 'do you want a receipt?'.

Another major use of touch screens are on smart phones and modern tablet computers. Each 'app' is accessed by an icon on the touch screen.

Pros

• Easy to use - intuitive, don't need much training.

• No extra peripherals such as a mouse are needed.

• Software can alter the screen while it is being used, making it more flexible than a concept keyboard which has a permanent overlay.

• Touch screen is the main interface on smart phones and tablet computers.

• Can make use of finger gestures to make sophisticated actions such as zooming and selecting.

• Excellent for selecting and controlling 'apps' (applications) that have been designed with a touch screen in mind.

Cons

• Not suitable for inputting large amounts of data.

• Not very accurate - selecting detailed objects can be difficult with fingers.

• Tiring to use for long periods.

• More expensive than alternatives such as a mouse (unless it is part of the computer/smartphone in any case).

• Less useful as a control input to a standard computer that makes use of the mouse/keyboard combination (e.g. laptop, desktop PC).

Interesting Facts

It is the only device that is both an input and an output device.
Because touch screens are so easy to use, they are often found in public places such as cashpoints at banks, ticket collection terminals at theaters or airports, information centres, and various other places.

Thank you for reading.