- Created by: hazel mills
- Created on: 08-03-16 13:35
What are Input Devices?
An input device is a piece of hardware that is used to enter data into a computer. There are many different kinds of input devices. They are split into two categories - manual input devices and automatic input devices.
Input Devices Keyboard
Keyboard – It is made up of buttons called 'keys'. The keys are arranged into sections:
- Alphabet keys
- Function or F keys,
- Numeric keys
- Arrow keys and command keys (insert, delete, home, end, page up/down)
- Most keyboards are called 'QWERTY' keyboards. This name comes from the first six letters on the top row of the alphabet keys.
- Most computers come with a keyboard supplied
- People are used to using keyboards to enter data, they need very little training
- A skilled typist can enter data very quickly
- It is easy to make mistakes when typing in data
- Keyboards are not suitable for creating diagrams
- Disabled people often find keyboards difficult to use
- Excessive use can lead to health problems such as repetitive strain injury (R.S.I.)
Input Devices Concept Keyboard
A flat board that contains a grid of buttons. Each button can be programmed to do whatever it wants. It inputs onto a system by someone typing something onto the keyboard.
- Much faster for making non-text selections such as menu choices on the till of a fast-food outlet.
- The keyboard is waterproof which can be useful where there is dirt or the risk of splashes
- Poor for text or numeric input - although some keyboards do include a numeric keypad so the operator can enter the amount sold.
- Limited to the options shown on the keyboard.
Input Devices Ergonomic Keyboard
It is a computer keyboard with keys into two halves shaped like a wide "V." its to minimise muscle strain and aching. It inputs onto a system by someone typing something onto the keyboard.
- More comfortable
Reduces strain on wrists and hands
- May take time getting use to it
Input Devices Digital Camera
- It is a camera which produces digital images and can be stored on a computer.
- It inputs onto a system by a USB port or memory card can be removed from the camera and put into the pc.
- Image can be instantly checked and taken again if its not good enough
- Image can be easily deleted or retaken
- The image can be viewed on a large screen TV, computer or laptop
- You can do video recording on there
- Has a lot of storage space but it wont take long till all the memory is full up
- It can be very complex
- The battery can go quite quickly
- They are sensitive to heat, cold, water etc.
Examples of ICT Systems that use a digital camera are webcams, gym card and passport
Input Devices Touchpad
- It is used on a laptop which is often used in a confined space where there isn't a flat surface for a mouse so they use a touchpad.
- It inputs data onto a computer system because it is touch-sensitive so by moving your finger around the pad which moves the cursor it allows you to do things.
- Useful for laptops when mouse isn't practical
- Very short finger movements are required to move the cursor
- Its fixed compared to the mouse or keyboard
- Doesn’t need a lot of pressure added to make the cursor move so very accurate
- It takes practise and skill to control the position of the cursor
- Moist fingers can disrupt the signals picked up by the sensors
- Gloves cannot be worn
- Its only available on laptops
Input Devices Scanners
- It is a device for reading, examining or monitoring something and it can be used to input an image.
- It inputs onto a computer system by shining a light at the image being scanned and computing how much light is reflected back using an optical sensor. The amount of light that is reflected back tells the computer how light or dark the image is at each point.
- It can copy things onto the computer and then you can change things you have copied
- They can produce high quality images
- Easy to use
- It can take up a lot of memory space
- The scanners output quality can vary
- Scanners are usually slow
- The maintenance of a scanner can be expensive
Input Devices Graphical Tablet
- It is a device with a special flat surface. It enables you to use your hand to draw images, animations and graphics.
- It inputs into a system by drawing a picture of something.
- Much easier to draw a picture with a stylus than a mouse
- It can be more accurate
- Can come in different sizes
- Can record levels of pressure
- Not useful for pointing and clicking on work
- They are much more expensive than a mouse
- Slower than drawing on paper
- Can be tricky to get the hang of and use
Examples of ICT Systems that use graphical tablets animations for cartoon films and adverts. Also architects use it when they are designing something.
Input Devices Mouse
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.
- Ideal for use with desktop computers
- Usually supplied as part of a new computer system
- Most computer users are familiar with them and require little training
- Works well in conjunction with a keyboard for data entry
- 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
Input Devices Joysticks
- 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.
- They give a better gaming experience for racing or flying styles of computer games
- 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.
Input Devices Touch Screen
- Touch screens allow the user to make selections by touching a screen. This technology is common in smartphones and ticket machines at railway stations.
- A touch screen has a grid of infrared beams in front of the screen. When the user presses the screen, they break the beams which therefore gives an indication of where the finger is.
- Touch screens are easy to use and are often found in public places such as cashpoints at banks, ticket collection terminals at theatres or airports, information centres at museums.
- Touch screens are not commonly used to input large amounts of data because they are not very accurate and they would be tiring on the hands to use for long periods of time
Input Devices Touch Screen 2
Touch Screen Advantages
- 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 sophisicated actions such as zooming and selecting.
- Excellent for selecting and controlling (applications) that have been designed with a touch screen in mind.
- 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
Input Devices Magnetic-Stripe Card
It has a ***** of magnetic material on the back of the card which stores encoded data that can be read by a computer when it is swiped(debit card, credit card etc.). The pattern of magnetisation is detected on the computer and converted into encoded binary.
- Added security (not in readable form)
- Immune to dirt, oil and moisture
- Data can be customised or rewritten
- Close contact to the reader/scanner
- Data can be harmed by stray magnetic fields
Magnetic Stripe Cards are in use as a way of controlling access (e.g. swipe cards for doors, ticket barriers) and confirming identity (e.g. use in bank and cash cards).
Input Devices Magnetic Stripe Reader
Magnetic Stripe Reader
- Magnetic *****s are usually found of the back of most credit cards, cheque guarantee cards, loyalty cards, membership cards etc.
- The magnetic ***** can hold personal details such as account number and name. The ***** can contain up to 60 characters, stored magnetically.
- 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
- Simple for people to use - little or no 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
- 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.
Input Devices Radio-Frequency Identification (RFI
Radio-Frequency Identification (RFID)
RFID involves tags that emit radio signals different tags emit different signals that can be recognised by the reader. It is not necessary for the tags to touch the reader as they can be read from around 65cm. It is a fast and a reliable method of identification.
- Doesn’t require it to touch
- Can trigger security alarm if removed from its location
- Each item can be individual labelled.
- More expensive
- Larger then bar code labels
- More then one tag can respond at the same time
New UK passports can immediately be checked against stolen and suspected terrorist, bas and underground passengers can use Oyster cards.
Input Devices Touch-Tone Telephones
Banking systems allows the user to entre the account number using the keys on the telephone handset, in response to voice commands. Can choose the type of transaction requires by pressing a specific key
- Access your bank account
- Type in the number and get directly taken to the service you wanted
- If you get it wrong you will have to start over
Banking systems use it to allow people to enter their account number
Input Devices Speech Recognition
Speech recognition is the a software which is used to identify words and phrases in a spoken language and convert them to a machine-readable format. A microphone is needed to input the sound onto the computer
- No keyboard needed
- Doesn’t make spelling errors
- Help people who have mental disabilities
- Easily made errors
- Requires large amount of memory
- Background noise can disrupt the voice recording
It is used on some telephones and people with disabilities so they have don’t have to write.
Input Devices Optical Character Recognition (OCR)
Optical Character Recognition (OCR)
OCR is a method of data capture where the device recognises characters by light-sensing methods.Which 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 that can be edited or processed by a normal word processing package.
- 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
- 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 difficult to read, more mistakes will occur
- Not worth doing for small amounts of text
Input Devices Optical Mark Recognition (OMR)
Optical Mark Recognition (OMR)
- Optical mark recognition is a form of mark sensing where the pre-printed documents are used.Eg lottery tickets.These will often contain boxes where a mark can be made to indicate choices. The reading device on the machine will detect the written marks on the page by shining a light on the page and detecting how much light goes through,boxes with marks will show less light than boxes without a mark in them.
- 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
- If the marks don't fill the space completely, or aren't in a 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.
Input Device Magnetic Ink Character Recognition
Magnetic Ink Character Recognition (MICR)
- Magnetic ink character recognition is another fast and reliable method of entering data.
- The documents are printed in a special ink form that can be magnetised. The shape of the characters is recognised by detecting the magnetisation of the ink.
- MICR is used almost exclusively in cheques. It is used in banks instead of OCR to minimise fraud.
- Ease of Readability and High Security
- The error rate for reading MICR characters is small as compared to other character recognition systems. MICR scanners precisely and accurately decipher the characters
- Time Consuming Standards - the printing of MICR is demanding, setting precise but difficult-to-achieve standards, which is a distinct disadvantage in terms of time consumption.
- Expensive Equipment
Input Devices Bar-Code Reader
Barcode readers are classed as automatic input devices. A barcode reader is an automatic input device which is used to scan or 'read' the barcode by using a visible red light. The reflected light is translated into digital data that is interpreted by the computer to identify the product and price from the database.Most items have a bar-code printed on the packing which is a series of vertical bars of varying widths that give information about, the country of manufacture, the name of the manufacturer and a product code
- Price change only needs to be made to the database and not every single product package.
- Can be portable/handheld
Barcodes are also used on books to show the book's ISBN number - have a look at any textbook that you have in your bag. They are also used on library tickets so that when your ticket is scanned, the database brings up your account and any books which you still have out on loan are displayed.