input devices_student
DESCRIPTION
TRANSCRIPT
Input DevicesManual and Automatic
By Laura and Gracie
Manual
KeyboardUsed to input data into the computer
Advantage• They are very common; all
computers have one and they are easy to use.
Disadvantage• Easy to make mistakes if you
can’t type quickly.
Concept KeyboardA pictorial keyboard which you can press.
Advantage• Easy to use and waterproof
Disadvantage• The screen can get dirty.• Might need to change the
pictures if your stock changes
Mouse Enables you to control the movement of the on screen curser by moving it around a surfaceAdvantage• Easy to learn to use• Accurate for selecting things
Disadvantage• Need a flat space next to the
computer.
Tracker BallLike an upside down mouse, you turn it with your hand to move the pointer on the screen
Advantage• Ideal for using when flat space
next to computer is limited
Disadvantage• Not supplied as standard.
JoystickSimilar to a tracker ball in operation except you have a stick which is moved rather than a rolling ball.
Advantage• Immediate feel of direction.
Disadvantage• Some people find them more
difficult to use than mice.
MicrophoneUsed to input soundAdvantages• Some systems can understand
most peoples voices with voice recognition software
Disadvantages• Some systems need to be trained
to understand each different voice.
Digital CameraLooks very similar to a traditional camera. However, unlike photographic cameras, digital cameras do not use film Advantage• No film needed.• Images can be digitally
manipulatedDisadvantage• Need to print out photographs
ScannerAnother way in which we can capture still images or text to be stored and used on a computer. Advantage• Can input things from paper
documents• With OCR software, text can be
scanned in Disadvantage• Images can take up a lot of
memory space.
Graphics tablet Produces much more accurate drawings on the screen than a mouse or a pointing device could.Advantage • Effective method of creating or
changing diagrams and images.
Disadvantage• Only useful for inputting data
about diagrams.• Can be very sensitive to
movement and difficult to get used to using
Automatic
MICRStands for Magnetic Ink Character Recognition. Banks use them; the reader reads the numbers on a cheque.Advantage• Read at 100% accuracy..
Disadvantage• The reader and ink is expensive
OMR Stands for Optical Mark Reader. Reads pencil marks on a specially designed form or document, e.g. on a lottery ticket. Advantage• Fast and accurate way of
inputting information.
Disadvantage• Only works if the marks have
been made accurately and clearly.
OCR Stands for Optical Character Recognition. It enables the computer to identify written or printed characters which have been scanned in. Advantage• 95% accurate
Disadvantage• Needs careful checking as letters
can be misread.
Barcode ReaderA bar code reader uses a visible red light to scan and read the barcode. The reflected light is translated into digital data that is interpreted by the computer and the correct price and product information is displayed.
Advantage• Any price change only needs to
be changed on the computer system, not on each item.
Magnetic Stripe Build into back of plastic cards, e.g. identity cards or credit cards. Holds information about the card owner.Advantage• Simple to use and cheap to
produce.
Disadvantage• Limited storage capacity – only
60 characters.
SensorsSensors are used to detect physical quantities outside a computer such as temperature, pressure and light.
To be able to process input from sensors a device called an analogue to digital converter must be connected between the computer and the sensors. This device converts signals from sensors into digital data that the computer can process