Www.ictlounge.com_work_inputandoutputdevices_Part 1 - Input Devices_Section 2.1 - Input Devices

Section 2.1

Input Devices

Key Words The following words will crop up as part of the following presentation.

You should use your notes sheet to log information about them when it is covered. You will be quizzed on these words later.

• Manual Input Device • Automatic Input Device • Keyboards • Numeric Keypad • Pointing Devices • Scanner • Digital Camera • Microphone • Remote Control

• Joystick • Touch Screen • Web Cams • Magnetic Stripe Reader • Chip and Pin Reader • Barcode Reader • Magnetic Ink Character Recognition • Optical Character Recognition • Optical Mark Recognition

NOTE: Sections of the presentation where you see the following symbol contains information about these keywords. This is your cue to make notes.

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Input Devices

Definition:

“Hardware devices that allow information to be input into a computer”.

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NOTE: There are tons and tons of input devices. We will explore some of the more common examples.

Two categories of Input Devices: 1. Manual Input Devices – data entered by hand

2. Automatic Input Devices – data entered by a machine/computer

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Examples of Manual Input Devices

Keyboard Numeric Keypad Pointing Device Remote Control

Joystick Touch Screen

Microphone

Scanner

Digital Camera

Graphics Tablet

Webcams Light Pens

Manual Input Devices

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Keyboards • The most common type of input device. • Key boards are used to input into the computer:

• Text • Numbers • Instructions

• Most keyboards use the QWERTY layout. The name comes from the keys on the top row which spell out QWERTY.

QWERTY Keyboard

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Ergonomic keyboards have recently been developed. These are designed to reduce health problems linked with typing. The hand rest pictured on the keyboard above is standard on an ergonomic keyboard. For example – Carpel Tunnel Syndrome and Repetitive Strain Injury (RSI).

Keyboards (Continued)

• Keyboards are used to input data into applications (For example – text into Microsoft Word and numbers into a spreadsheet).

• They can also be used to input commands into the computer.

For example Keyboard Shortcuts: • CTRL + P to print • CTRL + S to save • Print Screen to take a screenshot of work

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Uses:

Advantages Disadvantages

• Enable fast entry of new text into documents

• Users with arm/wrist problems can find keyboards hard to use

• Very easy to use • Fairly large and take up desk space

• Information appears on the screen as it is typed so it is easy to verify (Check for correctness)

• Entering data can be slow when compared to direct data entry (Scanning a bank card for example)

Numeric Keypads

• Entering personal identification numbers (PIN) into an automatic teller machine (ATM).

They can also be used to select how much money

you would like to take out. • Telephones have numeric keypads to allow phone

numbers to be keyed in.

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Uses:

Numeric Keypads are used for entering numbers. (“Numeric” means

Number). Some also have functions to allow text entry.

Numeric Keypads (Continued)

• Electronic Point Of Sale (EPOS) terminals have numeric keypads in case the barcode reader fails to read the barcode and the number needs to be keyed in manually.

• Chip and PIN devices have numeric keypads to

enter PIN numbers and amounts of money.

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Uses:


• Faster than standard keyboards for entry of numeric information

• Can be difficult to use due to small keys

• Usually small devices (Like Mobile Phones) and are easy to carry around

• Difficult (but not impossible) to enter text information

Pointing Devices eos

Pointing devices are pieces of hardware that can be used to move and control a pointer (curser) on a screen. There are 3 main types of pointing device:

• Mice • Touchpad • Trackerballs

Overview:

Pointing Device (Like a mouse) used to move and control a Pointer (curser) around a screen.

Pointing Device 1 - Mice • 2 types of mice are Ball and Optical. • This allows the user to control the position of a pointer on a screen.

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A Ball mouse uses a ball underneath the mouse to detect movement. An Optical mouse uses reflected light rather than a ball.

Ball detects movement

Light detects movement

Ball Mouse Optical Mouse

An advantage Optical Mice is they have no moving parts and so pick up no dirt. Optical Mice are also often more precise than Ball Mice which makes them useful for fine movements of the pointer for tasks like graphic design.

Mice (Continued) eos

• Mice have 2 buttons and a scroll wheel with different functions: • Left button used to select things • Right button used to bring up a drop-down menu • Scroll wheel helps you to move through a document

Right Button

Left Button

Scroll Wheel

Menu activated by right click

Cordless Mice are exactly the same as regular mice apart from the fact that they do not need a wire connected to the computer. They are an example of a Wireless Device.

Mice (Continued)

• Can be used for Opening, Closing and Minimising programs and files etc.

• Can used for Grouping, Moving and Deleting files.

• Useful when Editing Images – for example controlling Size and Position of an image.

• Can control the position of a pointer on the screen to allow you to select icons or scroll around the page.

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Uses:


• Faster to select an option compared to using a keyboard.

• People with poor hand movement or disabilities can find mice difficult

• Mice enable easy navigation around applications and Internet.

• Easily damaged and Ball Mice can pick up dirt and become clogged.

• Small and take up very little space. • Hard to use without a flat surface.

Pointing Device 2 - Touchpad • Used in many Laptop computers as a pointing device. • Pointer in controlled by the user moving their finger on the touchpad to

simulate the movements of a mouse.

• They also have buttons which have the same purpose as the left/right buttons on a mouse.

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Touchpad Left/Right Buttons

Touchpad (Continued)

• Touchpads have the same uses as a mouse.

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Uses:


• Faster to select an option compared to using a keyboard.

• People with poor hand movement or disabilities can find touchpads difficult.

• Touchpads enable easy navigation around applications and Internet.

• More difficult to control the pointer when compared with a mouse.

• Included in the laptop so no need for separate mouse. This helps improve portability.

• More difficult to perform operations such as drag and drop.

• Can be used even when there are no flat surfaces available.

• Don’t get clogged with dirt as ball mice can.

Pointing Device 3 - Trackerball • Similar to a mouse except that the ball is on the top of the device. • Users control the pointers on the screen by rotating the ball with their

hand.

• Trackerballs usually have two buttons which have the same use as the right/left mouse buttons.

• Some have a third button which is the equivalent to double click.

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Trackerball Left/Right and Third Buttons

Trackerball (Continued)

• They have the same pointing/curser control as a mouse.

• Very comfortable to use – even with people with hand/wrist disabilities.

• Can be faster to use than a mouse.

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Uses:


• People with limited hand/wrist movement find them easier to use.

• Trackerballs tend to be more expensive than mice.

• Pointer can be positioned more accurately on the screen than with a mouse.

• Can be quite tricky to get used to.

• Take up less desk space than a mouse as they do not need to be moved around.

Remote Controls • These are used to control other devices using Infra Red Signals. • Buttons on the keypad are used to select options. For example:

• Television Stations. • Volume on an music player. • Fast forwarding a DVD player.

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Buttons on Keypad

Infra Red Signal

Remote Control (Continued)

• Most home entertainment systems use Remote Controls. For example: • DVD players • Hi-Fi’s • Satellite Systems etc.

• Used in industry to remotely control machinery etc. Cranes for example

can be remotely controlled.

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Uses:


• Enable devices to be operated from any distance. Useful for people with mobility disabilities.

• People with limited hand/wrist movement can find them difficult to use.

• Useful in chemical plants where equipment close to hazardous materials can be operated from a distance.

• Signal between the control and the device can be easily blocked.

Joysticks • Perform similar functions to mice and trackerballs. • Moving the stick controls the pointer on the screen and buttons are used

to make selections.

• Most joysticks also have a button on the top of the stick that is used for gaming – e.g. to fire a weapon.

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Control Buttons

Fire button for Gaming

Control Stick

Joysticks (Continued)

• Video games are often controlled by joysticks. • They are used in simulators to mimic actual controls (Like flight

simulators and driving simulators).

• Can be used to control machinery (Like cranes).

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Uses:


• Easier to navigate around a screen and play games rather than a keyboard.

• People with limited hand/wrist movement can find them difficult to use.

• Simple to use. • More difficult to control a pointer on a screen compared to a mouse.

Touch Screens • This input device allows users to choose an option by simply touching the

button/icon on the screen. • The selection is made without the need for a pointing device (Like a mouse).

• Most joysticks also have a button on the top of the stick that is used for

gaming – e.g. to fire a weapon.

• Good for selecting from a limited range of options.

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Options chosen by touching the screen

Touch Screens (Continued)

• Self-service devices like shopping tills and petrol payment. • Some ATM’s use touchscreen to allow users to withdraw money. Public

information systems at airports and tourist offices also use touchscreen.

• Point of Sale Terminals (POS) at restaurants and cafes.

• PDA’s, Mobile Phones and Sat Nav systems all use touchscreens.

• Interactive whiteboards (Used in schools) are basically just large touchscreens.

• Some on-screen tests, like Computer Based Training, (CBT) use touchscreens to allow users to answer questions.

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Uses:

Touch Screens (Continued) eos


• Enable fast entry of options. • Limited number of options available.

• Very easy to choose options. • Using touchscreens too much can lead to health problems like arm strain or RSI.

• No training needed to show people how to use touch screens.

• Screen can get dirty and covered in germs with constant touching.

Scanners • Scanners are used to enter information on hard copy (Printouts, Photographs)

into the computer. • The hard copy is scanned by a light source and produces a digital image.

• The digital image can then be manipulated by a Graphics Editing Package

(Like Photoshop).

• Specialist scanners can be used to carry out different scanning tasks (Like barcode scanners in supermarkets).

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Image scanned on flat surface

Flatbed Scanner Handheld Scanner

Image scanned by

hand

Scanners (Continued)

• Used to scan in hard copy documents to convert them into a digital format. • Old documents (like family photos) can be scanned and stored on a

computer. This ensures you still have a copy if the original is lost/damaged.

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Uses:


• Images can be stored for editing at a later date.

• The quality of the scanned images can be limited depending on the quality of the scanner.

• Scanners are much faster than having to type in the documents again.

• Images lose quality during the scanning process

• You can scan in damaged documents then repair using Graphic Editing software.

• Images can take up a lot of disk space.

Graphics Tablet • Used by Graphic Designers and Illustrators.

• Consists of a flat pad (The Tablet) which can be drawn on with a special pen.

• Anything drawn onto the pad is transferred to the computer screen.

• Drawings can then be saved as images on your computer.

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Tablet

Special Pen

Graphics Tablets (Continued)

• These allow designers to produce much more accurate drawings on screen than they could using a mouse.

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Uses:


• Much more natural to draw using the special pen than it is using a mouse.

• Not very useful for general selection work like clicking on icons.

• You can produce much more accurate drawings.

• Much more expensive than a mouse or other input devices.

Microphone

• Peripheral that is plugged into the computer.

• Computers Sound Card converts the Analogue Sound produced by the microphone into Digital Sound (Which the computer understands).

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Analogue sound input via Microphone

Analogue sound converted to Digital by Sound Card

Digital Sound sent to computer

Microphones (Continued)

• Can input sounds/speech into the computer to be used in different ways (Presentations, Voice Recording, Special Effects in Movies etc).

• Used in Voice Recognition Software which can be used to automatically input text into a document using speech rather than typing.

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Uses:


• Faster to read in text rather than type it in using a keyboard.

• Sounds files can be quite large and take up a lot of computer memory.

• Sound input into your computer can be edited using Sound Manipulation Software.

• Voice recognition software isn’t very accurate and can lead to errors (For example cannot tell the difference between “their” and “there”).

• Voice recognition software can be used to make tasks safer. (Like using voice to operate a radio in a car)

Digital Camera • Replacing traditional film based cameras.

• Photographs are stored digitally in memory and can be transferred to a

computer via a Universal Serial bus (USB) connection.

• Saved images can be edited using Graphics Software. (For example – Photoshop could be used to change brightness, image size, crop etc)

• Quality of image depends on the resolution (Number of Pixels) the camera has. More pixels = better quality image.

Cameras range from 4 – 12 Megapixels (Millions of pixels in the image).

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Digital Camera

USB Connection

Digital Cameras (Continued)

• Produce photos that can be transferred to a computer or to print out directly.

• Most digital cameras also allow you to capture short video clips.

• Digital photographs can easily be copied or edited.

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Uses:


• No film needed. No developing costs to view the pictures.

• Digital cameras can be very expensive (especially for the high quality ones)

• Images can be viewed immediately and unwanted images can be deleted.

• Quality images can be quite large in size and can take up a lot of memory.

• Images can be copied edited, enlarged or enhanced.

• Resolution (quality) of digital images are still not as good as traditional printed images.

• Images can be added to websites or documents.

Webcams • Connect to the computer through the USB port.

• Images are captured by the webcam and sent straight to the computer.

• Many computers come with webcams attached to top of monitor as standard.

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Front of webcam captures images.

USB cable which attached the webcam to the

computer

Webcams (Continued)

• Input moving pictures into the computer. • Allows a more personal chat when having a conversation online.

• Enable Video Conferencing to take place (Even across continents).

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Uses:


• Webcams can be left on constantly. They only activate themselves when you need them.

• Picture is often of poor quality (Image breaks up).

• Allow people to have face to face conversations without needing to travel.

• They need to be connected to a computer and Internet connection in order to work.

Light Pens • These contain sensors that send signals to a computer whenever light changes

are detected.

• Light Pens work with CRT (Cathode Ray Tube) monitors but not TFT (Thin Film Transistor) monitors.

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Light Pens rely on the screens images being built up by Electron Beams.

The screen is refreshed 50 times every second which allows the computer to figure out where the pen is by recording when each light beam passes the tip of the light pen.

Light Pens (Continued)

• Used for selecting objects on CRT Screens.

• Can be used to draw on screen (Much easier than drawing with a mouse).

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Uses:


• More accurate than touch screens (Thinner end.. Allows the pen to touch smaller icons).

• Suffers from Lag on screen (Drag effect)

• Small so can be used on smaller screens.

• Only work on CRT Monitors (Not suitable for Laptop Screens.

• Very easy to use. • Because of lag, they are not very accurate when drawing.

Automatic Input Devices

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Examples of Automatic Input Devices

Magnetic Stripe Reader Chip and Pin Reader

Magnetic Ink Character Recognition (MICR)

Barcode Reader

Optical Mark Recognition (OMR) Optical Character Recognition (OCR)

Magnetic Stripe Reader • Used to read information from Magnetic Stripes found on items like Credit

Cards, Membership Cards etc.

• The stripe contains useful information like: • Account Numbers • Name of Account Holder • Expiry Date

• The card is read by being Swiped through the Magnetic Stripe Read Machine.

• Data that is read is then input into the computer through the machine.

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Magnetic Stripe Reader Magnetic Stripe

Magnetic Stripe Reader (Continued)

• Used by ATM’s and EFTPOS (Electronic Funds Transfer Point of Sale) terminals for easy transfer of money.

• Security cards for entry to buildings and hotel rooms use Magnetic Stripes.

• Travel systems (Like train tickets) use Magnetic Stripes.

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Uses:


• Entering data is very fast and easy. (You just swipe the card)

• If the Magnetic Stripe gets damaged then the data is lost.

• No chance of errors as there is no typing.

• Magnetic Card Readers need to be in contact with the card.

• Information held on the Magnetic Stripe cannot be read by the eye so there is no chance of someone being able to read your bank details.

• Can only store a small amount of information.

Chip and Pin Reader • Used at Electronic Funds Transfer Point of Sale terminals (EFTPOS) to pay for

goods electronically using a card (Like a credit card).

• The device has a small slot in which you place the card. A computer chip located on the card is then read.

• The user will then enter a PIN (Personal Identification Number) using a

keypad.

• The Chip and Pin Reader usually has a small screen which is used to give instructions.

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Chip and Pin Reader Card containing the Electronic Chip

Chip and Pin Readers (Continued)

• Chip and Pin Readers are for making payments by card in places like: • Restaurants • Supermarkets • Petrol Stations • etc

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Uses:


• More secure than Magnetic Stripe Readers as you also need a PIN to ensure that you are the cards owner.

• PINs can be forgotten which means the reader is pretty much useless.

• Chip and Pin Readers can be portable which means that the reader can be brought to you (A waiter in a restaurant for example).

• PIN can be read as it is being typed in. This increases chance of someone being able to access your money.


• MICR is a system which can read information printed in a special ink (The ink contains iron particles).

• This special ink is normally used on the bottom of bank cheques. • The MICR device reads the information then converts it to a form the

computer can understand.

• The converted information is then sent to the computer to be used or stored.

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MICR machine reading a cheque

MICR(Continued)

• Every day millions of cheques are sent to banks for processing. To process the information on these cheques would take far too long if it were done by hand.

• MICR automatically processes the information on these cheques with 100% accuracy (They can handle 300 per minute).

• Used to read the following information: • Customer account number • Sort code • Cheque number and Value

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Uses:

Characters read by MICR on a bank cheque

MICR(Continued 2) eos


• Greater security than OCR because the special ink characters cannot be changed.

• Only a very limited number of different characters can be read.

• NO manual input… therefor less errors. (User just swipes information through the reader).

• Both Reader and Magnetic Ink are more expensive than other methods of automatic data entry.

• Information can still be read even is someone writes over the magnetic ink characters (Like with a signature).

Barcode Readers/Scanners • Used to read information in the form of a Bar Code using a Visible Red Light

which is reflected and translated into Digital Information.

• A Computer uses this information to read a Database and identify the Product and Price.

• Barcode holds information about products (Product Code, Manufacturer etc)

• Barcode Scanners are usually built into POS terminals in Supermarkets. • Handheld scanners are also commonly used to read barcodes.

(Usually if items are too large and heavy to move to the scanner.

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Readable Barcode Barcode

Scanner

Barcode Readers (Continued)

• Used in supermarkets and other shops where goods are marked with a barcode. Barcodes hold information about the product which enables automatic very fast itemised billing to take place.

• They are used in libraries to scan in library cards and read ISBN numbers on books to find out which ones are on loan.

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Uses:


• If an item price is changed only the central database needs to updated. There is no need to change individual prices on each item.

• Quite an expensive way to gather information. Each item needs a barcode and the computer technology needed is also expensive.

• Quick and easy way of getting information into a system.

• Barcodes can be swapped on items which means people pay less for more expensive items.

• Enables automatic stock control.

Optical Mark Recognition (OMR) • System which reads Marks made in Pen or Pencil.

• The places where the pen or pencil marks can be made are shown on the

form.

• The OMR reader shines a light onto the form and Less Light is Reflected where a pencil mark has been made.

• This allows the reader to tell which options have been chosen and sends the results back to a computer.

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Example of shaded areas of a test that OMR reader can read

OMR Reader

OMR(Continued)

• OMR Devices are used to read the responses on documents like: • Questionnaires. • Multiple Choice Examination Papers. • School Registers • Lottery Tickets. • Anything else that requires responses to be shaded or coloured in.

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Uses:


• Very fast way of inputting information. (10,000 forms can be read per hour)

• Forms need to be accurately designed to make sure that the marks/shading are in correct position to be read by the device.

• 100% accurate as documents are fed in automatically and no need for user input.

• If forms have been incorrectly filled in they cannot be read properly.

(This means that they have to be manually checked which takes a lot of time and costs a lot)

• Can only read shaded areas (Cannot input or read text).

Optical Character Recognition (OCR) • This consists of a Normal Scanner and Special Software (OCR Software).

• Scanner is used to Scan the Text on a document into the computer.

• The OCR Software then Converts the text into form that the computer can

understand.

• The text can then be used in applications such as Microsoft Word, Publisher and PowerPoint.

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OCR(Continued)

• Used in the processing of Passports and Identity Cards.

• OCR is used when scanning in documents so they can be modified using Word Processing or Desktop Publishing Software.

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Uses:


• Much faster way of entering information into the computer compared with using a keyboard.

• The system can have difficulty reading handwriting.

• Cheaper than paying someone to manually enter information.

• Not a very accurate technique.

• 100% accurate as there is no manual entering of information. (Device does it automatically)

• As it is not 100% accurate, information needs to be manually checked for errors. This is time consuming.

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Examples of Manual Input Devices

Keyboard Numeric Keypad Pointing Device Remote Control

Joystick Touch Screen

Microphone

Scanner

Digital Camera

Graphics Tablet

Webcams Light Pens

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Examples of Automatic Input Devices

Magnetic Stripe Reader Chip and Pin Reader


Barcode Reader

Optical Mark Recognition (OMR) Optical Character Recognition (OCR)

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