Information & Communication Technology School Year 2012/2013 Manarat Jeddah International School for Girls

parisfawnAI and Robotics

Nov 17, 2013 (3 years and 8 months ago)

100 views

Information & Communication Technology

School Year 2012/2013

Manarat

Jeddah International School for Girls


List of Input Devices

Keyboard

(Ergonomic
Keyboard)

Concept Keyboard

Mouse

Tracker ball

Numeric Keypad

Touchpad

Video
Digitiser

Remote Control

Joystick

Touch Screen

Magnetic Strip
Reader

Smart Card Reader

Chip and PIN Reader

Scanner

Digital Camera

Microphone

Sensors

MIDI

Instruments

Graphics Tablet

MICR (Magnetic Ink
Character
Recognition)

OMR (Optical

Mark
Recognition)

OCR (Optical
Character
Recognition)

Barcode Reader

RFID Reader

Video Camera

Webcam

Biometric Devices

Light Pen

Keyboard


Most common input device


Used to input text, for example into a word
-
processed document


Also used to type commands into a computer, for example
pressing the control (Ctrl) key at the same time as pressing X (to
cut a selection)


Advantages


Most computer users are familiar with them/require little training


Allow accurate entry of data, in combination with a monitor to check
accuracy


Allow quick entry of original text; can enter a variety of text, not limited
to bar codes, OMR


Robust devices


Disadvantages


Continually typing can lead to RSI; difficult for people with disabilities
to use; take up more space than other input devices; not very fast when
compared to direct data entry devices such as OMR and barcode readers

Mouse


Pointing device that can


Select items from a menu


Left clicking will open a program or another window


Use to scroll up or down in the active window


Drag and drop


Inside the case can be a ball, which allows the mouse to glide
over a surface


Optical mouse relies on movement being detected using reflected
light, rather than a ball


Cordless mouse needs a transmitter and a receiver, connects via
bluetooth

(radio waves)


Advantages


Most computer users are familiar with them/require little training


Allow faster entry of options, compared to typing


Allow fast navigation through slideshows/websites


Smaller and more compact than keyboards


Disadvantages


Need a flat space; mice with balls can become clogged by dust and
grime; overuse can lead to RSI; difficult for people with disabilities
to use; difficult for entering data

Trackerball


Upside down mouse like device, designed for users that have
disabilities; since it is stationary, it is also useful where the user
has limited motor skills or there is a lack of space


There is a large ball in the middle that is controlled by using the
palm of the hand and enables the user to control the pointer on
the screen.


Used when the use of a mouse would be too difficult; can be used
in control applications where objects on a screen are used to
control a process


Advantages


Does not require the fine control a mouse does; easier for
people with RSI; can be more accurate when positioning a
pointer on a screen


Disadvantages


Difficult to enter data; can be slower to use than a mouse



Concept Keyboard


Flat board that contains a grid of buttons. Each button can be
programmed to do whatever you want.


Overlay sheet with pictures or symbols is placed on the grid so
that the user can tell what pressing on different areas will do


Used when fast input is needed and are ideally suited to
selecting from a limited range of choices such as fast food
restaurants, and for young children.


Advantages


Faster to use, and created waterproof


Disadvantages


Limited to the options shown


Poor for text input



Numeric Keypad


Used in ATM machines, mobile phones, when
entering PIN numbers, at EPOS (electronic point of
sale) terminals, if the barcode is damaged the person
can key in the barcode number quickly


Advantages


Small compact and portable; easy to cover up when
entering a PIN


Disadvantages


Difficult to enter text; can be too small for numbers to
be used effectively

Chip and Pin Reader

a magnetic strip reader.
These devices have a slot for entering the

chip card manually, a numeric keypad for entering the PIN and a

small display to show instructions. Some of these readers have a

separate magnetic strip reader across the top or side. The card

cannot be used in the chip and PIN reader unless the person knows the PIN. Used
anywhere a payment is required (grocery shops, etc.) The chip on a bank card
contains: Card number, PIN, Expiry date, Type of card/issuer, Security number


Advantages


Chips are more robust than a magnetic strip


More secure than magnetic strip cards; quicker than cash or
cheques


Disadvantages


If the customer forgets the PIN they cannot continue the
transaction


The person using the card needs to make sure no one can see the
PIN number as they enter it



These are a type of smart card reader, but tend to be used only at
EFT/POS terminals. There are a number of versions of these readers.
Sometimes the chip and pin reader does not have a

Magnetic Strip Reader


Can be used anywhere a payment is made using a bank or
credit card, such as: ATMs, part of Electronic Funds Transfer
at Point of Sale Terminals (EFTPOS) in hypermarkets and
other shops


In security, they are used to prevent
unauthorised

access to
restricted buildings or hotel rooms


Advantages


Faster, more accurate and more secure data entry than typing
on a keyboard


Disadvantages


If the strip is damaged, data has to be entered manually,
resulting in loss of speed at EFTPOS terminals


If the strip is damaged or the card is lost, the holder cannot
gain access to the building or hotel room

Smart Card Reader


The inside of a smart card usually contains an embedded
microprocessor, under a gold contact pad; microprocessor is
there for added security


Used in credit cards, computer security systems, mobile
phones, banking, satellite TV, ID cards


Advantages


Allow immediate updating, thereby preventing fraud


More robust and secure than a magnetic stripe


Prevents entry into restricted areas without a card


Disadvantages


If the card is lost the owner could lose the value on the card


There is a lot of information on some


cards, if it is stolen, hackers can use it


for fraudulent purposes and identity theft.



RFID (Radio Frequency ID)


Tags are attached to objects so they can be identified through the use of radio
waves.


The reader is used to transmit a radio signal in order to communicate with the
RFID tag.


Outside the realm of retail merchandise, RFID tags are tracking vehicles,
passports, library books, Alzheimer's patients and pets.


RFID tags are an improvement over bar codes because the tags have read and
write capabilities. Data stored on RFID tags can be changed, updated and
locked.


Advantages


Unlike barcode readers, they can cope with objects between the tag and the
reader


They can be read from and written to; are robust and more difficult to copy
than a barcode


Disadvantages


More expensive technology


When used to hold personal information, people’s movements can be tracked
easily, leading to a lack of privacy

Scanner


Used to enter hard copy images into a computer


Can be used with
OCR software


Used to obtain digital images of photographs


Used in retail stores for reading barcodes

Advantages


Allow images to be stored for further editing


Quicker than typing in a barcode

Disadvantages


Accuracy of reproduction is limited



OCR


Optical Character Recognition Software


Used after documents have been scanned in and saved to the
computer, converting the image into understandable text


Text is read by scanner


I
mage
compared with characters stored in computer


Converted to text for use with other software


USES:


Used to process passports, ID cards, car number plates and to sort
mail


Also used to input data from hard copy to word processor


Also can be used by blind people to scan in documents and have
them read out loud


Advantages:


Faster method of data entry; easier for people with disabilities


Disadvantages:


Lots of errors are produced; cannot read handwriting very well


Keyboard can be more accurate than OCR

Barcode Reader


The barcode does NOT contain the price of the item, this
is held on the company database. The barcode contains
the country and name of manufacturer, product code, etc.

Advantages


Price changes only need to be made to the database and not every
single product package


Faster and more accurate data entry than typing

Disadvantages


Can be expensive, especially for smaller businesses




Most items that are for sale in a shop
have a barcode printed somewhere on
the packaging, also used in libraries.
A barcode is normally a pattern of
thick and thin, dark and light lines.
A form of a scanner called a barcode
reader is used to read them


OMR
(Optical Mark Reader)


Use of a reader to input data from pencil or pen marks on a form


Pencil/pen marks are read by
scanner or reader


Position of marks are identified


Processing of many types of forms; for example,
e
xam
papers/school
registers/lottery/multiple choice
questionnaires


Advantages


Only one computer needed to collect and process data


Quick data entry; easy for the user to fill out forms


Disadvantages


If the marks don’t fill the space completely, or there is a smudge
somewhere on the paper they may not be read correctly


Keyboard and OCR can input text more easily than OMR


Only suitable for recording multiple choice answers


Forms have to be designed carefully, this can be expensive


Pre printed stationery is required for OMR

MICR
(Magnetic Ink Character Recognition)


Used in banking applications for the processing of cheques,
special magnetic font used at the bottom of cheques


Cheque

number; sort code; account #


C
haracters
read by magnetic reader


C
haracters
compared with characters stored in computer


C
onverted
to text for entry into system



Advantages


More secure than OCR as they cannot be tampered with


More accurate method than OCR or manually inputting the
information


Cheques can be read even if they have been overwritten


Disadvantages


Limit to the character set that can be used; expensive method of
data entry


Digital Cameras


Can be connected directly to a computer and photos
uploaded


Can be connected directly to photo printers


Can also take short videos


Can be used in software for image editing

Advantages


Can produce better quality images than traditional


Quicker to upload images directly than scan them


Memory card can hold more images than film

Disadvantages


Batteries needs frequent changing, more expensive

Microphones


Can be connected directly to the computer


Used to input sounds, can be stored and manipulated


Analog signal


sound card acts as an A/D converter


Used most often to input speech for a voiceover


Can be used with voice recognition software to
convert speech to text

Advantages


Quicker to input text by speaking than typing

Disadvantages


Computer cannot be used during recording


Voice recognition software not that accurate


MIDI Instruments


Performance can be directly recorded onto a computer and
stored as a MIDI file


Musicians can use to supplement other instruments

Advantages


Files can be manipulated; errors in performances can be
removed

Disadvantages


The music produced can sound manufactured




Instruments connected to a computer
using a
Musical Instrument Digital
Interface

Interface converts the output signals
from the instrument into a digital
form the computer can understand.



Graphics Tablet


Can be used with a stylus to input freehand work into a
computer and create graphics.


The stylus (can be a pencil if paper is used) is used to
draw or trace and input.


Used in East Asia to write Chinese, Japanese and other
character languages (easier than typing)

Advantages


More accurate way of drawing versus a mouse

Disadvantages


More expensive than mice


Webcams


Similar to video cameras, but are connected directly to the
computer


High quality webcams are used by businesses in
videoconferencing

Advantages


Can be online constantly; elderly people can keep in touch with
people without leaving their homes

Disadvantages


No storage capability, not portable, very limited features (ex.
cannot zoom , no video
-
editing facilities)


Light Pen


Device that allows a user to interact with a computer display (CRT)


The light pen can be used to select items on the display or to draw
on the display


Uses include retail sales in point
-
of
-
sale (POS) applications,
gaming, graphic arts, and healthcare applications


Healthcare Example: Light pens are now sometimes used with
ultrasonic

scanners and with some nuclear medicine imaging
apparatus to draw round a particular organ or region of interest
seen on the display. A typical application might be drawing a line
around the circumference of the fetal trunk.
The

computer

program might then present a figure for the area
contained, such as the estimated weight of the fetus, or its
estimated maturity.


Disadvantages


Strain of holding the pen to a screen over time limited the use of light
pens


Joystick


Used to play games


Used in the training of airline pilots to
control various aspects of flying an aircraft


Used for controlling machines such as
cranes, trucks and powered wheelchairs


Can be used to control objects in three
dimensions


Disadvantages


Not particularly robust; can be difficult to control


Biometric Devices


Biometrics means to measure and analyze human characteristics in order to
correctly identify an individual.


Examples of physical characteristics that can be used are:


Fingerprints


Voice Recognition


Retinas or irises


Facial patterns


Palm Prints




Special devices are needed to capture the biometric data which is then passed
onto the computer for processing and identification.

Biometric
authentification

methods can be used to identify you at ATMs to withdraw
cash, in computer networks to allow you to log on and many schools are now
introducing 'fingerprint registration'!


Advantages


Believed to be more secure because the physical characteristics are unique
to every individual and cannot be stolen, copied or lost.


Disadvantages


Far from foolproof;

many errors and false accepts are possible


Sensors


Device used to
input

data about physical changes in an
environment that is being monitored or controlled.


Used to collect data

Advantages


More reliable than humans; more accurate (no human error); can
be used in places humans cannot go; readings can be taken
continuously;
human resources can be allocated elsewhere

Disadvantages


Sensors need a power source, if they lose power, they will stop
working


Temperature Sensor


Read the temperature of their surroundings and send
the readings to the processor.


Sensors do
NOT

make decisions they
only collect and report data


Used in washing machines; computer
-
controlled
greenhouses; central heating and central cooling
systems; automatic cookers

Pressure Sensor


Measures the amount of pressure exerted and sends that
information to a processor which decides what action to
take, if any.


Used in burglar alarms, washing machines, robotic arms



Light Sensor


Measures the amount of light falling on the sensor


Used in computer
-
controlled greenhouses, headlights of
cars, streetlights, burglar alarms

Analogue & Digital Signals

Analogue Signal
= continually changing





with any value possible




For example: Temp = 18.454345
°

C


Digital Signal
= discrete values; limited number of
values




For example: Temp = 18.5
°

C



Computers

DO NOT
understand analogue signals



Computers
ONLY

understand digital signals


Analogue signals
must

be converted to digital signals via
an A/D converter