INTRODUCTION TO
COMPUTERS
LECTURE 7 : WEEK 7
TEXT AND REF. BOOKS
2
Text Book:
Peter Norton (2011), Introduction to Computers, 7 /e, McGraw-Hill
Reference Book:
Gary B (2012), Discovering Computers, 1/e, South Western
Deborah (2013), Understanding Computers, 14/e, Cengage Learning
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Presented by: Asma Khan
INPUT/OUTPUT
DEVICES
Learning Outcome
◻
Input Devices
◻
Keyboard, Mouse
◻
Variants of the Mouse
◻
Devices for the Hand
◻
Optical Input Devices
◻
Audiovisual Input Devices
Input And Output
7
◻
Input is any
data and instructions
entered
into the
memory
of a computer
◻
Input
Device
is any hardware component
that allows users to enter
data
and
Input And Output
◻
Input Device:
Keyboard and pointing devices
◻
Pointing devices:
Mouse is a pointing device because it
allows a user to control a pointer on the
screen.
Input And Output
◻
In GUI, a pointer is a small
symbol
on the
screen
whose location and shape
change
as a user
moves
a
pointing device.
◻
A pointing device can select
text
,
graphics
and
other
objects
and click
buttons
,
icons
,
links
and
menu
commands.
Input And Output
◻
Mouse
◻
There are 2 types:
Mechanical
mouse and
Optical
mouse.
◻
Mechanical mouse has a rubber or metal ball on its
underside.
You should place a mechanical mouse on a mouse pad.
Mouse pad is a rectangular rubber or foam pad that provides better traction than the top of a desk
◻
Optical mouse uses devices that
emit
and
sense
light
to
detect the mouse’s movement.
Input And Output
13
◻
Mouse
◻
Optical mouse is
More precise than a mechanical mouse
Dose not require cleaning as does a mechanical mouse. Also it is more expensive.
◻
Mouse connects to a computer in several way:
By cable through mouse port, USB port and serial port. By wireless through IR or Bluetooth.
◻
Wireless mouse or cordless mouse, is a battery-powered
Input And Output
14
◻
Trackball
◻ Is a stationary pointing device with a ball on its top or side, Similar to a mechanical mouse that has a ball on the bottom.
◻ To move the pointer using a trackball, you rotate the ball with your thumb, fingers or the palm of your hand.
Input And Output
◻
Touchpad
◻ Is a small, flat, rectangular pointing device that is sensitive to
pressure and motion.
◻ To move the pointer, slide your fingertip across the surface of the pad.
◻ You also can tap the pad’s surface to imitate mouse operations such as clicking.
◻ Around the edge of the pad there are one or more buttons that work like mouse buttons.
◻ Touchpad's are found most often on notebook computers.
Input And Output
◻
Pointing Stick
◻
Is a
pressure-sensitive
pointing device shaped like a
pencil eraser that is positioned between keys on a
keyboard.
◻
To move the pointer you
push
the
pointing
stick
with a finger.
◻
IBM
developed the pointing stick for its notebook
computers.
Input And Output
◻
Light Pen
◻
Is a
handheld
pointing device that detect the
presence
of
light
.
◻
To select
objects
on the screen, a user
press
the light
pen against the
surface
of the
screen
◻
Or
points
the light pen at the
screen
and then
press
a
button
on the pen.
Input And Output
◻
The Keyboard
◻ Is an input device that contains keys users press to enter data and
instructions into a computer
◻ Desktop computer keyboard often attach to the System Unit using
Cable: a serial port or USB port. Without cables : IR or Bluetooth
◻ Wireless keyboard or cordless keyboard, is a battery-powered device that transmits data using wireless technology
19
Computer Keyboard Keys
◻
Function Keys
◻
Cursor-Movement Keys
◻Numeric Keypad
◻
Toggle Keys (Caps Lock, Num Lock)
◻Modifier Keys (Shift, Alt, Ctrl)
◻
Windows Keys
Capturing a Screen Image
20
◻
Print Screen
– Captures an
image
of the
entire
desktop
to the Clipboard.
◻
Alt + Print Screen
- Captures
active
window
image
Standard Computer Keyboard
Input And Output
◻
Touch Screen
◻
Is a
touch-sensitive
display device.
◻
Users can interact with these device by
touching
areas of the screen.
◻
Because touch screens require a lot of arm
movements, you do not enter
large
amounts of
data
using a
touch
screen.
Input And Output
◻
Pen Input
◻
Mobile users often enter data and instructions with
a
pen-type
device.
◻
With pen input ,users
write
,
draw
, and
tap
on a flat
surface to enter
input
.
◻
The surface maybe a
monitor
, a
screen
, a special
type of paper or
graphic
tablet
.
Input And Output
◻
Pen Input
◻
2 devices used for pen input are
stylus
and
digital
pen.
◻
Stylus is a small
metal
or
plastic
device that looks like a
tiny ink pen but uses pressure instead of ink.
◻
A digital Pen, larger than a stylus
◻It’s available in 2 forms
Pressure-sensitive
Built in digital cameras.
Input And Output
26
◻
Pen Input
◻
Tablet
PCs use a
pressure-sensitive
digital pen and
PDAs
use a
stylus
.
◻
Pressure-sensitive digital pens provide more
functionality
than a stylus.
◻
Pen Input is possible on computers without touch screens
by
attaching
a
graphics
tablet
to the computer.
Input And Output
◻
Pen Input
◻ Digital pens that have built-in digital
cameras look like a ballpoint pen and
do not contain any additional buttons.
◻ As you write and draw on special digital paper with the pen, It capture
every hand written mark and then stores the images in the pen’s
memory.
◻ You then can transfer the image from the pen to a computer.
Input And Output
28
◻
Other Types of Input
◻
Voice Input
◻ Is the process of entering input by speaking into a microphone.
◻ Voice recognition , also called speech recognition, is the
computer’s capability of distinguishing spoken words.
◻ Some business software such as word processing and spreadsheet includes voice recognition as a part of the program.
Input And Output
◻
Audio Input
◻
Is the process of entering any
sound
into the
computer
such as
speech
,
music
, and
sound
effects
.
◻
User enter sound into computer via devices such as
Microphones
Tape players
CD/DVD players
Radios
Input And Output
◻
Other Types of Input
◻
Digital Cameras
◻
Allows users to
take
pictures and
store
the
photographed image
digitally
instead of on traditional
film.
◻
They use internal
flash
memory to
store
images.
◻
Others store images on mobile storage media, including
a flash memory, memory stick and mini CD/DVD.
Input And Output
◻
Digital Cameras
◻
A digital camera's
resolution
is defined in pixels.
◻
Pixel is a
smallest
element in an electronic image.
◻
The
greater
the number of pixels the camera uses to
capture an image, the
better
the quality of the image.
◻
Digital camera resolutions range from about
1 million
to more than
13 (or more) million
pixels (MP).
Input And Output
◻
Other Types of Input
◻
Video Input
Is the process of a capturing
full-motion
images and storing
them on a computer’s storage medium.
Many Digital Video(DV) camera have the capability of
capturing
still
frames
as well as motion.
To transfer recorded images to a hard disk or CD or DVD,
users connect
DV
directly to a
USB
port on the system unit.
you can
play
or
edit
video using video editing SW.
Input And Output
◻
Scanners and Reading Devices
◻
Some input devices save time by
capturing
data
directly from a
source
document
Optical scanner
Optical readers
Bar code readers
RFID readers
Magnetic strip card readers
Magnetic-ink character recognition reader.
Input And Output
34
◻
1- Optical scanner
, Usually called a scanner◻ Is a light-sensing input device that reads printed text and graphics
and then translates the results into a form the computer can process.
◻ Many scanner include OCR ( optical character recognition ) software, which can read and convert text documents into electronic
files.
Input And Output
◻
2- Optical Readers
◻
Is a device that uses a
light
source
to read characters,
marks
and
codes
and then converts them into
digital
data
that a
computer can process.
◻
Two technologies used by optical readers are
■ Optical character recognition.
Input And Output
◻
A- Optical Character Recognition (OCR)
◻ Involves reading handwritten, typewritten or printed text and translating the image into a form the computer can process.
◻ Most OCR devices include a small optical scanner for reading characters and sophisticated SW to analyze what read.
◻ It range from large machines that can read thousands of documents per minute to handheld that read one document at a time.
Input And Output
❑
B- Optical Mark Recognition (OMR)
❑
Devices read
hand-drawn
marks such as small
circles
or
rectangles
.
❑
One of the most familiar applications of optical mark
recognition is the use of
pencil bubble optical answer
Input And Output
◻
3- Bar Code Readers
◻ Also called bar code scanner
◻ Is an electronic device that uses laser beams for reading printed barcodes.
◻ Barcode is an identification code that consists of set of vertical lines and
spaces of different widths
◻ The barcode represent the data that identifies the manufacturer and the
item
Input And Output
◻
4- RFID Readers
◻
Radio-frequency identification
◻
Is a technology that uses
radio
signals
to communicate with
a
tag
placed in or
attached
to an
object
, an
animal
, or a
person
.
◻
RFID tags, which contain a
memory
chip
and an
antenna
,
are available in many
shapes
and
size
.
◻
RFID reader reads
information
on the tag via
radio
waves
. It
can be
handheld
devices or mounted in a
stationary
object
such as a
doorway
.
Input And Output
40
◻
5- Magnetic Strip Card Readers
◻
Often called a
magstrip
reader, reads the Magnetic strip on the
back of
credit
cards
or other similar cards.
◻
The strip contains
information
identifying you.
◻
Some information stored in the strip includes your
name
,
account
number
, the card
expiration
date, and a
country
code
.
◻
If the Magnetic strip card readers rejects your card, it is
possible that the Magnetic strip is
scratched
,
dirty
or
erased
.
Input And Output
◻
Biometric Input
◻ Is the technology of authenticating a person’s identity by verifying a personal characteristic.
◻ Biometric devices grant users access to programs, systems, or rooms by analyzing some physiological or behavioral characteristic.
◻ Such as fingerprints, eye patterns, voice patterns, facial features, signatures and hand geometry.
Input And Output
Biometric Input
Fingerprint scanner
Face recognition system
Hand geometry system
Voice verification
system
Signature verification
system
Iris recognition system
Input And Output
◻
Biometric Input
◻
Sometimes, fingerprint ,iris and other biometric data are
stored on a smart card.
◻