1. CHAPTERTHREE
Discovering Computers
Fundamentals,
2011 Edition
Living in a Digital World

2. Objectives Overview
Identify the keys and buttons
commonly found on desktop
computer keyboards, and
describe how keyboards for
mobile computers and devices
differ from desktop computer
keyboards
Describe different mouse types
Describe various types of touch
screens and explain how a
touch-sensitive pad works
Describe various types of pen
input
2

3. Objectives Overview
Explain other types of input
Explain the characteristics
of LCD monitors, LCD
screens, and CRT monitors
Identify the purpose and
features of speakers,
headphones, and ear-buds;
data projectors; and
interactive whiteboards
Summarize the various
types of printers
Identify input and output
options for physically
challenged users
3

4. What Is Input?
• Input is any data and instructions entered into the
memory of a computer
4

5. What Is Input?
An input device
is any hardware
component that
allows users to
enter data and
instructions into
a computer
5

6. Keyboard
• A keyboard is an input device that contains keys
users press to enter data and instructions into a
computer
6

7. Keyboard
• Most desktop computer keyboards have…
7

8. Keyboard
• An ergonomic keyboard has a design that reduces
the chance of wrist and hand injuries
• Ergonomics incorporates comfort, efficiency, and
safety into the design of the workplace
8

9. Keyboard
• Keyboards on mobile devices typically are smaller
and/or have fewer keys
• Some phones have predictive text input, which
saves time when entering text using the phone’s
keypad
Page 191
Figure 5-3
9

10. Pointing Devices
Page 189
10

11. Types of Pointing Devices:
• Mouse
• Devices used for games - joystick
• Devices used in laptops – track ball, touch pad,
pointing stick
11

12. Pointing Devices
• A mouse is a pointing device that fits under the
palm of your hand comfortably
– Most widely used pointing device on desktop
computers
• A mouse can be wired (mechanical/ optical) or wireless
(cordless)
12

13. Types:
• Mechanical – small ball on underside rolls as
mouse is moved
• Optical – uses a light beam to monitor mouse
movement
• Cordless – uses either infrared or radio waves
13

14. • A touchpad is a
small, flat,
rectangular
pointing device that
is sensitive to
pressure and
motion
• Sliding finger across
pad moves pointer
• Tapping with finger
recognized as click
Pointing Stick
• A trackball is a
stationary pointing
device with a ball
on its top or side
• Usually has one or
more buttons that
work just like
mouse buttons
Touchpad
Trackball
Pointing Devices
• A pointing stick is a
small pressuresensitive pointing
device shaped like a
pencil eraser that is
positioned between
keys on a keyboard
• Pushing post in any
direction moves
pointer
14

15. Pointing Devices
• A handheld vertical lever
with handgrip mounted
on a base
• User moves the lever in
different directions to
control the actions of the
simulated vehicle or
player
• Distance and speed of
movement control pointer
position
• Pressing trigger causes
actions to take place.
15

16. Touch Screens and Touch-Sensitive Pads
• A touch screen is a touch-sensitive display device
• Position of finger on screen
determines item to be input
into system
• Used at kiosks in public place
such as malls
16

17. Touch Screens and Touch-Sensitive Pads
Microsoft Surface
Touch-sensitive pads
17

18. Graphic tablet
• A
flat, rectangular, electronic, p
lastic board
• Architects, mapmakers, desig
ners, artists and home user
create drawings by using a
pressure sensitive pen
(stylus) on a graphic tablet
• Used to create or trace
precise drawings.
18

19. Pen Input
• With pen input, you touch a stylus or digital pen on a flat
surface to write, draw, or make selections
• A stylus -A small metal or
plastic device that looks like
a tiny ink pen. Often used in
PDAs or pocket PCs
• A pen digital- provide more
functionality than a stylus,
featuring electronic erasers and
programmable buttons
19

20. Other Types of Input
20

21. Other Types of Input
• Video games and computer games use a game controller
as the input device that directs movements and actions
of on-screen objects
Gamepads
Joysticks and
Wheels
Light guns
Motionsensing
controllers
Wii Remote
Dance pads
21

22. Other Types of Input
22

23. Other Types of Input
• A digital camera is a mobile device that allows
users to take pictures and store them digitally
Studio cameras
Field cameras
Point-and-shoot camera
23

24. Other Types of Input
24

25. Other Types of Input
• Two factors affect the quality of digital camera photos:
Resolution
• Resolution is the
number of horizontal
and vertical pictures
in a display device
• A pixel is the smallest
element in an
electronic display
25

26. Other Types of Input
• Voice input is the process of entering input by
speaking into a microphone
• Voice recognition is the computer’s capability of
distinguishing spoken words
• Audio input is the process of entering any sound into
the computer.
**used – microphone
- CD/DVD/Blu-ray Disk Players,
- MIDI (musical instrument digital interface)external music devices such as electronic keyboard,
guitars, drums, harmonica.
26

27. Other Types of Input
• Music production software allows users to record,
compose, mix, and edit music and sounds
27

28. Other Types of Input
• Video input is the process of capturing full-motion images and
storing them on a computer’s storage medium
Record video on a digital video (DV) camera or use a
video capture card to convert analog signals to digital
Connect the camera to a port on the system unit
Transfer video and images
28

29. Other Types of Input
• A Web cam is a type of digital video camera that
enables a user to:
Capture video and
still images
Send e-mail
messages with
video attachments
Broadcast live
images over the
Internet
Add live images to
instant messages
Make video
telephone calls
29

30. Other Types of Input
• A video conference is a meeting between two or
more geographically separated people
30

31. Other Types of Input
• A flatbed scanner creates a file of the document
in memory
– Works in a manner similar to a copy machine
31

32. Other Types of Input
• Optical character recognition (OCR) involves reading
characters from ordinary documents
• A turnaround document is a document you return to the
company that creates and sends it
32

33. Other Types of Input
• Optical mark recognition (OMR) reads hand-drawn
marks such as small circles or rectangles
33

34. Other Types of Input
• A bar code reader, also
called a bar code
scanner uses laser
beams to read bar
codes
34

35. Other Types of Input
• RFID (radio frequency identification) uses radio signals to
communicate with a tag placed in or attached to an object
• An RFID reader reads information on the tag via radio waves
• RFID can track:
Tracking times of
runners in a
marathon
Tracking location
of soldiers
Managing
inventory
Employee
wardrobes
Gauging pressure
and temperature
of tires
Airline baggage
Checking out
library books
Checking lift
tickets of skiers
Tracking toll
payments
35

36. Other Types of Input
• Magnetic stripe card readers read the magnetic
stripe on the back of cards such as:
Credit cards
Entertainment cards
Bank cards
Other similar cards
36

37. Other Types of Input
• MICR (magnetic ink character recognition) devices read text
printed with magnetized ink
• An MICR reader converts MICR characters into a form the
computer can process
• Banking industry uses MICR for check processing
37

38. Other Types of Input
• Biometrics authenticates a person’s identity by
verifying a personal characteristic
Fingerprint
reader
Face
recognition
system
Signature
verification
system
Hand
geometry
system
Iris recognition
system
Voice
verification
system
Retinal
scanners
38

39. Other Types of Input
iris
recognition
system
fingerprint
reader
39

40. Other Types of Input
• A terminal is a computer that allows users to send data
to and/or receive information from a host computer
A POS terminal
records purchases,
processes
payment, and
updates inventory
An automated
teller machine
(ATM) allows users
to access their
bank accounts
A DVD kiosk is a
self-service DVD
rental machine
40

41. What Is Output?
• Output is data that has been processed into a
useful form
41

42. Categories of output:
• Text : memos, letters, press
releases, report, classified
advertisements, envelops, mailing labels, text
messages.
• Graphics : logos, charts, drawings, clip
arts, photos.
• Audio : songs, narrations, speeches
• Video : video blogs, vodcast.
42

43. What Is Output?
• An output device is any type of hardware
component that conveys information to one or
more people
Display
devices
Speakers,
headphones,
and earbuds
Printers
Data
projectors
Interactive
whiteboards
43

44. Display Devices:
• A display device visually
conveys text, graphics, and
video information
• Information on display
device sometimes called
softcopy
• A monitor is packaged as a
separate peripheral
• 2 types of display devices:
– Flat -panel display (
LCD, plasma, digital
television /DTV)
– CRT monitors
44

45. Display Devices :Flat-panel display
• Liquid crystal display (LCD) uses a liquid compound to
present information on a display device
• Produce sharp, flicker free images
• Mobile devices that contain LCD display :
Notebook, Tablet PC, ultra personal computer, portable
media player, smart phone and PDA
Page 209
45

46. Resolution
Response time
Dot pitch
Brightness
Contrast ratio
46

47. Resolution:
• Number of a horizontal and vertical pixel in a
display device.
• Sharpness and clarity of images
• Higher resolution makes image sharper, display
more text on the screen, makes some elements
smaller.
47

48. Dot pitch:
• Distance in millimeters between pixel on a display
device.
• Text created with a smaller dot pitch is easier to
read.
• Average dot pitch on LCD monitors and screen
should be 0.30mm or lower. The lower the
number, the sharper the image.
48

49. Response time:
• The time in milliseconds (ms) that it takes to turn
a pixel on or off.
• LCD monitor’ and screens’ response time today
range from 3 to 16 ms. The lower the number, the
faster the response time.
49

50. Brightness:
• Measured in nits. A nit is a unit of visible light
intensity equal to one candela per square.
• Candela is the standard unit of luminous intensity.
• LCD monitor and screen range from 250 to 550
nits. The higher the nits, the brighter the images.
50

51. Contras ratio:
• Describe the difference in light intensity between
the brightness white and darkest black that can
be displayed on an LCD monitor.
• Contrast ratios today range from 500:1 to 2000:1.
higher contrast ratios represent colours better.
51

52. Display Devices:Flat-panel display
• Plasma monitors are display devices that use gas
plasma technology and offer screen sizes up to
150 inches
52

53. Display Devices:Flat-panel display
• Digital Television (DTV) -Uses
digital signals to produce
crisper, higher-quality output on
LCD and plasma televisions
• HDTV (high-definition
television) is the most advanced
form of digital television.
• Great for game playing,
watching movies, and browsing
the Internet
53

54. Display Devices: CRT monitor
• A CRT monitor is a desktop monitor that contains
a cathode-ray tube
Page 210
Figure 5-33
54

55. • Screen coated with tiny dots of phosphor
material. Each dot consist of a red, blue and green
phosphor.
• What determines the quality of a CRT monitor?
– Screen resolution
– Text created with a smaller dot pitch is easier to read.
– Refresh rate is speed at which monitor redraws images
on screen.
55

56. Printers
• A printer
produces text
and graphics on
a physical
medium
• Before
purchasing a
printer, ask
yourself a series
of questions
56

57. Printers
57

58. Categories of printer:
• Non impact printer
(Int-jet, Photo,Laser, Thermal,Mobile, Label,
Postage, Plotter and multifunction peripheral
(MFP)
• Impact printer.
(Dot matrix and line)
58

59. Printers : Non impact printer
• A nonimpact printer forms characters and
graphics on a piece of paper without actually
striking the paper
Ink-jet
printers
Photo
printers
Mobile
printers
Laser
printers
Plotters
Thermal
printers
Largeformat
printers
59

60. Printers : Non impact printer
• An ink-jet printer forms characters and graphics by
spraying tiny drops of liquid ink onto a piece of paper
– Print in Color or black-and-white
– Printers with a higher dpi (dots per inch) produce a higher
quality output
– Less expensive
than laser printer
60

61. Printers: Non impact printer
A photo printer produces color
photo-lab-quality pictures
• Most use ink-jet technology
• PictBridge allows you to print photos
directly from a digital camera
• Print from a memory card and preview
photos on a built-in LCD screen
61

62. Printers: Non impact printer
62

63. Printers : Non impact printer
• print text and graphics in high quality
resolution, ranging from 1200 to 2400
dpi.
•Typically cost more than ink jet printer,
but is much faster
Highspeed
Blackandwhite
Laser
printer
Highquality
Color
63

64. Printers: Non impact printer
• A multifunction peripheral (MFP) is a single
device that prints, scans, copies, and in some
cases, faxes
– Sometimes called an all-in-one device
64

65. Printers : Non impact printer
• A thermal printer generates images by pushing
electrically heated pins against the heat-sensitive
paper
2 types:
1. Dye-sublimation
printer
2. Thermal wax printer
Pages 215 – 216
Figure 5-40
65

66. Printers: Non impact printer
• A mobile printer is a
small, lightweight, batte
ry-powered printer that
allows a mobile user to
print from a mobile
device
Page 216
Figure 5-41
66

67. Printers: Non impact printer
• Plotters are used to produce high-quality
drawings
• Large-format printers create photo-realistic
quality color prints on a larger scale
Page 216
Figure 5-42
67

68. Printers: Non impact printer
• Label printer : Small printer that print on
adhesive –type material.
• Most also print bar codes
• Postage printer has built-in digital scale and print
postage stamps.
68

69. Printers: Impact printers
• Impact printers form characters and graphics on a
piece of paper by striking a mechanism against an
inked ribbon that physically contacts the paper
Dot-matrix
printer
Page 217
Line
printer
69

70. Printers: Impact printers
• A dot-matrix printer
produces printed
images when tiny wire
pins on a print head
mechanism strike an
inked ribbon
• Speed measured by the
number of character
per second (cps)
Page 217
Figure 5-43
70

71. Printers: Impact printers
• A line printer prints an
entire line at a time
• High speed impact
printer
• Speed measured in lines
per minute (lpm)
Page 217
Figure 5-43
71

72. Other Output Devices
• An audio output device produces
music, speech, or other sounds
Most computer users attach
speakers to their computers to:
• Generate higher-quality sounds for playing
games
• Interact with multimedia presentations
• Listen to music
• View movies
Page 217
Figure 5-44
72

73. Other Output Devices
• Headphones are
speakers that cover or
are placed outside of
the ear
• Earbuds (also called
earphones) rest inside
the ear canal
73

74. Other Output Devices
Voice output occurs when you hear a
person’s voice or when the computer
talks to you through the speakers
• Some Web sites dedicate themselves to
providing voice output
• Often works with voice input
• VoIP uses voice output and voice input
Page 218
74

75. Other Output Devices
• A data projector is a
device that takes the
text and images
displaying on a
computer screen and
projects them on a
larger screen
Page 218
Figure 5-45
75

76. Other Output Devices
• An Interactive Whiteboards is a
touch-sensitive device, resembling a
dry-case board, that display the image
on a connected computer screen.
• A presenter control the computer by
clicking a remote control, touching the
whiteboard, drawing on or erasing the
whiteboard with a special digital pen
and eraser, or writing on a special
tablet.
• Notes written can be directly on the
computer.
76

77. Putting It All Together
77

78. Putting It All Together
78

79. Putting It All Together
79

80. Input and Output Devices
for Physically Challenged Users
Head-mounted pointer
Braille printer
80

81. Summary
Various techniques for
entering input and
several commonly
used input device
Various methods of
output and several
commonly used
output devices
81

82. CHAPTER 3
Discovering Computers
Fundamentals,
2011 Edition
Living in a Digital World