Chapter 03 io csc&tts
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Transcript of Chapter 03 io csc&tts
Discovering Computers Fundamentals,
2011 Edition
Living in a Digital World
CHAPTERTHREE
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
3
Objectives Overview
Explain other types of input
Explain the characteristics of LCD monitors, LCD
screens, and CRT monitors
Summarize the various types of printers
Identify the purpose and features of speakers, headphones, and ear-
buds; data projectors; and interactive whiteboards
Identify input and output options for physically
challenged users
4
What Is Input?
• Input is any data and instructions entered into the memory of a computer
5
What Is Input?
An input device is any hardware component that allows users to enter data and
instructions into a computer
6
Keyboard
• A keyboard is an input device that contains keys users press to enter data and instructions into a computer
7
Keyboard
• Most desktop computer keyboards have…
Between 101 and 105 keys
A numeric keypad on the right side of
the keyboard
Function keys, CTRL keys, ALT
keys, and arrow keys
WINDOWS key APPLICATION key Toggle keys
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
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
10
Pointing Devices
A pointing device is an input device that allows
a user to control a pointer on the screen
A pointer is a small symbol on the screen whose location and
shape change as a user moves a pointing device
Page 189
11
Types of Pointing Devices:
• Mouse• Devices used for games - joystick• Devices used in laptops – track ball, touch pad,
pointing stick
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)
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
14
Pointing DevicesTr
ackb
all • A trackball is a
stationary pointing device with a ball on its top or side To
uchp
ad • A touchpad is a small, flat, rectangular pointing device that is sensitive to pressure and motion Po
intin
g Sti
ck • A pointing stick is a pressure-sensitive pointing device shaped like a pencil eraser that is positioned between keys on a keyboard
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.
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
17
Touch Screens and Touch-Sensitive Pads
Microsoft Surface Touch-sensitive pads
18
Graphic tablet
• A flat, rectangular, electronic, plastic board
• Architects, mapmakers, designers, artists and home user create drawings by using a pressure sensitive pen (stylus) on a graphic tablet
• Used to create or trace precise drawings.
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
20
Other Types of Input
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 Dance pads
22
Other Types of Input
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
24
Other Types of Input
25
Other Types of Input
• Two factors affect the quality of digital camera photos:
• Resolution is the number of horizontal and vertical pictures in a display device
• A pixel is the smallest element in an electronic display
Resolution
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.
27
Other Types of Input
• Music production software allows users to record, compose, mix, and edit music and sounds
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
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
Add live images to instant messages
Broadcast live images over the
Internet
Make video telephone calls
30
Other Types of Input
• A video conference is a meeting between two or more geographically separated people
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
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
33
Other Types of Input
• Optical mark recognition (OMR) reads hand-drawn marks such as small circles or rectangles
34
Other Types of Input
• A bar code reader, also called a bar code scanner uses laser beams to read bar codes
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
Employee wardrobes Airline baggage Checking lift
tickets of skiers
Managing inventory
Gauging pressure and temperature
of tires
Checking out library books
Tracking toll payments
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
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
38
Other Types of Input
• Biometrics authenticates a person’s identity by verifying a personal characteristic
Fingerprint reader
Face recognition
system
Hand geometry
system
Voice verification
system
Signature verification
system
Iris recognition system
Retinal scanners
39
Other Types of Input
fingerprint reader
iris recognition
system
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
41
What Is Output?
• Output is data that has been processed into a useful form
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.
43
What Is Output?
• An output device is any type of hardware component that conveys information to one or more people
Display devices Printers
Speakers, headphones, and earbuds
Data projectors
Interactive whiteboards
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
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
46
Resolution Response time
Brightness Dot pitch
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.
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.
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.
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.
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.
52
Display Devices:Flat-panel display
• Plasma monitors are display devices that use gas plasma technology and offer screen sizes up to 150 inches
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
54
Display Devices: CRT monitor
• A CRT monitor is a desktop monitor that contains a cathode-ray tube
Page 210 Figure 5-33
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.
56
Printers
• A printer produces text and graphics on a physical medium
• Before purchasing a printer, ask yourself a series of questions
57
Printers
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)
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
Laser printers
Thermal printers
Mobile printers Plotters
Large-format printers
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
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
62
Printers: Non impact printer
63
Printers : Non impact printer
Laser 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
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
65
Printers : Non impact printer
• A thermal printer generates images by pushing electrically heated pins against the heat-sensitive paper
Pages 215 – 216 Figure 5-40
2 types:1. Dye-sublimation printer2. Thermal wax printer
66
Printers: Non impact printer
• A mobile printer is a small, lightweight, battery-powered printer that allows a mobile user to print from a mobile device
Page 216 Figure 5-41
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
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.
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
Page 217
Dot-matrix printer
Line printer
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
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
72
Other Output Devices
• An audio output device produces music, speech, or other sounds
Page 217 Figure 5-44
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
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
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
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
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.
77
Putting It All Together
78
Putting It All Together
79
Putting It All Together
80
Input and Output Devices for Physically Challenged Users
Braille printerHead-mounted pointer
81
Summary
Various techniques for entering input and several commonly used input device
Various methods of output and several
commonly used output devices
Discovering Computers Fundamentals,
2011 Edition
Living in a Digital World
CHAPTER 3