This document provides an overview of computer output and output devices. It discusses the different types of output including text, graphics, video, and audio. Common output devices are then described, including monitors, printers, speakers, and others. The document focuses on monitors, explaining the differences between CRT and LCD monitors. It covers LCD monitor types, resolution, refresh rates, and other specifications for comparing monitors.

1. IT 111 InformationTechnology Fundamentals
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OUTPUT and its DEVICES

2. 2
CONTENTS
• Introduction
• Output Types
• Output Devices
Monitors
Printers

3. Introduction
3
 Output is data that has been processed into a useful
form.
 Output is an optional step in the information
processing cycle but may be ordered by the user or
program.
 The computer may be required to display the results
of its processing.
 The results may appear as text, numbers, or a graphic
on the computer’s screen or as sounds from its
speaker.
 The computer also can send output to a printer or
transfer the output to another computer through a
network or the internet.

4. Output Types
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1.Text output
-Textual information
2. Graphics output
-Visual images - photos,
diagrams, icons
3.Video output
-Moving images
4.Audio output
Sounds - music, voice,
podcasts
TEXT
AUDIO

5. Output Devices
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 Output devices are peripheral devices that enable us to view
or hear the computer’s processed data.

6. Commonly used Output Devices
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1. Monitors/Display devices
2. Printers
3. Speakers
4. Headphones and earbuds
5. Data Projectors
6. Interactive whiteboards
7. Force-feedback game controllers
8.Tactile output

7. 1. Monitors
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 A peripheral device which displays computer output on a
screen.
 Screen output is referred to as soft copy.
 It is the most commonly used output device on personal
computer systems
 Two important hardware devices determine the quality of
the image you see on any monitor:
1. monitor itself
2. video controller

8. Types of monitors
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 Cathode-ray tube (CRT)
 Liquid Crystal Display (LCD or flat-panel)
CRT LCD

9. Types of monitors
9
 CRT- Cathode RayTube
 Uses a large vacuum tube sealed glass tube.
 electron gun shoots a stream of electrons at a
specially phosphor-coated screen
 on impact, the phosphor flares up for a fraction of a
second
 electron gun sweeps across the screen many times a
second(R to L thenTop to bottom then refreshes
screen in a diagonal manner)
 Have been the standard for use with desktop computers
because they provide a bright, clear picture at a
relatively low cost.
 Disadvantages of CRT monitors
 They take up desktop space and can be difficult to move.
 Requires a lot of power to run
The CRT electron gun
“shoots” 3 electrons at
the screen representing
the amount of red,
green and blue for the
pixel

10. CRT- Cathode Ray Tube
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 Common screen sizes are 15, 17,
19,21, and 22 inches.
 A CRT monitor's viewable size is the
diagonal measurement of the actual
viewing area.
 A 21-inch monitor have a viewable
size of 20 inches.
 The popularity of CRT monitors
is declining

11. Types of monitors
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 LCD -Liquid Crystal Display
 one of several types of “flat-panel” displays
 contain fluorescent tubes that emit light waves to
liquid-crystal cells, sandwiched between two
sheets of material
 When an electrical charge passes through the
cells, the cells twist, causing some light waves to
be blocked and allows others to pass through,
creating images on the display
 forms output by solidifying liquid crystals
and “backlighting” the image with a light source
 Disadvantages
 Images can be difficult to see in bright light
 Limited viewing angle

12. Main categories of LCD
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 Passive matrix LCD
 relies on transistors to form a grid that define location of each
pixel
 the color displayed by a pixel is determined by electricity at the
end of the row and at the top of the column
 DISADVANTAGE – refresh rate is slow; limited viewing angle
proof is when you move the pointer too quickly, it
disappears(effect known as submarining); animated graphics is
blurry on this type
 Active matrix LCD
 assigns a transistors to each pixel
 each pixel is turned on and off individually allowing rapid refresh
rate
 Wider viewing angle throughTFT(Thin Film Transistor)
technology which employs four transistors per pixel
 anotherTFTcalled organic LED (OLED), uses organic molecules
that produce an even brighter, easier-to-read display

13. Other Types of Monitors
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1. Paper-white displays
 Sometimes used by document designers such as desktop publishing
specialists, newspaper or magazine compositors, and other persons
who create high quality printed documents.
 Produces a very high contrast between the monitor’s white
background and displayed text or graphics, which usually appear in
black.
2. Electroluminescent displays (ELDs)
 Similar to LCD monitors but use a phosphorescent film held
between two sheets of glass.
 A grid of wires sends current through the film to create an image
3. Plasma displays
 Are created by sandwiching a special gas (such as neon or xenon)
between two sheets of glass.When gas is electrified, it glows
projecting the image.
 Screen sizes up to 150 inches wide, richer colors, more expensive,
hang directly on a wall.

14. Plasma display
14

15. Categories of monitor by the way they display colors
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1. Monochrome
 Display only one color (such as green, amber, or white)
against a contrasting background, which is usually black.
 Used for text-only displays where the user does not need to
see color graphics
2. Grayscale
 Display varying intensities of gray (from a very light gray to black)
against a white or off-white background
 Used in low-end portable systems , especially handheld computers
 to keep costs down
3. Color
 Can display between 16 colors and 16 million colors.
 Most new monitors display in color. Many color monitors can be set to
work in monochrome or grayscale mode.

16. Comparing Monitors
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1. Size
 Affects how well you can see images.
 Are measured diagonally, in inches, across the front of the
screen.
 As a rule of thumb, buy the largest monitor you can afford.
Typical Display Sizes
 sizes of LCD monitors are, 17,19,20,22,24,26,27inches;
some are 45 or 65 inches; most are widescreen,
 Notebooks’ typical sizes of 14.1, 15.4, 17, and 20.1 inches.
 Tablet PC screens range from 8.4 inches to 14.1 inches.
 Ultra-Mobile PCs are 5 inches to 7 inches.
 Portable media players from 1.5 inches to 3.5 inches.
 Smartphones from 2.5 inches to 4.1 inches.
 Digital camera range from 2.5 inches to 4 inches.

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2. Resolution
 Determined by the number of pixels on the screen, a matrix.
 The more pixels a monitor can display, the higher its resolution
and the clearer and sharper its images appear
 As the resolution increases, the image on the screen gets smaller.
 Higher settings are not always better, they can cause objects on
the screen to appear too small, resulting in eyestrain and
squinting.
 For example, a monitor that has a 1440 X 900 resolution
displays up to 1440 pixels per row and 900 pixels per column,
for a total of 1,296,000 pixels to create a screen image.
 Resulting to better sharpness or clarity of an image.
 A recent study has shown that out of 6 million users surveyed,
nearly one-half use a 1024 X 768 screen resolution.
Comparing Monitors

18. Resolution
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 With LCD screens, a widescreen 19-inch LCD monitor typically has a
resolution of 1440 X 900, while a widescreen 22-inch has a resolution
of 1680 X 1050.
 LCDs are set to a specific resolution, called the native resolution.
 To change screen resolution,
1. right-click the desktop,
2. click Personalize on the shortcut menu,
3. click the Display Settings link,
4. make desired changes in the Display Settings dialog
box

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3. Refresh rate
 Number of times per second that the electron guns scan every
pixel on the screen.
 If the screen is not refreshed often enough, it appears to
flicker, and flicker is one of the main causes of eyestrain.
 Refresh rate is measured in Hertz (Hz), or in cycles per second
 If a monitor’s refresh rate is 100 Hz, it refreshes its pixels 100
times every second.
 Sometimes referred to as Response time
Comparing Monitors

20. 20
4. Dot pitch
 sometimes called pixel pitch
 The distance between the like-colored phosphor dots of
adjacent pixels.
 Is measured as a fraction of a millimeter (mm), and dot pitches
can range from .15 mm (very fine) to .40 mm or higher.
 Average dot pitch on LCD monitors and screens should be .30
mm or lower.
 The smaller the dot pitch, the finer and more detailed images
will appear on the monitor.
 Text created with a smaller dot pitch is easier to read.
 Advertisements normally specify a monitor's dot pitch or pixel
pitch.
Comparing Monitors

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5. Brightness
 measured in nits.
 a nit is a unit of visible light intensity equal to one candela
(formerly called candlepower) per square meter.
 the candela is the standard unit of luminous intensity.
 LCD monitors and screens today range from 250 to 550 nits.
 the higher the nits, the brighter the images.
6. Contrast ratio
 describes the difference in light intensity between the brightest
white and darkest black that can be displayed.
 Contrast ratios today range from 500:1 to 2000:1.
 Higher contrast ratios represent colors better.
Comparing Monitors

22. Standards
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 The aspect ratio defines a display's width relative to its
height.
 A 2:1 aspect ratio, for example, means the display is
twice as wide as it is tall.
 The aspect ratio for widescreen monitors is 16:lO.
 Some display devices support multiple video standards.

23. Comparing Monitors
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 SVGA SuperVideo GraphicsArray 800 x 600 4:3
 XGA Extended GraphicsArray 1024 x 768 4:3
 SXGA Super XGA 1280 x 1024 5:4
 WXGA Wide XGA 1280 x 1024 16:9
or 1366 x 768 16:10
 UXGA Ultra XGA 1600 x 1200 4:3
 WSXGA Wide Super XGA 1680 x 1050 16:10
 WUXGA Wide Ultra XGA 1920 x 1200 16:10
 WQXGA Wide Quad XGA 2560 x 1600 16:10
 Wide (widescreen) video standard formats are preferable for
users who watch movies and play video games on the
computer.

24. Video cards
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 Also called the video controller
or the video adapter
 Is an intermediary device between the CPU
and the monitor.
 It contains the video-dedicated memory
and other circuitry necessary to send information to the monitor
for display on the screen.
 To display the highest quality images, an LCD monitor should plug in
a DVI port, an HDMI port, or a DisplayPort.
 A DVI (DigitalVideo Interface) port enables digital signals to
transmit directly to the LCD monitor.
 An HDMI (High-Definition Media Interface) port combines
DVI with high-definition(HD) television and video.
 The DisplayPort is an alternative to DVI that also supports HDMI.
standard monitor port

25. Video Display Terminology
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 Pixel
 picture element (smallest unit of an image, basically a
single dot on the screen)
 Resolution
 number of pixels in the image
 Common resolution size is 1024x768
 Refresh rate
 how often a CRT’s electron gun rescans
 LCD displays do not use an electron gun, so do not
perform refreshing

26. 2. Printers
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 A printer is a peripheral
device that produces a
physical copy or hard copy
of the computer’s output.

27. Non-Impact Printers
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 A nonimpact printer forms characters and
graphics on a piece of paper without actually
striking the paper.
 Some spray ink, while others use heat or pressure to create
images.
 Commonly used nonimpact printers are:
ink-jet printers, photo printers, laser printers,
thermal printers, mobile printers, label and
postage printers, plotters, and large-format
printers.

28. Types of Non-Impact Printers
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 Inkjet printer, also called a
bubble-jet, makes characters
by inserting dots of ink onto
paper
 Letter-quality printouts
 Cost of printer is inexpensive
but ink is costly
 Laser printer works like a
copier
 Quality determined by dots
per inch (dpi) produced
 Color printers available
 Expensive initial costs but
cheaper to operate per page
Inkjet
Laser

29. Ink Jet Printer
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 Create an image directly on the paper
by spraying ink through tiny nozzles.
 The only part that needs routine replacement is the ink cartridge.
 The print head mechanism in an ink-jet printer contains ink-filled
cartridges. Each cartridge has fifty to several hundred small ink
holes or nozzles.
 uses two or more ink cartridges: one containing black ink and the
other(s) containing colors.
 Cartridges with black ink cost $15 to $30 each.
 Color ink cartridge prices range from $20 to $35 each.
 black ink cartridges typically print from 200 to 800 pages, and
color ink cartridges from 125 to 450 pages.

30. Ink Jet Printer
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-pages per minute (ppm) it can print is from 12 to
36 ppm
 Most ink-jet printers can print from 1200 to 4800 dpi.
 the higher the dpi, the better the print quality.The
difference in quality becomes noticeable when the size
of the printed image increases.

31. Ink Jet Printer
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 Ink-jet printers also print on other materials such as envelopes,
labels, index cards, greeting card paper (card stock),
transparencies, and iron-onT-shirt transfers.
 Many ink-jet printers include software for creating greeting
cards, banners, business cards, and letterhead.
 Most ink-jet printers can print from 1200 to 4800 dpi.
 Ink-jet printers are a popular type of color printer used in the
home.

32. Laser Printer
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 More expensive, faster, lower cost per page
 Uses technology similar to that in photocopiers.
 Toner – composed of tiny particles of ink, sticks to the drum
in the places the laser has charged.
 Toner cartridge prices range from $50 to $170 for about
5,000 printed pages.
 print in usually 1200 dpi for black-and-white printers and up
to 2400 dpi for color printers.
 a laser printer for the small business user can have up to 768
MB of memory and a 40 GB hard disk.
- To print a full-page 1200-dpi photo, you need 64 MB of
memory in the printer.

33. Laser Printer
33
 a laser printer for the small business user can have up to 768 MB of
memory and a 40 GB hard disk.
 use software to interpret a page description language (PDL)
 tells the printer how to arrange the contents of a printed page.
 two common page description languages: PCL or PostScript.
 Developed by HP, a leading printer manufacturer
 PCL (Printer Control-Language) is a standard
printer language that supports the fonts and layout used in standard office
documents.
 Professionals in the desktop publishing and graphic art fields commonly use
PostScript because it is designed for complex documents with intense graphics
and colors.

34. How a Black-and-White Laser Printer Works
34
/
Step 1
After the user sends an
instruction to print a
document, the drum rotates
as gears and rollers feed a
sheet of paper into the printer.
Step 3
The laser beam creates a
charge that causes toner to
stick to the drum.
Step 5
As the drum continues to
rotate and press against
the paper, the toner transfers
from the drum to the paper.
Step 2
A rotating mirror deflects a low-
powered
laser beam across the surface of a
drum.
Step 4
A set of rollers uses
heat and pressure to
fuse the toner
permanently to the paper.

35. Impact Printers
35
 An impact printer forms characters and graphics on paper by striking a
mechanism against an inked ribbon that physically contacts the paper.
 noisy because of this striking activity.
 produce near letter quality (NLQ) output, a print quality less acceptable for
business letters.
 Companies use them for routine jobs like printing labels, multipart forms
because they easily print through layers of paper.
 Factories, warehouses, and retail counters use them because these printers
withstand dusty environments, vibrations, and extreme temperatures.
 Two commonly used types of impact printers are dot-matrix printers and
line printers.

36. Dot Matrix Printers
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 Commonly used in workplaces
where physical impact with the
paper is important, such as when the
user is printing to carbon copy or
pressure sensitive forms.
 Can produce sheets of plain text
very quickly.
 Speed is measured in characters per
second (cps).
A dot-matrix printer produces
printed images when tiny pins
strike an inked
ribbon.

37. Line & Band Printers
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 Line Printer
 Works like a dot matrix printer but uses a special wide print head that can
print an entire line of text at one time.
 Do not offer high resolution but are incredibly fast.
 Band Printers
 Feature a rotating band embossed with alphanumeric characters.
 To print a character, the machine rotates the band to the desired character,
then a small hammer taps the band pressing the character against a ribbon.
 Very fast and very robust

38. Comparing Printers
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1. Image Quality
Also known as print resolution
Usually measured in dots per inch (dpi)
The more dots per inch a printer can produce, the higher its image quality.
2. Speed
Measured in the number of pages per minute (ppm) the device can print
Most printers have different ppm ratings for text and graphics because
graphics generally take longer to print.
3. Initial Cost
The cost of new printers has fallen dramatically in recent years, while their
capabilities and speed have improved just as dramatically.
4. Cost of Operation
The cost of ink or toner and maintenance varies with the type of printer.
Many different types of printer paper are available too and the choice can
affect the cost of operation.

39. High-Quality Printers
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1. Photo Printers
 Work slowly; some can take two or four
minutes to create a printout.
 Advantage: PictBridge enabled--can
print photos without a computer.
 PictBridge - a standard technology that
allows you to print photos directly from
a digital camera by connecting a cable
from the digital camera to a USB port
on the printer or by an infrared
connection.
 Many photo printers use ink-jet
technology. Printer prints photos in camera
when camera sits in docking
station.

40. High-Quality Printers
40
2.Thermal-Wax Printers
 Used primary for presentation graphics and
handouts.
 Create bold colors and have a low per-page
cost for printouts with heavy color
requirements, such as posters or book
covers
 Operate with a ribbon coated with panels
of colored wax that melts and adheres to
plain paper as colored dots when passed
over a focused heat source.
 Printing plastic labels for chemical
containers (because the cheaper types of
plastic would melt in a laser printer)

41. High-Quality Printers
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3. Dye-Sublimation Printers
 sometimes called a digital photo printer,uses heat to transfer
colored dye to specially coated paper.
 create images that are of photographic quality
 Used in Professional applications requiring high image
quality, such as photography studios, medical labs, and
security identification systems
 These high-end
printers cost thousands
of dollars and print
images in a wide range
of sizes.

42. High-Quality Printers
42
4. Plotters
 A plotter is a printer that uses a pen that moves over a large
revolving sheet of paper.
 It is used in engineering, drafting, map making, and
seismology.

43. Large format printers
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Label Printers

44. All-in-One Printers
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 Combine printing capabilities with scanning, photocopying, and
faxing capabilities.
 Small, lightweight, and easy to use.

45. Audio Output: Sound Cards and
Speakers
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 Audio output is the ability of the computer to output sound.
 Two components are needed:
 Sound card – Plays contents of digitized
recordings
 Speakers –Attach to sound card

46. Data Projectors
46
 Data Projectors
 Also called digital light projectors and video projectors
1. LCD Projectors - Liquid Crystal Display
– require the room to be darkened.They display blurry images in less-
than-optimal lighting conditions.
2. DLP Projectors - Digital Light Processing
– project brighter, crisper images. Can display clear images in normal
lighting conditions.