output devices uos fsd
TRANSCRIPT
Introduction To ICT
M.Sc. Semester 1st
Course Instructor: Mr. Waseeq Ul Islam
Assignment: Output Devices
M.Sc I.T 1st UoS Lyallpur Campus Faisalabad
Group Members:
Arbab Raza Hasan Nawaz
Humaira Nazir Inam Ul Haq
University of Sargodha,
Lyallpur Campus, Faisalabad
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Objective Overview
Describe the types of output
Explain the characteristics of various display
devices
Describe various ways to print
Differentiate between a
nonimpact printer and an impact
printer
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What Is Output? Output is data that has been processed
into a useful form
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Output Devices
Output Devices are all part of the Hardware of a computer system
Output Devices are about seeing the results of your work!
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Output Devices
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Display devices
Printers
Speakers, headphones, and earb uds
Data projectors
Display Devices
• The graphics processing unit (GPU) controls
the manipulation and display of graphics on a
display device
• LCD monitors use a
digital signal and
should plug into a
DVI port, and HDMI
port, or Display Port
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Types of Output
• Soft Copy
• Hard Copy
• Communications Channel
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Screen Output – Soft Copy
• Video Monitor
• Also called Video Display
Terminal (VDT)
• Image exists in video
memory—VRAM
• Monitor size is measured
diagonally across the screen
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Pixels • Images are made up of dots
called pixels for picture elements
• The number of pixels determines
clarity of the picture on the screen
• More pixels = higher resolution =
clearer picture
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Color Depth (Bit Depth) • This means the amount of information stored
in each pixel about what is being shown on the monitor
• Monochrome (1 bit of information per pixel)
• This can only be black or white
• Gray-scale (8 bits of information per pixel)
• This can show more shades of grey
• True color (24 or 32 bits of information per pixel)
• This can realistically reproduce a photograph on the screen that looks very close to the original
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Examples of Color Depth
1-bit depth 4-bit depth
8-bit depth 16-bit depth
The greater the color depth the more colours that can be represented on the screen
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CRT (cathode ray tube)
LCD (liquid crystal display)
Classes of Monitors
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CRT (Cathode Ray Tube)
• A CRT is a television-style monitor
• Its features include:
• Clear image
• Quick response time
• Low cost
• Very popular
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Monitor Specifications
• Screen size – The diagonal
measurement in inches (15, 17, 19, 21)
• Resolution – The sharpness of image
determined by the number of dots
(pixels) that the screen can display
(800 x 600, 1024 x 768, 1600 x 1200)
• Refresh rate – The speed at which the screen is
refreshed and measured in Hertz (Hz) (60Hz, 75Hz)
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Features of CRT Displays
• Display text and graphics
• Monitors differ in resolution
• Standards
• SVGA – 1024 x 768, 1208 x 1024 and 1600 x 1200
• XGA – has same resolutions but supports more colours
• Screen sizes vary from 15” to 21”
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LCD (Liquid Crystal Display)
• LCDs comprise flat-panel monitors
• Found on watches, calculators, digital cameras and
notebook computers
• Lighter weight
• Crisp,clear images
• Extra viewing area for same size
• More expensive to buy
• Consume less power
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Paper Output – Hard Copy
• A printer is a device that produces output on paper
• Most printers today can produce both text and graphics
• Two types of printers:
• Impact printers
• Non-impact printers
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Impact Printers
• There is some physical contact with the
paper to produce the image ie physically
striking the paper
• Types
• Line printers
• Dot matrix printers
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Line Printer • Line printers
• Used by mainframes for jobs that need a large volume of printing
• Limited characters available
• Print an entire line at a time
• Cheap to run
• Not high quality
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Dot Matrix Printer • Have a print head made up of columns
of pins
• The pins form characters and images as patterns of dots produced when the pins strike the paper
• Reasonable quality text and graphics
• Inexpensive to buy and run
• Noisy
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• 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
Label and postage printers
Plotters
Non-Impact Printers
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Ink-Jet Printers • Ink-jet
• Dots of ink are sprayed onto the paper to form the image
• Reasonably high quality
• Available in color or B/W
• Reasonably priced
• Expensive to run
• Speed measured in pages per minute
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Photo Printers
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
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Laser Printers • Laser printers
• Image transferred to paper with a
laser beam
• Faster and more expensive
than dot-matrix
• High-resolution output
• Expensive to buy
• Quite expensive to run
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Thermal Printers
Thermal wax-transfer printer
Dye-sublimation printer
• A thermal printer generates images by pushing
electrically heated pins against the heat-sensitive paper
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Mobile Printer
• A mobile printer is a
small, lightweight,
battery-powered printer
that allows a mobile
user to print from a
notebook computer,
smart phone, or other
mobile device
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Label Printer
• A label printer is a small
printer that prints on
adhesive-type material
• A postage printer prints postage stamps
• Postage also can be printed on other types of printers
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Plotters • Used by graphic designers/architects
• Image transferred to paper with ink pens
• Very high resolution
• Excellent for scientific and engineering applications
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Printing Terms
• Dots per inch (dpi)
• Pages per minute (ppm)
• Characters per second (cps)
• Laser printers – 50 ppm
• Ink-jet printers – 12 ppm
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Output You Can Hear
• Synthesizers can be
used to generate
music and sounds
• Many computers
have synthesizers
• Sound cards have
built-in synthesizers
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Speakers, Headphones,
and Ear buds • 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
Speakers, Headphones,
and Ear buds • Headphones are
speakers that cover or
are placed outside of the
ear
• Ear buds (also called
earphones) rest inside
the ear canal
Discovering Computers 2011: Living in a Digital
World Chapter 6
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Speakers, Headphones,
and Ear buds • Some speakers are specifically designed to
play audio from a portable media player
• Wireless speakers
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Speakers, Headphones,
and Ear buds
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
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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
• LCD projector
• Digital light processing
(DLP) projector
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