The document discusses different types of computer output devices. It describes monitors, printers, 3D printers, braille readers, GPS devices, plotters, headphones, projectors, sound cards, video cards, and different types of displays including CRT displays and LCD monitors. It provides details on what each device is and how it functions, as well as advantages and disadvantages of CRT and LCD displays.

1. M. Raihan
Email: rianku11@gmail.com

2. Output Devices
Part-1

3. Output Device
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An output device is any peripheral that receives data from
a computer, usually for display, projection, or physical
reproduction.
For example, the image shows an inkjet printer, an output
device that can make a hard copy of any information shown
on your monitor, which is another example of an output
device.
Monitors and printers are two of the most common output
devices used with a computer.

4. Types of Output Devices
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3D Printer
Braille reader
GPS
Headphones
Monitor
Plotter
Printer
Projector
Sound card
Speakers
TV
Video card

5. 3D Printer
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Created by Charles Hull in 1984.
3D printer is a printing device that creates a physical object from a digital model
using materials such as metal alloys, polymers, or plastics.
3D printers are used in many disciplines such as aerospace engineering, dentistry,
archaeology, biotechnology, and information systems are a few examples of
industries that utilize them.
As an example, a 3D printer might be used in the field of archaeology to physically
reconstruct ancient artifacts that have been damaged over time, thus eliminating
the need of a mold.

6. Braille Reader
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A braille reader, also called a braille display, is an electronic device that allows a
blind person to read the text displayed on a computer monitor.
 The computer sends the text to the output device, where it is converted to Braille
and "displayed" by raising rounded pins through a flat surface on the machine.
Braille readers come in various forms, including large units (about the size of a
computer keyboard) and smaller units, designed to work with laptops and tablet
computers.

7. GPS
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Global Positioning System (GPS) is a network of satellites that helps users
determine a location on Earth.
The thought of GPS was conceived after the launch of Sputnik in 1957.
The GPS system does not require the user to transmit any data, and it operates
independently of any telephonic or internet reception, though these technologies
can enhance the usefulness of the GPS positioning information.

8. Plotter
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A plotter is a computer hardware device much like a printer that is used for
printing vector graphics.
Instead of toner, plotters use a pen, pencil, marker, or another writing tool to
draw multiple, continuous lines onto paper rather than a series of dots like a
traditional printer.
Plotters can work on very large sheets of paper while maintaining high
resolution.
Plotters are quite large when compared to a traditional printer.

9. Headphones
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Headphones are a hardware output device that either plug into your
computer line out or your speakers to privately listen to audio
without disturbing others.

10. Projector
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A projector is an output device that can take images generated by a
computer or Blu-ray player and reproduce them onto a screen, wall, or
other surface.
Typically, the surface projected onto is large, flat, and lightly colored.
The digital projector we know today was created by Gene Dolgoff in 1984,
although he came up with the concept for it in 1968.
Today, most projectors use either an HDMI cable or VGA cable from a
computer as their input source.

11. Sound Card
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A sound card is an expansion card or IC for producing sound on a computer that
can be heard through speakers or headphones.
Although the computer does not need a sound device to function, they are included
on every machine in one form or another, either in an expansion slot or built into
the motherboard (onboard).

12. Video Card
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A video card is an IC or internal board that creates a picture on a
display.
Without a video card, you would not be able to see this page.
Video card ports: VGA connector, S-Video connector, DVI connector.

13. Flat-panel Display
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The flat-panel display refers to a class of video devices that have
reduced volume, weight and power requirement in comparison to the
CRT.
You can hang them on walls or wear them on your wrists.
Current uses of flat-panel displays include calculators, video games,
monitors, laptop computer, and graphics display.
The flat-panel display is divided into two categories −Emissive
Displays, Non-Emissive Displays.

14. CRT Display
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Glass tube that is narrow at one end and opens to a
flat screen at the other end.
Narrow end contains electron guns.
Single gun for monochrome and three guns for color.
The electron beam is directed towards the screen in the
front of the tube using a high voltage.
The screen is coated with a phosphor substance, which
emits light when the electrons strike the substance.
The color of the emitted light is the characteristics of the
phosphor substance.

15. CRT Display (continue)
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16. CRT Display (continue)
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The electron beam is swept from left to right in the
‘X’ direction across the screen by applying a sweep
voltage to the horizontal plates of the tube.
The beam is switched off when it reaches the right
most end of the screen and is returned back to the
left immediately.
Simultaneously, the beam is swept slowly in the Y
direction from the top to the bottom of the screen
by applying another swept voltage to the vertical
plates of the tube.

17. CRT Display (continue)
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It makes the beam to trace a new line every time it scans
from left to right.
The beam is switched off when it reaches the right bottom
corner and returned back to the left top corner to start
over.
A typical CRT display system sweeps the beam at the rate
of 15,600 Hz in the horizontal direction and 60 Hz in the
vertical direction. This is known as raster-scan.
The display system generates three signals to produce an
image on the screen.
The signals are horizontal sweep signal, vertical sweep
signal and video signal.

18. Advantages of CRT Display
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Color: Most are capable of displaying unlimited
colors.
Resolution: Multiple video Resolutions.
Response Time: Faster response time (25
milliseconds for LCD, 13 milliseconds for CRT)
Viewing Angle: Look @ a very wide angle

19. Disadvantages of CRT Display
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Physical size: Takes more desktop space.
Power Consumption and Radiation Emission
Consumes more energy
Emits harmful radiation. The metal shield behind the glass
of your monitor protects your body from a flood of
radiation.
It holds a dangerous electrical charge even after turned off
and can last up to several years and be hazardous and even
deadly to anyone who opens a CRT monitor casing.
Know to cause fires due to electrical malfunctions and
excessive heat if the ventilation holes are accidentally
covered up.

20. LCD Monitor
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A LCD screens are mostly used in portable systems
where the screen image is generated on a flat plastic disk.
that uses millions of liquid crystal elements for the pixels.
and transistors for switching on and off the pixels.
In 1997, manufactures began to offer full size LCD
monitors as alternatives to CRT monitors

21. LCD Monitor (continue)
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22. Advantages of LCD displays
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The LCD monitor is slim and the screen is flat.
 Images on LCD screen seem to have a softer quality
than images on CRT display.
 Images on LCD screens do not flicker and do not cause
strain to eyes.
 LCD screens do not emit radiation.
 LCD screens have more visible area than CRT of same
size.
 LCD monitors consume significantly less power.

23. Disadvantages of LCD displays
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LCD monitors are expensive and limited in
resolution.
LCD is not fast enough to display the fast changing
images.
LCD screens are designed to operate in specific
resolution.
LCD technology requires bright back light to shine
through the liquid crystal layer to create an image
Light that emerges from LCD is highly directional and
it limits the viewing angles.

24. Thank You
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