CRT monitors use electron guns to shoot electrons at phosphor particles to display an image, but they are heavy, emit radiation, and cause eye strain. TFT monitors use thin film transistors and liquid crystals to display each pixel and are lighter and cause less eye strain. Laser printers use toner and an electrically charged drum to produce high-quality, fast outputs while inkjet printers produce high-quality color prints but are slower. Dot matrix printers use pins and ink ribbons for noisy, multi-copy printing. Plotters can produce large, high-quality graphics and blueprints using pens or inkjets. Speakers output sound files from computers.

1. Hyper linking

2. What Are Output Devices?
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Output
Devices

4. CRT Monitors
• CRT stands for cathode ray tubes.
• Despite the fact that it is the cheapest monitor available it is becoming
less popular.
• It consists of an electron gun that shoots electrons against phosphor
particles.
 They are used in environments where space is not an issue.
Advantages Disadvantages
Cheaper than TFT monitors. Difficult to life and move
around
Produce better quality images Emit harmful radiation (small
as opposed to a TFT quantity)
Screen on the monitor can be They have a flickering screen;
viewed from a number of this can cause headaches and
angles. eye strain. Back to
Output
Devices

5. TFT Monitors
• TFT stands for thin film transistor. These monitors can also be
called LCD’s. LCD stands for liquid crystal display.
• The screen consists of thousands of miniature transistors. These
transistors are activated by the processor. Each pixel is formed from
RGB (Red, Green and Blue).
• Used when only 1 person needs to see the screen.
Advantages Disadvantages
Easy to move and carry around. Limited angle of viewing
Produce less glare (reduced eye Inconsistency of colour when
strain) viewed from different angles.
Emits less radiation as opposed Videos may blur
to CRT
More expensive than CRT Back to
Output
Devices

6. Laser Printers
× High quality hard copies are produced.
How does it work?
 Laser changes the charge on the drum for each dot.
 Electrically charged toner is attracted to the oppositely charged
dots.
 The paper then presses against the toner-coated drum
 This then outputs with the pattern of dots required.
 Page is only printed after whole documents has been stored in
buffer.
× Used usually in places where silence is required.
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Output
Devices

7. Laser Printers
Advantages Disadvantages
Fast output Limited in size of paper.
Running costs are cheaper Initial costs are high.
Large print jobs can be done First page may be slow to print.
quickly
Quality is high
Toner cartridges last longer; so
laser printers can be used on
longer print runs.
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Output
Devices

8. Inkjet Printers
• Ink is forced out of a nozzle directly onto the paper.
• Weighs less than a laser printer
• Printout is produced little by little as it receives the signals from the
computer.
• They are especially useful in those places where high quality is required
and speed is not an issue.
Advantages Disadvantages
High quality printout They are slow if you need to print
more than one page.
Fast if you are only printing one More expensive to run because the
page ink cartridges don’t last very long.
Cheaper than other printers Long print jobs may be difficult
because the ink cartridge may run
out.
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Are more mobile as opposed to
Output
other printers.
Devices

9. Dot Matrix Printer
• Impact printers.
How does it work?
× The print head (usually made up of several pins) pressing against a
carbon ribbon onto paper.
× Ink from the ribbon is the visible on the paper.
• They are commonly used in noisy industrial environments.
Advantages Disadvantages
Are able to work in Not suitable for office
environments where the laser environment as they are noisy.
and ink printer would not last.
Produce carbon copies. More expensive than inkjets
Running costs are low. Slowest type of printer.
Continuous print jobs are
more easily managed. Back to
Output
Devices

10. Plotter
• Its is able to produce hard copies but is not limited to the
size of the paper.
How does it work?
× Ink is placed on a roll of paper rather than individual sheets.
There are three types:
1- Pen plotter : prints to paper using different colour pens. It
relies on the computer to control the movement of the pen
and paper.
2- Electrostatic plotter:
3- Inkjet plotters
• They are used to produce printouts of graphs and
blueprints.
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Output
Devices

11. Plotters
Advantages Disadvantages
Large printouts can be Slow
produced
High quality graphic Filled areas of colour are
output. difficult to produce.
Expensive
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Output
Devices

12. Speakers
• Output sound that is produced or is stored by the
computer.
• They are required to play sound files attached to
presentations or websites.
• It is a very important part of a home entertainment
system.
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Output
Devices