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8/3/2019 Chap 4 _ Output Devices
http://slidepdf.com/reader/full/chap-4-output-devices 1/3
P a g e | 1 Lecturer Note 2012 _ Aidahani Ahmad
BBAASSIICC HHAARRDDWWAARREE IIIIII:: OOUUTTPPUUTT DDEEVVIICCEESS
TYPES OF OUTPUT DEVICES
i. DISPLAY DEVICES
MONITOR SCREEN
Devices that used to display information from the computer.
FEATURES THAT COMPARED MONITORS
• Size – A monitor size is the diagonal measurement of its face in inches.
• Resolution – Resolution is the number of pixels on the screen expressed as a
matrix such as 600 x 800.
•
Refresh Rate – Refresh rate is the number of time each second that the electronguns scan the screen’s pixels and measured in Hz.
• Dot Pitch – dot pitch is the distance between the phosphor dots that make up
single pixels.
TYPES OF MONITOR SCREEN
Cathode Ray
Tube (CRT)
Monitor
Disadvantages
⟩ They have a big back and take up space on desk.
⟩ CRTs emit an electromagnetic fields and a small amount of X-ray
band radiation which can result in a health hazard.
⟩ Easily overheated because it operates at very high voltage.
⟩ They are heavy to pick up and carry around
Advantages :
⟩ Cheaper than LCD
⟩ Produce more and high colour accuracy compared to plasma and
LCD.
⟩ Fast respond time and no motion artifact
Definition of
OUTPUT
DEVICES
The devices that send out information from
processing system to the outside word or user ina variety of means such as hardcopy or softcopy.
8/3/2019 Chap 4 _ Output Devices
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P a g e | 2 Lecturer Note 2012 _ Aidahani Ahmad
Plasma Monitor Disadvantages
⟩ Has a very short life span, estimate the life span to be around
20,000 hours to 30,000 hours.
⟩ More expensive than CRT monitors.
⟩ Fragile and easily broken.
Advantages
⟩ Larger viewing angle and free standing.
⟩ Thinner in width than the CRT monitor.
⟩ The plasma display units has a clearer image, brighter viewing
angle, better colour quality and higher contrast ratio than the
CRT and LCD display units.
Liquid Crystal
Displays (LCD)
monitors
Disadvantages
⟩ The cost of a LCD is considerably at a high price.
⟩ The LCD display will have slow response times.⟩ The LCD display has a fixed resolution display and cannot be
changed. LCDs use analog interface making careful adjustment
of pixel tracking/phase in order to reduce or eliminate digital
noise in the image.
⟩ The viewing angle of a LCD display is very limited due to the
Automatic pixel tracking/phase controls.
Advantages :
⟩ Absence of electro magnetic waves
⟩ Lower heat emission⟩ Power Savings
⟩ Less space and screens are perfectly flat.
⟩ Lack of flicker and low glare reduce eyestrain.
ii. PRINTERS - a peripheral which produces a hard copy as output
Non-Impact Printer
• Printing without
striking the paper.
• Expensive
• Less noisy
• High quality
printing
Ink Jet
Printer
Spray tiny drops of liquid ink from jet nozzles onto
paper that produce high resolution output andenergy efficient printers but slow when printing
graphic.
Laser Printer Use laser beam to produce an image on drum
before printing. Produce high-speed and high
quality images but in higher cost.
Thermal
Printer
Pushing electrical heated pins against heat-
sensitive / thermal paper to produce inexpensive
purchase receipt that has low quality and tend tofade over time.
8/3/2019 Chap 4 _ Output Devices
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P a g e | 3 Lecturer Note 2012 _ Aidahani Ahmad
Mobile
Printer
Use ink-jet or thermal technology for printing.
The printer will be small, lightweight and battery
powered that easily carried / mobile.
Plotters Large scale printer which is very accurate in
producing engineering drawings andarchitectural blue prints. Its produce photo-
realistic-quality colour prints.
Impact Printer
• Printing by striking
or physically
contacts the paper
• The cheapest
• The most noisy
printer
• Has a low print
quality.
Dot Matrix
Printer
Producing images and text by placing the dot
when print head strike an inked ribbon onto a
continuous-form paper.
Daisy Wheel
Printer
This printer consist of a wheel and attached
extensions on which molded metal characters
are mounted, its will produce letter quality printbut cannot produce graphics output.
Line Printer Producing image and text by placing the dot
entire line at a time when print head strike an
inked ribbon onto a continuous-form paper.
iii. SOUND OUTPUT DEVICES
SPEAKER To output sound raging from beeps and chirps to music when attached to the
sound card of the computer.
VOICE OUTPUT
DEVICES
Device that used to convert digital data into speech-like sound.
Two types of voice output device:
i. Speech coding uses actual human voice speaking words to provide a
digital database of words that can be output as voice sounds.
ii. Speech synthesis uses a set of 40 basic speech sounds called
phonemes, the bases of all speech in English to electronically create
any words.
iii. PROJECTOR – A device that reproduces images or video frames on white screen.
VIDEO
PROJECTOR
Output a corresponding picture frame on a projection screen using a lens
system, commonly used in conference and class room.
LCD PROJECTOR Used liquid crystal display technology to produce expressive colour image and
enlarged display will not changing the size the projected image.
HAND-HELD
PROJECTOR
Miniature size of projector can be use where ever and when ever desired.