basic level of computer & help full for that

1. Computers Are
Your Future
Week 3

2. Slide 2
Computers Are Your Future
Output Devices

3. Slide 3
Output Device
Transform processed digital information into forms
that make sense to human

4. Slide 4
Monitors
 A monitor is a peripheral device that displays
computer output on a screen.
 Screen output is referred to as soft copy.
 Types of monitors:
• Cathode-Ray Tube (CRT)
• Liquid Crystal Display (LCD or flat-panel)
• Light-emitting diode (LED)
CRT
LCD

5. Slide 5
Cathode-Ray Tube (CRT)
 Resemble televisions
 Use picture tube technology
 Less expensive than a LCD
monitor
 Take up more desk space and
use more energy than LCD
monitors

6. Slide 6
Liquid Crystal Display (LCD)
 Cells sandwiched between two transparent layers form images
 Used for notebook computers, PDAs, cellular phones, and
personal computers
 More expensive than a CRT monitor
 Take up less desk space and use less energy than CRT
monitors
 Types of LCD monitors:
• Passive-matrix LCD
• Active-matrix LCD
• Gas plasma display
• Field emission display

7. Slide 7
LED
40% less energy
Mercury free
Thinner (1/3 of LCD)

8. Slide 8
Monitor Specifications
 Screen size – The diagonal measurement of the screen surface
in inches (15, 17, 19, 21, 24)
 Resolution – The sharpness of the image determined by the
number of horizontal and vertical 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 redrawn
(refreshed) and measured in Hertz (Hz) (60Hz, 75Hz)

9. Slide 9
Printers
A printer is a peripheral
device that produces a
physical copy or hard
copy of the computer’s
output.

10. Slide 10
Inkjet Laser
Types of Printers
 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.

11. Slide 11
Thermal
Use heat elements to produce images on heat-
sensitive paper.
Dot-matrix
Form characters and images using series of small pins
on a print head.
Noisy, low cost, low quality
Types of Printers

12. Slide 12
Plotter
 A plotter is a printer that uses a ink-pen that moves
over a large revolving sheet of paper.
 It is used in engineering, drafting, map making, and
seismology.