Types of Output Devices
2. Sound System
3. PC Projector (Data Show)
It is the most common output device.
Shape of monitor is just like a T.V set.
Function of monitor is to display output on its screen.
Any picture is made up of small dots called Pixels.
Two technologies used in monitor are Cathode Ray Tube (CRT)
Liquid Crystal Display (LCD) or Flat Screens
Most computer monitors are based on CRT.
Relatively low in cost.
Uses a large vacuum tube, called CRT (cathode ray tube).
There are three electron guns one for each color that are RED, GREEN and BLUE (RGB).
A beam of electrons emitted by electron gun makes an image on screen.
Monitor’s screen coated with phosphors chemical that glow when they are struck by the electron beam.
Phosphors dots known as Pixels.
LCD (Liquid Crystal Display)
Also called Flat Screen monitors.
Liquid crystal displays (LCD) are flat screen.
Better picture quality than CRT monitor.
Flat screen monitors having no electron gun.
Image will made up with the help of liquid.
This technology is very expensive.
14-inch, 15-inch, 17-inch, etc
Number of times the electron gun scan every pixel is called Refresh Rate. Measured in cycles per seconds (cps)
640(H) X 480(V), 600 X 800, 1024 X 768, 1152 X 864, 1280 X 1024
Distance between phosphor dots is known Dot pitch.
Projects a video output onto an external surface.
Typically weight less than 10 pounds.
Can display 16 millions colors.
Support up to 1024 X 768 resolution.
Used to display still images, animated pictures or full video
Speakers (common Output device)
Sound is defined as air pressure.
Magnet produces the air pressure.
Sound card translate digital sound into electric current that is sent to the speakers.
Printers are used to produce hard copy of output.
Printers can print text and graphics.
Printers are available in both color and black & white.
The port of printer is called LPT1.
Main difference in printers depends on Quality of output
Ability to print graphics Printing speed
Printer are classified into two groups
1. Impact Printer
2. Non-Impact Printer
Prints the paper with the strikes of hammer, Pins or a ribbon
Works like the typewriter
o Dot Matrix Printer, Electric Typewriter, Line Printer, Band Printer
Dot Matrix Printer
Print one character at a time.
Typical matrix is 5×7 (5 wide, 7 high)
Uses color or black magnetic ribbon to print data.
Can print 200 to more than 1000 character/minute
Can also print charts, pictures, or different symbols
Uses laser or inkjet technology.
High in speed
Best in quality
High in cost
o Laser Printer o inkjet Printer
Is a non-impact printer
It creates output on paper by a spray of ink
Electric field control the spraying jet
Produce one character at a time
Quality is higher than dot matrix
Can print 1 page to 8 pages per minute
Color inkjet printers are also available
Is a non-impact printer, also called page printer
LASER stands for Light Amplification by Stimulated Emission of Radiation
Can print one page at a time
Buffer holds the data and print
Can print 5 to 300 pages per minute
Very high in cost or quality