Unleash Your Potential - Namagunga Girls Coding Club
Input and output devices ppt
1.
2.
3. • Input device captures information and translates it into a form
that can be processed and used by other parts of your computer.
Keyboards
Pointing devices
Game controllers
Scanners
Styluses
Microphones
Digital cameras
Web cams
4.
5. The keyboard is the most common input
device. Types of keyboards include:
• Wireless
• Multimedia and one-touch access
• Portable keyboards for PDAs
6.
7. Pointing devices are mainly used to choose and enter
commands
Pointing devices tend to have PS/2 connectors or
USB connectors
• PS/2 connector fits into a PS/2 port, which a small round
socket with small holes that fit the pins on the connector
• USB connectors fit into USB ports, and these are small
rectangular openings on the back or front of your computer,
or even on your keyboard or monitor
8. Various pointing devices are available
Types of pointing devices:
• Mouse
Mechanical mouse
Optical mouse
Wireless mouse
• Trackball
• Touchpad
• Pointing stick
9. Game controllers are used mainly to play games
Types of gaming devices
• Gamepads
• Joysticks
• Gaming wheels
• Force feed
10. Other types of input devices include:
• Scanners
• Styluses
• Microphones
• Digital cameras
• Web cams
11. •Scanner is a light sensitive device that helps you
copy or capture images, photos, and artwork
that exist on paper. Types of scanners include:
Flatbed
12. • Stylus is an input device consisting of a thin
stick that uses pressure to enter information
or to click and point
• Styluses are used with:
PDAs
Tablet PCs
Graphics tablets
13. • Microphones are used to input
audio
• Three main types of
microphones are:
Desktop microphones
Headsets
Directional microphones
• Speech recognition is
increasingly being included in
application software
14.
15. Output devices take information
within your computer and present
it to you in a form that you can
understand
Main output devices:
Monitors
Printers
Speakers
18. CRTs
Flat-panel displays
Gas plasma
LCD (liquid crystal display)
Passive matrix
Active matrix
Called TFT (thin film transistor)
Separate transistor for every pixel
19. Screen size measured as a diagonal line across the
screen – from corner to opposite corner
Resolution the number of pixels displayed on the
screen (the higher the resolution, the closer together
the dots)
Pixels (or picture element) dots that make up the
image on your screen
Dot pitch is the distance between the centers of a
pair of like-colored pixels
Refresh rate the speed with which a monitor redraws
the image of the screen, and is measured in hertz
20. Inkjet – most popular
Makes images by forcing droplets through
nozzles
Top speed is 20 pages per minute
Laser
Forms images using an electrostatic
process
Prints between 3 and 30 pages per minute
21. Resolution of a printer is the number of
dots per inch (dpi) it produces.
Higher the resolution, better the image,
and usually the more costly the printer
22. Multifunction printer:
• Scan, copy, fax, and print
• Can be either inkjet or laser
• Cost less than buying individual
units
• Take up less desk space
23. A speaker is a device that
produces computer output as
sound
Speakers are common devices
in computer systems
Examples include:
• Built-in speaker
• Two-device set speakers
• Surround sound speakers
Notes de l'éditeur
Good Exercise: Ask students if they can name any other input devices. A hard drive can be classified as both an input device and an output device.
Monitors come in two basic types.
CRTs (or cathode ray tubes) are the monitors that look like TV sets.
Very heavy
Fragile
Uses a lot of power.
Flat-panel displays are thin, lightweight monitors and take up much less space than CRTs.
Use comparatively little power
Can run on a notebook battery
Not as fragile as CRT monitors
The disadvantages of flat-panel
Gas plasma displays shine light through gas to make an image.
LCD (liquid crystal display) screens shine light through a layer of crystalline liquid to make an image.
LCDs are the most usual type of flat panel screens for computers and come in two types: passive matrix and active matrix.
Active matrix screens are sometimes referred to as TFT displays.
TFT (thin film transistor) are flat panel displays with active matrix screens.
Active matrix screens have a separate transistor for every pixel, or dot, on the screen and update faster providing a higher-quality, crisper image.
Mention to students that the features they should watch for when evaluating monitors are:
Screen size
Resolution
Dot pitch.
For desktops and notebook computers, there are three types of printers:
Dot matrix (not mentioned in the text because they’re on their way out)
Inkjet Printers
Inkjet printers are the most popular type of printers.
Great for color as well as black and white printouts.
Inkjet printers make images by forcing ink droplets through nozzles.
The top speed of an inkjet is about 7 ppm (pages per minute).
Laser Printers
Laser printers usually generate better quality output than inkjets, but they’re also more expensive - especially the color ones.
A laser printer forms images using an electrostatic process – the same way a photo copier works.
Laser printers print between 3 and 30 pages per minute depending on type.
Black-only laser printers have one toner cartridge.
Color laser printers require four, which increase the cost of cartridge replacement considerably.
For desktops and notebook computers, there are three types of printers:
Dot matrix (not mentioned in the text because they’re on their way out)
Inkjet Printers
Inkjet printers are the most popular type of printers.
Great for color as well as black and white printouts.
Inkjet printers make images by forcing ink droplets through nozzles.
The top speed of an inkjet is about 7 ppm (pages per minute).
Laser Printers
Laser printers usually generate better quality output than inkjets, but they’re also more expensive - especially the color ones.
A laser printer forms images using an electrostatic process – the same way a photo copier works.
Laser printers print between 3 and 30 pages per minute depending on type.
Black-only laser printers have one toner cartridge.
Color laser printers require four, which increase the cost of cartridge replacement considerably.