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Ch. 12 Input and Output Devices - Coggle Diagram
Ch. 12 Input and Output Devices
12.1 Input Devices
The hardware that allows users to enter data into a computer and converts the data into a computer-readable form
Examples
Keyboards
Allow user to enter data or commands into computers by pressing its keys
Pointing devices
Allow users to control a cursor of a pointer on a GUI
Mice
Trackballs
Touchpads
Track Points
Joysticks
Touch screens
Digitising Tablets
Handwriting Boards
Scanners
Is used to input text and graphics into computers
Resolution
Colour depth
Accuracy
OCR to convert the text on a printed document into an editable file
Optical readers
Is used to read predetermined characters, marks or codes and translate them into digital data
Bar code readers
Optical Mark Readers
Microphones
Usually connected to a sound card installed on the motherboard
Can be used with speech recognition software which translates vocal speech into text or commands
Digital cameras
Use a light-sensitive processor to capture scenes and turn them into digital images
Images are stored in a memory card and the amount of memory space taken depends on the compression ratio, the file format and image resolution
The larger the number of light-sensitive photosites in the light-sensitive processor chip, the higher the resolution of the digital image
Digital video cameras
Use a light-sensitive processor chip to capture the moving images
Store images as a sequence of high-quality digital images to form a video file
Storage media can be DV tapes, DVDs or internal hard disks
Web cam
Special type of digital cameras, connected to a computer
Commonly used for video conferencing and remote surveillance via a computer network
12.2 Output Devices
Hardware that translates computer processes and information into a form that humans can understand
Examples
Visual Display Units(monitor)
Cathode ray tube
Liquid crystal display
Quality depends on its
Resolution
Dot pitch
Contrast ratio
Speakers
Used to convert audio signals of a computer into sound
Connected to a sound card
Sound card will convert digital audio signals into analogue signals for outpouring through the speakers
Printers
Produce text and graphics on a physical medium such as paper or transparency film
Major factors of a printer’s performance
Resolution
Printing speed
Types
Dot-matrix printers
Inkjet printers
Laser printers
Thermal printers
Plotters
Multifunction printers
Include the functions of printing and communication
Examples
Printer
Scanner
Photocopier
Fax machine
Telephone
Suitable for small office, take up less space, cheaper than muting all the devices separately
Video projectors
Use high intensity and a set of optical lenses to project the computer display onto a large screen
Types
LCD projectors
DLP projectors
12.3 Daily Application of Input and Output Devices
Point-of-sale(POS)Terminal
Widely used in supermarkets and chain stores
Consists of the register itself and some various input devices and output devices
Input Device
Bar code reader
Keyboard
Readers fro credit cards, octopus cards, and ATM cards
Output Device
Thermal printers
Monitors
Cheque deposit Machine
Input Device
Touch screen
Readers for ATM cards
Scanner
Output device
Thermal printer
SOHO
Working space is a big concern
Prefer to use a multifunction printer and notebook computer
Conference Room
Equipment for presentations
Video projector
Wireless pointing devices
Speaker
Web camera