Input and Output
Describe input
Input Devices
Keyboard entry, pointing devices,
scanning devices
Image capture, digitizing, audio-input
devices
Output
Monitors, printers, audio output
Combination input and output devices
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INPUT
INPUT
Input is any data or instructions entered into the
memory of a computer.
Input Devices
An input device is any hardware component that
allows users to enter data or instructions,
programs, commands and user responses into a
computer.
Translate what language people understand into a
form that computer can process
 keyboard, mouse, stylus, digital pen,
microphone, digital camera and scanner,
audio input device.
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Keyboard Entry
Translate numbers, letters and special
characters
3 types of keyboard
– Traditional keyboard
– Space-saving folding keyboards
– Ergonomic keyboard
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Keyboard Entry
Traditional keyboard
ESC: escape key, cancel a selection or a procedure
– Function keys: shortcut for specific tasks
– Numeric keypad
• numbers, arithmetic symbols
• Controls cursor or insertion point
– Navigation keys
• Controls cursor or insertion point
– Windows key: displays the start menu
– Spacebar: enters blank spaces between
characters
– Caps lock: toggle key
– Ctrl, shift key: combination keys
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Pointing devices
The most natural gestures of human
Many kinds of pointing devices
– Mouse
• Mechanical mouse
– Left button
– Right button
– Roller ball
• Optical mouse
• Cordless or wireless mouse
– Something similar to mouse
• Trackball(roller ball)
• Touchpad
• Pointing stick
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Pointing devices
Many kinds of pointing devices
– Joystick
• Primary used for games
– Touch screen
• Touch-sensitive display device.
Users interface with these devices
by touching areas of the screen
with a finger
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pointing devices
– Light pen
• Light-sensitive
penlike device
– Stylus pen
– digital pen
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Examples of Direct Entry Input Devices(1)
Scanner
Also called optical scanner, is a light-sensing
input device that reads printed text and
graphics and then translates the results into a
form the computer can process.
 Flatbed、Pen、Sheet-fed、Drum
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Barcode Readers
A bar code scanner is an optical reader
that uses laser beams to read bar
codes. It is an identification code that
consists of a set of vertical lines and
spaces of different widths. The bar
code represents data that identifies the
manufacturer and the item.
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Character and mark recognition devices
– Scanners that are able to recognize
special characters and marks.
– 3 types
• Magnetic-ink character recognition
(MICR)
• Optical-character recognition (OCR)
• Optical-mark recognition (OMR),
mark sensing
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MICR
Application of OMR
OCR
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Image capturing devices
Create or capture original images
Digital cameras
– Images are recorded digitally on a disk or in
the cameras memory
– Take a picture, view it immediately
Digital video cameras
– Record motion digitally
Webcams
– Specialized digital video cameras
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Digitizing devices
Convert a sketch or figure into a form that can be
processed by a computer
Consist of flat surface and a writing device
2 kinds of digitizing devices
– Graphic tablets
• Used by artists, mapmakers, engineers
– Digital notebooks
• Use a notepad positioned on top of an
electronic pad or tablet
• Electronic pad records the notes taken
and drawings created by regular pen
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Graphic tablets
Digital notebook
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Audio-input devices
Convert sounds for processing
– Microphone
Voice recognition systems
– Use a microphone, sound card, special software
– 2 types of voice recognition systems
• Discrete-speech recognition systems
– Can recognize individual words
– Cannot distinguish between same-sound words
• Continuous-speech recognition systems
– Distinguish between same-sound words by
evaluating the context
– Example:IBM Via Voice
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Voice recognition system
and dictating a paper
Preparing
– Create your personal user profile,which will
store your speech patterns
– Read prearranged standard text to teach the
software your unique speech patterns
– Refine your profile to include specialized
vocabulary
Using a microphone, dictating the text in word
Surfing
– Start internet explore
– Go to address www.yahoo.com.
– Click auctions
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Examples of Direct Entry Input Devices(2)
Data Collection Device
obtains data directly at the location where
the transaction or event takes place.
Sensors
encode a physical event into data
pressure sensor
temperature sensor
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Terminals
a device that enables you to communicate
with a computer. Generally, a terminal is
a combination of keyboard and display
screen
Point-of-Sale Terminals(POS)
The POS transaction is captured using a
variety of devices which include
computers, cash registers, optical and
bar code scanners, magnetic card
readers, or any combination of these
devices.
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Terminals
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Terminals
Automated Teller Machine (ATM)
• A computerized telecommunications device that
provides the customers of a financial institution with
access to financial transactions in a public space
without the need for a human clerk or bank teller.
• On most modern ATMs, the customer is identified by
inserting a plastic ATM card with a magnetic stripe or a
plastic smartcard with a chip, which contains a unique
card number and some security information, such as an
expiration date.
• Security is provided by the customer entering a
personal identification number (PIN).
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Terminals
ATM
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Terminals
Smart Displays
Smart Display was a Microsoft initiative
to use a portable touchscreen LCD
monitor as a thin client for PCs,
connecting via Wi-Fi(Wireless Fidelity)
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Biometric Input
Biometrics
the study of measurable biological
characteristics.
In computer security, biometrics refers
to authentication techniques that rely on
measurable physical characteristics that
can be automatically checked
several types of biometric identification
schemes
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Biometric Input
Biometric devices
A biometric device is a device that
translates a personal characteristic into a
digital code that is compared with a
digital code stored in a computer
Biometric Flash Disk device
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User Interface(UI)
The junction between a user and a computer
program.
(1) A command-driven interface
(2) A menu-driven interface:
 Graphical User Interfaces (GUI)
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