1 IInformation Technology, Kontemporor FMIPA UGM Chapter 5 Input Devices • What Is Input? • The Keyboard • The Keyboard • Pointing Devices • Voice Input • PDAs, Tablet PCs, and Smart Phones • Digital Cameras 1 • Video Input • Scanners • Terminals • Biometric Input Information Technology Kontemporer, FMIPA UGM What Is Input? The two basic types of input: Unprocessed text, Data numbers, images, audio, and video Instructions Programs Commands User responses 2 User responses An Input device is any hardware component used to enter data or instructions
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IInformation Technology, Kontemporor FMIPA UGM
Chapter 5Input Devices• What Is Input?• The Keyboard• The Keyboard• Pointing Devices• Voice Input• PDAs, Tablet PCs, and
Smart Phones• Digital Cameras
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• Video Input• Scanners• Terminals• Biometric Input
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What Is Input?
The two basic types of input:
Unprocessed text, Data
numbers, images, audio, and video
Instructions Programs
Commands
User responses
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User responses
An Input device is any hardware component used to enter data or instructions
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The Computer Keyboard
The keyboard areas Typing area Numeric keypad Numeric keypad Function keys, special
keys that issue commands Often used with other
keys for shortcuts
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Types of keyboards: Standard USB or PS1 Wireless (communicates via a receiver) Built-in keyboards (notebooks)
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The Keyboard
Alternative forms for commands
Key Menu |
Many programs allow you to use
Command Combination Command Button
Copy Shift+F2 or Edit | CopyCtrl+C
Open Ctrl+F12 File | Open
P t Ct l+V Edit | P t
ow you o usekey combination, menu, or button to obtain same result
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Paste Ctrl+V Edit | Paste
The insertion point Blinking vertical bar that indicates where next
character you type will display Pointer changes location and shape
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Pointing Devices
A mouse is: Pointing device that fits under palm of hand
Pointing device controls movement of pointer, also called mouse pointer
Mechanical mouse has rubber or metal ball on
undersideAlso Optical mouse (light)
mouse buttonswheel button
ball
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Optical mouse (light) Laser mouse Wireless mouse
mouse pad
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Pointing Devices
The optical mouse:
Inside each optical mouse is a small camera that takes more than a thousand snapshot pictures every second. A small LED (light-emitting diode) provides light underneath the mouse, helping to highlight slight differences in the surface underneath the mouse.
No moving mechanical parts inside
Senses light to detect mouse’s movement
More precise than mechanical mouse
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mechanical mouse Connects using a
cable, or wireless
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Other Pointing Devices
A trackball is: A stationary pointing device
with a ball on its top To move pointer rotate ball To move pointer, rotate ball
with thumb, fingers, or palm of hand
A touch screen: Touch areas of screen with
finger or other device
Often used with kiosks
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Often used with kiosks Latest Developments: micro-touch
privacy glass for liquid crystal displays Actual touch registers up to 1mm (0.04”)
Touchpad is small, flat, rectang lar pointing de icerectangular pointing device sensitive to pressure and motion
Pointing stick is pointing device shaped like pencil eraser positioned between keys on keyboard
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Other Pointing Devices
Joystick and Wheel Joystick is vertical
lever mountedlever mounted on a base
Wheel is steering-wheel-type input device Pedal simulates
car brakes and
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car brakes and accelerator
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Other Pointing Devices
Light pen: Handheld input device that
can detect lightcan detect light The tip of the light pen contains a
light-sensitive element which, when placed against the screen, detects the light from the screen enabling the computer to identify the location
of the pen on the screen.
Stylus:A li h k i h
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Looks like a ballpoint pen, but uses pressure to write text and draw lines
Used with graphics tablets, flat electronic boards
A light pen can work with any CRT-based monitor, but cannot work with LCD screens,
projectors et cetera.
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Voice Input
How does voice recognition work?Step 2. An analog-to-digital converter (ADC) translates sound waves into digital measurements computer can process Measurements include pitch volume silences and
Step 1. A user dictates text into a microphone.
process. Measurements include pitch, volume, silences, and phonemes. Phonemes are sound units such as aw and guh.
10010111010110101100001101
Step 3. Software compares spoken measurements with those in its database to find a match or li t f ibl t h
Step 4. To narrow a list down, software presents user with a list of choices or uses a natural language component to predict most likely match. User may correct any selection
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list of possible matches.
Matches
made by software.
Natural Language Engine
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Other Input
MIDI (musical instrument digital interface):
E t l d i h External device, such as electronic piano keyboard, to input music and sound effects
General MIDI's most recognized feature is the defined list of sounds or "patches" However
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sounds or patches . However, General MIDI does not actually define the way the sound will be reproduced, only the name of that sound.
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PDAs, Tablet PCs, and Smart Phones
Entering data into a PDA:
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PDAs, Tablet PCs, and Smart Phones
A docking station is: An external device that
holds mobile computerholds mobile computer It provides connections to
peripherals
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PDAs, Tablet PCs, and Smart Phones
What is a smart phone? Users can input and send
text messages, graphics,text messages, graphics, pictures, video clips, and sound files
Many have a built-in or attachable camera
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Digital Cameras
What is a digital camera? Allows you to take
digital pictures Images viewable
immediately on camera if LCD screen is provided Download image files to
computer
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Post pictures to Web
Print (sometimes with purpose built printer)
Edit image files using image editing software
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Digital Cameras
How does a digital camera work?Step 1. Point to the image to photograph and take picture. Light passes into the lens of the
Step 2. Image is focused on a chip called a charge-coupled device (CCD).
Step 3. CCD generates an analog signal that represents the image.
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camera.( )
Step 4. Analog signal is converted to digital signal by analog-to-digital converter (ADC).
Step 5. Digital signal processor (DSP) adjusts quality of image and usually stores digital image on miniature mobile storage media in the camera.
Step 6. Images are transferred to a computer’s hard disk by plugging oneStep 7. Using software
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computer s hard disk by plugging one end of the cable into a camera and the other end into a computer; or images are copied to hard disk from storage media used in the camera.
p gsupplied with the camera, images are viewed on screen, incorporated into documents, edited, and printed.
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Digital Cameras
Image resolution: Sharpness and clarity of
imageimage The higher the resolution,
the better the image quality, but the more expensive the camera
Pixel (picture element) is single point in
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is single point in electronic image Greater the number of pixels
allows better image quality but also means larger image file size
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Video Input
Video input: The process of entering full-motion
images into computerg p
A Video capture card is an adapter card that converts analog video signal into a digital signal that computer can useDi it l id (DV)
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Digital video (DV) camera records video as digital signals
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Video Input
PC video camera & Web cam
DV camera used to capture video and still images and to makeand still images, and to make video telephone calls on Internet Also called PC camera
Web camc—cvideo camera whose output displays on a Web page
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Video conferencing: Is when two or more geographically separated
people who use network on Internet to transmit audio and video data
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Scanners and Reading Devices
What is a scanner?Flatbed
Light-sensing device that reads printed text and
Pen or Handheld
Sheet-fed
reads printed text and graphics Used for image processing,
converting paper documents into electronic images
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Drum
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Scanners and Reading Devices
Flatbed scanner:Step 1. Document to be scanned is placed face down on the glass window.
Step 2. Bright light moves underneath scanned document.Step 3. Image of the document is reflected into a series of mirrors.
Step 6 Users can print image
Step 4. Light is converted to analog electrical current that is
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Step 6. Users can print image, e-mail it, fax it, include it in a document, or place it on a Web page.
current that is converted to digital signal by an analog-to-digital converter (ADC).
Step 5. Digital information is sent to memory in the computer to be used by illustration, desktop publishing, or other software; or it is stored on disk.
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Scanners and Reading Devices
An optical reader is: Device that uses light source to read characters, marks,
and codes and then converts them into digital data
Optical character recognition (OCR) reads characters in OCR font
Optical mark recognition (OMR) reads hand-drawn pencil marks such as small circles
and codes and then converts them into digital data
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marks, such as small circles
Bar code scanner
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Scanners and Reading Devices
What is a bar code reader? Uses laser beams to read bar codes
What is a bar code? Identification code that consists of a set of vertical lines and
spaces of different widths Universal
ProductCode (UPC)
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Some widely used bar codes?
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A Magnetic-ink character recognition (MICR) reader:
Scanners and Reading Devices
Can read text printed with magnetized ink Can read text printed with magnetized ink Banking industry almost exclusively uses MICR
for check processing
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Scanners and Reading Devices
A data collection device:
Obtains data directly at location where transaction or event takes place
Transmits data over network or Internet
Often used to assist in stock
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Often used to assist in stock control in supermarkets
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Terminals
Point of sale (POS) terminal (s): Records purchases, processes credit or
debit cards, and updates inventory Swipe credit or debit card through card
readerc—creads customer’s personal data from magnetic strip
