It's is about the computer devices

1. Introduction to Computing
Lecture 5
Hamza Arif
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2. Devices for the Hand - Pen
 This is a light sensitive input device which when it
touches the screen detects the presence or absence
of light. It is used to select an entry or indicate a
position.
Uses of a Light Pen-:
i. To choose from a list of options on a screen by
pointing at the options required.
ii. To produce drawings on a screen by using a
special
function pad and a key board to indicate what the
computer should draw and the pen to point where it
should
be drawn.
 Tablet PCs, PDA
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3. Touch Screens
 accept input by allowing
the user to place a
fingertip directly on the
computer screen
 Use sensors to detect
touch
 Well suited for simple
applications
 ATM
 Public information kiosk
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4. Touch Screens
 work well in environments where dirt or
weather would render keyboards and
pointing devices useless, and
 Touch screens have become common in
 fast-food restaurants,
 department stores,
 drugstores, and supermarkets,
 where they are used for all kinds of purposes,
from creating personalized greeting cards to
selling lottery tickets.
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5. Game Controllers
 Enhances gaming experience
 Provide custom input to the game
 Modern controllers offer feedback
 Two broad Categories
 Joystick
 Game pad
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6. Joystick
 Around for long time
 Can be used other than games
 enable the user to “ fly” or “ drive”
through a game, directing a vehicle or
character
 popular in racing and flying games
 One variant is the racing game
controller, which includes an actual
steering wheel
 some racing game controllers even
include foot pedals and gearshifts
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7. Game Pad
 is a small, flat device that usually
provides two sets of controls— one for
each hand.
 extremely flexible and are used to
control many kinds of games
 If you do not have a joystick, you can
use a game pad to control most racing
and flying games.
 Many computer games still provide
support for a mouse or keyboard, so a
dedicated game controller is not always
required
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8. Optical Input Devices
 Allows the computer to see
input
 Optical input
devices insert data and
information into computer
systems using light beam
technology.
 Optical input devices used
light to transfer data.
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9. Bar Code Reader
 A barcode reader or barcode scanner is an optical
scanner that can read printed barcodes, decode the data
contained in the barcode to a computer. Like a flatbed
scanner, it consists of a light source, a lens and a light
sensor for translating optical impulses into electrical
signals.
 A barcode reader, also called a price scanner or point-of-
sale (POS) scanner.
 reader then feeds the data into the computer
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10. Image Scanners
 It is an input device. The data or text is written on paper.
The paper is feeded to scanner. The paper written
information is converted into electronic format; this format is
stored in the computer. The input documents can contain
text, handwritten material, picture extra.
 By storing the document in a computer document became
safe for longer period of time. The document will be
permanently stored for the future. We can change the
document when we need. The document can be printed
when needed.
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11. Optical Character Recognition (OCR)
 Optical character recognition (OCR) technology is a
business solution for automating data extraction from
printed or written text from a scanned document or image
file and then converting the text into a machine-readable
form to be used for data processing like editing or
searching.
 Converts scanned image into editable text
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12. Scanner types
 A handheld scanner, as the name suggests, refers to an
electronic device that performs the same tasks as that of a
flatbed scanner. It is used to scan physical documents into their
digital forms that can be stored, edited, transferred and emailed
digitally. This device is especially useful when space is a
concern, as flatbed scanners tend to take up a large amount of
space.
 Handheld scanners
 more portable but typically require multiple passes to scan a
single page
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13. Flatbed scanners
 a computer-controlled device which
electronically scans images placed on its flat plate,
allowing them to be stored in digital form
 flatbed scanner, which scans documents on a flat
surface.
 offer higher-quality reproduction than do handheld
scanners and
 can scan a page in a single pass
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14. Audiovisual Input Devices
 Microphones
 A microphone is an input device used to convert sound waves
into electric waves or input the audio into computers. It
captures audio by converting sound waves into an electrical
signal, which may be a digital or analog signal. This process can
be implemented by a computer or other digital audio devices.
 It is used for voice recording.
 It offers users the option of voice recognition.
 It allows users to record sound of musical instruments.
 It enables users to online chatting.
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15. Speech Recognition
 demand for translating spoken words into text
 Translating voice to text is a capability known as speech
recognition (or voice recognition).
 With it, you can dictate to the computer instead of typing,
and you can control the computer with simple
commands
 translates Phonemes into text or commands
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16. Musical Instrument Digital Interface (MIDI)
 Musical Instrument Digital Interface (MIDI) is a standard to
transmit and store music, originally designed
for digital music synthesizers. MIDI does not transmit
recorded sounds. Instead, it includes musical notes,
timings and pitch information, which the receiving device
uses to play music from its own sound library.
 Connects musical instruments to computer
 Digital recording or playback of music
 Musicians can produce professional results
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17. 17
Video Input
 With growth of multimedia and the
Internet, computer users are adding
video input capabilities to their systems
in great numbers
 Applications such as video
conferencing enable people to use full-
motion video images
 Videos are commonly used in
presentations and on Web pages

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Video Camera and Webcam
 video cameras used with computers
digitize images by breaking them into
individual pixels
 pixel is one or more dots that express
a portion of an image
 Each pixel’s color and other
characteristics are stored as digital
code
 With Webcam the user can “capture”
images of himself or herself while
working at the computer

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Digital Cameras
 portable, handheld devices that
capture still images
 digitizes the image
 compresses it, and
 stores it on a special memory card.
 user can then copy the information to
a PC, where the image can be edited,
copied, printed, embedded in a
document, or transmitted to another
user

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Digital Cameras
 Digital cameras have become standard
equipment for designers of all kinds.
 In Web page design, digital cameras enable
designers to shoot a subject and quickly load
the images onto their computers.
 This process saves the step of acquiring
existing photographs or developing and
printing film-based photos—which must be
scanned into the computer.
 Designers can update a Web site’s
illustrations quickly and regularly using digital
cameras.
 Graphic designers can edit and enhance
digital photographs in innumerable ways,
using photo-editing software