Transcript Input Device - Bulbul Ahamed

Standard Input Devices
Week # 02
Course: Introduction to Computers
Course Code: CIT-1101
Presented by: Bulbul Ahamed
Assistant Professor of CSE, NUB
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Outline
 Definition of Input Device
 Keyboard
 Mouse, Trackball
 Touchpad, Microphone
 Digital Camera, Web Cam
 Scanners
 Bar Code Reader
 OMR, OCR
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Input Devices
Enter data to be processed
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Input Device …
An input device is any hardware component
that allows users to enter data and instructions
into a computer.
Examples:

Keyboard

Mouse
 Trackball

Touchpad
 Microphone
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
Digital Camera
 Web Cam
 Scanner
 Bar Code Readers
 OMR
 OCR
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Keyboard
 The most common input device, used to enter letters,
numbers, symbols, punctuation and commands into the
computer.
 A standard computer keyboard has 101 keys; each key sends
a different signal to the CPU.
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Keyboard (Cont…)
 IBM computers has 101 keys. They are arranged in five
groups:

Alphanumeric keys: A-Z, 0-9, Symbols (#, $, @, &, %
etc), Enter, Backspace, Caps Lock, Tab, Spacebar etc.
 Modifier Keys: Shift, Ctrl, Alt

Numeric Keypad: Num Lock, 0-9, /, *, -, +

Function Key: F1-F12

Cursor-Movement Keys: Arrows (Up, Down, Left,
Right), Insert, Home, Page up, Delete, End, Page Down,
Print Screen Sys Rq, Scroll Lock, Pause Break
------------------------- Special-Purpose Keys: Start, Shortcut
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Keyboard (Cont…)
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Mouse
 A mouse is a hand-movable input device
that controls the position of the cursor
or pointer on a screen.
 Commonly used with desktop computers
 Frequently one can upgrade the mouse
 2 button with wheels
 Optical Mouse.. no trackballs!
 Wireless Mouse …no tail!
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Configuration of a Mouse
Wheel
Right Button
Left Button
Trackball
 A trackball is a pointing device with a
ball on its top or side.
 The onscreen pointer is moved by the
trackball with a thumb or finger.
 Most trackballs feature two buttons,
although three button models are also
available.
 Trackballs are used frequently with
laptop computers.
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Touchpad
 A pressure-sensitive input device used
to control the on-screen pointer by
moving the fingertips over the pad's
surface.
 Used especially on laptop computers as
an alternative to a mouse.
 It has two or three buttons that perform
the same functions as mouse buttons.
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Microphones - Speech Recognition
 Use a microphone to talk to your computer
 Add a sound card to your
computer
 Sound card

digitizes audio input into
0/1s
 A speech recognition program
can process the input and
convert it into machinerecognized commands or input
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Digital Camera
 A digital camera (or digicam for short) is a camera that
allows users to take pictures or video digitally, instead of
on traditional film.
 Used to record images that can be viewed and edited on a
computer.
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Web Cam
 Webcams are video capturing devices connected to
computers or computer networks.
 A Web cam or Web camera connected to a computer
or server that allows anyone connected to the Internet
to view still pictures or motion video of a user.
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**A PC Equipped with a Computer Camera
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Scanners
 An optical scanner, usually called 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.
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Scanners (Cont…)
Image
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Scan
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Edit
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Optical Reader
 An optical reader is a device that uses light
source to read characters, marks, and codes and
then convert them into digital data that a
computer can process.
Optical
Character
Reader
(OCR)
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Optical
Mark
Reader
(OMR)
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Bar
Code
Reader
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Bar Code
 A bar code is made up of vertical printed
lines (bars) and spaces. The sequence of bars
and spaces of different thickness represents a
sequence of numbers.
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Bar Code Readers (Cont…)
 Bar Code Reader – also called a bar code
scanner, is an optical reader that uses laser
beams to read bar codes by using light
patterns that pass through the bar code lines.
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Optical Mark Reader
 OMR is a special scanning device that reads
hand drawn marks such as small circles or
rectangles on specially designed documents.
 Example: The OMR device scans the answer key
sheet to record correct answers based on patterns
of light.
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Optical Mark Reader (Cont…)
Use lead pencil to mark on scan sheet
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Feed the scan sheets into the OMR
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Where do we use OMR?
School registration
Lottery Tickets
Some questionnaires
Multiple choice examinations
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Optical Character Recognition
 OCR technology that enables a computer
to
translate optically scanned text into character
codes, that you can edit.
 OCR software can be installed in
a computer to perform character
recognition.
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Optical Character Recognition (Cont…)
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Any
Thanks for your Attention !!
Questions…?
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