Input Devices

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Input Device
Roll_No. Name
296 Jasavant VirK
298 Dikshali Wagh
299 Tushar Waghmare
300 Ashok Yadav
301 Chandan Yadav
303 Rakesh Yadav

 When we work with computer we need to enter data and instructions to the
computer using some devices.
 These devices are called input devices.
 These devices convert data and instructions to a form that can be recognized
by the computer.
 Some of the commonly used input devices are :
 Keyboard
 Mouse
 Scanner
 Joystick
 Microphone
 Digital camera

Input devices are things we use to put information into a computer.
An input device is any hardware device that sends data to the
computer, without any input devices, a computer would only be a display
device and not allow users to interact with it, much like a TV.
For example, a keyboard is an input device.
Input devices other than the keyboard are sometimes called
alternate input devices.
Mice, trackballs, and light pens are all alternate input devices.
In the picture to the right, is a Logitech trackball mouse is an
example of an input device.

Input Devices & Their Uses
 Input devices are necessary to convert our information or data in to a
form which can be understood by the computer.
 A good input device should provide timely, accurate and useful data to the
main memory of the computer for processing followings are the most useful
input devices.
 If the hard drive, RAM and processor are the brains of a computer, the
input devices such as the keyboard, mouse and microphone are its eyes and
ears, feeding the computer information and telling it where to focus its
attention.
 Without input devices, a computer is a brain with nothing to think about.
 But combined with memory and processing power, they make computers
some of the most valuable pieces of equipment in our lives.

Examples of Input Devices
 Graphics Tablets

 Trackballs

 Gamepad

 Joystick

 Keyboard

 Microphone

 Mouse

 Scanner

 Webcam

The PC’s keyboard is the
primary human input device on the
system.

In other words, The keyboard
is the primary input device for most
software, so learning how to program
the keyboard properly is very
important to application developers.

Most modern keyboards
provide at least 101 different keys.

 The keyboard is an input device designed to
enter text, characters and other commands into the
computer.
 The keyboard is a way to input letters or
numbers into different applications or programs.
 A keyboard also has special keys that help
operate the computer.
 The keyboard is the primary way of entering
text in a computer, although it may be replaced by
handwriting and speech recognition programs in the
future.
 It look like a typewriter and is used for key
entry of data into a computer.
 Keyboards are used to enter data to order
fulfilment systems and to interact with electronic
catalogs.
 Most actions you can perform with your mouse
can also be performed with your keyboard.

Microsoft, Logitech etc.

 Modern computer keyboards
were modelled after, and are still
very similar to, classic typewriter
keyboards.
 Many different layouts are
available around the world but most
keyboards are of the QWERTY type.
 Keyboards may be wired or
wireless but they always
communicate with the computer
via PS/2or USB connections, usually
located on the motherboard.
 Even though the keyboard sits
outside the main computer housing,
it is an essential part of the complete
system.

COMPUTER KEYBOARDS SHARE MANY SIMILARITIES TO AND
SOME DIFFERENCES FROM A TYPEWRITER KEYBOARD.
 Alphabet layout is basically the same.
 The location of some punctuation keys is different
 Additional keys include directional keys and the number pad on the right.

THE BASIC HAND PLACEMENT ON A KEYBOARD TAKES SOME PRACTICE.
 Rest both thumbs on the space bar.
 Starting with the little finger of your left hand on
the letter “A”, the other three fingers will rest on
the next three letters “S” “D” and “F”.
 Skip “G” and “H” and put index finger of your right
hand on the “J” key. The other three fingers of
your right hand will rest on “K” “L” and the
semicolon key.
 Notice how you can reach all the other keys quite
easily.
 Hunting and pecking is good, too. Use whatever is
most comfortable to you!

THE BASIC HAND PLACEMENT ON A KEYBOARD TAKES SOME
PRACTICE.

 ESC-ESCAPE KEY (In DOS and Windows
environments, pressing the Escape key usually
cancels or aborts the current operation.)
 Space bar
 TAB moves the document over a set number of
spaces
 BACKSPACE backs over the document erasing as
it goes.
 ENTER is a multipurpose key and will either allow
you to enter information on the computer or act
as a return carriage key on a typewriter.
 Forward slash vs. back slash.

THERE ARE SEVERAL SPECIALTY KEYS ON THE KEYBOARD THAT
WILL HELP WITH FORMATTING YOUR TYPING AND MAKE SOME
COMPUTER STEPS FASTER. MANY CAN BE USED IN COMBINATION
WITH OTHER KEYS TO CREATE SHORTCUTS FOR SPECIAL ACTIONS.
 ARROW KEYS will move you anywhere within a document
without making any changes.
 HOME/END
 PAGE UP/DOWN
 INSERT/DELETE
 Number/directional pad with NUMLOCK on and off
 Multiple key commands-Many people find it less efficient
to have to take their hands off the keyboard to click
buttons with the mouse so there are keyboard shortcuts
using two or more keys together (See the Keyboard
shortcuts hand-out)
 You use both the SHIFT key and the CAPS LOCK key to
create upper case letters.

A graphics tablet is a computer input device that
enables a user to hand-draw images and
graphics, similar to the way a person draws images
with a pencil and paper.
These tablets may also be used to capture data or
handwritten signatures.
It can also be used to trace an image from a piece
of paper which is taped or otherwise secured to the
surface.
Capturing data in this way, either by drawing or
entering the angles of linear poly-lines or shapes is
called digitizing.
The device consists of a flat surface upon which the
user may "draw" or touch an image using an attached
stylus, a pen-like drawing device.
The image generally does not appear on the tablet
itself but, rather, is displayed on the computer
monitor.

 The first electronic handwriting tablet was the Telautograph, patented by Elisha
Gray in 1888.

 The first graphics tablet like modern tablets and used for handwriting respect by
a computer was the Stylator in 1957.

 The first digitizer tablet is the RAND Tablet and introduced in 1964.

 The acoustic tablet, or spark tablet, used a stylus that generated clicks with a
spark plug.

 The first home computer graphics tablet was the KoalaPad.

 In 1981, musician Todd Rundgren created the first color graphics tablet
software for personal computers, which was licensed to Apple as the Utopia Graphics
Tablet System.

 In the 1980s, several vendors of graphics tablets began to include additional
functions, such as handwriting recognition and on-tablet menus.

PUCK
 After styli, pucks are the most commonly used tablet accessory.
 A puck is a mouse-like device that can detect its absolute position and
rotation.
 Most tablet drivers are capable of allowing a puck to emulate a mouse
in operation, and many pucks are marketed as "mice".

EMBEDDED LCD TABLETS
 Some graphics tablets incorporate an LCD into the tablet itself,
allowing the user to draw directly on the display surface.
 Graphics tablet/screen hybrids offer advantages over both touch
screens and ordinary tablets.
 Unlike touch screens, they offer pressure sensitivity, and their
resolution is generally higher.

•Graphic tablets can be used in place of a mouse.
•They use the fluid motion and natural positioning of
the human hand to its best advantage.
•Using a graphic tablet is as easy and as comfortable
as using a pen, pencil or airbrush.

GRAPHIC TABLETS CAN BE USED AT SUCH
FIELDS:
•Illustrators, Animators, Photographers & Graphic
Designers.
•Industrial Design, Architects & Engineers.
•Medical & Healthcare.
•Education & Training.
•Business & Office.
•Geographic Information Systems Mapping & Control
Systems.

INTRODUCTION TO THE MOUSE:
 A computer mouse is an
input device that is most often used with
a personal computer.
 Moving a mouse along a flat
surface can move the on-screen cursor to
different items on the screen.
 Items can be moved or selected
by pressing the mouse buttons (called
clicking).
 It is called a computer mouse
because of the wire that connects the
mouse to the computer.
 The people who designed the
first computer mice thought that it
looked like the tail on a mouse.
 Today, many computer mice use
wireless technology and have no wire.

FORMAL DEFINITION AND INTRODUCTION:
 A mouse is an external computer
hardware device.
 It allows a user to control the
motion of a computer cursor.
 It also select objects on the screen
by moving and clicking the device.
 During the 1980’s, computer mice
became the dominant way for people to
interface with personal computers after
testing with various devices showed it to
be the most convenient and simple to use.
 The mouse works on the basic
principle that the movement of the
device is translated into the movement of
the cursor on the screen.

Parts of Mouse:
1. Top Casing
2. Right‐Click Cover
Plug
3. Left‐Click Cover
Scroll Wheel
4. Scroll Wheel
5. Connecting Wire/Cord Left‐Click Cover

6. Plug
Connecting Wire
7. Bottom Casing
8. Track Ball
Right‐Click Cover
9. Internal Circuit Board
Top Casing

 On most computers, the user can move
the mouse to move the cursor in the same
direction.
 If there is something on the screen that
the user wants to choose, he can move the cursor
over it and "click" the mouse button.
 The right mouse button is used to open
menus that are different depending on where the
cursor is.
The other mouse buttons can do different
things, depending on the software.
 A mouse can have 1 to 6 buttons to click,
but most mice have two or three. Most mice also
have a "scroll wheel" -- a small wheel found
between the two main mouse buttons.
 The user can move the wheel up or down
to "scroll" through things like a website or folder,
which means to move it up or down on the screen,
or he or she can click the wheel down like another
button.

 A scanner is a device that captures images
from photographic prints, posters, magazine pages, and
similar sources for computer editing and display.
Scanners come in hand-held, feed-in, and flatbed types
and for scanning black-and-white only, or color.

 Very high resolution scanners are used for
scanning for high-resolution printing, but lower resolution
scanners are adequate for capturing images for computer
display.

 Scanners usually come with software, such as
Adobe's Photoshop product, that lets you resize and
otherwise modify a captured image.

 Scanners usually attach to your personal
computer with a Small Computer System Interface (
SCSI ). An application such as PhotoShop uses the
TWAIN program to read in the image.

 Some major manufacturers of scanners include:
Epson, Hewlett-Packard, Microtek, and Relisys.

 A scanner is used to input paper documents or
photos into the computer.
 They are typically "scanned" as images (like
pictures) and stored in TIFF, GIF, or JPG format, and can
also be scanned into the Portable Document Format (PDF),
or converted to text using Optical Character Recognition
(OCR).

THE MANY USES OF A SCANNER:
 One of the most useful inventions to come along
with the computer age is the scanner.
 Unlike a photocopier which simply makes a copy
of an article, a scanner allows you to preserve a digital
image of just about anything you can fit on a scanner bed.

COPYING DOCUMENTS - You can turn a good flatbed scanner into a copying machine
by scanning in those receipts and other important documents and then use your printer
to have a copy or just keep a digital copy.

SCANNING PHOTOS FOR PRINTING - Photographs are nice especially if you are a
professional photographer, but you could use the photos for websites to display your
latest DIY project. The images could be used for desktop wallpaper or sending to
friends and family through email. Because they are digitized you can use computer
software to edit them, and make interesting images on top of the first.

FAXING DOCUMENTS - You can Fax a document that is already in your computer,
but if that document is on a sheet of paper, you have a problem. A scanner can scan it
in, then you can send it out by using the fax driver.

OCR - Optical Character Recognition (OCR) software is used to convert images to
readable text. OCR software usually comes with the scanner.

ADVANTAGES
 The advantages of using scanners are: It can copy things onto
computers then you can alter the things you copied.
 Flatbed scanners are very accurate and can produce reasonably
high quality images Any image which is digitised by the scanner can then
be included on electronic documents Images once digitised can be
enhanced with a graphics application.

DISADVANTAGES
 The disadvantages of using scanners is that if there is a
blackout, the whole system goes out.
 Images can take up a lot of memory space Images lose some
quality in the scanning and digitising process The quality of the final
image is dependent on the quality of the original image.

Input Devices

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Input Devices