This document provides an overview of input and output devices presented by a group to their instructor. It discusses keyboards, mice, touchpads, microphones, webcams, scanners, and various pointing devices as examples of input devices. It then covers printers, monitors, speakers, plotters, and projectors as examples of output devices that communicate information from the computer. The document discusses the definition, types, advantages and disadvantages of each device.

1. Presentation
Group Introduction:
1. Pakeeza Shahzadi (19011502-063)
2. Muqadas Fatima (19011502-053)
3. Rabia Irfan (19011502-054)
4. Shaista Munawar (19011502-067)

2. Introduction to Computer
Course Code: IT-101
Section: BS-II(B)
Session: 2019-2023
Date: 04-07-2020
Topic: Input and Output devices
Presented to:
Miss Mahrukh Iftikhar

3. Input Devices
Input devices defined as the hardware components of computer
that are used to enter the data into the memory of the computer.
Examples:
1. Keyboard
2. Pointing Devices
3. Microphone
4. Scanner
5. Web Camera

4. 1.Keyboard
It is the most common used input device.
It is used to input data into written form.
Keyboard is a collection of momentary switches.
It is a main input device in most of the computers.
The most popular is the QWERTY design.
The button of keyboard are called Keys.
A standard computer has about 100 keys.

5. Keys of Keyboard
1. Functional Keys
2. Alphabetical Keys
3. Numerical Keys
4. Navigational Keys
5. Modifier Keys
6. Toggle Keys
7. Other Keys

6. Advantages and Disadvantages of
Keyboard
Advantages Disadvantages
 Fast entry of texts into
documents.
 A well known method of data
entry.
 Most people find it easy to
use.
 Easy to do verification test.
 People with limited
arm/wrist may not find it
easy to use
 Data entry may be slow
 They use up valuable desk
space.

7. 2.Pointing Devices
Pointing device is defined as a device which is used to control
the position of cursor on a computer screen.
Examples:
 Mouse
 Touchpad
 Joystick
 Stylus
 Pointing stick
 Digital pen
 Trackball

8. Mouse
 It is a pointing device which is used to control the position of
cursor on the screen.
 It is a hand held device.
 It has two buttons e.g. left and right click button.
 It also has scrolling wheel between left and right click buttons.
 Left click button is used to select an object on the screen.
 Right click button is used to open a programme.
 Scroll wheel is used to scroll the screen of computer up and
down.

9. Mouse

10. Categories of Mouse
There are two types of mouse:
1. Mechanical mouse
2. Optical Mouse

11. Mechanical Mouse
Mechanical mouse is defined as a mouse which has a metal or
rubber ball on it under side.
The ball present under the mouse can be rolled in any direction.
It has sensor in it which detect the motion of mouse.
Those sensors helps to control the position of cursor on the
screen.
Mechanical mouse are not commonly used nowadays.

12. Optical Mouse
• It is an advance pointing device.
• Optical mouse used light source, typically a light emitting-
diode.
• It used a laser light to control the position of a pointer on the
• screen.
• It contain a light detector such as an array of photodiodes
which detect the position of pointer on the screen.

13. Advantages and Disadvantages of
Mouse
Advantages Disadvantages
 Faster to select option
 Rapid navigation through
applications
 Take up little desk space
 People with restricted
hand/wrist movement may
not find it easy to use
 They get damaged easily
 They are difficult to use
where there is no flat surface
to use

14. Touchpad
 It is another pointing device.
 It is a flat, rectangular shaped device.
 It is normally used in laptop and notebook computers.
 It also contains two buttons as mouse and perform
similar function as mouse.

15. Touchpad

16. Joystick
 It contains a vertical lever that is fixed on its base.
 It has two buttons.
 The buttons used to select an option.
 It is used to play games.
 It also provide stimulations to mimic actual control.

17. Joystick

18. Advantages of Joystick
 Joystick provide easier navigational round of a screen than a
mouse.
 Its control works in three dimensions.

19. Stylus
• It is a wireless device.
• It is used on touch screens.
• Normally it is used on smart phones and graphical tablets.
• Its shape is as same as pen.
• It is made of a metal or plastic.

20. Stylus

21. Pointing Stick
 A pointing stick is a pointing device which exists between the
keys of keyboard.
 It controls the movement of pointer on the screen.
 It is like an eraser of pencil.
 It will be useful in case when your main pointing device get
damaged.

22. Pointing Stick

23. Digital pen
 The other name for digital pen is light pen.
 This is connected with our computer with the help of wire.
 They are mostly used by designers.
 It helps to draw on the screen in a similar way to a touch screen
but with great positional accuracy.

24. Digital Pen

25. Trackball
 Trackball is an input device which contains a ball at the top of
the body.
 The ball can rotate with the help of finger or thumb but the
body of the trackball cannot move.
 It has two buttons same as mouse.
 It is used when we have less desk space.

26. Trackball

27. 3.Scanner
Scanner is an input device which is used to convert the hardcopy
into softcopy.
It is commonly used in offices to convert the paperwork into
softcopy to send mails and to check the data through websites.
High resolution scanners are used for scanning high resolution
printing and vice versa.

28. Scanner

29. Types of Scanner
 There are four types of scanners:
1. MICR
2. OMR
3. OCR
4. Barcode reader

30. MICR
MICR stands for magnetic ink character recognition.
It is commonly used in banks.
In banks it is used to scan the cheques and drafts
MICR is used to scan the branch code and account numbers on
the left lower edge of cheque.

31. MICR

32. Advantages and Disadvantages of
MICR
Advantages Disadvantages
 It offers greater security as
compared to OCR since the
printed characters can not be
altered
 There is no manual input, so
errors are reduced
 Characters cab still be read
when somebody write on
them
 Only certain characters can
be read
 It is more expensive method
of data entry

33. OMR
 OMR stands for optical mark reader.
 It is used to scan the objective type bubble sheet.
 It is also used to scan the surveys, assessments and evaluations.
 It has been widely used in educational purposes.
 It has been in educational uses since 1960 and still going on.

34. OMR

35. Advantages and Disadvantages of
OMR
Advantages Disadvantages
 Very fast way of inputting the
results of survey or research
 It is more accurate then
keyboard
 Reduced cost of inputting
 Very useful when results of
tests are needed fast
 Input data maybe inaccurate
if forms are not handled or
shaded
 There maybe need for
manual check if forms are not
properly filled and this may
lead to a waste of time

36. OCR
 OCR stands for optical character reader.
 It is used to scan the characters that are written on paper.
 It is commonly used to convert printed text into machine
readable texts.
 Its examples are hand held scanner and flat bed scanner.

37. OCR

38. Advantages and Disadvantages of
OCR
Advantages Disadvantages
 It is more faster data entry
system than manually keying
in data
 Numbers of error is reduced
 It usually have difficulties
reading handwriting
 It is not a very accurate
technique

39. Barcode Reader
 It is an optical scanner that can read printed barcodes, decode
the data printed in barcodes and send the data to the computers.
 It is commonly used in departmental stores.
 It is used to read the UPC (Universal product code) which
contains the vertical lines and blank spaces.
 It contains light source for scanning.

40. Barcode Reader

41. Advantages and Disadvantages of
Barcode Reader
Advantages Disadvantages
 Faster in data entry
 Less data entry error
 Enables automatic stock
control
 When the price of an item
changes, only the central
database needs to be update
 It is relatively expensive to
setup
 It relatively expensive to
manage
 Works with computers or
POS terminals

42. 4. Microphone
 It is an input device which is used to convert the analog signals
into digital signals with the help of sound card.
 It is used in various applications to input the data.
 It is also used in voice recognition soft wares.

43. Microphone

44. Advantages and Disadvantages of
Microphone
Advantages Disadvantages
• It is faster to read-in text than to
• type it in using the keyboard
• Sound can be manipulated in real
• time than a recording done at
• earlier stage
• It can improve safety and security
• when used in voice activation
• Systems E.g. switching on a radio
• while driving
•
 Sounds files can be used up a
lot of computer memory
 Voice recognition software is
not as accurate as manual
typing. For instance, it maybe
not able to difference
between ‘there’ and ‘their’

45. 5.Web-Camera
 It is used to capture the pictures and videos of an object.
 It is also used to make a video, and then store it in its storage
devices
 It is used in video conferencing
 With the help of web-cam it is also possible to display the
image of people during live chatting

46. Web-Camera

47. Advantages and Disadvantages of
Web-Camera
Advantages Disadvantages
 Cab be left on constantly on the
computer rather then use of
digital computer
 Allowed images of someone
faraway to be viewed while
chatting
 Pictures are often of poor
quality
 Some webcam needs to be
connected to computer
before use.

48. Output Devices
Output devices are the hardware component that are used to
display the information in hard form or soft form.
Output devices let computer to communicate with you.
Examples:
• Printer
• Monitor
• Speaker
• Plotter

49. Hard copy Output
 Produced on a paper or some material that can be touched and
carried being away shown to others
 Permanent in nature and can be kept in paper files or can be
looked at a later time when the person is not using the
computer
 The output printed on paper called hard copy output

50. Soft copy Output
 A softcopy is the unprinted digital document file. It can be
viewed with the help of appropriate editing program.
 Such as word processing programs, database programs or
presentation software depending on the file type.
 The output shown on display screen is called soft copy.

51. 1. Printer
• Printer is an output device that is used to print the characters
and the images on the paper.
• They are useful to create the hardcopies of digital documents
files.
• Its resolution can be measured in Dpi(dot per resolution).

52. Types of Printer
There are two types of printers.
1. Impact Printer
2. Non-impact Printer

53. Impact Printer
 Impact printers are those printers which creates hardcopy by
direct contact between ink ribbon and paper.
 They are like type writers.
 They print the data by striking on the paper through the sets of
pins and hammers.
 They produced noise.
 The quality of the printed content of impact printer is not good.
 They are cheap as compared to others.
 Daisy wheel and dot matrix printer are the examples of impact
printer.

54. Impact Printer

55. Non-Impact Printer
 Non-impact printer are those printers which prints data on the
paper without striking on the paper.
 These printers use ink spray, color wax and ink in the powder
form.
 These printers use cartridge filled with toner or liquid ink, that
allows them to produce high quality image.
 They don’t produce any noise.
 The quality of printed paper is very good.
 Laser or inkjet printer are the examples of non-impact printer.

56. Non-impact printer

57. 2. Speakers
 Speaker is an output device that accept the audio input from the
computer sound card and convert the audio output in the form
of waves.
 Some computer systems have built in speakers.
 They often have low-power internal amplifier.
 The computer speakers typically packaged with computer
systems are small plastic, and have mediocre sound quality.
Some computer have speakers have equalization features such
as bass and treble.

58. Speaker

59. 3. Plotter
 Plotter is an ideal type of output device that is used by
architectures, engineers and graphic designers.
 It creates high precision output in the form of sheet.
 The required output can be printed on the sheet with the help of
ink pens.
 Plotters have very high resolution power.
 Plotters are excellent output devices for scientific and
engineering applications.

60. Types of Plotter
 There are two types of plotters:
1. Drum plotter
2. Flatbed plotter

61. Drum Plotter
A drum plotter is a plotter that uses a drum revolver to move the
paper during the printing while the actual pen performs the
printing.
The drum turns to produce one direction while pen move to
provide the other direction.
A drum plotter printer can produce images as long as an
entire paper roll while the images width is restricted to the
drum width.

62. Drum Plotter

63. Flatbed Plotter
 Flatbed plotter is a plotter that contains flat surface on which
the paper is placed on.
 The size of the surface determine the size of the drawing on the
paper.
 Flatbed plotters are perfect for short run production.

64. Flatbed Plotter

65. 4. Display screen
 A display screen is defined as a surface area upon which texts,
graphics and videos are temporarily made to appear for
viewing purposes.
 The information we feed or input in computer will appear on
display screen in the form of output.
 It is one of the most important output devices and has greater
impact on the performance of computer.

66. Sizes of Display Screen
Display screens comes in different sizes for different computing
devices.
1. Digital Camera (2.5 inches)
2. Mobile (5-7 inches)
3. Tablets ( 7-10 inches)
4. Laptop ( 12-17 inches)
5. Desktop ( 17-30 inches)

67. Types of Display Screens
There are five types of display screen:
1. CRT
2. LCD
3. LED
4. Gas Plasma
5. Projector

68. CRT
 CRT stands for cathode ray tube.
 It is coated with phosphode dots inside the screen.
 It contains guns that are used to fire the beam of electrons
inside the screen.
 The projections of beams of these electrons create image on
the screen.
 CRT monitors display images in consistent colors and viewed
in different angles.
 CRT monitors are the old display screen and pretty much heavy
as compared to other display screens.

69. CRT

70. LCD
 LCD stands for liquid crystal display.
 It is the most commonly used display screen.
 There are million of pixels in it and each pixel is divided
into small areas called sub-pixels.
 Each pixel has a polarizing glass behind it and another
one in front of it at 90 degree.
 Pixel is normally dark but when we switch on the light, it
rotates the light through 90 degree which affectively
allows light flow through the polarizing filters and cause
the pixels to look bright.
 Each pixel is controlled by separate switch.

71. LCD

72. LED
 LED stands for light emitting diode.
 It use fluorescent light instead of normal light for its backlight.
 So due to this reason we can also referred it as backlit LCD.
 It is mostly used in the mobile phones displays due to fast
speed and good response time.
 The angle of viewing for LED is wide.
 Its cost is also pretty much low as compares to other displays.

73. LED

74. Gas Plasma
 It is called plasma screen as there are small sized cells present
in it.
 These cells are of noble gases.
 When voltage is provided to them the ultra-violet ray is
generated and every light brightened.
 The light is produced emitted through the display screen.
 Plasma displays are thinner than CRT and brighter than LCD.
 Plasma displays are less expensive than LCD per square inch
but equivalent in performance.

75. Plasma Screen

76. Projectors
• A projector is an output device that projects an image onto a
large surface such as white screen and wall.
• The projectors are used to project the data on the wall.
• It enables the sharer of the data to share hisher data with lots
of people at a same time.
• It use as the replacement of monitor and television when
showing images and videos to the large group of people.
• Some projectors project images by the use of transparent lens
and some by lasers.

77. Projectors

78. The End
Thank you