1. INTRODUCTION TO COMPUTER
LECTURE # 7
Course Instructor : Sehrish Rafiq
Govt. Girls Degree College Maneri Swabi
Higher Education Department KP

2. LECTURE OVERVIEW
 Hard copy devices
Plotters
 Types of plotters
Printers
 Types of printers
 Input-output devices

3. HARD COPY DEVICES

4. DEVICES USED FOR HARD COPY
 Plotter
 Inkjet Plotter
 Flatbed Plotter
 Drum Plotter
 Printer
 Impact Printer
 Non-Impact Printer

5. PLOTTER
 A plotter is a special output device used to produce hard copies of
large graphs and designs on paper.
 They are used to draw construction maps, engineering drawings,
architectural plans and business charts.
 The plotter is either a peripheral component that can be add to a
computer system or a standalone device with its own internal
processor.
 They are mostly used by engineers and designers who need to draw
complicated diagrams.
 They are also used by marketing agents for printing huge
advertisements and posters.
 Types of plotters
 Flat-bed plotter
 Ink-jet plotter
 Drum Plotter

6. FLAT-BED PLOTTER
 A flat-bed plotter is a mechanical device used with many CAD
programs for designers.
 The paper remains stationary on a flat surface.
 A pen moves across it horizontally and vertically on the paper.
 This plotter may use several different pen colors to create the
graphics.
 The size of the graphic is limited to the size of the flat-bed plotter's
surface.

7. INKJET PLOTTER
 The inkjet plotter creates an image by spraying small droplets
of ink on a paper.
 It is a popular choice for advertising agencies and graphic
designers.
 It is used generally for printing large outputs, such as banners,
billboards and large signs often seen along roadsides.
 Inkjet plotters typically produce better quality graphics than
other plotter types.

8. DRUM PLOTTER
 A drum plotter is also known as roller plotter.
 It consists of a drum or roller on which a paper is placed.
 The drum rotates back and forth to produce the graph on the paper.
 It also consists of mechanical device known as robotic drawing arm
that holds a set of colored ink pens or pencils.
 The robotic drawing arm moves side to side as the paper are rolled
back and forth through the roller.
 In this way, a perfect graph or map is created on the paper.
 This work is done under the control of computer.
 Drum Plotters are used to produce continuous output, such as
plotting earthquake activity.

9. TYPES OF PLOTTERS
Flat-bed plotter
Drum plotter
Inkjet plotter

10. PRINTER
 A printer is an external output device that takes data from a
computer and generates output in the form of graphics / text on a
paper.
 The printed output is a permanent form of output.
 In early days, printers were mostly monochrome but nowadays
color printers are also available.
 Printers are categorized according to whether or not the image
produced is formed by physical contact of the print mechanism
with the paper.
 Types of printers
 Impact printers
 Non-Impact printers

11. IMPACT PRINTER
 An impact printer makes contact with the paper.
 It usually forms the print image by pressing an inked ribbon
against the paper using a hammer or pins.
 They are noisy.
 Types of impact printers
 Dot-Matrix Printer
 Daisy-Wheel Printer
 Drum Printer
 Chain Printer
 Line Printer

12. DOT-MATRIX PRINTER
 The dot-matrix printer uses print heads containing from 9 to 24
pins / tiny hammers.
 These pins individually strike an inked ribbon to produce patterns
of dots on the paper.
 These dots form individual characters.
 The general rule is: the more pins, the clearer the letters on the
paper.
 Dot-matrix printers are inexpensive but noisy.

13. CONTINUED…
 They can also print graphics, although the reproduction quality
is poor.
 Typically they print at speeds of 100-600 characters per
second.

14. OUTPUT OF A DOT MATRIX PRINTER

15. DAISY-WHEEL PRINTER
 The daisy wheel is a wheel made of plastic or metal on which
characters are mounted along the outer edge.
 To print a character, the printer rotates the wheel until the desired
letter is facing the paper.
 Then a hammer strikes the wheel, forcing the character to hit an
inked ribbon to leave an impression of the character on the paper.
 Daisy-wheel printers cannot print graphics.
 They are noisy and slow.
 They can print 10 to 75 characters per second.

16. DAISY WHEEL PRINTER

17. OUTPUT OF A DAISY WHEEL PRINTER

18. DRUM PRINTER
 A drum printer consists of a solid, cylindrical drum that has raised
characters for each print position on its surface.
 The number of print positions across the drum typically range from 80-
132 print positions.
 The drum rotates at a rapid speed.
 For each possible print position there is a print hammer located behind
the paper.
 These hammers strike the paper, along the ink ribbon, against the
proper character on the drum as it passes.
 One revolution of the drum is required to print each line.
 Typically, they print at a speed of 300 to 2000 lines per minute.

19. DRUM PRINTER

20. CHAIN PRINTER
 A chain printer uses a chain of print characters wrapped around two
pulleys.
 There is one hammer for each print position.
 When the correct character appears at the desired print location on the
page, the hammer strikes the paper which presses the paper against a
ribbon and the character located at the desired print position.
 As a result, the impression of the character is left on the page.
 The chain keeps rotating until all the required print positions on the line
have filled.
 Chain printer are one of the fastest impact printers.
 Their speed ranges from 400 to 2500 characters per second.

21. CHAIN PRINTER

22. BAND PRINTER
 A band printer operates similar to chain printer except it uses a
band instead of a chain and has fewer hammers.
 Band printer has a steel band divided into five sections of 48
characters each.
 The hammers on a band printer are mounted on a cartridge that
move across the paper to the appropriate positions.
 Characters are rotated into place and struck by the hammers.
 Font styles can easily be changed by replacing a band or chain.

23. BAND PRINTER

24. LINE PRINTER
 A high-speed printer capable of printing an entire line at a time.
 A fast line printer can print 1,200 to 6,000 lines per minute.
 The disadvantages of line printers are that they cannot print
graphics.
 Their print quality is low, and they are very noisy.

25. NON-IMPACT PRINTERS
 Non-impact printers do not use a striking device to produce
characters on the paper.
 Because they do not use hammers ,they are much quieter.
 Non-Impact printers offer excellent speed, print quality and
beautiful graphics.
 Types of non-impact printers
 Laser-Jet printer
 Ink-Jet printer
 Thermal printer

26. NON-IMPACT PRINTERS
Laser-Jet printer Ink-jet printer
Thermal printer

27. LASER-JET PRINTER
 A laser printer works like a photocopy machine.
 It produces highest quality print but is expensive than inkjet printers.
 A laser printer place an electrical charge(+ve) on a rotating drum.
 Using patterns of small dots, a laser beam conveys information from
the computer to a positively charged drum by placing negative
charge on it.
 The drum is then coated with positively charged toner(an ink
powder) which sticks to those areas of the drum only which are
negatively charged.

28. CONTINUED…
 The paper is given a strong positive electrical charge by a wire
known as corona wire.
 As the paper rolls by the drum, its positive charge attracts the
negatively charged toner particles away from the drum.
 As a result, the toner is transferred to the paper printing the letters
or other graphics on the paper.
 A laser printer provide the highest quality print but is more
expensive than inkjet printers.

29. CONTINUED…
 Laser printers have built-in RAM chips to store documents output
from the computer before print.
 The speed of laser printers is high and they print quietly without
producing much noise.
 Many laser printers can print eight pages per minute, but faster
laser printers can print 437 pages per minute if each page
contains 48 lines.

30. OUTPUT OF A LASER JET PRINTER

31. INK-JET PRINTER
 Ink-jet printers also form images with little dots.
 Ink-jet printers spray small, electrically charged droplets of ink
from four nozzles through holes in a matrix at high speed onto
paper.
 Ink-jet printers can print in color and are quieter and much less
expensive than a color laser printer.
 However, they are slower than laser printers.
 Some new, expensive ink-jet printers print up 1200 or 1400 dpi.

32. THERMAL PRINTER
 Thermal printers use chemically-treated paper known as thermal
paper that darkens or turns black when heated by a thermal print
head.
 The thermal print head applies heat only to those areas where ink
should be printed.
 When the ink becomes cold, it becomes permanent.
 Thermal printers do not use separate ink, toner, or ribbon supplies.
 They are most commonly used to print items such as receipts and
shipping labels.
 Color thermal printers can print few colors only.

33. OUTPUT OF A THERMAL PRINTER

34. INPUT-OUTPUT DEVICES

35. INPUT- OUTPUT DEVICES
 These devices are input and output devices at the same time.
 Types of input-output devices
 Headset
 Touchscreen devices

36. HEADSET
 Headsets are a combination of speakers and microphones
which makes them input and output device at the same time.
 Headsets are a very efficient method for communicating with
friends and family over the internet using communication
software such as Skype and Yahoo messenger.

37. TOUCH SCREEN
 A touchscreen is a computer screen that can be used by touching
it with a finger or a stylus pen.
 It enables the user to interact directly with what is displayed.
 It can be described as a touchpad with a screen built-in to it.
 Today, all kinds of devices, both big and small, make use of
touchscreens.
 However, tablet computers and smartphones have made them
popular and are the most widely known and used products that
use touchscreens.

38. TOUCH SCREEN DEVICES