Printers

Introduction to printers

• There are two main categories of printers , Impact and Non Impact printers

• Impact printers  include Daisy Wheel printers and Dot Matrix printers.

• Non Impact Printers  include Inkjet and Laser Printers.

• We must be aware of the printing process in all the mentioned printers .

• We must also know how to install printers  in windows environment.

Key Topics

Impact and Non impact printers Daisy wheel Printers Dot Matrix Printer Non Impact Printers   Maintenance and troubleshooting  of Dot Matrix Printers

Inkjet Printer Maintenance and troubleshooting  of Inkjet printers Laser Jet Printer Laser Jet Printer Components Troubleshooting of Laser Jet Printer Installing Printers in Windows

Impact and Non impact Printers

• There are two main categories of printers  Impact and Non-Impact printer.

·        Impact printer’s work pretty much like typewriters, the printer head strikes the ribbon that in turn strikes the paper printing the character or dots onto the paper.

• Non-Impact printers  cause the ink or toner  to print directly on to paper. 

Impact Printers

• Similar in design to a typewriter where pre-formed characters are punched on to a sheet of paper through an ink ribbon.

• Workhorse usually works for many years without any problems.

• They include daisy wheel and dot matrix printers .

• Very noisy.

• Fairly slow.

• Limited in resolution .

• Limited in quality of printout.

• Relatively cheap.

• Good for printing on multipart paper.

• Printing speed is measured in characters per second (CPS ).

 

 

 

 

 

 

 

 

 

 

 

 

 

Daisy wheel Printers

• Daisy wheel printers  have characters embossed on the head, which punch on to the paper

• They have limited and fixed number of printable fonts and sizes available

• No graphical capabilities.

• Speed ranges from 10 to 75 CPS .

Dot Matrix Printers

The printer head contains pins lined up which strike the ribbon that in turn strikes the paper.

Dot matrix printers  include 9-pin, 18-pin, and 24-pin heads.

 

Produces draft quality printouts

Can print low-resolution  graphical printouts

Have both 80 columns and 136-column format .

Can use continuous form paper moved by the tractor feed.

Can print at speeds between 50 to 1200 CPS .

 

Maintenance and Troubleshooting of Dot Matrix Printer

 

 

 

 

 

 

 

 

 

 

Non-Impact Printers

• The ink or toner  comes in direct contact with the paper.

• They use either inkjet, thermal, or electrostatic  mechanism for printing.

• They include Thermal printers , Inkjet printers, and Laser jet printers.

• They are usually quiet when printing.

• They usually print very high quality printouts.

• Not suitable for printing on multipart paper.

 

 

Inkjet Printers

• Comes as both Inkjet  and Bubble jet  printers  that use similar technologies to print

• Prints by spraying ink on to the paper

• Relatively cheap compared to the print quality

• Prints at faster speeds and with a higher quality than impact printers

• Can produces almost laser quality printouts using high quantities of ink.

• Can print color images with photograph quality using color ink cartridges .

• Has both 80 column and 136 column format

• Print speeds measured in pages per minute (PPM)

• Can print from 4 to 15 (PPM) depending on print quality.

 

 

Inkjet Printer Operation

• Different print heads are available by a variety of manufacturers that pressurize  their ink cartridges  and prevent the ink from leaking.

• The thermal print head is used by HP, where each nozzle is heated and the ink within it expands spraying a dot of ink on to the paper in the intended position.

• The thermal head is by far the more popular used in the market but it has a short life span, and is not worth refilling.

• A piezoelectric head is used by Epson , which changes shape when charged thereby squirting a small amount of ink on to the paper.

 

Maintenance and Troubleshooting of Inkjet Printers

 

Laser Printer

• The laser printer  works a lot like a print shop units.

• The printing process can be broken down into 6 steps

• The six steps in laser printing are Charging , Writing , Developing , Transfer , Fusing , and cleaning .

 

Laser Printer Components

The main components of a laser jet printer are: -

a) Corona Wires

b) High Voltage Power  Supply

c) DC controller board  

d) Laser scanner  

e) Paper transport  rollers

f) Toner container

g) Fusing  assembly

h) Photo sensitive drum  

I) Printer system board

 

Laser Jet printer design

The general design of the laser jet printer is illustrated in the diagram bellow that has been divided in to six separate stages.

 

Laser Printer Operation

1. Charging  :The primary corona   transfers a charge of –6000V to the surface of the photosensitive drum known as the organic photoconductor (OPC).

2. Writing  : The writing unit uses a laser beam to trace what needs to be printed on to the surface of the drum. The (OPC ) will become a full conductor in the places where the laser beam shines on it, which results in a surface of –6000V charge and 0 volts.

3. Image development : The negatively charged toner  is attracted to the 0V regions on the drum which results its transfer to the drums surface and producing a copy of what needs to be printed on the surface of the drum.

4. Image transfer : The paper is picked up from the tray and moved below the positively charged transfer corona  which charges the paper. When the paper passes beneath the drum, the toner  is attracted and transferred to the paper from the drum.

5.     Fusing  : This unit melts the powdered toner  on to the paper.

 

6. Cleaning : This unit shines a even layer of light on to the drum surface to discharge its surface and also scraps the surface of any access toner

 

There exists an ozone filter  within laser jet printers  that must be cleaned or replaced regularly during preventative maintenance.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Troubleshooting of Laser Jet Printer

 

Printer Ports

• Most modern printers  use either a parallel port  or a USB  port to connect to the computer.

• The 8bit Parallel port is the old standard means of communicating to the printer from the LTP1 port using the IEEE  1284  cable .

• The IEEE1284  cable  has a has a 25 pin male connector at one end which connects to the computers parallel port  and a 36 pin centronics connector at the other end which connects to the printer.

• The USB  connector is used on the more modern printers  because it is much faster the parallel ports , hot swappable  and enables plug and play as soon as the printer is connected.

Installing your Printer

• There are two ways to get to the Add new printer  icon, a) Start  àSettings àPrinters or b) My Computer à Printers and Select Add Printer.

• Now you need to follow the steps in the Print wizard .

• Select Local printer  if the printer is connected to your machine

• The Printer wizard brings you to the select printer screen.

• Make sure you select the printer of choice using the manufacturers list  and then the printer list.

• If your printer is not on the list  then click on the have disk button to use the drivers  that came with the printer for your OS.

• You have the option of using a previously installed printer driver  or updating the driver.

• The Port where the Printer is connected to must be defined (usually LPT1 ).

• Now you must define the name of your printer.

• Finally before finishing you can select for a printout test page.

  

Questions

1) Which of the following printers  is a non-impact printer? (Choose all that apply)

a) Inkjet printer

b) Dot matrix printer

c) Laser printer

d) Daisy wheel printer

e) Thermal printer

 

2) Which of the following printers  is an impact printer? (Choose all that apply)

a) Inkjet printer

b) Dot matrix printer

c) Laser printer

d) Daisy wheel printer

e) Thermal printer

 

3) How may pins can exist on a dot matrix printer head? (Choose all that apply)

a) 9 pins

b) 12 pins

c) 14 pins

d) 18 pins

e) 24 pins

 

4) How is the speed of a dot matrix printer measured?

a) Pages Per Minute (PPM)

b) Characters Per Second (CPS )

c) Characters Per Minute (CPM)

d) Dots Per Inch (DPI)

e) Dots Per Minute (DPM)

 

5)How is the speed of a ink jet printer measured?

a) Pages Per Minute (PPM)

b) Characters Per Second (CPS )

c) Characters Per Minute (CPM)

d) Dots Per Inch (DPI)

e) Dots Per Minute (DPM)

 

6)Which printers  produce the most economical color printouts?

a) Inkjet printer

b) Dot matrix printer

c) Laser printer

d) Daisy wheel printer

e) Thermal printer

 

7) Which printers  produce the highest quality black and white printouts?

a) Inkjet printer

b) Dot matrix printer

c) Laser printer

d) Daisy wheel printer

e) Thermal printer

 

8)Which printers  produce the lowest quality printouts?

a) Laser printer

b) Dot matrix printer

c) Ink jet printer

d) Thermal printers

e) Photo printers

 

9) Which component of the laser printer  defined its resolution ?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) DC Controller board

 

10) Which component of the laser printer  produces the error 55 on the display?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Printer Memory

f) Toner container

g) Photo sensitive drum

h) DC Controller board

 

11) Which component of the laser printer  produces the error 20 on the display?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Memory error

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

12) Which component of the laser printer  produces the error that causes a completely black sheets being printed

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

13) Which component of the laser printer  produces the error that causes smearing of the printed data when touched?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

14) Which component of the laser printer  produces the error which causes a blank output  on the paper?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

                            

15) Which component of the laser printer  produces the error that causes many pages of garbage to be printed?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Wrong printer driver

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

16) Which component of the laser printer  places a uniform negative charge on the Drum?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

17) Which component of the laser printer  produces a uniform charge on the paper?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

18) Which component of the laser printer  melts the toner  to the paper?

a) Cleaning unit

b) Writing  unit

c) Fusing  unit

d) Primary corona

e) Transfer  corona

f) Toner container

g) Photo sensitive drum

h) Printer Memory

i) DC Controller board

 

19) Which cables can be used to connect a printer to a computer? (Choose all that apply)

a) IEEE  1284  cable

b) IEEE  1394  cable

c) USB  cable

d) IEEE  1294 Cable

e) SCSI  cable

 

20) What is the shape of the end of the parallel printer cable , which is connected to a printer?

a) 36 pin male D shape connector

b) 25 pin male D shape connector

c) 36 pins male D shape centronics connector

d) 50 pins male D shape centronics connector

e) 36 pins female D shape centronics connector

 

Answers

1. A,C,E

2. B,D

3. A,D,E

4. B

5. A

6. A

7. C

8. B

9. B

10. H

11. D

12. D

13. C

14. E

15. D

16. D

17. E

18. C

19. A,C,E

20. C