Printers

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Chapter 11

• Printers

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You Will Learn

• How printers work and how to troubleshoot them

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Printers

• Local printers connect directly to computer via
  parallel port, serial port, USB port, infrared
  connection, wireless connection, IEEE 1394 port,
  SCSI port, or PC Card connection
• Network printers are accessed over the network

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Main Types of Printers

• Laser
• Ink-jet
• Dot-matrix
• Thermal printers and solid ink printers

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Laser Printers

• Use electrophotographic process
• Range from small, personal desktop models to
  large network printers capable of handling and
  printing large volumes continuously
• Require interaction of mechanical, electrical,
  and optical technologies

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How a Laser Printer Works

• Places toner on electrically charged rotating
  drum
• Deposits toner on paper as paper moves through
  the system at same speed the drum is turning

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Six Steps of Laser Printing

• Cleaning
• Conditioning
• Writing
• Developing
• Transferring
• Fusing

• Take place inside toner cartridge
• Use components that undergo the most wear

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Six Steps of Laser Printing
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Step 1 Cleaning
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Step 2 Conditioning

• Conditions drum to contain a high electrical
  charge

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Step 3 Writing

• Laser beam discharges a lower charge to only
  those places where toner is to go

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Step 3 Writing

• Data from PC is received by formatter (1) and
  passed to DC controller (2) which controls laser
  unit (3)
• Scanning mirror (4) is turned clockwise by
  scanning motor
• Laser beam is reflected off scanning mirror,
  focused by focusing lens (5) and sent to the
  mirror (6)
• Mirror deflects laser beam to a slit in the
  removable cartridge and on to the drum (7)

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Step 3 Writing
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Step 4 Developing

• Toner is placed onto the drum where the charge
  has been reduced

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Step 4 Developing
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Step 5 Transferring

• Strong electrical charge draws toner off drum
  onto paper takes place outside the cartridge

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Step 6 Fusing

• Heat and pressure fuse toner to paper

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Ink-Jet Printers

• Small
• Print color inexpensively
• Tend to smudge on inexpensive paper
• Slower than lasers

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How an Ink-Jet Printer Works

• Print head moves across paper, creating one line
  of text with each pass
• Shoots ionized ink at a sheet of paper in a
  matrix of small dots
• Several technologies are used to form ink
  droplets (eg, bubble-jet)
• Uses ink cartridges

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Ink-Jet Cartridges
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Photo-Quality Ink-Jet Printers

• New generation of ink-jet printers that give
  photo-quality results
• Mix different colors of ink to produce a new
  color that then makes a single dot

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Dot-Matrix Printers

• Less expensive lesser quality
• Impact printer can print multicopy documents
• Print head moves across width of the paper, using
  pins to print a matrix of dots on the page
• Uses a ribbon
• If print head fails, buy a new printer

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Dot-Matrix Printers
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Thermal Printers andSolid Ink Printers

• Relatively new printer technologies
• Non-impact printers that use heat to produce
  printed output

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Thermal Printers

• Use wax-based ink that is heated by heat pins
  that melt ink onto paper
• Internal logic of the printer determines which
  pins get heated in order to produce the printed
  image
• Popular in retail applications for printing bar
  codes and price tags
• Can burn dots onto special paper or use a ribbon
  that contains wax-based ink

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Solid Ink Printers

• Store ink in solid blocks that are easy to
  handle several can be inserted in printer to be
  used as needed
• Solid ink is melted into the print head which
  spans the width of the paper
• Head jets the liquid ink onto the paper as it
  passes by on a drum

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Solid Ink Printers

• Advantages
• Simple design
• Excellent print quality
• Easy to set up and maintain
• Disadvantage
• Time it takes (15 minutes) for the print head to
  heat up

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Printer Manufacturers
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Installing a Local Printer

• Physically attach printer to computer (via
  parallel, serial, USB, SCSI, IEEE 1394 port PC
  Card or Infrared connection or wireless access
  point)
• Install printer drivers
• Have Windows do it
• Use printer manufacturers installation program
  (best way)
• Alternately, use Windows Printer window to
  install
• Test the printer

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Installing a Network Printer

• Network printer contains a NIC and connects
  directly to the network or is shared on the
  network by another PC
• Can use Network Neighborhood or My Network Places
  to install a network printer on a remote PC

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Troubleshooting Guidelinesfor Printers

• Printer maintenance
• General printer troubleshooting
• Problems with laser printers
• Problems with ink-jet printers
• Problems with dot-matrix printers

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Printer Maintenance

• Procedures vary widely from manufacturer to
  manufacturer and printer to printer
• Make sure consumables for the printer are on hand
• Research printer documentation or manufacturers
  Web site for specific maintenance tips
• Clean inside and outside of the printer

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General Printer Troubleshooting

• Isolate the problem
• Application attempting to use the printer
• OS and printer drivers
• Connectivity between PC and printer
• Printer itself

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Addressing Printer Problems Caused by Hardware

• Verify a printer self-page can print
• Problem with printer cable

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Problems with Laser Printers

• Poor print quality due to low toner
• Printer stays in warm-up mode
• Paper Jam or Paper Out message is displayed
• Printer images are distorted
• Printing is slow
• A portion of the page does not print

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Problems with Ink-Jet Printers

• Print quality is poor
• Printing is intermittent or absent
• Lines or dots are missing from the printed page
• Ink streaks appear on the printed page

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To Clean Ink-Jet Nozzles
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Problems with Dot-Matrix Printers

• Print quality is poor
• Print head moves back and forth, but nothing
  prints

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Chapter Summary

• Printers and how to support them