3.7 - Laser Printers

Question 1

Laser printer

Answer 1

• Combine a laser, high voltage, charged ions,
  powdered ink, heat, and paper
• Very high quality
• Fast printing speeds
• Very complex, many moving parts, requires on-printer
  memory and messy on the inside

Question 2

Imaging drum

Answer 2

• Image is drawn onto a photosensitive drum
  – “Painted” with a laser
• Picks up toner - Transfers toner to the paper
• Can be separate from the toner cartridge or combined

Question 3

Fuser assembly

Answer 3

• Heat and pressure - Melt plastic toner powder
  – Permanently bond toner to paper

Question 4

Transfer belt and roller

Answer 4

• Color laser printers
  – Cyan, yellow, magenta, black
• Four separate toner cartridges
• Image is transferred from all cartridges to the single belt
  – And then to a single transfer roller

Question 5

Pickup rollers

Answer 5

• Pickup paper - Should be a single page at a time
  – Problems if no paper is picked up
  or multiple sheets are picked
• Should be periodically cleaned or replaced

Question 6

Separation pad

Answer 6

• Pull just the top sheet from the paper tray
  – Not multiple sheets
• Small and inexpensive - Easy to clean or replace

Question 7

Duplexing assembly

Answer 7

• Printers usually print on a single side
  – Not both sides simultaneously
• Printing on both sides is a two step process
  – Print side one, print side two
• You need mechanisms to “flip” the page
  – Automatically
• Can be built-in to the printer
• Or available as an add-on

Question 8

Laser printing steps

Answer 8