Printers

Question 1

Types of printers

Answer 1

Impact printers (dot-matrix printers)
Inkjet printers
Thermal printers
Laser printers
3-D printers

Question 2

Laser printer parts

Answer 2

Toner cartridge
Imaging drum
Erase lamp
Primary corona/charge roller
Laser
Toner
Transfer corona/transfer roller
Fused assembly
Power supply
Turning gears
System board
Ozone filter
Sensors and switches

Question 3

Printer languages

Answer 3

Postscript
PCL (Printer control language)

Question 4

Postscript

Answer 4

Device independent language capable of high resolution graphics and scalable fonts
Postscript interpreters are embedded in the printing device
Majority of image processing is done on the printer itself and not the CPU
Postscript printers print faster
Files are extremely portable (can be created on one machine and reliably printed on another machine)

Question 5

PCL

Answer 5

Printer command language
Developed by HP
More advanced language to supersede simple ASCII codes
Features a set of printer commands greatly expanded from ASCII
Designed with text based output in mind
Does NOT support advanced graphical functions
Commands must be supported by the printer model (less portable than postscript files)

Question 6

GDI

Answer 6

Graphical driver interface
Uses the CPU rather than the printer to process a print job
Sends completed job to the printer
Sends information as bitmapped images, not as text
If printer has a capable enough raster processor and plenty of RAM, you do not need to worry about printer language in most situations

Question 7

XPS

Answer 7

XML Paper Specification (also known as OpenXPS)
Enhanced color management
Better print layout fidelity
Requires driver support for XPS specifically

Question 8

Laser printer process

Answer 8

1. Processing
2. Charging
3. Exposing
4. Developing
5. Transferring
6. Fusing
7. Cleaning

Question 9

Processing

Answer 9

Printer processes the image of the print job once some or all of print job has been received
Creates a raster image (a pattern of dots that represents what final product should look like) of the page (done one whole page at a time)
Uses laser imaging unit to “paint” the image to the imaging drum
Uses a Raster Image Processor (RIP) to translate the raster image into commands to the laser

Question 10

Charging

Answer 10

Uniform NEGATIVE charge is applied to the drum (usually between -600 and -1000 volts)

Question 11

Exposing

Answer 11

Laser is used to create a positive image on the surface of the drum
Every particle on the drum hit by the laser releases most of its negative charge

Question 12

Developing

Answer 12

Exposed particles with lesser negative charge are positively charged in relation to the toner particles to attract them

Question 13

Transferring

Answer 13

Printer transfers the image from the drum to the paper
Paper is given a positive charge to attract the negatively charged toner particles
Particles are merely resting on the paper and must be permanently fused to paper

Question 14

Fusing

Answer 14

Paper is run through the fuser rollers to permanently fix the toner to paper
One heated non-stick roller to heat the toner
One pressure roller to press the toner to the paper
Static charge eliminator removes the positive charge from the paper
Printer ejects paper

Question 15

Cleaning

Answer 15

Remaining toner is removed from drum, usually with a rubber cleaning blade
Deposits residual toner in a debris cavity or recycles it by returning it to the toner supply
One or more lamps bombard the drum with wavelengths of light causing the surface particles to discharge into the grounded drum
Drum should be completely free of toner and at a neutral charge