printers Flashcards
laser printer
Combine a laser, high voltage, charged ions,
powdered ink, heat, and paper.
pros: very high quality, fast printing speeds
cons: very complex, many moving parts, requires on printer memory and messy inside
imaging drum
Image is drawn onto a photosensitive drum
Picks up toner - Transfers toner to the paper
Can be separate from the toner cartridge or combined
fuser assembly
Heat and pressure - Melt plastic toner powder
Permanently bond toner to paper
Transfer belt and roller
Color laser printers. CYMB
Four separate toner cartridges
Image is transferred from all cartridges to the single belt and then to a single transfer roller
Pickup rollers
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
Separation pad
Pull just the top sheet from the paper tray
Not multiple sheets
Small and inexpensive - Easy to clean or replace
Duplexing assembly
Printers usually print on a single side not both sides simultaneously
Printing on both sides is a two step process
You need mechanisms to “flip” the page automatically
Can be built-in to the printer or available as an add-on
laser printing steps
- processing 2. charging 3. exposing 4. developing 5. transferring 6. fusing 7. cleaning
Processing
build the entire page in memory
Charging
prepare the drum with a negative electrostatic charge
Exposing
write the image with the laser
Developing
add toner to the charged areas of the imaging drum to the paper
Fusing
heat and pressure
Cleaning
remove excess toner
Replacing the toner cartridge
Look for the messages
– Low doesn’t mean empty
The toner can also contain the OPC (Organic Photoconductor) drum
Power down printer and remove packing strips from the new drum and replace it with the old
Laser printer maintenance kit
replacement feed rollers, new fuser unit, etc. check the printer’s page counter to see when to perform maintenance. power down and replace components, reset the page counter when done
Laser printing calibration
different toner cartridges print with different densities, laser printer calibration can adjust the density, can be automated or a manual process
Laser printer cleaning
water + IPA
outside: damp cloth
inside: wipe dust, dont use normal vacuum or compressed air, clean rollers with IPA
Inkjet (ink-dispersion) printer
Relatively inexpensive technology, Quiet, High-resolution
Expensive ink, Proprietary, Eventually fades, Clogs easily
Ink cartridge
Place drops of ink onto a page
CMYK - Cyan, Magenta, Yellow, Key (black)
Print head
Some consumer printers integrate the print head
into the ink cartridge
Others separate the ink cartridge from the print head
Feed rollers
Pick up and feed paper through the printer
Duplexing
Carriage and belt
Ink cartridges are moved over the paper
Belt moves the carriage back and forth
Inkjet printer calibration
Align nozzles to the paper
Printer includes a calibration option
Cleaning print heads
Small droplets of ink - And small holes in a print head
Clogged heads is a big issue
– Output has streaks or sections of missing color
Some print heads/cartridges can be removed
Replacing inkjet cartridges
Usually separate colors
Takes seconds to replace
Recycle the empty cartridge - All plastic
Clearing jams
Remove tray paper
Remove paper from the path
Check for any scraps of paper
