Printers and Multi-Function Print Devices Flashcards
Laser printer
A printer which uses focused light, electrical charges, and a dry powder ink (called toner) to transfer an image onto paper.
Inkjet printer
A printer which uses ink-dispersion and wet ink to transfer an image onto paper.
Piezo-electric technology
A method in which a current is applied to a Piezo crystal at the rear of the ink reservoir.
Impact printer
A printer that works by banging a print head or needle against an ink ribbon to make a mark on the paper, very similar to an old typewriter.
Daisy-wheel
A type of impact printer which uses a wheel-shaped printing mechanism containing predefined character glyphs arranged like petals on a flower.
Thermal printer
A printer which uses heat to create images on paper.
Duplexing assembly
A feature that automatically reverses a piece of paper after the first side has been printed, allowing the printer to print on both sides of a single sheet of paper.
Virtual printer
An application that replicates the software interface for a physical printer and allows the user to carry out various tasks without actually printing anything.
3D printer
A printer that builds physical objects using raw materials such as plastic, metal, plaster, or even living tissue instead of placing text or images onto the paper.
laser printing process: Step 1 - Cleaning
a physical and electrical process cleans the previous image off the photosensitive drum.
laser printing process: Step 2 - Charging
the primary corona wire applies a negative charge to the photosensitive drum as the surface of the drum rolls across the surface of the conditioning roller. This removes any electrical charges that might remain from the previous print image.
laser printing process: Step 3 - Exposing
the laser projects the image on the photosensitive drum. Where the light hits the drum, the negative charge is dissipated to the grounded center of the drum. This results in areas with a lower negative charge than the rest of the drum. These areas create an electrical image of the print data on the surface of the drum.
laser printing process: Step 4 - Developing
The drum passes by a developing roller covered in toner. The toner is a negatively-charged combination of plastic and metal particles. Areas of the drum where the laser hits lose their electrical charge, this attracts the negatively charged toner from the control blade of the roller. Areas on the drum that still have a negative charge repel the toner. This creates a mirror image of what is to be printed in toner on the drum.
laser printing process: Step 5 - Transferring
Pickup rollers grab a single sheet of paper from the paper tray or manual feed slot and move it into the printer. A separator pad (commonly two or three inches wide) placed in the middle of the paper path keeps the pick up to one paper at a time. Once the paper moves into the printer, it receives a positive charge as it passes through the secondary corona wire or transfer roller. The negatively charged toner is attracted to the positively charged paper and transfers from the drum to the paper.
laser printing process: Step 6 - Fusing
the paper passes through a set of rollers that apply heat and uniform pressure to the paper and toner, curing the image onto the paper. As the paper passes by a static eliminator strip, it neutralizes any remaining electrical charges on the paper. This prevents the paper from jamming in other areas of the printer.
Inkjet printing process: Thermal technology
using this method, tiny heating elements heat the ink to create a bubble. Pressure forces the bubble to burst and eject ink droplets onto the paper from the print head’s nozzles. Most thermal inkjets have print heads containing between 300 and 600 nozzles, each about the diameter of a human hair. After the bubble collapses, the element cools, which causes a vacuum to form drawing ink from the reservoir to replace the ink that was ejected.
Inkjet printing process: Piezo-electric technology
using this method, a current is applied to a Piezo crystal at the rear of the ink reservoir. The current causes it to flex and force a drop of ink out of the nozzle. This is an Epson’s proprietary inkjet technology.
What are the 3 types of quality that an inkjet printer can print off?
- Normal: 300 × 300 or 320 × 320 dpi
- High quality: 600 × 600 or 720 × 720 dpi
- Photo quality: 1200 × 1200, 1440 × 1440 dpi, 2880 ×
1440 and up
Impact printer type: Daisy-wheel
Uses a wheel-shaped printing mechanism containing predefined character glyphs arranged like petals on a flower. Much like a mechanical typewriter, a mechanism moves the wheel across the paper and a hammer strikes one petal against the ink ribbon, leaving an imprint of the character on the printer. Daisy wheel printers can produce high quality text output, but they’re slow and are limited to the specific glyphs (typically 96) on the wheel. To even change the font or text size, you must change the wheel.
Impact printer type: Dot matrix
Prints one character at a time using a print head made up of small pins. The pins are individually struck against the ribbon to create a pattern of dots which can form characters or pictures. Dot matrix printing is faster and more flexible than daisy wheel printing, but it produces lower quality text. Print heads typically have between 9 and 24 pins. Higher pin counts create sharper output.
Impact printer type: Line
Prints an entire line at once, allowing faster output. Depending on the type, an impact line printer might use a wide comb to produce dot matrix output, or it might have character glyphs arranged on a drum, chain, or bar.
