What Goes On Inside A Printer?


Printing: it's not something we really think about, is it? We press a button, wait for our page to come out and walk away – until we need to print something again. But have you ever wondered what goes on inside of a printer? Will it be full of clever little mechanisms all moving in sync to create the desired page, or something far more clever than that? There are two common printers – and both work very differently: inkjet printers and laser printers.

If you're wondering what the difference between the two printers and which one you have, an inkjet uses ink cartridges and a laser printer uses toner. These are very different, so you will now know which printer you have if you were unsure.

Let's hit print on this shall we, and see what really goes on inside our printers.


Inkjet printer
The technology behind an inkjet printer is simpler to that of a laser printer. It works by placing tiny drops of ink to form what needs to be printed. The key parts which form the inside of an inkjet printer include:

  • Print head

This is the core of the printer and holds the tiny which are used to drop the ink out of (and they sometimes get blocked)

  • Print head stepper motor

It's this that moves back and forth above the paper

  • A belt

This is used to attach the print head to the stepper

  • Stabiliser bar

This does exactly what it says on the tin and is needed to ensure movement is precise.

How it works:
You will click print on your computer, which will then send the data to your printer. Once it has translated your page, the paper will be fed into the printer from the paper tray. The print head stepper motor will then use the belt to move the print head across the page – stopping for a split second each time the ink droplets are sprayed on the page. Once it's finished printing, the print head is parked, the paper feed is stopped, and the page is pushed into the output tray.


Laser printer
Laser printers are more complex than inkjet printers and uses heat, a laser and static electricity to achieve the finished product. The printer cleverly combines all of it's elements to the desired image. Inside a laser printer you will find:

  • A laser

One of the most important parts of the printer, the laser is used to create the image you want to print

  • A drum

What you want to print is beamed onto the drum by the laser

  • Corona wire

This is used to pass its positive charge to the drum

  • Mirrors

The laser beams against the mirrors which reflect on the drum

  • Fuser unit

This will help melt the toner onto the page


How it works:
Again, once the print button is hit, the data is sent to the printer. The printer will then need to warm up – literally. The corona wire will need to heat up and get ready to send a positive static charge to the drum. The drum then begins to roll receiving this charge. The laser is then activated which sends a beam against the mirrors to reflect the shape of what you want printing onto the drum. The toner cartridge next to the drum then releases positively charged toner particles onto the drum as it moves – toner is attracted to any parts of the drum which have a negative charge, leaving positively charged areas untouched. The toner is then melted onto the page by the fuser unit.

Featured image source.