How do Laser Printers Work?

Mar 09, 2016

Most people have come in contact with a laser printer at least a few times while printing a report or spreadsheet, but most people don’t know how laser printers actually work.

Laser printers have a lot in common with photocopiers! In fact, the first laser printers were built from photocopiers that were modified to take information off of the screen and not from an image that had already been created.

In photocopiers, light is used to make a copy of a page. The light is then reflected onto a drum where static electricity sticks ink particles to the drum. The ink is then pressed onto the paper and hot rollers seal it on. Laser printers do this same thing, but they write the image from start to finish instead of copying one. Let’s dig in a little bit deeper to how laser printing really works.

Parts of the Printer

In order to understand the way a laser printer creates such a quick copy of your data, you have to understand the various pieces of the printing process:

  • Data - the information your computer sends to the printer to be printed
  • Electronic circuit - small piece of software that is in charge of organizing the data
  • Corona wire - high voltage wire that gives static electricity
  • Photoreceptor drum - holds the image that will be printed
  • Laser - draws the image on the photoreceptor drum
  • Ink roller - places toner on the photoreceptor drum before printing
  • Fuser unit - two hot rollers that press together to stick the toner to the paper

How the Laser Printer Works

  1. Data moves from the computer to the printer.
  2. An electronic circuit organizes the data and discovers how to print an exact copy of the data.
  3. The electronic circuit activates the corona wire, which gives static electricity to anything close.
  4. The corona wire charges the photoreceptor drum so it can gain a positive charge over its entire surface.
  5. The laser activates from the circuit to make it draw the image onto the drum. But the laser doesn’t move! It reflects off a mirror that moves and scans it over the drum. When the lasers hit the drum, it removes the positive electrical charge and creates a negative one instead. This negative charge becomes what will be printed, and the remaining positive charge will be the white space on the page.
  6. An ink roller coats the drum with toner, which has been given an electrical charge. Ink is not attracted to the parts of the drum with a positive charge, only the negative.
  7. The corona wire gives a moving sheet of paper a strong positive charge to attract the negatively charged ink to the page.
  8. The image transfers from the drum to the paper, but only as toner particles sitting on the surface of the page.
  9. The paper goes through two hot rollers called a fuser unit, which fuse the particles to the paper.
  10. Out comes the final print! The fuser unit is warm, so your paper will be, too.

Now that you understand a little bit more about the mechanics of the laser printer, hopefully you can appreciate all the quick and wonderful work it does for us! If you need a laser printer, we can help at PrinterStop. We know we have the perfect laser printer to fit your needs.