You may be wondering, how do laser printers work? each time you press that print button on your computer, and far from it being some kind of magical spell like something from the wizarding world of Harry Potter, there are actually complicated processes involving lasers, mirrors, carbon, static and heat. Read on to find out how laser printers work:
How Do Laser Printers Work – Quick Explanation
If you’d rather not hear about the technical process involved, here’s the quick fire explanation of how a laser printer works:
The laser inside the printer beams the image or text on to a specially coated metal cylinder called a drum giving it a static charge. When the drum rolls around, the carbon toner particles with opposite static charge attract to the drum and transfer to the paper as it passes through, which is then heated to fuse the toner to the page.
Find the full technical explanation here.
What is a laser printer?
There are many different types of printer available on the market today and each use various different technologies to achieve a similar end result of the printed page. The laser printer was the first to be invented and was done so in 1969 by Gary Starkweather while working in the Xerox product development team. His idea was to use lasers to imprint an image onto a copier drum which would then be transferred onto paper. Hence, the name ‘Laser printer’.
So why choose a laser printer over any other type of printer like an inkjet? Well, laser printers are very efficient and cost effective to use when you have a need to print in large quantities over short periods. The toner cartridges hold enough to print thousands sometimes tens of thousands of pages which is beyond the capabilities of most inkjet printers. However, as inkjet technology is advancing, there are now many exceptions to the rule.
How Do Laser Printers Work? – Full Technical Explanation
And now for those who love a good technical explanation including all the ins and outs, and science behind how a laser printer works, read on…
There are many moving parts and components inside a laser printer that work together to produce your final document or image, each have an important part to play. The key parts of the printer include, toner cartridges, image drum (also known as drum unit or photoconductor), transfer roller or belt, fuser unit, laser, and mirrors.
- The moment you press print on your computer, tablet or mobile device the information is sent to the printer memory, where the data is stored.
- The printer begins to warm up. This is the point where you usually need to wait and it’s because the corona wire is heating up and getting ready to pass its positive static charge to the drum.
- As the drum (coated metal cylinder) begins to roll, it received a positive charge across it’s whole surface. Some printers contain 4 drums, one for each colour – Cyan, Magenta, Yellow & Black.
- The laser activates, and beams against a series of mirrors to reflect across the surface of the drum(s) imprinting the shape of your print using an opposite negative electrical charge.
- The toner cartridge and hopper, sat next to the drum(s) slowly releases positively charged carbon toner particles on to the drum as it turns and the toner is attracted to any areas of negative charge leaving positively charged areas of the drum untouched.
- The transfer belt rolls the paper through the printer giving it a positive charge, and as it passes the drum, the negatively charged toner is attracted to the page in the shape of your print.
- The toner is then melted to the paper by hot rollers called the fuser unit and voila, your page is printed!
Here’s a fantastic video created by Static Control showing the whole process to help explain things a little better:
Printer Components explained
Toner Cartridge – Equivalent to an ink cartridge but much larger and instead of ink, a toner cartridge contains coloured or black carbon / iron oxide powder (toner) that is positively charged and melted to form the final print out on your paper. Toner Cartridges are the consumable item that frequently needs to be replaced in a laser printer once the cartridge is empty and toner used up.
Drum unit – A drum unit is a metal cylinder that has a special coating (giving the green colour) that can receive a static positive and negative electrical charge from the laser within a laser printer. The laser uses a negative electrical charge to form the shape of your printout on the green rotating drum which is then transferred onto the paper. The drum can be seen in the printer as green in colour and can often actually be built into the toner cartridge rather than a separate unit.
Laser – The laser part of the printer transmits light from the diode across to a series of mirrors that reflects the laser onto the drum unit to imprint the shape of what you intend to print out. The Laser itself is a light that that reflects on a rotating mirror and applies a negative electrical charge to the drum unit in the shape of your print out.
Transfer belt – The transfer belt moves the paper through your printer and passes it across the drum and fuse so that the toner can move from the drum onto the paper as it passes. Some smaller printers do not have a transfer belt but instead have transfer rollers that act in the same way as a transfer belt.
Fuser unit – The fuser unit is a heated roller that melts the toner particles onto the page as the paper passes past it. This then seals the toner to the page so it’s no longer in powder form and makes sure that the toner doesn’t smudge of fall off the paper when it comes out of the printer.
So there you have it. Was our guide easy to follow? Let us know what you think in the comments below or if you have any more questions, we’d love to hear from you!