What happens during the transferring step of the laser printer printing process?

Updated 25/04/2022

Do you wonder how laser printers work? Far from it being some kind of magical spell, there are complicated processes involving lasers, mirrors, carbon, static and heat. Read on to find out how laser printers work and what they do.

How does a laser printer work?

1. The printers laser beams your print onto a metal drum.
2. The drum uses static electricity to attract powdered toner to the drums cylinder.
3. The drum rolls the toner onto the paper in the form of your print.
4. The toner is melted & pressed onto the paper by heat from a fuser as it passes through its rollers.
5. Your print comes out of the printer.

Find the full technical explanation here.

What does a laser printer do?

There are many different types of printer available on the market today, and each uses various technologies to achieve a similar 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’.

Do laser printers need ink?

No, laser printers use coloured powder called toner which is very different from the liquid ink used in inkjet printers.

Are laser printers better than inkjet printers?

Why choose a laser printer over any other type of printer like an inkjet? Laser printers are very efficient and cost-effective to use when you 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. This also makes them more cost effective than inkjet printers.

However, as inkjet technology is advancing, there are now many business inkjet machines that are exceptions to the rule.

How Laser Printers Work – Full Technical Explanation

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 photo-conductor), transfer roller or belt, fuser unit, laser, and mirrors.

Step-by-step

1. 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 temporarily.
   
2. 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.
3. As the drum (coated metal cylinder) begins to roll, it received a positive charge across its whole surface. Some printers contain four drums, one for each colour – Cyan, Magenta, Yellow & Black.
4. 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.
5. 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. The toner is attracted to any areas of negative charge leaving positively charged areas of the drum untouched.
6. The transfer belt rolls the paper through the printer giving it a positive charge. As it passes the drum, the negatively charged toner is attracted to the page in the shape of your print.
7. 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

A toner cartridge contains coloured or carbon / iron oxide powder (toner) that is positively charged, then melted onto the paper. Toner Cartridges are a consumable item that needs to be replaced in a laser printer once the cartridge is empty and is available in 4 different colours black, cyan, magenta and yellow (CMYK).

Drum unit

A drum unit is a metal cylinder that has a special coating (green colour) That can receive a static positive and negative electrical charge from the laser within a laser printer. The drum can be seen in the printer as a green cylinder and can sometimes be built into the toner cartridge rather than a standalone unit.

The drum receives its initial static charge from the corona wire which is heated during the printer warm up process.

Laser

The laser part of the printer transmits light from the diode across a series of mirrors. They reflect the laser onto the drum unit to imprint the shape of the intended print.

Transfer belt

The transfer belt moves the paper through your printer and passes it across the drum so that the toner can be transferred. Some smaller printers do not have a transfer belt but instead have rollers that act in the same way as a belt.

Fuser unit

The fuser unit is a heated roller that melts the toner particles onto the page as it passes through. This 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.

About Stuart Deavall

I have been working in the printing industry with TonerGiant for over 15 years, and I'm the resident technical printer expert, helping people fix their printer problems for over 10 years. I'm also the Digital Marketing Manager at TonerGiant.co.uk (degree qualified).