What type of printer have you got? Inkjet? Laser?
Do you know the difference? Do you know how your printer actually puts print to paper?
Ok, no more questions! The point I’m trying to make is that almost all of us will have used printers at some stage for printing documents but few people know how the magic actually happens.
There are many different types of printers such as inkjet printers, dot matrix printers, LED/LCD printer and laser printers.
However, unlike other printers, laser printers use toner, static electricity and heat to create an image onto paper.
To help explain how a laser printer works, we will take a look at the 3 main components:
- A Toner Cartridge
- The Drum Unit (also known as a PC-unit, photo conductor or imaging drum)
- The Fuser Unit
The toner cartridge is the part of a laser printer that contains the coloured powder (toner) that will be used to form text and images on the paper. Toner cartridges come in four different colours – cyan (a shade of blue), magenta (a shade of red), yellow and black.
Toner is a dry carbon powder mixed with plastic polymer particles that gets electrically charged and then heated, causing it to stick to the paper.
Each colour has a separate cartridge and usually needs to be replaced every few thousand pages, depending on the ‘page yield’ or ‘life’ of the cartridge.
Toner cartridges come in OEM (Original Equipment Manufacturer – made by the printer manufacturer) and compatible versions. Compatible cartridges offer a cost effective alternative when it comes to buying new cartridges for your printer.
When should I replace a toner cartridge?
Your printer will let you know when you are running low on toner and which colour cartridge needs to be replaced. However, you should also be able to tell from the quality of printed pages, as they may look faded, whilst stripes and spots will occasionally appear on the page.
The drum unit is responsible for transferring the toner and images or text to the paper. A drum unit has several different names, and you may also know it as the image drum, imaging unit or photoconductor unit.
So how does the Drum Unit work?
For the drum unit to transfer the text and toner to the page, it first receives a positive electrical charge. A laser writes over the drum and leaves a negative charge where the text and/or images need to appear on the paper. When the toner hits the drum, it sticks to the oppositely charged areas to create an impression of text and images.
Next, the paper is fed by through the printer and given a stronger negative charge. Once the paper passes the drum, the toner is pulled onto the paper by the static charge.
When should I replace my drum unit?
Similar to a toner cartridge, a drum has a ‘page yield’ or ‘life’.
During printer use, the laser writes on the drum for every print, which means the drum unit goes through a lot of wear and tear, and it must be replaced after a certain amount of prints.
Many printers require a separate drum, but some printer manufacturers develop drums and toner cartridges combined into one unit (Eg. the HP Q6000a toner cartridge). This way, every time you replace the toner cartridge, you’re also replacing the drum.
For printers with a separate drum unit, just before it needs replacing it will begin to show signs of wear. When it’s time for a new unit, you’ll start to see spots and/or lines on your print-outs, and images will be lighter than normal.
The drum unit will have a longer lifespan compared to a toner cartridge, some last 10,000 pages while others can last up to 100,000.
Ever wondered why paper is warm when it comes out of your laser printer?
Well it’s because of the fuser unit. A fuser unit is a pair of heated rollers within the printer which fuses the toner onto the paper.
Once toner particles are pulled to the paper through the drum unit, the paper is directed to the fusers so that the plastic polymer content is melted and “fused” onto the paper. The fuser unit does this by using heat and pressure.
Why does the fuser unit need to be replaced?
Like the toner cartridge or drum unit, the fuser unit needs to be replaced every so often because of the constant wear within the printer. For example, because toner is a powder, it can sometimes spray onto parts of the printer when being pulled to the paper.
The build-up of all these particles creates scratches on the fuser, which can leave lines on your final print. Most printers will let you know when your fuser unit needs to be replaced.
Do you use a laser printer? Why do you prefer them to other printers? We’d love to hear from you!