How Do Laser Printers Work?
Everyone understands that printing is the process of transferring the data represented as pixels on your computer screen onto tangible paper.
But not many people know that the ways to do this are quite numerous including using ink or a laser beam.
But how can a highly focused beam of light be able to write words and draw pictures on paper?
In this article, we’ll unravel all the intricate and intelligent processes that go on inside a laser printer to deliver your prints.
How Laser Printers Work
The short answer is that the laser inside the printer beams the text or image onto a cylinder which is specially coated to give it a static charge. This cylinder is known as the drum.
The carbon toner particles that carry opposite static charge to the one that the drum is coated with stick onto the drum when it rolls around.
This transfers your text or image onto the paper as it passes through, and then it gets heated to fuse the toner to the page.
Let’s Check Out The Components of a Laser Printer
1. The Toner Cartridge
The toner cartridge contains the carbon or iron oxide powder (toner) which positively charged.
This is a “consumable” which means that you have to replace the toner cartridge once the toner runs out.
2. The Drum Unit
The drum unit is a metal cylinder that is coated with a special green color coating.
It has the capability to receive both a positive electrical charge or a negative one from the laser inside the laser printer.
Furthermore, the drum can usually be seen in the printer as a standalone green cylinder or it can be built into the toner cartridge.
The laser’s job is to emit light from the diode across to a series of mirrors.
The mirrors then reflect the laser onto the drum unit to form the shape of the print to be produced.
4. Transfer Belt
The transfer belt is the part that moves the paper through your printer and passes it across the drum in order for the toner to be transferred.
On the other hand, smaller printers may replace the transfer belt with rollers that behave in a similar way to the belt.
5. Fuser Unit
The fuser unit is a roller that’s heated to melt the toner particles onto the paper as it passes through the fusion and pressure rollers.
Its function is to ensure the sticking of toner onto the page so it’s no longer in powder form.
Moreover, it makes sure that the toner doesn't fall off or smudge as the paper comes out of the printer.
The Seven Steps of The Laser Printing Process
The technical, step-by-step explanation to how these various units work in tandem with each other to produce your final print is right here:
- After you press “print” on your computer, tablet, smartphone, or mobile device, the data is sent to and stored in the memory of the printer.
- The printer starts to warm up in preparation to print. This is the part where you have to wait for the corona wire to heat up and get ready to transfer positive static charge to the drum.
- As the drum begins to roll, the positive static charge starts being stuck onto its entire surface.
If you’re printing in color, your printer would probably take more time as it would roll 4 drums for each color –Cyan, Yellow, Black, and Magenta.
- After that, the laser is activated and is breamed against a series of mirrors to reflect across the surface of the drum(s) to produce the shape of your print by using an opposite negative electrical charge.
- Next to the drum(s), the toner cartridge and hopper slowly release positively charged carbon toner particles onto the drum as it rolls and the toner stocks to any area that carries a negative charge while the areas carrying a positive charge remain untouched.
- The transfer belt, then, rolls the paper through the printer to give it a positive charge. As the paper passes the drum, the negatively charged toner is attracted to the page to form the shape of your text or image.|
- Finally, the fuser unit (a set of hot rollers) melt the toner onto the paper and your print is right there in your hands!
What Is a Laser Printer?
Laser printing was invented by Gary Starkweather –a member of the Xerox product development team- in 1696.
He invented laser printers to reach a more cost-effective way of printing that beats inkjet printers.