It’s hard to imagine a world without printers.
Just think: if we didn’t have printers – or printing technology – we might still be writing everything down with a quill and ink on vellum paper.
And without printers, barcodes most likely wouldn’t even exist.
But thankfully, we don’t have to rely on quills and ink (unless you’re acting in a period drama or like to write old-school for some reason, like our forefathers of yore), and printers do exist.
And quite frankly, they’re pretty fascinating.
In 2018, there are many different kinds of printers out there, but they generally fall into two camps: inkjet printers and laser printers.
Though we use both kinds of printers every day, the science and mechanics behind how they work might surprise you.
So today, we’re going to pull back the curtains à la The Wizard of Oz.
Let’s look into how inkjet and laser printers work.
How Inkjet Printers Work
To start out with, what do inkjet printers print with?
You probably won’t be shocked to find out that that inkjet printers print using ink – they are called inkjet printers, after all.
Modern-day ink usually comes in two forms: liquid or paste.
The ink usually includes black and three primary colors like blue, yellow, or red.
And as you learned in our recent post about the difference between ink and toner cartridges, inkjet printers have tiny, microscopic nozzles that spray this ink onto the page.
The ink is pronounced into tiny, exact dots to form an image, letter, or symbol.
How many dots dictates that image resolution and sharpness. A good rule of thumb is to remember that more dots=higher resolution.
Resolutions, meanwhile, are measured in dots per inch, or dpi.
Inside a basic inkjet printer, you’ll find cartridges that are either refillable or replaceable.
Your typical cartridge includes a printhead that’s made up of the nozzles that spray the ink onto whatever surface it’s printing on.
These printheads can even be built into the printer.
You’ll also find other important components in the printer cartridges such as microchips that are key elements to controlling and holding the ink in the printer.
To make this process begin, inkjet printers will use piezoelectrical crystals or thermal print technology to propel the ink forward onto whatever media it’s printing on.
And voila! That’s how inkjet printers work.
Now, onto laser printers….
How Laser Printers Work
All right, it’s time to explore the way laser printers work.
Laser printers don’t use ink; they print using toner, which is a powder consisting of tiny plastic particles that come in various colors.
And guess what the main component is that allows laser printers to use toner?
(Clearly, whoever came up with the names of inkjet and laser printers wasn’t very inventive. But at least it’s easy to remember the difference between the two. Inkjet printer, ink; laser printer, laser. Super simple.)
But to backtrack, the laser printers’ lasers will project images onto belts or rotating drums. Either is usually coated in a material that’s photosensitive.
Electromagnetic static will then charge the toner because it’s of the opposite polarity.
Then, the drum or the belt inside the laser printer will roll through the toner.
Because it uses static electricity, the toner will be drawn to the image area.
Afterwards, the toner will be pressed onto a sheet of paper.
With the magic of static electricity again, the toner will decide that it’s not really into the image area anymore and that the paper looks like a better option.
All jokes aside, though, the toner will be “attracted” to the paper because the paper is using the exact opposite charge the toner is using.
Literal opposites attract.
Next, the paper will be heated and pressed through the rollers.
The toner then melts, and then presto! Using a fusion process, the image appears on the paper.
And there you have it, folks: the science and mechanics behind how inkjet and laser printers work.