Understanding Impact Printers – CompTIA A+ 220-801: 4.1


Impact printing has been around for a long time, and it’s common to see dot-matrix printers used today in many computing environments. In this video, you’ll learn about dot-matrix printers and the components inside of the printer that are used in this impact printing process.

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A type of impact printer that’s very common to see is a dot matrix printer. We commonly see these dot matrix printers used when we’re putting out a contract or putting out some type of output that needs to have multiple pages printed at exactly the same time.

One of the advantages of a dot matrix printer is it’s relatively low cost. There’s not a lot of ink cartridges. There’s toner cartridges involved. And the actual ink that we’re going to use inside of these printers is relatively inexpensive.

Unfortunately, these printers won’t work for everyone. One big challenge with an impact printer, as the name implies, is there’s a lot of impacting going on. There’s a loud noise that occurs when we are printing to the page. And when you compare that to a laser printer or an inkjet printer or even a thermal printer, the dot matrix printer is a very, very loud output device.

Because we’re using tiny pins to create the output on the page, the resolution of the final output really isn’t that great. It’s really designed for doing types of characters like the ones that you see here. But even the ABC and D on the screen are not the highest resolution. There are some additional higher resolutions you can get from dot matrix printers. But even those aren’t anywhere close to the types of clear outputs we would get from something like a laser printer or an inkjet printer.

If we were to take the head of the dot matrix printer and look at the section that hits the page, it looks something like this. The big print head is around it. And it’s these tiny pins that are right here in the middle that are actually creating the information output on the page itself.

If we zoom in, we can see all of the tiny little pins that are here. This is a 24-pin matrix printer. There are also 9-pin dot matrix printers. The 24 pins obviously gives us a little bit more resolution and makes that output a little bit clearer.

I mentioned how inexpensive it was to print with these dot matrix printers. And this is why we’re using a ribbon to be able to do this. The ribbon is constantly moving and rolling back into it. And inside of this ribbon case is a lot more ribbon on the inside.

This ribbon is saturated with ink. So as we’re using the ribbon, we’re using more and more of that ink onto the page. And this will rotate through a number of times, until finally the output gets so light to see that we have to now remove this ribbon and put a brand new ribbon in its place.

Dot matrix printers also usually use a different kind of paper. Usually it’s one that has these tractor feeds on the side of it. Instead of moving the paper through with rollers, it is using these holes in the side of the paper to effectively pull the paper through the printer itself. And because we’re pulling the paper in this way, it’s usually one very, very long piece of paper, with perforations that are built into the different pages to separate them out.

It’s common to see forms printed this way. If we pulled them all through the paper with this tractor feed and you’d have one form after the other, after the other. And as you finish your form, you can simply tear it off at the end and start another printout on the same form.