Dot-matrix printers are one of the most common impact printer types. In this video, you’ll learn about the dot-matrix printer head, the printer ribbon, and using tractor-feed paper on a dot-matrix printer.
A dot matrix printer is a type of impact printer, and as the name implies, an impact printer is one that presses against a ribbon to make a mark on the paper. It’s literally impacting with the paper in order to create the output. The pins in this matrix itself can be seen in the output. If we zoom up on one of these letters, you can see that this number seven is made up of very small dots. Each one of those dots is part of the printing matrix.
These dot matrix printers are perfect if you’re making multiple copies because you can have carbon paper and multiple pages being printed at the same time. This gives a relatively low cost per page compared to other printing types because the only thing that you need to be able to create that image on the page is the ink that’s inside the ribbon. One downside to impact printers is the process of making that impact against the paper creates noise. And in some cases, these are much louder printers than any other type that you might use.
As you can see here, the output created by a dot matrix printer is not the highest resolution. So you probably would not use this type of printer if you have a very graphical output. But if all you need is a low cost printer that’s able to provide output of letters and numbers, this might be the printer for you.
Here’s a close up of the printing mechanism on a dot matrix printer. There’s the paper. There is a ribbon in front of the paper, and on the other side of the ribbon is the print head. This print head is going to move back and forth across this paper, and it’s going to use the tiny pins that are in the print head to create the output.
The component containing the print head is relatively large because most of this is a heat sink that dissipates the heat that’s created during this printing process. If we were to look at the other side of the print head that’s physically connecting to the paper, you would find that the print head is relatively small. There are 24 pins inside of this print matrix, and the width of these pins is about the width of a single character. So you can see why you might have to move this entire print head all the way across the page to create the output.
To be able to show output on the page, we need to move ink that is inside of a ribbon onto the printed page itself. So our pins are pressing into the ribbon, the ribbon is pressing into the page, and that’s what’s leaving the marks or the output on the printed page. The ribbons themselves are made of fabric, and they’re usually one very long ribbon that is constantly cycling through the printing process. This also makes it very easy to replace. Once we’re done using this ribbon cartridge, we can easily pop it out, pop a new ribbon cartridge in place, and in a matter of seconds, we’re back up and running.
If you are planning to swap out these ribbons, you have to make sure you have exactly the right model. Each ribbon is proprietary to a specific printer type. So you want to be sure that the ribbons you’re purchasing are designed to match the model of the printer that you’re using. If you were to take the top off of one of those ribbon cartridges, you would see that it was one long piece of fabric that provides us with that ink for the printing process.
Dot matrix printers commonly use a tractor feed to be able to pull the paper all the way through the printer. This means there are holes on the left and right side that are used to pull the paper. And then the paper itself may have perforations between the pages so that you can separate those pages once you’re printing is done. Since this piece of paper is one very long piece that has perforations, we use this tractor feed to pull the paper through the printer and to control it much better than using something like friction. These tractor feed guides lift up to allow you to put the paper in place. You would line these up so that it is perfectly straight across both of them, and then you can lock those guides in place.
Here’s a better view of this paper being just installed onto this printer. Once you’ve confirmed that the paper has been installed properly, you can press the paper feed button, and it will pull the paper through the printer and prepare for the next print. Here’s a better view of this paper. You can see it is one very long folded piece of paper, one page after the other. Once you finish printing on this paper, you can usually remove the left and right side tractor feeds to have simply the page left over at the end. Of course, there are also perforations between the pages so that you can separate these into individual pages instead of having one very long piece of paper.
And if you’ve used impact printers or dot matrix printers for any amount of time, you might be familiar with this type of paper. This is green bar paper that’s commonly associated with mainframe printing, although it will work on any dot matrix printer. This already has the tractor feed that is built into the left and right side of the paper, and it’s a very large format page. It’s 11 inches high by 14 inches wide. It was very common to see this type of paper being used with mainframes.