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

If you’ve been handed a credit card receipt before, then you’re probably familiar with the output from a thermal printer. In this video, you’ll learn about the components used in thermal printing and the special paper used in this almost silent printing process.

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A thermal printer is one that uses heat to be able to create an output on a piece of paper. We’re usually using this white paper. We’re adding heat to it. And when it comes out of the printer, we see the black markings where the heat was applied.

This is usually very quiet. It’s almost silent when it is printing. And so we usually see this in places where you’re using something like a terminal that’s printing out a point of sale or we use it for receipt printing in other places. It certainly is a very quick way of printing, as well.

But it’s very sensitive to light. You don’t want to take these receipts and leave them somewhere where they’re going to get warm, like on the dashboard of a car. You’ll also notice if you apply other chemicals to them, like the chemicals that are in a piece of clear tape, that will also cause the image to disappear over time. So it’s not designed to be a permanent type of printing. But it’s one that is very inexpensive and very easy to create for temporary use.

These thermal printers are usually designed for receipts, so they’re usually not as wide as the paper that we might use inside of an ink jet printer or inside of a laser jet printer. But we still need some of the same technologies. For instance, there is a paper feed assembly that’s inside of the printer itself, that takes the thermal paper off the roll and it sends it through the printer and finally to the outside.

Before it gets to the outside of course, we have to heat it. And usually there is a heating element that’s inside of the printer that’s able to heat different parts of this long strip that’s inside of it. And as the paper passes by, it heats just that particular section of the paper.

This thermal printing process uses a very specific kind of paper. We can’t use the paper that we might use in a laser printer or an ink jet printer. We have a very specific kind of paper that’s been treated with a chemical. And when that chemical is exposed to heat, it changes color and we’re able to get the outputs to show up on this device.

Because this printing process is relatively inexpensive and it’s so quiet, it’s very simple to use. So it makes perfect sense to use this for those temporary uses like a point of sale receipt or a credit card receipt.