How Does a Photocopier Work?

Video Transcript

"How a photocopier works. Well the first step is once you put your image down on the glass and press the button, basically a light element is going to run across the or it's going to run across your image, photo, whatever it is, text, paper. And what that does and while it's doing that it's basically going to collect the results of that onto a special drum. If the light hits white paper it's going to reflect back. If the light hits something else it's not basically white paper or a reflective surface although I don't know why you would be trying to photocopy a mirror, it's going to basically record that as, it's going to do an exact copy. Instead of doing it like a photographic negative, it produces a positive copy so it's a direct duplicate, it doesn't do like photography where it goes positive to negative then back to positive again. Once this image is collected onto the drum, the drum passes over toner particles. Particles are charged in such a way that they will stick to the areas that did not reflect light when they passed over the original image. Once the toner has adhered itself to the charged non-white areas on the drum, paper is charged to the opposite polarity and run in contact with the drum. So basically the toner will transmit itself from the positive image that's on the drum directly to the paper. Once the toner is sticking to the charged, has adhered itself to the charged parts of the original image on the drum, paper is charged to the opposite polarity and passed over the drum. As it's passed over, the toner particles actually will kind of jump from the drum to the paper. The paper is then partially discharged so that it will separate from the drum. Once it's separated from the drum, the toner is permanently affixed to the paper by one of two processes, fusing which involves a special array of heated wires is a little less common, tends to be more expensive but it's easier to maintain and you get a slightly higher quality or by fixing which is a little bit more common, it uses a combination of heat and pressure from rollers to affix the toner to the paper permanently. Once the copy is finished and been sent to the tray, the toner will be swept off of the drum and into a special hopper where it will either be discarded or reused depending on the model of the copier."