Your photocopier probably receives a lot of use even if you are attempting to establish a paperless office. Its inner workings may seem mysterious and magical despite how much you depend on it because it spits out hard copy copies of everything you slap on the glass. Understanding your photocopier’s inner workings at least somewhat can help you troubleshoot issues and brainstorm solutions with staff and service personnel.
When toner is applied to a page, it adheres to some parts of the copier drum and not to others, making it resemble a rolling stamp. But instead of carving the image into rubber, light is used to etch it into static electricity. A semiconducting substance called selenium is applied to the surface of the drum of a photocopier. These materials fall into a grey area between being poor insulators and poor conductors of electricity. Selenium can be charged to prevent a static electricity field from dissipating or flowing away.
The ability of selenium to transfer images is due to the material’s ability to change conductivity when it is exposed to light. The selenium drum surface becomes more strongly charged where it is exposed to more light when the copier flashes an image of the document to be copied onto it.
Toner, the powder your photocopier uses in place of ink, attaches to the statically charged drum of your photocopier in the same way that your statically charged pants stick to your socks. Even modest amounts of iron are added to certain toner to increase its receptivity to electrical charges. The statically charged drum moves past the toner cartridge after being exposed to the picture. Less toner is drawn to the areas with lower charges and more is drawn to the areas with higher charges. On the surface of the drum, toner is used to produce a mirror copy of the page being copied.
Toner must be applied to paper after being coated on the drum. Before the paper hits the drum, it receives a significant static charge. As a result, the toner is transferred from the drum to the paper when the drum moves over the paper. After being heated to melt the toner, it is fixed to the paper so that it won’t come off when the static charge is removed. Brushes remove any remaining toner from the drum so that it is prepared for the following page.