How does the copier work?

In the copier, the photoconductor of the toner cartridge is exposed to form a latent image on the surface of the toner cartridge in the form of an electric charge. This image is then developed and transferred using a special charged toner. The following is the process of copying each part:

1.In order for the copier to function, the surface of the photoconductive material must first be coated with a layer of cations by corona wires.

Before you press the start button, the photoconductive selenium, germanium or silicon surface of the toner cartridge is covered with positive charge.

2.When you press the "Start" button, the bright light sweeps through the inside of the copier, shining light on the paper to be copied, and the toner cartridge starts to rotate. When the blank area of the paper reflects the light back, the mirror projects the reflected light onto the surface of the drum. Just as we wear dark clothes in sunny hot weather, the dark area of the original will also absorb light, so it will not illuminate the corresponding area on the surface of the toner cartridge.

3.Where the light hits the rotating drum, the energy of the photons kicks the electrons out of the photoconductive atoms.

4.Opposite attraction-cations outside the photoconductive layer attract the released electrons. The combination of an ion and an electron produces a neutral particle. The only places where charged particles are left are those where the original does not reflect light and therefore the light does not reach the toner cartridge, I .e. the dark parts of the text and pictures on the paper!

Less rigorously, this part of the process is similar to the way a camera takes pictures. If you have ever read the basics of photographic film, you should know that when the film is exposed, the energy of photons will cause chemical changes in the silver halide grains coated by the film. This forms the negative of the image you see through the viewfinder. But in the case of a photocopier, what you end up with is a real image formed by the positive charge remaining after exposure. Moreover, you must use special chemical processing to develop the film and print it onto photosensitive photo paper, while the copier only needs dry ink, heat and plain paper to produce a visible image.

5.A voltage is applied to the aluminum core of the toner cartridge. Since light makes selenium conductive, current can flow through the photoconductive layer when illuminating the drum, and the electrons that form the current quickly replace the electrons released by the atoms.

6.The exposed area of the toner cartridge rotates past the roller covered with toner particles. Tiny toner particles are pressed against the surface of the drum. The plastic toner particles have a negative charge, so they are adsorbed to the remaining positively charged areas on the surface of the drum.

7.The corona wire passes over the paper to charge the surface of the paper.

8.The area of the drum that has just been coated with toner touches the paper with a positive charge as it rotates. The electric field around the paper exerts a stronger attraction than the ions on the surface of the drum, so the toner particles stick to the paper as the drum passes.

9.Once the entire original is re-created from the toner on the paper, the paper continues through the copier to the fuser. The weak suction force between the toner particles and the paper surface is easily destroyed. In order to fix the toner image at the corresponding position to the paper surface, the entire paper is passed between the heating rollers of the fuser. The heat melts the plastic material in the toner and fakes the pigment onto the paper.

By the time you reach for a copy from the paper tray, the copier has once again removed the surface of the toner cartridge and applied a new cationic coating to it, ready for the next run.