Wait for the cycle of the seven major steps. The entire laser printing process is carried out by the action of "charging". First, the photosensitive drum is filled with negative or positive charges. The raster bitmap image data in the printing controller is converted into the laser beam information of the laser scanner, and the photosensitive drum is directed through the reflecting prism. "Exposure", the surface of the photosensitive drum forms image information that is exactly the same as the printed image represented by a positive charge, and then adsorbs the toner particles in the toner cartridge to form a toner image on the surface of the photosensitive drum. The printing paper is charged with a negative charge by a charging unit before it comes into contact with the photosensitive drum. When the printing paper passes through the photosensitive drum, the toner image of the photosensitive drum is transferred to the printing paper because the positive and negative charges attract each other. After the heat transfer unit is heated, the carbon* particles are completely absorbed by the paper fiber, forming a printed image. Then the remaining toner on the photosensitive drum is "cleaned up". The final action is "de-image", which is also to remove the static electricity, so that the electric potential on the photosensitive drum surface returns to the initial state to start the next cycle.