In which step of the laser printing process is a laser used to reduce the charge to 100VDC on areas of the photosensitive drum?

In the laser printing process, the laser is used during the "exposure" step. During this phase, the laser scans the surface of the photosensitive drum, selectively reducing the charge in specific areas to 100VDC, corresponding to the image being printed. This creates a latent electrostatic image on the drum that will later attract toner.