HP 2100 Service Manual - Page 90

Image Formation System The image formation process consists of six stages: 1. Drum Cleaning 4. Developing 2. Primary Charge 5. Transfer and Separation 3. Laser Beam Exposure 6. Fusing When the Formatter sends a print command to the Engine Controller Assembly, it in turn drives the main motor to rotate the photosensitive drum, primary charging roller, developing cylinder, and transfer charging roller. The primary charging roller uniformly applies negative charges to the surface of the photosensitive drum. To form a latent electrostatic image on the drum, its surface is then exposed to the laser beam. Toner on the developing cylinder changes the latent electrostatic image on the drum's surface to a visible image, and then the transfer charging roller transfers the image to the paper. The cleaning blade scrapes residual toner from the surface of the photosensitive drum. The primary charging roller again uniformly applies negative charges to the drum's surface in preparation for the next latent electrostatic image. Figure 5-6 Image Formation System Block Diagram 80 5 Functional Overview C4170-90959