HP 2820 Service Manual - Page 107

Developing stage The developing cylinder comes in contact with the photosensitive drum to deposit toner onto the electrostatic latent image. NOTE The charges on the exposed area on the drum are shown as positive in Figure 4-18 Developing block. The charges are actually negative, but they are more positive than the charges on the developing cylinder. Figure 4-18 Developing block Step 3: auxiliary developing The DC bias applied to the blade imports a uniform negative potential to the toner. Step 4: developing Toner acquires a negative charge through friction from the developing cylinder and the blade. When the negatively charged toner comes in contact with the drum, the toner adheres to the electrostatic latent image. The image on the drum becomes visible because of the toner. Figure 4-19 Developing ENWW Image-formation system 95