HP Enterprise CP5525 manual Latent-image formation block, Pre-exposure, Primary charging

Latent-image formation block

During the latent-image formation stage, the laser scanner forms invisible images on the photosensitive drums in the print cartridges.

Pre-exposure

Step 1: Light from the pre-exposure LED strikes the photosensitive drum surface. This eliminates the residual electrical charges on the drum surface.

Figure 1-14 Pre-exposure

LED

Photosensitive drum

Primary charging

Step 2: DC and AC biases are applied to the primary charging roller, which transfers a uniform negative potential to the photosensitive drum.

Figure 1-15Primary charging

Primary charging roller

Photosensitive drum

Primary charging bias

ENWW Image-formation system 29