HP 5000n manual 8Photosensitive Drum Image Formation System

Photosensitive Drum

The special properties of the photosensitive drum allow an image to be formed on the drum surface and then transferred to paper. The drum is an aluminum cylinder. The outside of the cylinder is coated with a layer of organic-photoconductive material (OPC) which is non- toxic. The OPC material has properties similar to a photo-resistor. It becomes electrically conductive when exposed to light. (The negative charges deposited on the drum are conducted to the ground potential of the drum base.) Areas not exposed to light remain non-conductive and maintain their negative charge. The aluminum base of the photosensitive drum is electrically connected to ground potential.

Photosensitive

Layer

Aluminum

Base

Figure 5-8Photosensitive Drum

EN Image Formation System 5-21