Drum Processes - Ricoh FW780 Service Manual

3. DRUM PROCESSES

2
1
8
7
3
4
6
5
1. Charge
In the dark the charge corona unit applies a negative charge to the drum. The
grid plate ensures the charge is applied uniformly. The charge remains on the
surface of the drum because the photoconductive drum has a high electrical
resistance in the dark.
2. Exposure
High intensity light from a fluorescent lamp is reflected from the moving original
through the fiber optic array. The charge on the drum surface is dissipated in
direct proportion to the intensity of the reflected light, thus producing an electric
latent image on the drum surface.
SM 1-4 A163