Oki B 4100 Maintenance Manual page 531

5) Transfer
The transfer roller is composed of conductive sponge material and is designed to make the EP
(image) drum surface and the paper closely into contact.
Paper is placed over the EP (image) drum surface, and a positive charge, opposite in polarity to
the toner, is applied to the paper from its reverse side.
The application of a high positive voltage (+1 KVDC) from the Power Supply Unit (1VP/2VP
board) to the transfer roller causes the positive charge induced on the transfer roller surface to be
transferred to the paper at the contact between the transfer roller and the paper. As a result, toner
charged negative that is attracted to the EP (image) drum surface is transferred to the upper side of
the paper by the positive charge on the lower side of the paper.
EP drum
Paper
Transfer roller
Power
supply unit
531 /
40055101TH Rev.4