Oki OKIPAGE 14i Service Manual page 51

(5) Transfer
The transfer roller is composed of conductive sponge material, and is designed to get the image drum surface and the paper in a close contact.
Paper is placed over the image drum surface, and the positive charge, opposite in polarity to that of the toner, is applied to the paper from the reverse side.
The application of a high positive voltage from the power supply to the transfer roller causes the positive charge inducement on the transfer roller surface,
transferring the charge to the paper as it contacts the transfer roller. The toner with negative charge is attracted to the image drum surface, and it is transferred to
the upper side of the paper due to the positive charge on the reverse side of the paper.