Image forming apparatus with transfer voltage controlled according to temperature and humidity

摘要

An image forming apparatus has a voltage information storing unit in which data of transfer voltages in correspondence to predetermined discontinuous temperatures and humidity are stored. In the case that measured temperature and humidity of an atmosphere out of the apparatus do not coincide with discontinuous temperature and humidity stored in the voltage information storing unit, a proper transfer voltage is applied to a medium transfer roller by interpolating data of the stored transfer voltage so as to calculate the transfer voltage and applying the transfer voltage to the medium transfer roller.