Image forming apparatus that adjusts the start timings of transfer bias voltage applications to prevent nonuniformity in printed image density

摘要

An image forming apparatus includes a plurality of photosensitive drums, and a controller for executing, when an absolute value of a set point of a charged potential is not higher than a predetermined threshold, an operation in a first mode in which charging bias voltages and transfer bias voltages are applied to image regions of the drums, at a preset length of time before image exposures are carried out by the exposure members and thereafter, the image exposures are carried out by the exposure members, respectively, and for executing, when the absolute value of the set point of the charged potential is higher than the predetermined threshold, an operation in a second mode in which timings of starting applications of the transfer bias voltages to the transfer members are delayed as compared with those in the first mode, respectively.