Patent ID: 9086646
Filing Date: 2015-07-21
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a photosensitive drum configured to be driven for rotation; a developing roller configured to carry toner for developing an electrostatic latent image formed on said photosensitive drum, said developing roller being disposed in a manner opposed to said photosensitive drum and driven for rotation; and a memory and a processor, wherein the memory and processor are configured to: apply a developing bias voltage for forming a developing electric field between said photosensitive drum and said developing roller, to said developing roller, formation of the developing electric field causing the electrostatic latent image to be developed with toner carried by said developing roller; detect a current value corresponding to an electrostatic capacitance between said photosensitive drum and said developing roller; detect a rotation phase of said photosensitive drum; perform operation for sampling a current value detected by said current value detection unit at a fixed time interval, in synchronism with a detected rotation phase, a plurality of times while changing detection start timing, and store a current value sampled each of the plurality of times, into a storage section; interpolate current sampled values at each of the plurality of times of sampling to thereby calculate interpolated current values over one rotation of said photosensitive drum, for each time; calculate an average value of interpolated current values at each same phase of the calculated interpolated current values over one rotation of said photosensitive drum, for each time; create a correction table for correcting the developing bias voltage to be applied, using the calculated average value; and control the developing bias voltage based on the created correction table.