Patent ID: 8452198

Claim:
An image forming apparatus comprising: an endless belt; a plurality of image carriers juxtaposed along an outer peripheral surface of the belt; a plurality of transfer members which are respectively provided in correspondence with the image carriers, which are respectively disposed opposite the image carriers with the belt interposed therebetween, and configured to receive application of a first bias; a cleaning member disposed in contact with the outer peripheral surface of the belt; a current sensor configured to measure a value of electric current flowing across the cleaning member; and a controller configured to control a second bias, which is applied to the cleaning member based on the value of the electric current measured by the current sensor, wherein the controller is configured to control the second bias based on the value of the electric current measured when a predetermined measurement range of the belt is in contact with the cleaning member, and wherein the measurement range is a range in which conditions, under which the first bias and the second bias are applied, are identical.