Patent ID: 8135302
Filing Date: 2012-03-13
Classification: G03G

Abstract:
1. An image forming apparatus comprising: a primary transfer unit to primarily transfer toner images of a plurality of colors onto an intermediate transfer member, each of the toner images having been formed on a rotating image carrier; a secondary transfer unit to secondarily transfer the toner images formed on the intermediate transfer member onto a transfer material; and a pre-secondary transfer discharge unit to discharge electrical charges of the toner images carried by the intermediate transfer member, wherein the pre-secondary transfer discharge unit comprises: a scorotron charging unit having a grid electrode disposed to face the intermediate transfer member, and a discharging electrode; an opposing electrode disposed to oppose the grid electrode through the intermediate transfer member; a first voltage applying unit to apply a voltage of reverse polarity to a charge polarity of toners forming the toner images to the discharging electrode; a second voltage applying unit to apply a voltage of same polarity as the charge polarity of the toners to the grid electrode; a cleaning unit to clean the grid electrode; a detecting unit to detect an electric current value flowing to the opposing electrode; and a controller to control a timing for the cleaning unit to clean the grid electrode, in accordance with the electric current value detected by the detecting unit.