Patent ID: 7630671
Filing Date: 2009-12-08
Classification: G03G

Abstract:
1. An image forming apparatus including a developing system which comprises: a plurality of image carriers; a plurality of developing devices for developing electrostatic latent images, formed on the plurality of image carriers, with respective liquid developers of different colors of which carrier is nonvolatile solvent; and developer collecting means which are disposed at a plurality of locations for collecting excess developers, wherein the developer collecting means include image carrier squeezing means, image carrier cleaning means, intermediate transfer member squeezing means, intermediate transfer member cleaning means, and secondary transfer roller cleaning means, wherein collected developers collected by the developer collecting means are merged into a same path and are collected into a buffer tank, and carrier is distributed from the buffer tank to the plurality of developer containers, said image forming apparatus further including an intermediate transfer member to which developed toner images are sequentially transferred at primary transfer sections corresponding to the plurality of image carriers and are superposed on each other and which carries and transports the superposed toner image, and secondary transfer means which transfers the superposed toner image at a secondary transfer section from the intermediate transfer member to a sheet on a feeding path, wherein the buffer tank is provided with a toner concentration sensor, and the buffer tank is set into a banning mode for banning the use of carrier from the buffer tank, a tank replacing mode for calling on user to replace the buffer tank, and/or a filter replacing mode for calling on user to replace the filter when the toner concentration sensor detects a concentration higher than a predetermined concentration.