ELECTICALLY BIASED TONER FILTER

PROBLEM TO BE SOLVED: To provide a device for filtering polluted material from the recording grains inside a conduit. SOLUTION: This device 90 is includes a moving body 120 for moving recording grains 50 inside of a conduit 132, a screen 142 arranged adjacent to the conduit 132 so that the recording grains 50 passes there through. This device 90 includes an applying device 190 for applying the electric bias between the moving body 120 and the screen 142 so as to facilitate the passing of the recording grains 50 through the screen 142.