PURPOSE: To prevent the lowering of printing density and the filming of a developer carrier in a developing device where the uniform thin layer of developer is formed on the developer carrier and the developer is supplied to a latent image carrier.
CONSTITUTION: As for a one-component developing device developing a latent image by pressing the developer carrier 9 carrying the developer to the latent image carrier (photosensitive drum) 1, variable DC voltage is impressed on a reset roller 11 for replenishing the developer carrier 9 with the developer, and a potential difference between the DC voltage impressed on the roller 11 and the DC voltage impressed on the developer carrier 9 is set on a side where the developer is supplied to the developer carrier 9 when a print is outputted and on a side where the developer is recovered from the developer carrier 9 at the partial time when the print is not outputted. The developer carrier 9 and the roller 11 are reversely rotated simultaneously with setting the potential difference when the print is not outputted.
NAKAJIMA TETSUO
ISHIJIMA HIROYASU
TAKIZAWA YOSHIMI
