PURPOSE: To factionally removing the cohered toner in the circulating flow passage of the developing solution and make the handling at its recovering and exchanging easy by dissolving the cohered toner in an organic solvent which is not compatible with the developing solution and is of large specific gravity.
CONSTITUTION: A fractionating device 9 is mounted in communication with the developing tank 7 of a developing device 2 and contains an organic solvent 11. The solvent 11 which is not compatible with the developing solution 3, is of large specific gravity and has solubility is used. The cohered toner precipitates much near the bottom 8 of the tank 7. When this precipitate deposits up to the interface 13 where the developing solution 3 and the solvent 11 are in contact, the precipitate is successively dissolved by the solvent 11 and is gradually fractionated from the developing solution 3. At the time of exchanging and recovering the solvent 11 in which the cohered toner has been dissolved, only required is to replace the case alone for this solvent 11. Thereby, the handling at the exchanging and recovering may be made easy and the cohered toner may be fractionated surely.
MOCHIZUKI MANABU
ARAI MAKOTO
