Patent ID: 7412179

Claim:
A wet-type electrophotographic image forming apparatus, comprising: a development unit for developing an image on a photosensitive medium; a developer cartridge for supplying developer to the development unit; a developer collection unit disposed between the development unit and the developer cartridge for collecting developer remaining within the development unit into the developer cartridge, wherein the developer collection unit includes a drain providing a developer flow passage for allowing developer remaining in the development unit to be collected into the developer cartridge in a natural manner, and a pump for collecting developer in the development unit and pumping developer into the developer cartridge in a compulsory manner; and a control unit for controlling the amount of developer passing through the developer collection unit from the development unit to prevent an overflow of developer at the developer cartridge while the developer is collected, wherein the control unit controls the pump based on the amount of compulsorily collected developer and the amount of naturally collected developer.