Patent ID: 6480683
Filing Date: 2002-11-12
Classification: G03G

Abstract:
A device for adjusting a developing solution for an electrostatic wet-type electrophotographic printer comprising:a storage tank for storing the developing solution; a carrier cartridge for storing a liquid carrier; a toner cartridge for storing a concentrated liquid toner; a carrier feed pump for feeding the liquid carrier in the carrier cartridge into the storage tank; a toner feed pump for feeding the concentrated toner in the toner cartridge into the storage tank; a storage tank stirrer for stirring the liquid carrier and the concentrated toner fed into the storage tank to prepare a developing solution; a developer for effecting the developing with the developing solution fed from the storage tank; a developing solution feedback passage for feeding the developing solution used by the developer back to the storage tank; and developing solution drain means for draining an excess of the developing solution in the storage tank into the toner cartridge; wherein provision is further made of: a concentration sensor for measuring the toner concentration of the developing solution in the storage tank; a level sensor for measuring the volume of the developing solution in the storage tank; and control means for controlling, in real time, the carrier feed pump and the toner feed pump based upon values detected by the concentration sensor and the level sensor during the printing operation, in order to adjust the volume and the toner concentration of the developing solution in the storage tank so as to lie within predetermined ranges, wherein the storage tank is of a sealed structure, normally-closed valves are disposed between the developer and the storage tank and in the developing solution feedback passage, and the control means is provided with a valve opening/closing function for opening or closing the valves upon detecting the start and end of the printing operation.