Patent ID: 6131001
Filing Date: 2000-10-10
Classification: G01N,G03G

Abstract:
An image forming apparatus, comprising:a photoconductive carrier for carrying a latent image formed by an electrophotographic process;a developing device for developing said latent image with a first liquid type developer composed of solid particles and a liquid type solution material;a liquid type developer supplying means for supplying at least one of second and third liquid type developers to said developing device;a developer density detecting device for detecting density of the first liquid type developer, said developer density detecting device including,a developer circulating pipe for circulating the first liquid type developer;a pump for sending the first liquid type developer into said developer circulating pipe;a plurality of pressure sensors for respectively sensing pressure of the first liquid type developer flowing through said developer circulating pipe, said plurality of pressure sensors being disposed in said developer circulating pipe;a viscosity calculating device for calculating viscosity based upon a pressure gradient obtained from said plurality of pressure sensors;a density determining device for determining density based upon said calculated viscosity;a density controller for controlling said liquid type developer supplying device to supply either the second or third liquid type developer to said developing device to maintain density of the first liquid type developer within a predetermined range, wherein the second liquid type developer is supplied to said developing device in a case that said density determining device determines density of the first liquid type developer as less than the predetermined range, and the third liquid type developer is supplied to said developing device in a case that said density determining device determines density of the first liquid type developer as greater than the predetermined range.