IMAGE DENSITY CONTROLLER

摘要

PURPOSE:To execute density control to keep the control input of an electrostatic charge voltage or exposure within a regulation range, to regulate at least one output image density equal to a target density and to decrease the errors between the other output image density and the target density when the control input described above exceeds the regulation range. CONSTITUTION:A first judging section 208 judges whether the control input determined by the change rate of the computed control input exceeds the regulation range or not. A second control input change rate computing element 210 computes the change rate of the control input to equal the output image density of at least one arbitrary density to the target density within the regulation range and to decrease the errors between the output image density and the target density of the other densities as well from the errors between the output densities and the target, the regulation range and change rate conversion function and executes control in accordance therewith.