METHOD FOR DESIGNING DEVELOPING DEVICE, DEVELOPING DEVICE, AND OPERATING METHOD THEREOF

PROBLEM TO BE SOLVED: To easily determine respective developing conditions of the shape of a developer (flatness degree), the toner deposition amount and the peripheral speed ratio of a developing roller, while ensuring a target development density in a developing device, and to operate the device by setting the respective developing conditions. SOLUTION: When a developing density obtained by setting the following developing conditions of a developing device and the developing density is almost equal to a target development density, constants in one of (formula 1):m*k≥a*sf+b, (formula 2):m*k≥a*(1-(1-α)2/2)+b, and (formula 3):m*k≥c*α-3, (wherein a, b, and c are constants) are set, based on the developing conditions. The developing conditions are the toner deposition amount m (mg/cm2), the peripheral speed ratio k of a developing roller, and the circularity sf of a projected area of the toner or the aspect ratio α of the minor axis to the major axis in an elliptic projected image of the toner. Then developing conditions in the developing device are determined so as to satisfy the formulae with set constants. COPYRIGHT: (C)2006,JPO&NCIPI