| 摘要 |
PROBLEM TO BE SOLVED: To prevent a developing device capable of securing the reproducibility of a fine line, without impairing developability and stabilizing development, for instance, reducing bias in the development by improving stirring screws, so as to miniaturize the developing device and further, enhancing the property of stirring toner supplied to the developing device, for keeping the distribution of an electric charge quantity sharp, and an image forming device using the developing device. SOLUTION: In the developing device 14 provided with a developing sleeve 141 for carrying a developer to the developing region of an image forming body 10 and the stirring screws 145 and 146 for stirring/carrying the developer, the thickness (F) of the roots of the spiral blade parts of the stirring screws 145 and 146 and the pitches (p) of the stirring screws are set 0.6<=F/p<=1 and setting is attained to hold the developing region between magnetic poles different in polarity. Then, magnetic force in the normal direction of the surface of the developing sleeve 141 is 700-2000G, the difference in the magnetic force in the normal direction of the surface of the sleeve 141, between the magnetic poles holding the developing region is <=200G and an opening angle at which a magnetic line of force in the normal direction holds the developing region is 50-90 deg.. |
