| 摘要 |
PROBLEM TO BE SOLVED: To provide a developing device capable of always preventing toner scattering by setting the upper limit concentration of toner with which a developer carrier is replenished in accordance with carrier particle size and toner particle size. SOLUTION: The developer carrier 4 having plural magnetic poles on its surface, turning while carrying developer by magnetic force and developing an electrostatic latent image on the surface of an image carrier 1 is used in this developing device, which is provided with a developer regulating member 6 regulating the quantity of the developer 3 fed while being carried on the carrier 4 and a developer stirring chamber 5 having an aperture on the upstream side of the member 6; is provided with a toner concentration sensor 8 and an agitator 7 for stirring the magnetic carrier and the toner in the stirring chamber 5; and provided with a toner storing part 10 having a toner replenishing aperture 11a communicating with the stirring chamber 5 and an agitator 12 for replenishing the toner in the storing part 10. Then, the toner concentration in the stirring chamber 5 is set so that carrier coating rate Tn may be <=130% so as to control the toner concentration in the stirring chamber 5. |
