Patent ID: 10018942

Abstract:
A developing device has a developer container, a first stirring member, and a first stirring chamber. The developer container stores toner. The first stirring member conveys toner while stirring it. The first stirring chamber is in the developer container. The first stirring member is in the first stirring chamber. In a top surface of the first stirring member is a toner supply port through which toner is supplied from outside by action of gravity. The first stirring member has, on the downstream side of the toner supply port in the toner conveying direction, a reduced conveying power portion exerting reduced conveying power to toner. The first stirring chamber has a developer stagnation portion at a position facing the reduced conveying power portion. The inner surface of the developer stagnation portion has a smaller surface roughness than the inner surface of the stirring chamber except for the developer stagnation portion.