Developing apparatus for judging residual amount of developing agent using detection member moving at predetermined cycle

摘要

A developing apparatus includes a developing container for storing a developing agent, a developing agent carrier which is disposed at the opening of the developing container, and carries the developing agent, a detection member which is disposed in the developing container and moves at a predetermined cycle, and a judging means for judging the residual amount of developing agent on the basis of changes in voltage induced at the detection member in the cycle.