Image forming apparatus and cartridge detachably mountable on image forming apparatus

摘要

In conventional art, when a detected electrostatic capacity value of a point at which a developer container is full of a developer is larger or smaller than an initially set value, the developer residual amount is respectively estimated more or less than an actual amount since an output of antenna is sometimes influenced by an antenna tolerance. Therefore, it is provided an image forming apparatus in which a residual amount of a developer can accurately be detected and a cartridge which is detachably mountable on the image forming apparatus.