Patent ID: 8699894
Filing Date: 2014-04-15
Classification: G03G

Abstract:
1. An image forming apparatus comprising: an image bearing member configured to bear a latent image on a surface thereof; a plurality of developing apparatuses each including a developer containing chamber containing a developer, a developer bearing member including a first electrode member, the developer bearing member being configured to bear and convey the developer to the image bearing member and to develop the latent image, and a developer supply member arranged inside the developer containing chamber in contact with the developer bearing member and including a second electrode member, the developer supply member being configured to supply the developer to the developer bearing member; a rotatable holding unit configured to hold the developing apparatuses and to rotationally move each of the developing apparatuses to a development position where the developer bearing member and the image bearing member are contacted with each other, and detection positions where the developer having deposited in a nip between the developer bearing member and the developer supply member at the development position is dropped from the nip; and a detection device configured to execute detection modes of detecting electrostatic capacitance between the first electrode member and the second electrode member at the detection positions, and wherein one detection position is in a state where all of the developing apparatuses are not located at the development position and another detection position is in a state where one of the developing apparatuses is located at the development position.