Patent ID: 8818244
Filing Date: 2014-08-26
Classification: G03G

Abstract:
1. A developing device for developing an electrostatic latent image on an image bearing member, comprising: a developer bearing member which is opposed to the image bearing member and which bears thereon a developer including a toner and a magnetic carrier while feeding the developer to develop the electrostatic latent image with the developer; a developer containing part to contain the developer to supply the developer to the developer bearing member; an agitating or feeding member to agitate or feed the developer in the developer containing part; a developer feeder; a toner feeder that feeds toner to the developer in the developer feeder; a first feeding member located in the developer feeder to feed the developer, in a developer feeding direction within the developer feeder, to the developer containing part a driver to drive the first feeding member independently of the agitating or feeding member; and a magnetic permeability sensor located on the developer feeder at a location below the first feeding member and downstream of the toner feeder in the developer feeding direction, to measure magnetic permeability of the developer fed through the developer feeder.