Patent ID: 9291944
Filing Date: 2016-03-22
CPC Classification: G03G

Claim Text:
1. A developing device comprising: a housing that accommodates developer supplied from a supply means and including toner and carrier therein; a stirring member that rotates in the housing to stir the developer in the housing; a developing unit body that rotates in the housing to convey the developer in the housing toward an image carrying member from the stirring member and attaches the toner included in the developer to the image carrying member; a driving device that rotationally drives at least one of the stirring member and the developing unit body; a detecting device that detects torque of the driving device; a development bias power source that applies a development bias obtained by superposing a DC voltage and an AC voltage to the developing unit body such that reversal development is performed; and a control device, wherein the developing unit body comprises: a magnetic roller disposed to face the stirring member and carry the developer; and a developing roller disposed to face the magnetic roller, receive the toner from the developer carried by the magnetic roller, and carry the toner, and wherein the control device performs a recovery process of controlling the supply means to supply at least one of the carrier and the developer to an interior of the housing when a detection result of the detecting device has a value lower than a threshold value, and controlling the development bias power source or a charging bias power source for charging the image carrying member, thereby reducing a potential difference between a potential of an exposure portion of the image carrying member and a DC voltage of the development bias to below a reference potential difference.