Developing device, image forming apparatus, and method for controlling developing device

摘要

A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, and a control signal generating unit. The developing roller carries toner. The magnetic roller performs supply of toner to the developing roller and removal of toner from the developing roller. The transformer includes a primary side to which a capacitor is connected and a secondary side from which an AC voltage is output and applied to the developing roller. The control signal generating unit inputs a control signal to the capacitor and adjusts a DC bias value of the control signal so that a DC component of the control signal is the same before and after the change of the duty ratio of the control signal.

主权项

1. A developing device comprising:
a developing roller which is opposed to a photosensitive drum and carries toner; a magnetic roller which is disposed to be opposed to the developing roller and performs supply of toner to the developing roller and removal of toner from the developing roller using a magnetic brush; a capacitor; a transformer to a primary side of which the capacitor is connected and from a secondary side of which an AC voltage to be applied to the developing roller is output; and a control signal generating unit which generates a control signal to be input to the capacitor, and adjusts a DC bias value of the control signal, when changing a duty ration of the control signal, in accordance with the duty ration change so that a DC component of the control signal is the same before and after the change of the duty ratio of the control signal.