US 8,478,150 B2Granted

Image forming apparatus and method for controlling same

AssigneeKyocera Mita Corporation

InventorsKensuke Fujihara, Tamotsu Shimizu, Ryota Maeda, Koji Fujii

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Abstract

An image forming apparatus has: a photoconductive drum that rotates; a developing roller that carries toner to be charged and to which a first voltage application portion outputting an AC voltage is connected; a contact member that makes contact with the photoconductive drum to remove residual toner; a detection portion for detecting occurrence of electric discharge between the developing roller and the photoconductive drum; and a developing unit that feeds toner to the developing roller, that supports the developing roller opposite the photoconductive drum with a gap secured in between, and that feeds toner to the developing roller with prescribed timing and for a prescribed time during electric discharge detection.

Claims18

Dependent claims

An image forming apparatus comprising:

a photoconductive drum
rotatably supported, and
rotating by receiving a drive force from a drive source;
a first voltage application portion outputting an AC voltage;
a developing roller
carrying toner to be charged,
connected to the first voltage application portion, and
feeding toner to the photoconductive drum;
a contact member making contact with the photoconductive drum to remove residual toner;
a detection portion detecting occurrence of electric discharge between the developing roller and the photoconductive drum;
and
a developing unit
feeding toner to the developing roller, and
supporting the developing roller opposite the photoconductive drum with a gap secured in between,
the developing unit feeding toner to the developing roller with prescribed timing and for a prescribed time during electric discharge detection in which, while the photoconductive drum rotates and the first voltage application portion stepwise varies a peak-to-peak voltage of an AC voltage applied to the developing roller, a voltage at which electric discharge occurs between the photoconductive drum and the developing roller is detected.

12 more elements

A method for controlling an image forming apparatus, comprising:

a step of rotating a photoconductive drum that is rotatably supported, that rotates by receiving a drive force from a drive source, and that is provided with a contact member making contact with the photoconductive drum to remove residual toner;
a step in which a first voltage application portion outputting an AC voltage applies the AC voltage, while stepwise varying a peak-to-peak voltage of the AC voltage, to a developing roller that carries toner to be charged and that feeds toner to the photoconductive drum, to make a detection portion detect occurrence of electric discharge between the developing roller and the photoconductive drum, in order to detect a voltage at which electric discharge occurs between the photoconductive drum and the developing roller;
and
a step of feeding toner to the developing roller and making a developing unit supporting the developing roller opposite the photoconductive drum with a gap secured in between feed toner to the developing roller with prescribed timing and for a prescribed time.

1 more element

Dependencies are inferred from the claim text.