Image forming apparatus including anomaly detection for charging members

An image forming apparatus comprising:

• a plurality of photoconductors;
• a plurality of chargers each disposed opposite to a corresponding photoconductor, the plurality of chargers comprising a plurality of charging members each of which is provided in a corresponding charger and configured to charge the corresponding photoconductor by a corona discharge;
• a voltage application unit to which the charging members are connected in parallel and which is configured to apply a voltage to the charging members;
• a memory unit;
• a controller configured to exercise control over the voltage application unit;
• and
• a messaging unit configured to produce a notification to advise a user of presence or absence of an anomaly,
• wherein the controller is further configured:
• to change, upon startup of the image forming apparatus, the voltage to be applied by the voltage application unit to the charging members from a first voltage to a second voltage of which an absolute value is smaller than that of the first voltage, to obtain amounts of electric currents caused to flow through the respective charging members by application of the second voltage, the first voltage being a previously applied voltage stored in the memory unit;
• to make a determination as to whether or not any anomaly is present, based upon the obtained amounts of the electric currents for the charging members;
• and
• to cause the messaging unit to produce a notification of the anomaly being present, if any anomaly is present, and
• wherein the charging members connected in parallel to the voltage application unit comprise a first charging member and a second charging member, and the controller is further configured to calculate an absolute value of a difference between amounts of electric currents caused to flow through the first and second charging members by application of the second voltage, whereby if the calculated absolute value is greater than a second reference value predetermined based upon amounts of electric currents caused to flow through the first and second charging members by application of the first voltage, the controller makes a determination that anomaly is present.

An image forming apparatus comprising:

• a plurality of photoconductors;
• a plurality of chargers each disposed opposite to a corresponding photoconductor, the plurality of chargers comprising a plurality of charin members each of which is provided in a corresponding charger and configured to charge the corresponding photoconductor by a corona discharge;
• a voltage application unit to which the charging members are connected in parallel and which is configured to apply a voltage to the charging members;
• a memory unit;
• a controller configured to exercise control over the voltage application unit;
• and
• a messaging unit configured to produce a notification to advise a user of presence or absence of an anomaly,
• wherein the controller is further configured:
• to change, upon startup of the image forming apparatus, the voltage to be applied by the voltage application unit to the charging members from a first voltage to a second voltage of which an absolute value is smaller than that of the first voltage, to obtain amounts of electric currents caused to flow through the respective charging members by application of the second voltage, the first voltage being a previously applied voltage stored in the memory unit;
• to make a determination as to whether or not any anomaly is present, based upon the obtained amounts of the electric currents for the charging members;
• and
• to cause the messaging unit to produce a notification of the anomaly being present, if any anomaly is present,
• wherein the plurality of chargers further comprise a plurality of grid electrodes each of which is disposed between a corresponding photoconductor and a corresponding charging member, and
• wherein the controller is further configured to obtain amounts of electric currents flowing through the grid electrodes, as the amounts of electric currents flowing through the corresponding charging members.