Image forming apparatus having a controller to control the current flowing between a cleaning member and a collecting member

An image forming apparatus comprising:

• an image forming part having a photosensitive drum on which a developer image is formed, and a holding roller that holds the developer image remaining on a surface of the photosensitive drum;
• a conveyance belt configured to convey a sheet;
• a cleaning part having a cleaning roller that collects developer attached to the conveyance belt, a metal roller that collects developer attached to the cleaning roller by being applied with a current between the cleaning roller, and a container that contains developer attached to the metal roller;
• a backup roller that presses the conveyance belt against the cleaning roller and allows the cleaning roller to collect the developer attached to the conveyance belt by being applied with a current between the cleaning roller through the conveyance belt;
• a feeder cassette that receives the sheet;
• a feeder mechanism that feeds the sheet received in the feeder cassette to the image forming part;
• and
• a controller configured to:
• apply a first current between the backup roller and the cleaning roller and between the cleaning roller and the metal roller in response to receiving a print job;
• control the feeder mechanism to feed the sheet to the image forming part after applying the first current between the backup roller and the cleaning roller and between the cleaning roller and the metal roller;
• perform a printing operation to transfer the developer image formed on the photosensitive drum to the sheet fed by the feeder mechanism;
• determine whether the print job is completed after the printing operation;
• in response to determining that the print job is completed, transfer the developer held on the holding roller to the conveyance belt via the photosensitive drum and collect the developer attached to the conveyance belt to the metal roller via the cleaning roller;
• determine whether a base time, starting from a time at which the sheet is fed from the feeder cassette to the image forming part, has elapsed at or prior to a time at which the print job is determined to be completed;
• and
• in response to determining that the base time has elapsed at or prior to the time at which the print job is determined to be completed, apply a second current that is smaller than the first current between the cleaning roller and the metal roller until the time at which the print job is determined to be completed.

An image forming apparatus comprising:

• an image forming part having an image carrier configured to carry a developer image;
• a conveyance belt configured to convey a recording sheet via a position opposing the image carrier;
• a cleaning roller configured to contact the conveyance belt to remove adhered matters adhered on the conveyance belt;
• a collecting member configured to collect adhered matters adhered on the cleaning roller by current flowing between the cleaning roller and the collecting member;
• and
• a controller configured to:
• start a printing operation in response to receiving a print job after the image forming apparatus is powered on, wherein the printing operation is an operation for forming the developer image on the recording sheet;
• apply the current between the cleaning roller and the collecting member after the printing operation is started;
• determine whether the printing job is completed after applying the current between the cleaning roller and the collecting member;
• determine whether a preset number of sheets is printed after the printing operation is started;
• decrease the current flowing between the cleaning roller and the collecting member when the preset number of sheets, beginning from the start of the printing operation, is printed during a period from the start of the printing operation to a time at which the printing job is determined to be completed;
• end the printing operation in response to determining that the printing job is completed;
• and
• stop applying the current between the cleaning roller and the collecting member without decreasing the current in response to determining that the printing job is completed before the preset number of sheets is printed.