Image forming apparatus having image bearing member and collection device to collect materials adhered on the image bearing member

A method for controlling an image forming apparatus including:

• an image bearing member having a surface and configured to rotate;
• a collection device in contact with the surface, and configured to collect materials adhered to the surface;
• and a developing roller configured to provide a charged toner having a first polarity, the method comprising:
• executing a print job in a printing period;
• executing, in a non-printing period, a first process in which the image bearing member is rotated at least one rotation while a holding bias is applied to the collection device, the holding bias having a second polarity opposite to the first polarity;
• and
• executing, in the non-printing period after the first process, a second process in which the image bearing member is rotated while an ejection bias is applied to the collection device, the ejection bias having the first polarity.

A non-transitory computer readable storage medium storing a set of program instructions installed on and executed by a computer for controlling an image forming apparatus including:

• an image bearing member having a surface and configured to rotate;
• a collection device in contact with the surface, and configured to collect materials adhered to the surface;
• a developing roller configured to provide a charged toner having a first polarity, the set of program instructions comprising:
• executing a print job in a printing period;
• executing, in a non-printing period, a first process in which the image bearing member is rotated at least one rotation while a holding bias is applied to the collection device, the holding bias having a second polarity opposite to the first polarity;
• and
• executing, in the non-printing period after the first process, a second process in which the image bearing member is rotated while an ejection bias is applied to the collection device, the ejection bias having the first polarity.