Image forming apparatus

An image forming apparatus for forming an image by transferring developer of regular polarity onto a transfer material, the image forming apparatus comprising:

• an image bearing member;
• a charging member that is provided in contact with the image bearing member and charges the image bearing member;
• a developer bearing member that supplies developer to the image bearing member charged by the charging member;
• and
• a controller that executes a collection sequence in which the developer bearing member collects developer of opposite polarity adhering to the charging member, the opposite polarity being opposite to the regular polarity,
• wherein the collection sequence includes a first sequence and a second sequence, the controller executes the first sequence by:
• setting a first potential difference to allow the developer of opposite polarity to move from the charging member to the surface of the image bearing member;
• setting a second potential difference to allow the developer of opposite polarity, which moves from the charging member to the surface of the image bearing member by the first potential difference, to move from the surface of the image bearing member to the developer bearing member when the surface of the image bearing member reaches a position facing the developer bearing member as a result of rotation of the image bearing member;
• the controller executes the second sequence by:
• setting a third potential difference to not allow the developer of regular polarity, which moves from the developer bearing member to the surface of the image bearing member by the second potential difference, to move from the surface of the image bearing member to the charging member when the surface of the image bearing member reaches again a position facing the charging member as a result of rotation of the image bearing member;
• and
• setting a fourth potential difference to allow the developer of regular polarity, which moves from the developer bearing member to the surface of the image bearing member by the second potential difference, to move from the surface of the image bearing member to the developer bearing member after passing through a position facing the charging member and when the surface of the image bearing member reaches again the position facing the developer bearing member as a result of rotation of the image bearing member.

An image forming apparatus for forming an image by transferring developer of regular polarity onto a transfer material, the image forming apparatus comprising:

• an image bearing member;
• a charging member that is provided in contact with the image bearing member and charges the image bearing member;
• a developer bearing member that supplies developer to the image bearing member charged by the charging member;
• and
• a controller that executes a first collection sequence in which the developer bearing member collects developer of opposite polarity adhering to the charging member, the opposite polarity being opposite to the regular polarity,
• wherein the controller executes a second collection sequence in which the developer bearing member collects the developer of regular polarity which moves from the developer bearing member to the surface of the image bearing member when the developer of opposite polarity moves from the surface of the image bearing member to the developer bearing member in the first collection sequence;
• and
• in the second collection sequence, the controller sets a potential difference such that the developer of regular polarity, which moves from the developer bearing member to the surface of the image bearing member, moves from the surface of the image bearing member to the developer bearing member without moving to the charging member.