Image forming apparatus

An image forming apparatus comprising:

• a rotatable image bearing member;
• an exposure unit configured to form an electrostatic latent image on a surface of the image bearing member by exposing the surface of the image bearing member;
• a rotatable developer bearing member configured to, at a developing portion, supply toner to the surface of the image bearing member and develop the electrostatic latent image as a toner image;
• a cleaning member configured to form a contact portion by coming into contact with the image bearing member and, at the contact portion, remove toner adhering to the surface of the image bearing member;
• and
• a control unit configured to, by causing the image bearing member and the developer bearing member to rotate and controlling the exposure unit, perform control to enable performing (i) an image forming operation which forms the toner image on a recording material, and (ii) a toner supply operation which is an operation different from the image forming operation and which supplies the toner to the contact portion by moving the toner from the developer bearing member to the image bearing member,
• wherein a region of the image bearing member facing the developer bearing member at the developing portion in a state in which the image bearing member and the developer bearing member are rotating is defined as a first region, a region of the image bearing member facing the developer bearing member at the developing portion after a region of the developer bearing member facing the first region makes one revolution is defined as a second region, and a region of the image bearing member between the first region and the second region in a rotational direction of the image bearing member is defined as a third region,
• wherein, when the toner supply operation is performed, the control unit performs control to form, in the third region, a toner supply pattern which includes a first pattern for exposing a part of the surface of the image bearing member by the exposure unit, a second pattern for not exposing a part of the surface of the image bearing member after the first pattern in the rotational direction or for exposing a part of the surface of the image bearing member with an exposure amount smaller than an exposure amount with which the first pattern is used for exposure, a third pattern for exposing a part of the surface of the photosensitive member by the exposure unit after the second pattern in the rotational direction, and a fourth pattern for not exposing a part of the surface of the photosensitive member after the third pattern in the rotational direction or for exposing a part of the surface of the image bearing member with an exposure amount smaller than an exposure amount with which the third pattern is used for exposure, and
• wherein the toner supply pattern is configured so a length of the second pattern is larger than a length of the first pattern in the rotational direction and that a length of the fourth pattern is larger than a length of the third pattern in the rotational direction.