Image forming apparatus

An image forming apparatus that executes an image formation operation for forming an image on a recording material, the 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 based on output image data;
• a rotatable developer bearing member configured to form a toner image by supplying a developer to the surface of the image bearing member and developing the electrostatic latent image formed on the surface of the image bearing member;
• an intermediate transfer member to which the toner image formed on the surface of the image bearing member is transferred at a transfer portion, the transfer portion being formed by the intermediate transfer member contacting the surface of the image bearing member;
• a transfer member configured to transfer the toner image transferred to a surface of the intermediate transfer member to the recording material;
• a drive unit configured to drive the image bearing member and the developer bearing member;
• a transfer voltage application unit configured to apply a transfer voltage to the transfer member;
• and
• a control unit configured to control the drive unit and the transfer voltage application unit,
• wherein the control unit is configured to control execution of a first mode in which the developer bearing member rotates with respect to the image bearing member at a first circumferential speed ratio, and a second mode in which the developer bearing member rotates with respect to the image bearing member at a second circumferential speed ratio greater than the first circumferential speed ratio, and
• wherein, in a case where the control unit controls execution of the image formation operation in the second mode to consecutively output two sheets of the recording material:
• i) in response to output of first image data on a first sheet of the recording material, the first sheet being one of the two sheets of the recording material, with a first pattern of a first gradation, the toner image of the first pattern is transferred to the first sheet of the recording material, the control unit controls application of a first transfer voltage, and
• ii) in response to output of second image data on a second sheet of the recording material, the second sheet being another sheet of the two recording materials, with the first pattern and a second pattern of a second gradation with lower density than the first gradation, the toner image of the first pattern and the second pattern is transferred to the second recording material, and the control unit controls application of a second transfer voltage with an absolute value less than the first transfer voltage.