Patent ID: 8326166

Claim:
An image forming apparatus comprising: a rotatable image bearing member on which a latent image is to be formed; a developing device, including a developer carrying member for carrying a developer and developing bias application means for applying a developing bias to the developer carrying member, for developing the latent image formed on said image bearing member into a developer image; a rotatable intermediary transfer member; a primary transfer member, provided opposed to said image bearing member through said intermediary transfer member, for forming a primary transfer nip by causing said intermediary transfer member to contact said image bearing member and for transferring the developer image from said image bearing member onto said intermediary transfer member; a secondary transfer member, contactable to said intermediary transfer member to form a secondary transfer nip, for secondary-transferring the developer image from said intermediary transfer member onto a recording material; wherein an area of said image bearing member in which the latent image for image formation on the recording material is to be formed includes a first area at least containing an area located in the primary transfer nip at a time when a speed of said intermediary transfer member is temporarily decreased and includes a second area located in the primary transfer nip when there is no temporary change in speed of said intermediary transfer member; and a control device for controlling a developing bias so that a potential difference between an image portion potential of the latent image and a potential of the developing bias to be applied to the developer carrying member when the latent image in the first area is developed is smaller than a potential difference between the image portion potential of the latent image and a potential of the developing bias to be applied to the developer carrying member when the latent image in the second area is developed.