Patent ID: 7366438

Claim:
An image forming apparatus comprising: an image bearing member; toner image forming means for repeatedly forming a plurality of toner images on said image bearing member, said toner image forming means forming a detection patch in an inter-toner image area on said image bearing member; a transfer member which contacts said image bearing member to form a transfer nip portion, said transfer member electrically transferring the toner image formed on said image bearing member to the recording material in the transfer nip portion; detecting means for detecting the detection patch on said image bearing member; controlling means for variably controlling a toner image forming condition of said toner image forming means based on the detection result of said detecting means; and toner removing means for forming a cleaning electric field to remove toner adhering to said transfer member when the inter-toner image area passes through the transfer nip portion, the cleaning electric field electrostatically moving the toner adhering to said transfer member to said image bearing member, wherein a length of time of the cleaning electric field formed in a time period when the inter-toner image area on which the detection patch is formed passes through the transfer nip portion, is longer than a length of time of the cleaning electric field formed in a time period when the inter-toner image area on which the detection patch is not formed passes through the transfer nip portion.