Image forming apparatus

An image forming apparatus comprising:

• a photosensitive member;
• an exposing portion configured to expose the photosensitive member and to form a first electrostatic latent image and a second electrostatic latent image on the photosensitive member;
• a developing portion configured to develop the first electrostatic latent image and the second electrostatic latent image on the photosensitive member as a first toner image and a second toner image, respectively;
• a transfer portion configured to transfer the first toner image and the second toner image onto a first surface and a second surface of a sheet, respectively;
• a re-conveyance portion configured to reverse a front surface and a back surface of the sheet on which the first toner image is transferred on the first surface by the transfer portion and to convey the sheet to the transfer portion again;
• a first detecting portion, in an upstream position of the transfer portion with respect to a sheet conveyance direction, configured to detect a first detecting position which is a position of the sheet before the first toner image is transferred to the first surface with respect to a widthwise direction perpendicular to the sheet conveyance direction;
• a second detecting portion, in the re-conveyance portion, configured to detect a second detecting position which is a position of the sheet after the first toner image has been transferred to the first surface and before the second toner image is transferred to the second surface with respect to the widthwise direction;
• and
• a control portion configured to control the exposing portion so as to form the first electrostatic latent image on the photosensitive member at a first image forming position and to form the second electrostatic latent image on the photosensitive member at a second image forming position,
• wherein the control portion executes in a first mode in which the control portion determines the first image forming position before the first detecting position of the sheet is detected by the first detecting portion and determines the second image forming position based on the first image forming position, the first detecting position and the second detecting position.