Image forming apparatus

An image forming apparatus comprising:

• a rotatable intermediate transfer member configured to bear a toner image;
• a first image forming unit configured to form a first adjustment toner image on the intermediate transfer member;
• a rotatable photosensitive member arranged downstream of the first image forming unit in a rotating direction of the intermediate transfer member;
• a second image forming unit configured to form a toner image on the photosensitive member;
• a transfer member configured to transfer the toner image on the photosensitive member to the intermediate transfer member at a transfer portion;
• an optical sensor disposed downstream of the second image forming unit and upstream of the transfer member in a rotating direction of the photosensitive member, and configured to detect a second adjustment toner image formed by the second image forming unit by irradiating the photosensitive member with light;
• a voltage application member configured to apply a voltage to the transfer member;
• an adjustment unit configured to adjust image forming conditions of the second image forming unit based on a result of the detection by the optical sensor;
• and
• an execution unit configured to execute a voltage application mode for applying, in the case where the second adjustment toner image, which is longer than a predetermined value that is greater than or equal to a circumferential length of the photosensitive member in the rotating direction of the photosensitive member, is to be formed, a voltage of a same polarity as a charge polarity of toner and less than a discharge start voltage to the transfer member while a region of the photosensitive member which the optical sensor has irradiated with light passes through the transfer portion, and a voltage of the same polarity as the charge polarity of the toner and greater than or equal to the discharge start voltage to the transfer member while the photosensitive member rotates at least once after the region of the photosensitive member which the optical sensor has irradiated with light passes through the transfer portion.