Image forming apparatus

An image forming apparatus comprising:

• an image bearer to bear a toner image;
• multiple image forming stations to form the toner image on the image bearer, each of the multiple image forming stations including a latent image bearer;
• a transfer member to transfer the toner image from the image bearer onto a sheet;
• a cleaning member to clean a surface of the image bearer;
• and
• control circuitry configured to:
• control the image forming apparatus to operate in a first mode in which the toner image is formed on the image bearer by one image forming station of the multiple image forming stations, and a second mode in which the toner image is formed on the image bearer by the multiple image forming stations;
• control formation, on the image bearer, of a toner image pattern to be input to the cleaning member;
• and
• in a case that a required toner input amount calculated based on an indicator value and a toner amount of the toner image pattern input to the cleaning member exceeds a threshold, determine whether to form the toner image pattern or to skip formation of the toner image pattern, and set a number of times of skipping formation of the toner image pattern based on an operation ratio of the second mode during a predetermined period,
• the indicator value being calculated by multiplying an indicator value conversion coefficient by either a travel distance of the latent image bearers of the multiple image forming stations in the second mode or a number of printed sheets in the second mode.