Image forming apparatus

An image forming apparatus comprising:

• an image carrier on which an image is formed;
• a driving source that drives the image carrier;
• an image forming unit that forms the image on the image carrier based on image data;
• a transfer unit that transfers the image formed on the image carrier onto a transfer member;
• an image detecting unit that detects the image transferred onto the transfer member;
• and
• a control unit that controls the driving source, the image forming unit, and the transfer unit, wherein
• the control unit executes
• a fluctuation-pattern detecting process of forming a speed-fluctuation detecting image formed of a plurality of predetermined visual images on the image carrier, while causing the image carrier to rotate at a standard linear speed, transferring the speed-fluctuation detecting image onto the transfer member, and detecting a speed fluctuation pattern per single rotation of the image carrier based on detection time period intervals detected by the image detecting unit, for each visual image in the speed-fluctuation detecting image,
• a fine-tuning-pattern determining process of determining a driving speed fine tuning pattern per single rotation of the image carrier of the driving source based on the speed fluctuation pattern, and
• an image forming process of forming the image based on the image data while driving the driving source based on the driving speed fine tuning pattern,
• a process of forming the image based on the image data while causing the image carrier to rotate at a nonstandard linear speed that differs from the standard linear speed is executed as the image forming process,
• a fluctuation-pattern correcting process of correcting the speed fluctuation pattern based on the nonstandard linear speed is executed before the image forming process, and
• a process of determining the driving speed fine tuning pattern based on the speed fluctuation pattern that is corrected by the fluctuation-pattern correcting process is executed as the fine-tuning-pattern determining process.