Image forming apparatus

An image forming apparatus comprising:

• a stacking unit configured to stack a recording material;
• a feeding unit configured to feed the recording material stacked on said stacking unit;
• an image forming unit configured to form an image on the recording material;
• a discharge stacking unit configured to stack a discharged recording material;
• a detecting unit configured to detect the recording material to be discharged on said discharge stacking unit;
• a double-side feeding passage along which the recording material, on which the image is formed on one side by said image forming unit to form images on double sides of the recording material, is fed;
• and
• a controller configured to control feeding of the recording material by said feeding unit,
• wherein in a case that subsequent to a current recording material, a subsequent recording material is discharged on said discharge stacking unit, said controller,
• determines a feeding timing of the subsequent recording material depending on a discharge interval time from discharge of the current recording material on said discharge stacking unit to discharge of the subsequent recording material on said discharge stacking unit, and
• determines the discharge interval time on the basis of print information of at least the subsequent recording material.