Image forming apparatus

An image forming apparatus comprising:

• a storage unit configured to store a recording sheet;
• an image forming unit configured to form an image on a recording sheet fed from the storage unit;
• a first detection unit configured to detect the presence or absence of a recording sheet stored in the storage unit;
• a second detection unit configured to detect a remaining amount of recording-sheets in of the storage unit;
• an insertion unit including an interleaf tray configured to load an interleaf fed from the interleaf tray between recording sheets conveyed from the image forming unit;
• and
• a control unit configured to control the timing of start of interleaf feeding by the insertion unit, based on a detection result of the second detection unit, the control unit being configured to start interleaf feeding from the interleaf tray regardless of a detection result of the first detection unit, in a case where the recording-sheet remaining amount of the storage unit is more than a first threshold, and the control unit being configured to start interleaf feeding from the interleaf tray based on a detection result of the first detection unit, in a case where the recording-sheet remaining amount of the storage unit is less than the first threshold,
• wherein the image forming apparatus has
• a first mode of changing the feeding origin of a recording sheet, according to the detection of the absence of a recording sheet in the storage unit by the first detection unit during execution of an image forming job, and
• a second mode of changing the feeding origin of a recording sheet, according to detection of a recording-sheet remaining amount of the storage unit being less than a second threshold during execution of an image forming job, and
• wherein the second threshold is larger than the first threshold.