Image forming apparatus

An apparatus comprising:

• an image forming unit configured to form an image onto the sheet fed from a cassette sheet feeding unit or a manual sheet feeding unit;
• an ejection unit on which the sheet with the image formed by the image forming unit is ejected;
• a sorting unit configured to sort the sheets ejected on the ejection unit into subsets;
• and
• a control unit configured to perform control to allow manual duplex printing so that a first side of each sheet fed from the cassette sheet feeding unit is subjected to image formation and a second side of the sheet ejected on the ejection unit, manually placed on the manual sheet feeding unit, and then fed therefrom is subjected to image formation,
• wherein in the manual duplex printing, the control unit controls the sorting unit to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on a manual feeding tray.

An image forming apparatus comprising:

• a feeding unit configured to feed each sheet;
• an image forming unit configured to form an image onto the fed sheet;
• an ejection unit on which the sheet with the image formed by the image forming unit is ejected;
• a sorting unit configured to sort the sheets ejected on the ejection unit into subsets;
• and
• a control unit configured to, when executing a mode for preparing insert sheets to be used in an inserter by forming images on the fed sheets and ejecting the sheets on the ejection unit, control the sorting unit so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on a tray of the inserter on which the insert sheets to be fed are placed.

A method comprising:

• forming an image onto each sheet;
• sorting sheets ejected on an ejection tray into subsets;
• and
• when executing a mode for forming images on first sides of the sheets, ejecting the sheets with the images on the first sides, and forming images on second sides of the ejected sheets manually placed on a feeding unit for second-side image formation, controlling the sorting to sort the ejected sheets after first-side image formation into subsets so that the number of sheets in each subset does not exceed a maximum number of sheets stackable on the feeding unit.