Image forming apparatus and image forming method for prohibiting or allowing recovery printing based on number of times of printing in case of discrepancy between sizes of sheet

An image forming apparatus comprising:

• conveying means for conveying a sheet;
• detecting means for detecting the sheet conveyed by the conveying means;
• and
• control means for:
• causing the conveying means to eject the sheet without stopping conveyance of the sheet and prohibiting recovery printing when a size of the sheet determined based on detection of the sheet by the detecting means is different from a setting size in a first operation mode;
• and
• causing the conveying means to stop conveyance of the sheet and allowing recovery printing when the size of the sheet is different from the setting size in a second operation mode in which a number of times of printing is larger than a number of times of printing in the first operation mode.

An image forming method comprising:

• detecting a sheet conveyed by a conveyor;
• causing the conveyor to eject the sheet without stopping conveyance of the sheet and prohibiting recovery printing when a size of the sheet determined based on detection of the sheet is different from a setting size in a first operation mode;
• and
• causing the conveyor to stop conveyance of the sheet and allowing recovery printing when the size of the sheet is different from the setting size in a second operation mode in which a number of times of printing is larger than a number of times of printing in the first operation mode.