Printing apparatus

A printing apparatus which performs digital printing on one or both surfaces of a sheet, comprising:

• a sheet transfer unit configured to hold sheets and transfer the sheets one by one continuously;
• a printing unit configured to perform printing on the sheet transferred by the sheet transfer unit;
• a sheet supply unit configured to supply the sheets one by one to the sheet transfer unit;
• and
• a speed switching device, for the sheet supply unit, configured to switch a speed of the sheet supply unit between a case in which printing is performed on one surface of the sheet and a case in which printing is performed on both surfaces of the sheet,
• wherein when printing is performed on one surface of the sheet, the sheet supply unit is driven at a first supply speed at which the sheets are supplied to the sheet transfer unit one by one continuously, and the sheet transfer unit is driven at a transfer speed at which the sheets supplied from the sheet supply unit one by one continuously are transferred, and
• when printing is performed on both surfaces of the sheet, the sheet transfer unit is driven at the transfer speed and the sheet supply unit is driven at a second supply speed which is ½ the first supply speed.