Printing apparatus

A printing apparatus comprising:

• a print head that ejects ink;
• an ink tank that holds ink that is supplied to the print head;
• a supply channel for supplying ink from the ink tank to the print head;
• a collection channel for collecting ink from the print head to the ink tank;
• a pump disposed in the collection channel;
• a first one-way valve disposed between the pump and the ink tank in the collection channel, the first one-way valve allowing movement of ink from the pump to the ink tank and blocking movement of ink from the ink tank to the pump;
• a circulation channel that connects the ink tank to the collection channel at a position between the pump and the first one-way valve, the circulation channel enabling circulation of ink from the ink tank, through the print head, and to the ink tank;
• and
• a second one-way valve disposed in the circulation channel, the second one-way valve allowing movement of ink from the ink tank to the pump and blocking movement of ink from the pump to the ink tank,
• wherein, when the pump is driven in a first direction, ink is supplied from the ink tank to the print head through the supply channel and ink is collected from the print head to the ink tank through the collection channel, and
• wherein, when the pump is driven in a second direction, the circulation is performed through the circulation channel, a part of the collection channel, and the supply channel.