Liquid ejection head

A liquid ejection head, comprising:

• a printing element substrate comprising:
• an ejection port row in which a plurality of ejection ports are arrayed in an arrayment direction;
• a plurality of pressure chambers communicating with the plurality of ejection ports, respectively;
• a plurality of printing elements provided in the plurality of pressure chambers, respectively;
• a liquid supply channel extending in the arrayment direction and supplying a liquid to the plurality of pressure chambers;
• and
• a liquid collection channel extending in the arrayment direction and collecting the liquid from the plurality of pressure chambers;
• a supply communication port supplying the liquid to the printing element substrate via a supply opening;
• a collection communication port collecting the liquid from the printing element substrate via a collection opening;
• and
• at least either of two or more flow-in bypasses and two or more discharge bypasses as flow channels that do not pass through the pressure chambers, wherein
• the two or more flow-in bypasses connect a plurality of flow-in bypass openings with the collection opening;
• the two or more discharge bypasses connect a plurality of discharge bypass openings with the supply opening;
• and
• each flow-in bypass opening is positioned between the supply communication port and the liquid collection channel in a positional relation along a route through which the liquid is supplied and is an opening supplying the liquid to the liquid collection channel, and each discharge bypass opening is positioned between the liquid supply channel and the collection communication port and is an opening collecting the liquid from the liquid supply channel.