Liquid discharge head, liquid discharge apparatus, and manufacturing method

A liquid discharge head comprising:

• a recording element substrate having a first discharge port group, a second discharge port group, a third discharge port group, and a fourth discharge port group, each of which includes a plurality of discharge ports for discharging liquid;
• a first flow path connecting a first liquid tank to the first discharge port group;
• a second flow path connecting a second liquid tank to the second discharge port group;
• and
• a third flow path connecting a third liquid tank to the third discharge port group and the fourth discharge port group,
• wherein a flow resistance in the first flow path is smaller than a flow resistance in the second flow path and larger than a flow resistance in the third flow path,
• wherein a ratio of the flow resistance in the second flow path to the flow resistance in the third flow path is 4 or less,
• wherein the recording element substrate further has a fifth discharge port group and a sixth discharge port group,
• wherein the liquid discharge head further includes a fourth flow path connecting a fourth liquid tank to the fifth discharge port group and the sixth discharge port group,
• wherein a flow resistance in the fourth flow path is smaller than the flow resistance in the first flow path, and
• wherein a ratio of the flow resistance in the second flow path to the flow resistance in the fourth flow path is 4 or less.

A liquid discharge apparatus comprising:

• a liquid discharge head including
• a recording element substrate having a first discharge port group, a second discharge port group, a third discharge port group, and a fourth discharge port group, in each of which a plurality of discharge ports for discharging liquid is arranged,
• a first flow path connecting a first liquid tank and the first discharge port group,
• a second flow path connecting a second liquid tank and the second discharge port group, and
• a third flow path connecting a third liquid tank to the third discharge port group and the fourth discharge port group,
• wherein a sum of opening areas of the plurality of discharge ports included in the first discharge port group is larger than a sum of opening areas of the plurality of discharge ports included in the second discharge port group, and is smaller than a sum of opening areas of the plurality of discharge ports included in the third discharge port group and a sum of opening areas of the plurality of discharge ports included in the fourth discharge port groups,
• wherein a flow resistance in the first flow path is smaller than a flow resistance in the second flow path and larger than a flow resistance in the third flow path, and
• wherein a ratio of the flow resistance in the second flow path to the flow resistance in the third flow path is 4 or less;
• and
• a carriage configured to hold the liquid discharge head.