Patent attributes
A liquid ejection head includes a plurality of ejection members, each having an ejection port for ejecting liquid, an element for ejecting a liquid from the ejection port, a liquid chamber for storing liquid to be supplied to the ejection port and a heater for heating liquid, and a base substrate bearing the plurality of ejection members arranged thereon and having a common flow channel for supplying liquid to the plurality of liquid chambers. The common flow channel communicates with the liquid chambers by way of respective branch ports and each of the branch ports is provided with a notch portion at the upstream side thereof as viewed in the flow direction of liquid flowing through the common flow channel and the upstream side of each of the branch ports has a profile asymmetric with regard to a straight line passing through the center of gravity of the branch port and extending in the flow direction.