Liquid ejection head

A liquid ejection head comprising:

• a plurality of pressure chambers arrayed in an array direction and each configured to receive an ejection pressure for ejecting liquid from a corresponding nozzle;
• a supply manifold extending in the array direction and communicating with the pressure chambers, the supply manifold including a supply opening through which liquid enters from an exterior;
• a return manifold disposed below the supply manifold and formed by a first forming unit to extend in the array direction and communicate with the pressure chambers, the return manifold including a return opening through which liquid exits to the exterior;
• and
• a bypass channel connecting the supply manifold and the return manifold,
• wherein the first forming unit includes:
• a first top surface defining a top surface of the return manifold;
• and
• a first protrusion protruding downward from the first top surface and having a lower end at which the bypass channel is open,
• wherein the supply manifold is formed by a second forming unit including:
• a second bottom surface which defines a bottom surface of the supply manifold and on which the bypass channel is open;
• a second top surface facing the second bottom surface;
• and
• a second protrusion facing an opening of the bypass channel and protruding downward from the second top surface, and
• wherein a protruding dimension of the first protrusion is less than a protruding dimension of the second protrusion.

A liquid ejection head comprising:

• a plurality of pressure chambers arrayed in an array direction and each configured to receive an ejection pressure for ejecting liquid from a corresponding nozzle;
• a supply manifold extending in the array direction and communicating with the pressure chambers, the supply manifold including a supply opening through which liquid enters from an exterior;
• a return manifold disposed below the supply manifold and formed by a first forming unit to extend in the array direction and communicate with the pressure chambers, the return manifold including a return opening through which liquid exits to the exterior;
• and
• a bypass channel connecting the supply manifold and the return manifold,
• wherein the first forming unit includes:
• a first top surface defining a top surface of the return manifold;
• and
• a first protrusion protruding downward from the first top surface and having a lower end at which the bypass channel is open,
• wherein the supply manifold is formed by a second forming unit including:
• a second bottom surface which defines a bottom surface of the supply manifold and on which the bypass channel is open;
• a second top surface facing the second bottom surface;
• and
• a second protrusion facing an opening of the bypass channel and protruding downward from the second top surface, and
• wherein the second forming unit includes a second top surface plate including:
• a second upper surface;
• a second lower surface opposite to the second upper surface;
• a second recess recessed upward from the second lower surface to the second top surface;
• and
• a second protrusion formed by a step between the second lower surface and the second top surface.

A liquid ejection head comprising:

• a plurality of pressure chambers arrayed in an array direction and each configured to receive an ejection pressure for ejecting liquid from a corresponding nozzle;
• a supply manifold extending in the array direction and communicating with the pressure chambers, the supply manifold including a supply opening through which liquid enters from an exterior;
• a return manifold disposed below the supply manifold and formed by a first forming unit to extend in the array direction and communicate with the pressure chambers, the return manifold including a return opening through which liquid exits to the exterior;
• and
• a bypass channel connecting the supply manifold and the return manifold,
• wherein the first forming unit includes:
• a first top surface defining a top surface of the return manifold;
• a first protrusion protruding downward from the first top surface and having a lower end at which the bypass channel is open;
• a first bottom surface which faces the first top surface and on which the bypass channel is open;
• and
• a third protrusion facing an opening of the bypass channel and protruding upward from the first bottom surface,
• wherein the supply manifold is formed by a second forming unit including:
• a second bottom surface which defines a bottom surface of the supply manifold and on which the bypass channel is open;
• a second top surface facing the second bottom surface;
• and
• a second protrusion facing an opening of the bypass channel and protruding downward from the second top surface.

A liquid ejection head comprising:

• a plurality of pressure chambers arrayed in an array direction and each configured to receive an ejection pressure for ejecting liquid from a corresponding nozzle;
• a supply manifold extending in the array direction and communicating with the pressure chambers, the supply manifold including a supply opening through which liquid enters from an exterior;
• a return manifold disposed below the supply manifold and formed by a forming unit to extend in the array direction and communicate with the pressure chambers, the return manifold including a return opening through which liquid exits to the exterior;
• and
• a bypass channel connecting the supply manifold and the return manifold,
• wherein the forming unit includes:
• a first top surface defining a top surface of the return manifold;
• and
• a protrusion protruding downward from the first top surface and having a lower end at which the bypass channel is open, and
• wherein the return manifold is tapered toward the return opening.

A liquid ejection head comprising:

• a plurality of pressure chambers arrayed in an array direction and each configured to receive an ejection pressure for ejecting liquid from a corresponding nozzle;
• a supply manifold extending in the array direction and communicating with the pressure chambers, the supply manifold including a supply opening through which liquid enters from an exterior;
• a return manifold disposed below the supply manifold and formed by a forming unit to extend in the array direction and communicate with the pressure chambers, the return manifold including a return opening through which liquid exits to the exterior;
• and
• a bypass channel connecting the supply manifold and the return manifold,
• wherein the forming unit includes:
• a first top surface defining a top surface of the return manifold;
• and
• a protrusion protruding downward from the first top surface and having a lower end at which the bypass channel is open, and
• wherein the supply manifold is tapered toward the supply opening.