Droplet ejection head, method of manufacturing droplet ejection head, and droplet ejection apparatus

1. A droplet ejection head that is attachable to and removable from a droplet ejection apparatus, the droplet ejection head comprising:

a nozzle plate having multiple nozzle holes to eject droplets;

an individual-channel substrate in which multiple individual-liquid-chambers to supply liquid to the nozzle holes are formed, the individual-channel substrate including pressure generating units that apply pressure to liquid in the individual-liquid-chambers;

a common-channel substrate to supply liquid to the individual-channel substrate;

a base plate made of metal and including a first positioning part to be engaged with a part of the droplet ejection apparatus at a given position to perform positioning with respect to the droplet ejection apparatus in a direction along an opening surface of the nozzle plate at which the nozzle holes are opened;

a housing made of resin and including a second positioning part to perform positioning with respect to the droplet ejection apparatus in a direction intersecting with the opening surface and a sealing member extending from a surface of the housing in the direction intersecting with the opening surface; and

a plurality of fasteners extending through the base plate and into the sealing member to join the base plate and the housing.

2. The droplet ejection head according to claim 1 , wherein the first positioning part is provided in a direction intersecting with a nozzle array in which the nozzle holes are formed, and the first positioning part is provided on a protrusion protruding from an edge of the base plate along the nozzle array.

3. The droplet ejection head according to claim 2 , wherein the sealing member includes a protrusion corresponding to the protrusion protruding from the edge of the base plate.

4. The droplet ejection head according to claim 1 , wherein, when the droplet ejection head is attached to the droplet ejection apparatus, a side surface of the base plate engages with the part of the droplet ejection apparatus at the given position.

5. The droplet ejection head according to claim 1 , wherein the base plate and the common-channel substrate are formed by press molding.

6. The droplet ejection head according to claim 1 , wherein the pressure generating unit is an electromechanical conversion element including a lower electrode, a piezoelectric element, and an upper electrode.

7. A method of manufacturing a droplet ejection head that is attachable to and removable from a droplet ejection apparatus and that comprises:

a nozzle plate having multiple nozzle holes to eject droplets;

an individual-channel substrate in which multiple individual-liquid-chambers to supply liquid to the nozzle holes are formed, the individual-channel substrate including pressure generating units that apply pressure to liquid in the individual-liquid-chambers;

a common-channel substrate to supply liquid to the individual-channel substrate;

a base plate made of metal and including a first positioning part to be engaged with a part of the droplet ejection apparatus at a given position to perform positioning with respect to the droplet ejection apparatus in a direction along an opening surface of the nozzle plate at which the nozzle holes are opened;

a housing made of resin and including a second positioning part to perform positioning with respect to the droplet ejection apparatus in a direction intersecting with the opening surface and a sealing member extending from a surface of the housing in the direction intersecting with the opening surface; and

a plurality of fasteners,

the method comprising:

manufacturing a first head structure by optically aligning and joining the nozzle plate and the individual-channel substrate;

manufacturing a second head structure by aligning, using an opening provided in the common-channel substrate and the base plate, and joining the common-channel substrate and the base plate;

optically aligning and joining the first head structure and the second head structure; and

extending the plurality of fasteners through the base plate of the second head structure joined to the first head structure into the sealing member to join the base plate and the housing.

8. A droplet ejection apparatus comprising an attachable and removable droplet ejection head, wherein the droplet ejection head comprises:

a nozzle plate having multiple nozzle holes to eject droplets;

an individual-channel substrate in which multiple individual-liquid-chambers to supply liquid to the nozzle holes are formed, the individual-channel substrate including pressure generating units that apply pressure to liquid in the individual-liquid-chambers;

a common-channel substrate to supply liquid to the individual-channel substrate;

a base plate made of metal and including a first positioning part to be engaged with a part of the droplet ejection apparatus at a given position to perform positioning with respect to the droplet ejection apparatus in a direction along an opening surface of the nozzle plate at which the nozzle holes are opened;

a housing made of resin and including a second positioning part to perform positioning with respect to the droplet ejection apparatus in a direction intersecting with the opening surface and a sealing member extending from a surface of the housing in the direction intersecting with the opening surface; and

a plurality of fasteners extending through the base plate and into the sealing member to join the base plate and the housing.