Ink jet printer head and ejector unit for use in the printer head

An ejector unit for use in an ink jet printer head including a frame member having at least one ink supply passage through which an ink is supplied from at least one ink supply source to the ejector unit, the ejector unit being fixed to the frame member, the ejector unit comprising:

• a cavity unit which has a plurality of nozzles provided in an outer surface thereof and arranged in a reference direction, a plurality of ink chambers which communicate with the plurality of nozzles, respectively, and in each of which the ink is accommodated, and a plurality of ink channels communicating with the plurality of nozzles via the plurality of ink chambers, respectively;
• and
• an actuator which applies an energy to said each of the ink chambers so as to eject a droplet of the ink from a corresponding one of the nozzles via a corresponding one of the ink channels,
• the cavity unit including a channel unit having the ink chambers and the ink channels, and a nozzle sheet having the nozzles arranged in the reference direction, the nozzle sheet being fixed in position to the channel unit,
• the nozzle sheet having, in two end portions thereof that are opposite to each other in the reference direction, two first positioning holes, respectively, into which two first positioning pins of a first jig are inserted when the nozzle sheet is fixed to the channel unit,
• the nozzle sheet additionally having, in said two end portions thereof, two second positioning holes, respectively, into which corresponding two second positioning pins out of a plurality of pairs of second positioning pins of a second jig are inserted when a plurality of ejector units including the ejector unit are fixed to the frame member,
• the channel unit having two first blind holes in communication with the two first positioning holes, respectively, and two second blind holes in communication with the two second positioning holes, respectively, the two first positioning pins of the first jig being inserted via the two first positioning holes into the two first blind holes, respectively, when the nozzle sheet is fixed to the channel unit, the two second positioning pins of the second jig being inserted via the two second positioning holes into the two second blind holes, respectively, in a state in which the nozzle sheet is fixed to the channel unit.

An ink jet printer head, comprising:

• a plurality of ejector units each of which has a plurality of nozzles, a plurality of ink chambers which communicate with the plurality of nozzles, respectively, and in each of which an ink is accommodated, a plurality of ink channels communicating with the plurality of nozzles via the plurality of ink chambers, respectively, and an actuator which applies an energy to said each of the ink chambers so as to eject a droplet of the ink from a corresponding one of the nozzles via a corresponding one of the ink channels;
• the cavity unit of said each of the ejector units including a channel unit having the ink chambers and the ink channels, and a nozzle sheet having the nozzles, the channel unit and the nozzle sheet of said each ejector unit being fixed to each other;
• and
• the nozzle sheet of said each ejector unit having two first positioning holes, and two second positioning holes.

A method of manufacturing an ink jet printer head including (a) a plurality of cavity units each of which has a plurality of nozzles, a plurality of ink chambers which communicate with the plurality of nozzles, respectively, and in each of which an ink is accommodated, and a plurality of ink channels communicating with the plurality of nozzles via the plurality of ink chambers, respectively, and (b) a plurality of actuators each of which applies an energy to each of the ink chambers of a corresponding one of the cavity units so as to eject a droplet of the ink from a corresponding one of the nozzles via a corresponding one of the ink channels, the method comprising the steps of:

• preparing a plurality of nozzle sheets each of which has the plurality of nozzles, two first positioning holes, and two second positioning holes,
• preparing a plurality of channel units each of which has the plurality of ink chambers to accommodate the ink and communicate with the plurality of nozzles, respectively, of a corresponding one of the nozzle sheets, and the plurality of ink channels to communicate with the plurality of nozzles of said corresponding nozzle sheet via the plurality of ink chambers, respectively,
• causing two first positioning pins of a first jig to fit in the two first positioning holes of said each of the nozzle sheets so as to position said each nozzle sheet relative to the first jig,
• fixing said each nozzle sheet positioned relative to the first jig, and a corresponding one of the channel units, to each other, so as to provide a corresponding one of the cavity units,
• causing a first pair of second positioning pins of a second jig to fit in the two second positioning holes of the nozzle sheet of a first one of the cavity units, and causing a second pair of second positioning pins of the second jig to fit in the two second positioning holes of the nozzle sheet of a second one of the cavity units, so that the first and second cavity units are positioned relative to the second jig and are thereby positioned relative to each other, and
• fixing the first and second cavity units positioned relative to each other, to a frame member.