Abstract: A method of manufacturing a nozzle plate and having a nozzle passage therethrough is provided as follows. First, a member having an ink ejection surface and an nozzle passage is formed. The member includes a straight conduit portion which is formed at one end portion of the nozzle passage located near the ink ejection surface and extending straight to an opening of the nozzle passage located on the ink ejection surface in order to eject an ink straight. A recess is formed on the ink ejection surface of the member such that an area of an opening of the recess is greater than an area of the opening of the nozzle passage and such that a depth of the recess is greater than a predetermined thickness. Subsequently, the ink ejection surface is ground by the predetermined thickness on the basis of a depth of the recess remaining on the ink ejection surface after grinding.

Abstract: A cavity plate of an ink jet printer head is adapted to be attached to a piezoelectric element member and has walls prescribing a plurality of ink storing chambers and a plurality of ink discharge holes. A mold for molding the cavity is provided with: a corniform block member including (i) a plurality of corniform convex portions to mold the ink storing chambers, each having an opening portion on a side of an attachment surface of the cavity plate to be attached to the piezoelectric element member, and (ii) a plurality of corniform concave portions to mold partition walls of the cavity plate for partitioning each of the ink storing chambers; and plurality of pin members to mold the ink discharge holes, which are continuous to the ink storing chambers such that the ink discharge holes have straight tubular portions respectively from the ink storing chambers to ink discharge tip portions at an ink discharge surface of the cavity plate on an opposite side of the attachment surface.

Abstract: An ink jet printer head for discharging ink is provided with: a cavity plate prescribing (i) an ink flow path through which the ink is supplied, (ii) a plurality of ink storing chambers, each of which is connected to the ink flow path in which the supplied ink is temporarily stored, and (iii) a plurality of ink discharge holes which are connected to respective one of the ink storing chambers though which the temporarily stored ink is discharged; a piezoelectric element member, which is shaped in a plate opposed to the cavity plate and has a plurality of piezoelectric elements for selectively changing capacities of the ink storing chambers; and a partition plate interposed between the cavity plate and the piezoelectric element member such that each of the ink storing chambers be a closed space for temporarily storing the ink.

Abstract: Abrasive blasting of fine particles is used to remove flash, burrs and dust from a nozzles in a nozzle array plate formed by injection molding. The abrasive blasting is applied from the entry side of the nozzles to remove the flash and roughen the interior of the nozzles. A thin solid flash portion can be formed on the exit side of each nozzle to ensure uniform conditions of all the nozzles before the abrasive blasting is applied.

Abstract: In a motion conversion mechanism for converting mechanical expansion and compression of a material, such as a piezo electric element, to the motion of the other material, provided are moving member arranged to be movable in accordance with the motion of the material along a predetermined direction, transmitting member for transmitting the movement of the moving member toward the other material along the predetermined direction, and regulating member for regulating the transmitting operation of the transmitting member so as not to be skewed from the predetermined direction. Thus, the transmitting operation of is accurately executed.