摘要 |
An aperture plate for an ink jet head is formed by micro electrical discharge machining one surface of the plate to form a dimple-like recess with a relatively wide flat base. An aperture is then formed through the plate in the region of the dimple, as by micro electrical discharge machining. In one method of the invention, recesses are formed in two plates which are then mounted to the body of an ink jet head. A third plate with a formed third aperture is then mounted to the body such that the first, second and third plates overly one another and the third aperture is aligned with the recesses. Apertures of a smaller cross-section than the third aperture are then formed in the first two plates by drilling through the third aperture. The aperture through the first plate is then enlarged. |