Ink-jet head and method of manufacturing the same

A method of manufacturing an ink-jet head that includes a passage component made of resin and a filter plate through which ink is filtered, an ink passage formed in the passage component, the filter plate being fixed to the passage component and having a melting point higher than that of the passage component, the method comprising the steps of:

• preparing the passage component having an annular face that annularly extends in a plane, a step face that is continuous with an inner circumferential border of the annular face and extends in a direction crossing the plane, and a protrusion that is formed on the annular face;
• preparing the filter plate through which a plurality of holes are formed in a thickness direction of the filter plate;
• bringing one face of the filter plate into contact with the protrusion while opposing at least one of the holes to the protrusion;
• and
• heating the protrusion and pressing the filter plate to the annular face, in such a manner that the melted protrusion is embedded in at least one of the holes and, in its portion beyond the holes, radially expands thus having a diameter larger than a diameter of the holes and thus being exposed to the ink passage, to thereby fix the filter plate to the passage component.

An ink-jet head comprising a passage component made of resin and a filter plate through which ink is filtered, the filter plate being fixed to the passage component and having a melting point higher than that of the passage component, wherein:

• the filter plate has an annular region and an inner region surrounded by the annular region, and a plurality of holes are formed through the filter plate in a thickness direction of the filter plate, in the annular region and the inner region, respectively;
• the passage component has a filter support face that supports one face of the filter plate extending in a direction perpendicular to the thickness direction, the filter support face being in contact with the annular region but out of contact with the inner region;
• a holder is formed on the filter support face, the holder penetrating through at least one of the holes formed in the annular region and covering the other face of the filter plate;
• and
• a diameter of the holes formed in the annular region is equal to or smaller than a diameter of the holes formed in the inner region.

A method of manufacturing an ink-jet head that includes a passage component made of resin and a filter plate through which ink is filtered, the filter plate being fixed to the passage component and having a melting point higher than that of the passage component, the method comprising the steps of:

• preparing the passage component having an annular face that annularly extends in a plane, a step face that is continuous with an inner circumferential border of the annular face and extends in a direction crossing the plane, and a protrusion that is formed on the annular face;
• preparing the filter plate through which a plurality of holes are formed in a thickness direction of the filter plate;
• bringing one face of the filter plate into contact with the protrusion while opposing at least one of the holes to the protrusion;
• and
• heating the protrusion and pressing the filter plate to the annular face, in such a manner that the melted protrusion is embedded in at least one of the holes and, in its portion beyond the holes, radially expands thus having a diameter larger than a diameter of the holes, to thereby fix the filter plate to the passage component,
• wherein, in the step of preparing the filter plate, the holes are formed in an annular region of the filter plate which will be in contact with the annular face of the passage component, and a diameter of the holes is equal to or smaller than a diameter of the holes formed in an inner region of the filter plate which is surrounded by the annular region and will not be in contact with the annular face.