Abstract: An ink jet head for discharging a plurality kinds of inks includes a discharge port surface provided with a plurality of discharge ports for discharging ink, the discharge ports being arranged into different groups for ejecting discharging different kinds of inks. The groups of the discharge ports each for discharging different kind of ink are provided in a line, and the discharge port surface has a central water-repellent area provided with the discharge port groups and a hydrophilic belt is provided adjacent to the central water-repellent area and along an array of the discharge ports. The hydrophilic belt is separately provided for each of the groups of the discharge ports.

Abstract: A liquid jet head can be detachably fitted into an opening portion of a liquid tank having a liquid absorbing member therein by a liquid receiving member with a liquid path formed therein. The liquid head has a filter, and the peripheral part of the filter is immovably embedded in the foremost end of the liquid receiving member such that the radially outermost end of the filter is not exposed, and the filter is maintained so as to have a dome-shaped contour adapted to come in pressure contact with the liquid absorbing member when the liquid jet head is fitted to the liquid tank by the immovable embedding of the peripheral part of the filter therein. A liquid jet apparatus with a liquid tank has a liquid absorbing member and an opening portion formed thereon, as well as a liquid jet head of this type. A method of immovably securing a filter to a liquid receiving member of a liquid jet head is also described.

Abstract: An ink jet head has a substrate on which ejection energy generating elements are provided, and a ceiling plate having a plurality of grooves for forming ink passages. The ceiling plate is pressed against the substrate by a pressing member, i.e., a spring. To improve the ejection performance of the ink jet head, the contact portion of the ceiling plate pressed by the pressing member is divided into a plurality of portions.

Abstract: An ink jet recording head includes a top plate having recesses for forming ink paths connected to a plurality of ejection outlets from which ink is ejected; a substrate for forming the ink paths by joining it with the top plate, with the recesses facing inward; wherein the top plate overhangs from an edge of the substrate in the direction of a plane of the joint between the top plate and substrate.

Abstract: A replaceable ink cartridge, usable with a bubble jet printer, includes a container having front, back, top bottom and side walls, the container being divided internally into a first chamber and a second chamber having a common partition extending downward perpendicularly toward the bottom wall to provide an opening between the chambers formed by the partition proximate to the bottom wall. The first chamber contains a reservoir of liquid ink and is generally sealed from ambient air except through the opening, and the second chamber has an air vent for admitting ambient air into the second chamber and an ink supply outlet in the front wall.