Ink-jet print head

An ink-jet print head including a plurality of plates laminated onto each other, comprising:

• a first ink chamber that stores ink and is located within a first one of said plurality of plates;
• a second ink chamber that stores the ink, is located within a second one of said plurality of plates, and is located above said first ink chamber;
• a pressure chamber that is to be supplied with the ink from the first ink chamber and the second ink chamber;
• a nozzle that communicates with the pressure chamber;
• an actuator that causes pressure change in the pressure chamber;
• and
• a narrowed portion that is provided between the first ink chamber and the pressure chamber and is narrower than a cross-sectional area of the pressure chamber, wherein the narrowed portion, the pressure chamber and the nozzle form an ink passage, and a percentage of an ink-flow resistance of the narrowed portion is 50% or more with respect to an ink-flow resistance of the ink passage.

An ink-jet print head including a base plate, spacer plate, a first manifold plate, a second manifold plate and a nozzle plate laminated onto each other, comprising:

• a first ink chamber that stores ink and is located within the second manifold plate;
• a second ink chamber that stores the ink and is located within the first manifold plate which is above the second manifold plate;
• a pressure chamber that is to be supplied with the ink from the first ink chamber and the second ink chamber, and is located within the base plate;
• a nozzle that communicates with the pressure chamber and is located within the nozzle plate which is located below the second manifold plate;
• an actuator that causes pressure change in the pressure chamber;
• and
• a narrowed portion that is provided between the first ink chamber and the pressure chamber and is narrower than a cross-sectional area of the pressure chamber, wherein the narrowed portion, the pressure chamber and the nozzle form an ink passage, and a percentage of a resistance of an ink-flow resistance of the narrowed portion is 50% or more with respect to an ink-flow resistance of the ink passage.