Abstract: In a liquid injection recording apparatus having discharge ports for discharging liquid and forming flying droplets, liquid flow paths communicating with the discharge ports, and energy generating means generating energy for causing the liquid to be discharged from the discharge ports, when the shortest length from the center line of the discharge ports to the central position of the energy acting surface of the energy generating means is a and the length from the center line of the discharge ports to the bottom surface of the liquid flow paths just beneath the center of the discharge ports is b, the value of a/b is 50 or less.

Abstract: A liquid injection recording apparatus has liquid flow paths communicating with an inflow path for supplying liquid and with an outflow path for discharging the liquid and having in the intermediate portions thereof discharge ports for discharging the liquid and forming flying drops of liquid, and a liquid projection energy generating member for forming the drops of liquid. The liquid is forcibly discharged from the outflow path.

Abstract: An improved ink jet recording head is provided which comprises a substrate, and a cured film of a photosensitive resin for the formation of ink pathways and a covering over said pathways. Said covering comprises a flat plate made of a UV-light transmissive material having a photosensitive resin film adhered on both surfaces thereof. This ink jet recording head is precise, reliable and durable.

Abstract: An ink jet recording head is made by laminating on a substrate a cured photosensitive resin film for forming ink pathways on the substrate and a cover of said pathways are provided. In the head, the thicknesses of the wall defining the ink pathways, the grooves and the spaces are not more than 15 times the thickness of the cured photosensitive resin film. Such ratio of the wall thickness to the film thickness and the existence of grooves and spaces serve to prevent the peeling-off at the lamination interfaces.